Trial Outcomes & Findings for Decision Support for Intraoperative Low Blood Pressure (NCT NCT02726620)

NCT ID: NCT02726620

Last Updated: 2019-05-16

Results Overview

Postoperative Acute Kidney Injury (AKI), Stage I or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. This will be the primary outcome for the Vanderbilt University Medical Center. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or \>0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to \> 4, or initiation of renal replacement therapy.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 22435 participants
• Primary outcome timeframe: Within 7 days after surgery
• Results posted on: 2019-05-16

Participant Flow

Participant milestones

Measure	Usual Care Group The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Historic Cohort - Three Years STARTED	17463	0
Historic Cohort - Three Years MAP < 65 mmHg: Primary Analysis	15624	0
Historic Cohort - Three Years COMPLETED	17463	0
Historic Cohort - Three Years NOT COMPLETED	0	0
Month 1: Attending Randomization STARTED	0	485
Month 1: Attending Randomization MAP < 65 mmHg: Primary Analysis	0	432
Month 1: Attending Randomization Correct IOH Notifications	0	313
Month 1: Attending Randomization COMPLETED	0	485
Month 1: Attending Randomization NOT COMPLETED	0	0
Months 2-3: In-room Providers Randomized STARTED	0	1253
Months 2-3: In-room Providers Randomized MAP < 65 mmHg: Primary Analysis	0	1103
Months 2-3: In-room Providers Randomized Correct IOH Notifications	0	825
Months 2-3: In-room Providers Randomized COMPLETED	0	1253
Months 2-3: In-room Providers Randomized NOT COMPLETED	0	0
Through End of Study: All Interventions STARTED	0	3234
Through End of Study: All Interventions MAP < 65 mmHg: Primary Analysis	0	2793
Through End of Study: All Interventions Correct IOH Notifications	0	2072
Through End of Study: All Interventions COMPLETED	0	3234
Through End of Study: All Interventions NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Incomplete patient demographics section resulted in a row population difference from the Overall.

