Methohexital v Propofol as General Anesthetic in Patients on ACEIs or ARBs

Study Overview
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Brief Summary
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Patient undergoing general anesthesia in elective surgery will be assigned to receive either methohexital or propofol general anesthesia. Hypotensive events during the first 15 minutes of induction will be compared between the groups to ascertain which drug is less likely to cause a hypotensive event.

Detailed Description
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Patients taking angiotensin converting-enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) are susceptible to hypotensive events during general anesthesia. The purpose of this study is to determine if the use of either methohexital or propofol general anesthesias is more likely to result in hypotensive events in these patients during their induction. Hemodynamic metrics like blood pressure, mean arterial pressure, and heart rate will be monitored during the induction process, under both drugs, for use as the main metrics, as well as the need for vasopressors in response to patient hypotension.

Official Title
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Comparison of Methohexital With Propofol for Anesthetic Induction in Patients Treated With an Antagonist of the Renin-Angiotensin System.

Conditions
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Hypotension, Anesthesia

Intervention / Treatment
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* Drug: Methohexital
* Drug: Propofol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: treated for at least 6 weeks with ACEIs or ARB undergoing elective surgery under general endotracheal anesthesia ASA Physical Class I or II Exclusion Criteria: BMI >45kg/m^2 taking both ACEI and ARB history of difficult intubation in the past require rapid sequence induction and intubation uncontrolled baseline blood pressure (SBP>180mmHg or DBP >110 mmHg) at anesthesia preoperative clinic visit contraindication to the use of propofol or methohexital significant coronary artery disease history of systolic heart failure history of renal failure (creatine level >2 mg/dL)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Methohexital<br>Methohexital will be administered intravenously as a general anesthetic at a dosage of 1.5mg per kg of patient body weight. | Drug: Methohexital<br>* Both drugs of interest are standard of care for use as general anesthetics. The purpose of the study is the determine the susceptibility of both drugs to inducing a hypotensive event.<br>* Other names: Brevital;|
| Active Comparator: Propofol<br>Propofol will be administered intravenously as a general anesthetic at a dosage of 2.5mg per kg of patient body weight. | Drug: Propofol<br>* Both drugs of interest are standard of care for use as general anesthetics. The purpose of the study is the determine the susceptibility of both drugs to inducing a hypotensive event.<br>* Other names: Diprivan;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants Who Had Hypotensive Events | Hypotensive events under either methohexital or propofol general anesthesia will be counted as the primary outcome measure | Hemodynamic measurements will be taken during the first 15 minutes of anesthetic induction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Refractory Hypotension | Refractory hypotension is defined as a hypotensive event that continues after 3 doses of vasopressors | Hemodynamic measurements will be taken during the first 15 minutes of anesthetic induction | 
| Duration of Each Hypotension Episode | This is the length of time that systolic blood pressure was either: (1) < 85 mmHg, or (2) a decrease of more than 30% from the individual's baseline SBP. | Hemodynamic measurements will be taken during the first 15 minutes of anesthetic induction | 
| Systolic Blood Pressure | Systolic blood pressure will be measured through standard monitoring. | Hemodynamic measurements will be taken during the first 15 minutes of anesthetic induction | 
| Diastolic Blood Pressure | Diastolic blood pressure will be measured through standard monitoring. | Hemodynamic measurements will be taken during the first 15 minutes of anesthetic induction | 
| Heart Rate | Heart rate will be measured through standard monitoring. | Hemodynamic measurements will be taken during the first 15 minutes of anesthetic induction | 
| Serum Concentration of Norepinephrine (NE) (at Baseline (Time 0) and 3,5,10 and 15 Min After Anesthetic Induction) | Serum concentrations of NE at predetermined time points (Baseline (Time 0) and 3,5,10 and 15 min) following anesthetic induction | Time 0,3,5,10 and 15 min following anesthetic induction | 
| Blood Levels of Epinephrine (at Baseline (Time 0) and 3,5,10 and 15 Min After Induction of Anesthesia) | Serum concentrations of Epinephrine at predetermined time points (Baseline (Time 0) and 3,5,10 and 15 min) following anesthetic induction | Time 0,3,5,10 and 15 min following anesthetic induction | 
| Blood Levels of Angiotensin II (AII) (at Baseline (Time 0) and 3,5,10 and 15 Min After Anesthetic Induction) | Serum concentrations of Angiotension II at predetermined time points (Baseline (Time 0) and 3,5,10 and 15 min) following anesthetic induction | Time 0,3,5,10 and 15 min following anesthetic induction | 
| Blood Levels of Arginine Vasopressin (AVP) (at Baseline (Time 0) and 3,5,10 and 15 Min After Anesthetic Induction) for Participants Who Did Not Receive AVP for Refractory Hypotension | Serum concentrations of AVP at predetermined time points (Baseline (Time 0) and 3,5,10 and 15 min) following anesthetic induction determined for participants who did not receive AVP for refractory hypotension | Time 0,3,5,10 and 15 min following anesthetic induction | 
| Blood Levels of AVP (at Baseline (Time 0) and 3,5,10 and 15 Min) for Participants Who Received AVP for Refractory Hypotension | Serum concentrations of AVP at predetermined time points (Baseline (Time 0) and 3,5,10 and 15 min), following anesthetic induction, determined for Participants who did not receive AVP for refractory hypotension | Time 0,3,5,10 and 15 min following anesthetic induction | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ACEI, ARB, Hypotension, General Anesthesia, Methohexital, Propofol