Trial Outcomes & Findings for Effect of Location of Tetanic Stimuli on Photoplethysmogram (NCT NCT03648853)

Results Overview

Change in the PPG signal in response to tetanic stimulus. A tetanic stimulus will cause vasoconstriction which can be recorded as a decrease in PPG AC/DC. The outcome measure is the maximum decrease in AC/DC from baseline. Maximum decrease happens typically in 30-60 seconds after the stimulus. Thus, data was collected immediately before (baseline) and for 2 min after the stimulus. After the stimulus AC/DC values return to baseline in a few minutes. Baseline AC/DC measures a relative state of blood vessel tone. In anesthetized patients the AC/DC values can range from close to 0 to above 10. The higher the value, the more vasodilated the subject is.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

12 participants

Primary outcome timeframe

1-2 minutes

Results posted on

2020-05-22

Participant Flow

12 surgical patients were recruited between 10/3/19/2018 and 11/30/2018. All subjects completed the study. Study was conducted in surgical patients under general anesthesia at UCSF

Participant milestones

Participant milestones
Measure	Intervention All subjects received the same intervention
Overall Study STARTED	12
Overall Study COMPLETED	12
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Intervention n=12 Participants All subjects received the same intervention
Age, Continuous	49 years STANDARD_DEVIATION 18 • n=12 Participants
Sex: Female, Male Female	8 Participants n=12 Participants
Sex: Female, Male Male	4 Participants n=12 Participants
Region of Enrollment United States	12 Participants n=12 Participants
photoplethysmagraph AC/DC values 60 seconds before each tetanic stimulus was considered as the basee	5.4 arbitrary units STANDARD_DEVIATION 1.95 • n=12 Participants

PRIMARY outcome

Timeframe: 1-2 minutes

Change in the PPG signal in response to tetanic stimulus. A tetanic stimulus will cause vasoconstriction which can be recorded as a decrease in PPG AC/DC. The outcome measure is the maximum decrease in AC/DC from baseline. Maximum decrease happens typically in 30-60 seconds after the stimulus. Thus, data was collected immediately before (baseline) and for 2 min after the stimulus. After the stimulus AC/DC values return to baseline in a few minutes. Baseline AC/DC measures a relative state of blood vessel tone. In anesthetized patients the AC/DC values can range from close to 0 to above 10. The higher the value, the more vasodilated the subject is.

Outcome measures

Outcome measures
Measure	Intervention n=12 Participants All subjects received the same intervention
Photoplethysmography (PPG)	3.3 arbitrary units Standard Deviation 1.6

Adverse Events

Intervention

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

Pekka Talke

UCalifornia San Francisco

Phone: 415 306 3602

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place