Baseline characteristics by cohort

Measure	Usual Care Group n=17463 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4972 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.	Total n=22435 Participants Total of all reporting groups
Age, Continuous	68 years n=17463 Participants	68 years n=4972 Participants	68 years n=22435 Participants
Sex: Female, Male Female	7731 Participants n=17438 Participants • Incomplete patient demographics section resulted in a row population difference from the Overall.	2141 Participants n=4963 Participants • Incomplete patient demographics section resulted in a row population difference from the Overall.	9872 Participants n=22401 Participants • Incomplete patient demographics section resulted in a row population difference from the Overall.
Sex: Female, Male Male	9707 Participants n=17438 Participants • Incomplete patient demographics section resulted in a row population difference from the Overall.	2822 Participants n=4963 Participants • Incomplete patient demographics section resulted in a row population difference from the Overall.	12529 Participants n=22401 Participants • Incomplete patient demographics section resulted in a row population difference from the Overall.
Race (NIH/OMB) American Indian or Alaska Native	18 Participants n=17463 Participants	4 Participants n=4972 Participants	22 Participants n=22435 Participants
Race (NIH/OMB) Asian	113 Participants n=17463 Participants	36 Participants n=4972 Participants	149 Participants n=22435 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=17463 Participants	0 Participants n=4972 Participants	0 Participants n=22435 Participants
Race (NIH/OMB) Black or African American	1111 Participants n=17463 Participants	380 Participants n=4972 Participants	1491 Participants n=22435 Participants
Race (NIH/OMB) White	15571 Participants n=17463 Participants	4348 Participants n=4972 Participants	19919 Participants n=22435 Participants
Race (NIH/OMB) More than one race	0 Participants n=17463 Participants	0 Participants n=4972 Participants	0 Participants n=22435 Participants
Race (NIH/OMB) Unknown or Not Reported	650 Participants n=17463 Participants	204 Participants n=4972 Participants	854 Participants n=22435 Participants
Region of Enrollment United States	17463 participants n=17463 Participants	4972 participants n=4972 Participants	22435 participants n=22435 Participants
Body Mass Index	28 kg/m^2 n=17306 Participants • Incorrect demographics data resulted in row population differences from overall.	28 kg/m^2 n=4930 Participants • Incorrect demographics data resulted in row population differences from overall.	28 kg/m^2 n=22236 Participants • Incorrect demographics data resulted in row population differences from overall.
ASA Class ASA Class 1	74 Participants n=17463 Participants	16 Participants n=4972 Participants	90 Participants n=22435 Participants
ASA Class ASA Class 2	3109 Participants n=17463 Participants	765 Participants n=4972 Participants	3874 Participants n=22435 Participants
ASA Class ASA Class 3	12344 Participants n=17463 Participants	3578 Participants n=4972 Participants	15922 Participants n=22435 Participants
ASA Class ASA Class 4	1885 Participants n=17463 Participants	585 Participants n=4972 Participants	2470 Participants n=22435 Participants
ASA Class ASA Class 5	51 Participants n=17463 Participants	28 Participants n=4972 Participants	79 Participants n=22435 Participants
Hypertension	11403 Participants n=15718 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	3348 Participants n=4500 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	14751 Participants n=20218 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.
Cardiac disease	4843 Participants n=15718 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	1489 Participants n=4500 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	6332 Participants n=20218 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.
Renal Disease	1432 Participants n=15718 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	511 Participants n=4500 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	1943 Participants n=20218 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.
Peripheral vascular disease	1947 Participants n=15718 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	596 Participants n=4500 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	2543 Participants n=20218 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.
Diabetes Mellitus	4456 Participants n=15718 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	1296 Participants n=4500 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.	5752 Participants n=20218 Participants • No preoperative data on comorbidities was available in a structured form, resulting in missings.
Type of anesthesia General anesthesia	17051 Participants n=17463 Participants	4750 Participants n=4972 Participants	21801 Participants n=22435 Participants
Type of anesthesia Central neuraxial anesthesia	412 Participants n=17463 Participants	222 Participants n=4972 Participants	634 Participants n=22435 Participants
Procedure urgency Elective surgery	16452 Participants n=17463 Participants	4631 Participants n=4972 Participants	21083 Participants n=22435 Participants
Procedure urgency Emergency surgery	1011 Participants n=17463 Participants	341 Participants n=4972 Participants	1352 Participants n=22435 Participants
Procedure duration	201 minutes n=17463 Participants	196 minutes n=4972 Participants	200 minutes n=22435 Participants
Surgical service ENT	1891 Participants n=17463 Participants	528 Participants n=4972 Participants	2419 Participants n=22435 Participants
Surgical service Gynecology	113 Participants n=17463 Participants	30 Participants n=4972 Participants	143 Participants n=22435 Participants
Surgical service General surgery	3638 Participants n=17463 Participants	1001 Participants n=4972 Participants	4639 Participants n=22435 Participants
Surgical service Neurosurgery	2138 Participants n=17463 Participants	622 Participants n=4972 Participants	2760 Participants n=22435 Participants
Surgical service Orthopedic surgery	4283 Participants n=17463 Participants	1222 Participants n=4972 Participants	5505 Participants n=22435 Participants
Surgical service Plastic surgery	776 Participants n=17463 Participants	195 Participants n=4972 Participants	971 Participants n=22435 Participants
Surgical service Thoracic surgery	1056 Participants n=17463 Participants	310 Participants n=4972 Participants	1366 Participants n=22435 Participants
Surgical service Urology	2648 Participants n=17463 Participants	778 Participants n=4972 Participants	3426 Participants n=22435 Participants
Surgical service Vascular surgery	920 Participants n=17463 Participants	286 Participants n=4972 Participants	1206 Participants n=22435 Participants
AKI risk based on IOH depth and duration AKI risk: none	3684 Participants n=17463 Participants	1174 Participants n=4972 Participants	4858 Participants n=22435 Participants
AKI risk based on IOH depth and duration AKI risk: mild	6622 Participants n=17463 Participants	1985 Participants n=4972 Participants	8607 Participants n=22435 Participants
AKI risk based on IOH depth and duration AKI risk: moderate	4290 Participants n=17463 Participants	1136 Participants n=4972 Participants	5426 Participants n=22435 Participants
AKI risk based on IOH depth and duration AKI risk: high	2867 Participants n=17463 Participants	677 Participants n=4972 Participants	3544 Participants n=22435 Participants

