Effect of Changing Physiological Conditions on Myogenic Oscillations: Pilot Study

University of California San Francisco (UCSF)

Status and phase: Completed; Early Phase 1

Conditions: Vascular Diseases

Treatments: Other: Increased venous pressure; Other: tetanic stimulus; Drug: Calcium Chloride; Drug: Clevidipine; Drug: Dexmedetomidine; Drug: Phenylephrine

Study type: Interventional

Funder types: Other

Identifiers

NCT03719001

PT1802

Details and patient eligibility

About

Spontaneous myogenic oscillations will be studied under general anesthesia using finger photoplethysmography. This pilot study will explore potential physiological conditions that will effect the amplitude and/or frequency of myogenic oscillations.

Full description

This is a single center, nonrandomized, nonblinded, interventional clinical pilot research study that plans to enroll 40 patients.

Study will be conducted while subjects are under general anesthesia.

Myogenic oscillations will be measured using finger photoplethysmography. Changes in the amplitude and/or frequency of these oscillations will be analyzed in response to the interventions. Arterial blood pressure will be recorded to verify the efficacy of the interventions.

Six different interventions that will either lower or increase blood pressure will be applied to the subjects. Each subject will receive 1 or 2 of the six interventions. Each of the 6 interventions will be applied to 8 subject.

The interventions that the subject will not be randomized. They will be determined by the subjects blood pressure immediately before the intervention to guarantee that the blood pressure manipulations are within a safe range.

Data will be analyzed offline using Matlab.

Enrollment: 40 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Over 18 yrs of age
2. Undergoing surgery in Moffitt-Long operating rooms
3. Receiving general anesthesia
4. Will have an intra-arterial catheter for clinical purposes
5. Able to consent in english

Exclusion criteria

1. Under 18 years of age
2. unable to provide informed consent
3. Pregnancy

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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40 participants in 6 patient groups

Phenylephrine

Experimental group

Description:

Phenylephrine (100 ug/ml) infusion will be used to increase blood pressure by 20 mmHg

Treatment:

Drug: Phenylephrine

Dexmedetomidine

Experimental group

Description:

Dexmedetomidine infusion will be used to increase blood pressure by 20 mmHg

Treatment:

Drug: Dexmedetomidine

Clevidipine

Experimental group

Description:

Clevidipine infusion will be used to increase blood pressure by 20 mmHg

Treatment:

Drug: Clevidipine

Calcium Chloride

Experimental group

Description:

Calcium Chloride will be administered to increase blood pressure and to increase blood calcium concentration

Treatment:

Drug: Calcium Chloride

tetanic stimulus

Experimental group

Description:

A 5 second 70 mA tetanic stimulus will be used to increase peripheral vascular tone

Treatment:

Other: tetanic stimulus

Increased venous pressure

Experimental group

Description:

A 5 minute inflation of a noninvasive blood pressure cuff to 30 mmHg to increase venous pressure in the arm.

Treatment:

Other: Increased venous pressure