Trial Outcomes & Findings for Serratus Plane Versus Paravertebral Nerve Blocks for Breast Surgery (NCT NCT03860974)

NCT ID: NCT03860974

Last Updated: 2022-09-21

Results Overview

Opioid consumption as measured in milligram morphine equivalents. The primary outcome measure will be the mean or median (depending on whether data is normally or not normally distributed) of the cumulative opioid consumption within the recovery room following surgery and prior to recovery room discharge.

• Recruitment status: COMPLETED
• Study phase: PHASE4
• Target enrollment: 100 participants
• Primary outcome timeframe: Within the recovery room following surgery and prior to recovery room discharge
• Results posted on: 2022-09-21

Participant Flow

Participant milestones

Measure	Serratus Plane (Single Injection) A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Overall Study STARTED	49	51
Overall Study COMPLETED	49	51
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Measure	Serratus n=49 Participants Ropivacaine 0.5% (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) will be administered via the needle into the target plane(s). For serratus blocks, local anesthetic will be deposited above rib 5 and deep to serratus muscle in the lateral position.	Paravertebral n=51 Participants Ropivacaine 0.5% (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) will be administered via the needle into the target plane(s). For PVBs without axillary involvement, this will be at the T3 and T5 levels. For PVBs with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral PVBs, 8 mL of local anesthetic will be injected per level.	Total n=100 Participants Total of all reporting groups
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment United States	49 participants n=49 Participants	51 participants n=51 Participants	100 participants n=100 Participants
Age, Continuous	55 years n=49 Participants	53 years n=51 Participants	53 years n=100 Participants
Sex: Female, Male Female	49 Participants n=49 Participants	48 Participants n=51 Participants	97 Participants n=100 Participants
Sex: Female, Male Male	0 Participants n=49 Participants	3 Participants n=51 Participants	3 Participants n=100 Participants

PRIMARY outcome

Timeframe: Within the recovery room, averaging approximately 2 hours

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. The primary outcome measure will be the mean or median (depending on whether data is normally or not normally distributed) of all reported NRS within the recovery room following surgery and prior to recovery room discharge.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Mean/Median Numeric Rating Scale Pain Score Within the Recovery Room	4 score on a scale Interval 0.0 to 5.5	0 score on a scale Interval 0.0 to 3.0

PRIMARY outcome

Timeframe: Within the recovery room following surgery and prior to recovery room discharge

Opioid consumption as measured in milligram morphine equivalents. The primary outcome measure will be the mean or median (depending on whether data is normally or not normally distributed) of the cumulative opioid consumption within the recovery room following surgery and prior to recovery room discharge.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Mean/Median Opioid Consumption Within the Recovery Room	14 milligrams of morphine equivalents Interval 10.0 to 19.0	10 milligrams of morphine equivalents Interval 10.0 to 16.0

SECONDARY outcome

Timeframe: Within the recovery room, averaging approximately 2 hours

This outcome is measured based on whether the patient needed an anti-emetic in the recovery room following surgery and prior to discharge from the recovery room. An "anti-emetic" is a medication given if the patient complains of nausea or exhibits vomiting.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Number of Participants Requiring an Anti-emetic Within the Recovery Room	19 Participants	8 Participants

SECONDARY outcome

Timeframe: Between the recovery room discharge to the postoperative day 1 data collection phone call

cumulative opioid consumed between the recovery room discharge to the postoperative day 1 data collection phone call measured in morphine milliequivalents

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Opioid Consumption After Recovery Room Discharge	2 mg in morphine equivalents Interval 2.0 to 4.0	2 mg in morphine equivalents Interval 0.0 to 4.0

SECONDARY outcome

Timeframe: Between the recovery room discharge to the postoperative day 1 data collection phone call

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the "worst" pain experienced by the patient Between the recovery room discharge to the postoperative day 1 data collection phone call as reported during that data collection phone call.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
WORST Pain Measured Using the Numeric Rating Scale Pain Score	5 score on a scale Interval 3.0 to 6.0	3 score on a scale Interval 2.0 to 5.0

SECONDARY outcome

Timeframe: between the recovery room discharge to the postoperative day 1 data collection phone call

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the "least" pain experienced by the patient between the recovery room discharge to the postoperative day 1 data collection phone call as reported during that data collection phone call.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Lowest Pain Measured Using the Numeric Rating Scale Pain Score	1 units on a scale Interval 0.0 to 3.0	0 units on a scale Interval 0.0 to 1.0

SECONDARY outcome

Timeframe: between the recovery room discharge to the postoperative day 1 data collection phone call

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the "average" pain experienced by the patient between the recovery room discharge to the postoperative day 1 data collection phone call as reported during that data collection phone call.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Average Pain Measured Using the Numeric Rating Scale Pain Score	3 score on a scale Interval 2.0 to 4.0	2 score on a scale Interval 0.5 to 3.0

SECONDARY outcome

Timeframe: within the recovery room following surgery and prior to recovery room discharge