PRIMARY outcome

Timeframe: Within 7 days after surgery

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Postoperative Acute Kidney Injury (AKI), Stage I or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. This will be the primary outcome for the Vanderbilt University Medical Center. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or >0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to > 4, or initiation of renal replacement therapy.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Postoperative Acute Kidney Injury AKI stage I or greater	1333 Participants	372 Participants
Postoperative Acute Kidney Injury No AKI - Confirmed by measurement	9670 Participants	2785 Participants
Postoperative Acute Kidney Injury No postoperative creatinine measurement	4621 Participants	1171 Participants

SECONDARY outcome

Timeframe: 30 days after surgery

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). For a large group of patients no mortality information was available.

Vanderbilt University Medical Center: combination of in-hospital mortality and 'alive-index' (which checks for visits to the hospital in the electronic healthcare record as indication of being alive at 30 days)

Outcome measures

Measure	Usual Care Group n=4667 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=1285 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
30-day Mortality	511 Participants	143 Participants

SECONDARY outcome

Timeframe: All postoperative days during a single hospital admission, expected median of 5 days

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Hospital mortality rate during a single hospital admission after the surgery

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
In-hospital Mortality	487 Participants	137 Participants

SECONDARY outcome

Timeframe: Within 7 days after surgery

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Postoperative Acute Kidney Injury (AKI), Stage II or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or >0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to > 4, or initiation of renal replacement therapy.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Postoperative Acute Kidney Injury Stage 2 No stage II or greater - Confirmed by measurement	11002 Participants	3157 Participants
Postoperative Acute Kidney Injury Stage 2 AKI stage II or greater	1 Participants	0 Participants
Postoperative Acute Kidney Injury Stage 2 No postoperative creatinine measurement	4621 Participants	1171 Participants

SECONDARY outcome

Timeframe: Within 7 days after surgery

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). Patients with no routine postoperative creatinine measurements are excluded from the analysis.

Absolute values for serum creatinine before and after surgery will be compared. When multiple postoperative creatinine measurements are made, the maximum difference is reported.

Outcome measures

Measure	Usual Care Group n=11003 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3157 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Postoperative Rise in Creatinine Levels	0.00 mg/dL Interval -0.1 to 0.13	0.00 mg/dL Interval -0.09 to 0.14

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 60 mmHg during anesthesia for 1 minute or more.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 60 mmHg	13779 Participants	3798 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 55 mmHg during anesthesia for 1 minute or more.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 55 mmHg	10991 Participants	3045 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 50 mmHg during anesthesia for 1 minute or more.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 50 mmHg	7781 Participants	2196 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 60 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 60 mmHg for > 10 Minutes	6989 Participants	1723 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 55 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 55 mmHg for > 10 Minutes	3181 Participants	759 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 50 mmHg for a cumulative duration of all hypotensive episodes of more than 10 minutes during the anesthetic phase of the procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 50 mmHg for > 10 Minutes	1159 Participants	326 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 60 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 60 mmHg for > 20 Minutes	3632 Participants	792 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 55 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 55 mmHg for > 20 Minutes	1223 Participants	284 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Incidence of a mean arterial pressure (MAP) < 50 mmHg for a cumulative duration of all hypotensive episodes of more than 20 minutes during the anesthetic phase of the procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Incidence of a MAP < 50 mmHg for > 20 Minutes	304 Participants	85 Participants

