Median Sevoflurane Concentration for Hypotension Between Young and Elderlypatients: Adaptive Clinical Trial

Study Overview
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Brief Summary
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Two arms: elder group, young group. Dixon's up and down adaptive methodology for ED50. Executed after Anesthesia induction for 10min without touching the patient after starting mechanical ventilation.

Detailed Description
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This adaptive clinical trial will vary target end tidal sevoflurane by 0.4, then by 0.2 and by 0.1 thereafter in order to minimize sample size.

Official Title
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Comparison of Median Alveolar Sevoflurane Concentration for Hypotension Between Young and Elderly Patients: Adaptive Clinical Trial

Conditions
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Hypotension

Intervention / Treatment
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* Drug: Sevoflurane


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Understands experiment, is voluntary, signs informed consent; Does not take medication that influences arterial pressure; Normotensive. Exclusion Criteria: Received any medication that influences arterial pressure before experiment;

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 120 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: Adaptive up and down methodology. Anesthesia will be induced using etomidate, rocuronium and remifentanil. After intubation and mechanical ventilation, a high fresh gas flow and variable vaporizer target concentration will be used to stabilize the patient's target end tidal sevoflurane in less than two minutes. Each patient's target end tidal sevoflurane is determined by the concentration used in the previous patient of the same group and by the incidence of hypotension. If the previous patient suffered hypotension, next patient's target concentration will drop. If there was no hypotension, next patient's target concentration will rise. The first patient on each group will be 2%. Target end tidal will vary 0.4% until the first crossover, then drop to 0.2% until the second crossover and will vary 0.1% thereafter.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Young patients<br>Patients between 19 and 40 years-old | Drug: Sevoflurane<br>* Inhaled sevoflurane until allocated dose (see adaptive protocol)<br>|
| Experimental: Elder patients<br>Older than 65 | Drug: Sevoflurane<br>* Inhaled sevoflurane until allocated dose (see adaptive protocol)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypotension incidence related to sevoflurane | Any mean arterial pressure drop > 10% compared to baseline | During the first 10 minutes after end tidal sevoflurane concentration stabilizes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic hypotension | Systolic arterial pressure drop >10% | During the first 10 minutes after end tidal sevoflurane concentration stabilizes | 
| Diastolic hypotension | Systolic arterial pressure drop >10% | During the first 10 minutes after end tidal sevoflurane concentration stabilizes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypotension, Sevoflurane, Elderly