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the highest/maximum pain score reported by the patient within the recovery room.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Worst RECOVERY ROOM Pain Measured Using the Numeric Rating Scale Pain Score	5 units on a scale Interval 3.0 to 6.0	3 units on a scale Interval 2.0 to 5.0

SECONDARY outcome

Timeframe: the first evening after surgery, averaging approximately 8 hours

The number of times the subject recalls awakening from sleep due to pain the prior evening

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Awakenings Due to Pain	0 number of awakenings Interval 0.0 to 0.0	0 number of awakenings Interval 0.0 to 0.0

SECONDARY outcome

Timeframe: within the recovery room following surgery and prior to recovery room discharge

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the lowest pain score reported by the patient within the recovery room.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
LEAST RECOVERY ROOM Pain Measured Using the Numeric Rating Scale Pain Score	0 units on a scale Interval 0.0 to 3.0	0 units on a scale Interval 0.0 to 1.0

SECONDARY outcome

Timeframe: Within the operating room, averaging approximately 2 hours

cumulative opioid consumed between entry into the operating room and discharge to the recovery room as measured in morphine milliequivalent

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Opioid Consumption Within the Operating Room	10 mg in morphine equivalents Interval 10.0 to 10.0	10 mg in morphine equivalents Interval 8.75 to 10.0

SECONDARY outcome

Timeframe: between discharge from the recovery room and the data collection phone call on postoperative day 1

A likert scale was used in which 0 represented no nausea experienced, and 10 represented active vomiting.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Nausea and Vomiting Following Recovery Room Discharge	0 units on a scale Interval 0.0 to 0.0	0 units on a scale Interval 0.0 to 0.0

SECONDARY outcome

Timeframe: between discharge from the recovery room and the data collection phone call on postoperative day 1

The time in hours between recovery room discharge and the first use of an opioid as reported by patients during the data collection phone call on postoperative day 1. For patients who did not consume any opioids following recovery room discharge, their time was recorded as 24 hours for calculation purposes.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Time From Recovery Room Discharge Until First Opioid Use	14 hours Standard Deviation 4	8 hours Standard Deviation 1

SECONDARY outcome

Timeframe: between local anesthetic injection completion during the nerve block and the time when block resolution began

Population: \*\* This outcome was erroneously left off of the case report forms, so we did not collect the data for this outcome measure.

The time in hours between local anesthetic injection completion during the nerve block and the time when block resolution began as reported by patients during the data collection phone call on postoperative day 1.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: During the placement of the nerve block

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the "worst" pain experienced by the patient during the placement of the nerve block between the time the block needle was inserted until the time the block needle was withdrawn.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
WORST Pain Measured DURING NERVE BLOCK Using the Numeric Rating Scale Pain Score	2 score on a scale Interval 0.0 to 4.0	1 score on a scale Interval 1.0 to 3.5

SECONDARY outcome

Timeframe: During the placement of the nerve block

Numeric Rating Scale: the NRS is a segmented numeric version of the Visual Analog Scale (VAS) in which the study subject selects a whole number (0-10 integers) that best reflects the intensity of his/her pain. This 11-point numeric scale ranges from 0 representing "no pain" to 10 representing "worst imaginable pain." Higher numeric scores represent increased pain and thus worse outcomes. This outcome was the "average" pain experienced by the patient during the placement of the nerve block between the time the block needle was inserted until the time the block needle was withdrawn.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Average Pain Measured DURING NERVE BLOCK Using the Numeric Rating Scale Pain Score	1 score on a scale Interval 0.0 to 2.0	1 score on a scale Interval 0.0 to 2.0

SECONDARY outcome

Timeframe: The time from initial nerve block needle insertion until nerve block needle withdrawal

The time in minutes between the time from initial nerve block needle insertion until nerve block needle withdrawal, measured in minutes.

Outcome measures

Measure	Serratus Plane (Single Injection) n=49 Participants A single injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL on each side for bilateral surgery) Serratus Plane block (single injection): A single-injection serratus plane block will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL of local anesthetic for unilateral surgery; 16 mL of local anesthetic each side for bilateral surgery).	Paravertebral (Single Injection) n=51 Participants Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery) Paravertebral block (single injection): Single injection paravertebral blocks will be administered using ropivacaine 0.5% with epinephrine 1:200,000-400,000 (20 mL for unilateral surgery; 16 mL each side for bilateral surgery). For paravertebral blocks without axillary involvement, this will be at the T3 and T5 levels. For paravertebral blocks with axillary involvement, this will be at the T2 and T4 levels. For unilateral PVBs, 10 mL of local anesthetic will be injected per level. For bilateral paravertebral blocks, 8 mL of local anesthetic will be injected per level.
Time to Perform Nerve Block	1.25 minutes Interval 0.0 to 4.0	4 minutes Interval 2.0 to 6.0

Adverse Events

Serratus Plane (Single Injection)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Paravertebral (Single Injection)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Brian Ilfeld

University of California, San Diego

Phone: 8582493660

Email: bilfeld@health.ucsd.edu

Results disclosure agreements

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