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Depth and Duration of Intraoperative Hypotension - Threshold MAP 75 mmHg	485 mmHg*minute Interval 243.0 to 915.0	417 mmHg*minute Interval 206.0 to 764.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Depth and Duration of Intraoperative Hypotension - Threshold MAP 70 mmHg	273 mmHg*minute Interval 126.0 to 543.0	235 mmHg*minute Interval 109.0 to 451.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Depth and Duration of Intraoperative Hypotension - Threshold MAP 65 mmHg	96 mmHg*minute Interval 34.0 to 225.0	86 mmHg*minute Interval 30.0 to 193.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Depth and Duration of Intraoperative Hypotension - Threshold MAP 60 mmHg	57 mmHg*minute Interval 21.0 to 131.0	52 mmHg*minute Interval 20.0 to 117.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Depth and Duration of Intraoperative Hypotension - Threshold MAP 55 mmHg	23 mmHg*minute Interval 5.0 to 59.0	23 mmHg*minute Interval 5.0 to 62.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Depth and duration of intraoperative hypotension will be modeled by calculating areas under the threshold for mean arterial pressures (MAPs). Thresholds will vary from 75 mmHg to 50 mmHg in 5 mmHg decrements. Together these variables represent the depth and duration of intraoperative hypotension. To optimize goodness of fit of these variables, the decremental steps may be increased to 10 mmHg and more restrictive lowest and highest thresholds may be chosen for the statistical analysis.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Depth and Duration of Intraoperative Hypotension - Threshold MAP 50 mmHg	19 mmHg*minute Interval 7.0 to 43.0	19 mmHg*minute Interval 8.0 to 47.0

SECONDARY outcome

Timeframe: During the surgical procedure: an expected average of 2 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

The estimated blood loss in mL during the surgical procedure

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Estimated Intraoperative Blood Loss	100 mL Interval 25.0 to 250.0	75 mL Interval 20.0 to 200.0

SECONDARY outcome

Timeframe: A specific time frame on the day of surgery: from the start of admission to the PACU to discharge from the PACU, an expected average of 4 hours

Population: Only patients with a postoperative stay at the postanesthesia care unit (PACU). Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

The time from arriving at the postanesthesia care unit (PACU) until the time the patient is considered ready for discharge (in minutes).

Outcome measures

Measure	Usual Care Group n=13082 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3580 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Time to Discharge Readiness at the Postanesthesia Care Unit (PACU)	67 minutes Interval 46.0 to 101.0	60 minutes Interval 42.0 to 89.25

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 65 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of propofol infusion rates during MAP < 65 mmHg episodes

Outcome measures

Measure	Usual Care Group n=14333 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3926 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg	60.10 mcg/kg/min (propofol) Interval 35.0 to 100.0	48.59 mcg/kg/min (propofol) Interval 28.55 to 83.88

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 60 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of propofol infusion rates during MAP < 60 mmHg episodes

Outcome measures

Measure	Usual Care Group n=11621 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3145 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg	61.07 mcg/kg/min (propofol) Interval 37.39 to 100.0	50.00 mcg/kg/min (propofol) Interval 27.65 to 81.5

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 55 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of propofol infusion rates during MAP < 55 mmHg episodes

Outcome measures

Measure	Usual Care Group n=8254 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=2196 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg	63.95 mcg/kg/min (propofol) Interval 37.5 to 100.0	50.00 mcg/kg/min (propofol) Interval 29.12 to 83.33

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 50 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of propofol infusion rates during MAP < 50 mmHg episodes

Outcome measures

Measure	Usual Care Group n=5135 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=1413 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Intravenous Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg	65.00 mcg/kg/min (propofol) Interval 40.0 to 100.0	50.00 mcg/kg/min (propofol) Interval 30.0 to 82.71

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any ephedrine are analyzed.

Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in <1% of cases are not reported, as the average dosages would be meaningless.

