Effect of Location of Tetanic Stimuli on Photoplethysmogram

Not Applicable

Completed

• Conditions: Stress Reaction
• Interventions: Device: Tetanic Stimulus

• Registration Number: NCT03648853
• Lead Sponsor: University of California, San Francisco

Brief Summary

The effect of the location of tetanic stimulus on photoplethysmography signals will be studies in patients under general anesthesia.

Detailed Description

A 5 second 100 Hz 70 mA tetanic stimulus will be applied to three different locations in a random order in patients who are under general anesthesia. Tetanic stimuli are used routinely during general anesthesia to assess effectiveness of neuromuscular blockade. These tetanic stimuli are noxious stimuli that elicit a stress response which can be quantified using photoplethysmography. This study investigates if the magnitude of the tetanus induced stress response is dependent on the location of the tetanic stimulus as measured by photoplythysmography.

Study Timeline

• Study First Submitted: 2018-08-24
• Study First Submitted QC: 2018-08-24
• Study First Posted: 2018-08-27
• Study Start: 2018-09-01
• Primary Completion: 2018-11-30
• Study Completion: 2018-11-30
• Results First Submitted: 2020-03-07
• Results First Submitted QC: 2020-04-18
• Results First Posted: 2020-04-30
• Status Verified: 2020-05
• Last Update Submitted: 2020-05-09
• Last Update Posted: 2020-05-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 12

Inclusion Criteria

• Surgical patients general anesthesia able to consent in english

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Exclusion Criteria

• regional anesthesia unable to consent in english under 18 yrs of age

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
intervention	Tetanic Stimulus	all participants receive the same intervention

Primary Outcome Measures

Name	Time	Method
Photoplethysmography (PPG)	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.

Trial Locations

Locations (1)

University of California San Francisco; 🇺🇸 San Francisco, California, United States