Outcome measures

Measure	Usual Care Group n=9310 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=2718 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Average Use of Cardiovascular Drugs: Ephedrine	20 mg Interval 10.0 to 25.0	15 mg Interval 10.0 to 25.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any phenylephrine are analyzed.

Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in <1% of cases are not reported, as the average dosage would be meaningless.

Outcome measures

Measure	Usual Care Group n=12211 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3685 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Average Use of Cardiovascular Drugs: Phenylephrine	0.90 mg Interval 0.3 to 3.69	1.30 mg Interval 0.4 to 5.03

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any glycopyrrolate are analyzed.

Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in <1% of cases are not reported, as the average dosage would be meaningless.

Outcome measures

Measure	Usual Care Group n=11093 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=1257 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Average Use of Cardiovascular Drugs: Glycopyrrolate	0.40 mg Interval 0.4 to 0.6	0.40 mg Interval 0.2 to 0.4

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any epinephrine are analyzed.

Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in <1% of cases are not reported, as the average dosage would be meaningless.

Outcome measures

Measure	Usual Care Group n=1215 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=409 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Average Use of Cardiovascular Drugs: Epinephrine	1.00 mg Interval 0.5 to 2.0	0.70 mg Interval 0.5 to 2.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section). In addition, only patients that actually received any norepinephrine are analyzed.

Cardiovascular drugs as defined under interventions. Average use for each drug will be calculated. Cardiovascular drugs that were given in <1% of cases are not reported, as the average dosage would be meaningless.

Outcome measures

Measure	Usual Care Group n=762 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=233 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Average Use of Cardiovascular Drugs: Norepinephrine	0.62 mg Interval 0.27 to 1.35	0.70 mg Interval 0.33 to 1.56

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 65 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 65 mmHg) and 15 minutes after the start of the episode.

Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 60 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.

Outcome measures

Measure	Usual Care Group n=13932 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3975 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Timing of Cardiovascular Drugs for MAP < 65 mmHg	2 minutes Interval 0.4 to 4.0	1.14 minutes Interval 0.0 to 3.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 60 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 60 mmHg) and 15 minutes after the start of the episode.

Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 60 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.

Outcome measures

Measure	Usual Care Group n=12292 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3458 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Timing of Cardiovascular Drugs for MAP < 60 mmHg	0.8 minutes Interval -0.37 to 2.5	1.5 minutes Interval 0.0 to 3.5

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 55 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 55 mmHg) and 15 minutes after the start of the episode.

Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 55 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.

Outcome measures

Measure	Usual Care Group n=9706 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=2752 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Timing of Cardiovascular Drugs for MAP < 55 mmHg	1 minutes Interval -0.333 to 3.0	0.5 minutes Interval -0.75 to 2.33

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 50 mmHg and an administration event of a cardiovascular drugs within 5 minutes before the start of the hypotensive episode (the first value below 50 mmHg) and 15 minutes after the start of the episode.

Cardiovascular drugs as defined under interventions. Time of first administration of cardiovascular drug relative to the time at which the mean arterial pressure (MAP) drops below 50 mmHg. Per patient the average time to first administration of all hypotensive episodes was calculated. That average time is used as the outcome variable. A negative value indicates that administration occurred before the drop in MAP.

Outcome measures

Measure	Usual Care Group n=6789 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=1989 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Timing of Cardiovascular Drugs for MAP < 50 mmHg	1 minutes Interval -0.833 to 3.0	0 minutes Interval -1.0 to 2.17

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Total amount (mL) of intravenous fluids (as defined under interventions) administered during the surgical procedure.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Intraoperative Administration of Intravenous Fluids	1500.00 mL Interval 1000.0 to 2300.0	1400.00 mL Interval 1000.0 to 2000.0

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 65 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of inhalational anesthesia during MAP < 65 mmHg episodes

Outcome measures

Measure	Usual Care Group n=14333 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3926 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg Sevoflurane (EndTidal %)	1.35 EndTidal% (other) Interval 1.03 to 1.6	1.27 EndTidal% (other) Interval 0.98 to 1.55
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg Isoflurane (EndTidal %)	0.68 EndTidal% (other) Interval 0.56 to 0.8	0.68 EndTidal% (other) Interval 0.56 to 0.8
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 65 mmHg Desflurane (EndTidal %)	4.10 EndTidal% (other) Interval 3.31 to 4.64	2.31 EndTidal% (other) Interval 1.15 to 3.46

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 60 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of inhalational anesthesia during MAP < 60 mmHg episodes

Outcome measures

Measure	Usual Care Group n=11621 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=3145 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg Sevoflurane (EndTidal %)	1.35 EndTidal% (other) Interval 1.02 to 1.62	1.25 EndTidal% (other) Interval 0.95 to 1.57
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg Isoflurane (EndTidal %)	0.68 EndTidal% (other) Interval 0.55 to 0.8	0.67 EndTidal% (other) Interval 0.55 to 0.8
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 60 mmHg Desflurane (EndTidal %)	4.36 EndTidal% (other) Interval 3.4 to 4.8	2.33 EndTidal% (other) Interval 1.116 to 3.49

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 55 mmHg and either a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of inhalational anesthesia during MAP < 55 mmHg episodes

Outcome measures

Measure	Usual Care Group n=8254 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=2196 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg Sevoflurane (EndTidal %)	1.34 EndTidal% (other) Interval 1.0 to 1.62	1.25 EndTidal% (other) Interval 0.94 to 1.55
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg Isoflurane (EndTidal %)	0.68 EndTidal% (other) Interval 0.52 to 0.82	0.67 EndTidal% (other) Interval 0.52 to 0.8
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 55 mmHg Desflurane (EndTidal %)	4.60 EndTidal% (other) Interval 3.49 to 4.88	4.65 EndTidal% (other) Interval 4.65 to 4.65

SECONDARY outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: All patients with any MAP \< 50 mmHg and a continuous administration of one of the following anesthetics: propofol, sevoflurane, isoflurane, desflurane. On occasion, the anesthesiologist may switch between anesthetic drugs. The numbers analyzed in one or more rows thus does not match the overall number analyzed.

Average concentrations of inhalational anesthesia during MAP < 50 mmHg episodes

Outcome measures

Measure	Usual Care Group n=5135 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=1413 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg Sevoflurane (EndTidal %)	1.32 EndTidal% (other) Interval 1.0 to 1.65	1.23 EndTidal% (other) Interval 0.89 to 1.57
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg Isoflurane (EndTidal %)	0.65 EndTidal% (other) Interval 0.5 to 0.82	0.65 EndTidal% (other) Interval 0.5 to 0.8
Inhaled Anesthetic Drug Use During Intraoperative Hypotension: MAP < 50 mmHg Desflurane (EndTidal %)	4.28 EndTidal% (other) Interval 3.61 to 4.78	4.70 EndTidal% (other) Interval 4.7 to 4.7

POST_HOC outcome

Timeframe: Within 7 days after surgery

Population: Post-Hoc analysis: all patients, not only those with any MAP \< 65 mmHg.

Postoperative Acute Kidney Injury (AKI), Stage I or higher according to the KDIGO criteria (Kidney Disease: Improving Global Outcomes). The staging will be based on serum creatinine values, as documentation of urine output is probably not sufficiently accurate. This will be the primary outcome for the Vanderbilt University Medical Center. The creatinine measurements are part of routine clinical care. Therefore, absence of creatinine postoperative measurements are considered to be 'no suspicion of kidney injury'. KDIGO defines AKI as any of the following: Increase in serum creatinine by 0.3mg/dL or more within 48 hours or Increase in serum creatinine to 1.5 times baseline or more within the last 7 days or Urine output less than 0.5 mL/kg/h for 6 hours. Stage 1 is 1.5-9x baseline or >0.3 increase; Stage 2 is 2-2.9x baseline; Stage 3 is 3x baseline, or increase to > 4, or initiation of renal replacement therapy.

Outcome measures

Measure	Usual Care Group n=17463 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4972 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Postoperative Acute Kidney Injury AKI stage I or greater	1477 Participants	435 Participants
Postoperative Acute Kidney Injury No AKI - Confirmed by measurement	10690 Participants	3166 Participants
Postoperative Acute Kidney Injury No postoperative creatinine measurement	5296 Participants	1371 Participants

POST_HOC outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in <1% of cases are not reported.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Usage Frequency of Cardiovascular Drugs: Ephedrine	9310 Participants	2718 Participants

POST_HOC outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in <1% of cases are not reported.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Usage Frequency of Cardiovascular Drugs: Phenylephrine	12211 Participants	3685 Participants

POST_HOC outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in <1% of cases are not reported.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Usage Frequency of Cardiovascular Drugs: Glycopyrrolate	11093 Participants	1257 Participants

POST_HOC outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in <1% of cases are not reported.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Usage Frequency of Cardiovascular Drugs: Ephinephrine	1215 Participants	409 Participants

POST_HOC outcome

Timeframe: During the anesthetic phase of the surgical procedure: an expected average of 2.5 hours

Population: Per study protocol only patients with any MAP \< 65 mmHg will be included in the primary analysis (See also 'Participant Flow' section).

Cardiovascular drugs as defined under interventions. Frequency of patients receiving the drug. Cardiovascular drugs that were given in <1% of cases are not reported.

Outcome measures

Measure	Usual Care Group n=15624 Participants The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4328 Participants The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Usage Frequency of Cardiovascular Drugs: Norepinephrine	762 Participants	233 Participants

Adverse Events

Usual Care Group

Serious events: 1811 serious events

Other events: 0 other events

Deaths: 534 deaths

Hypotension Decision Support

Serious events: 541 serious events

Other events: 0 other events

Deaths: 158 deaths

Serious adverse events

Measure	Usual Care Group n=17463 participants at risk The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).	Hypotension Decision Support n=4972 participants at risk The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
Renal and urinary disorders Acute Kidney Injury Stage I or greater	8.5% 1477/17463 • We analyzed adverse events in this patient population during their intraoperative course (adverse events sourced from our adverse event reporting system; from entry into OR to exit from OR), and during their hospitalization (source for mortality data; from hospital admission to hospital discharge). We utilized our perioperative information management system to determine the number of adverse events that occurred associated with the patients' intraoperative course. We used our hospital registration system to determine all cause mortality for this patient population.	8.7% 435/4972 • We analyzed adverse events in this patient population during their intraoperative course (adverse events sourced from our adverse event reporting system; from entry into OR to exit from OR), and during their hospitalization (source for mortality data; from hospital admission to hospital discharge). We utilized our perioperative information management system to determine the number of adverse events that occurred associated with the patients' intraoperative course. We used our hospital registration system to determine all cause mortality for this patient population.
Investigations Mortality	3.1% 534/17463 • We analyzed adverse events in this patient population during their intraoperative course (adverse events sourced from our adverse event reporting system; from entry into OR to exit from OR), and during their hospitalization (source for mortality data; from hospital admission to hospital discharge). We utilized our perioperative information management system to determine the number of adverse events that occurred associated with the patients' intraoperative course. We used our hospital registration system to determine all cause mortality for this patient population.	3.2% 158/4972 • We analyzed adverse events in this patient population during their intraoperative course (adverse events sourced from our adverse event reporting system; from entry into OR to exit from OR), and during their hospitalization (source for mortality data; from hospital admission to hospital discharge). We utilized our perioperative information management system to determine the number of adverse events that occurred associated with the patients' intraoperative course. We used our hospital registration system to determine all cause mortality for this patient population.

Other adverse events

Adverse event data not reported

Additional Information

Jonathan Wanderer

Vanderbilt University Medical Center

Phone: 615-536-5194

Email: jon.wanderer@vanderbilt.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place