Acceleration of Recovery From General Anesthesia - Efficacy of Isocapnic Hyperpnoea in Obese Patients Undergoing Isoflurane Anesthesia

Study Overview
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Brief Summary
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Faster recovery from anesthesia is important for obese patients because they are at high risk of respiratory complications following tracheal extubation. Isoflurane has several properties that make it a preferable agent for anesthesia in obese patients. Its main limitation is a longer recovery time due to slower elimination in comparison to other agents. Elimination of isoflurane from the lungs can be accelerated by increasing in patient's minute ventilation, which decreases the level of CO2 in blood (hypocapnia).Isocapnic Hyperpnoea (IH) is a method allowing increased ventilation and therefore enhancement of the elimination of inhalation agents while maintaining a normal blood CO2 level. The investigators will compare recovery time from isoflurane anesthesia in obese patients during standard anesthesia management protocol (control) to a group treated with IH.

Official Title
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Acceleration of Recovery From General Anesthesia - Efficacy of Isocapnic Hyperpnoea in Obese Patients Undergoing Isoflurane Anesthesia

Conditions
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Recovery Time From Isoflurane Anesthesia in Obese Patients

Intervention / Treatment
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* Other: Isocapnic Hyperpnoea


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective gynecological or urological procedure, BMI > 35 kg/m², ASA I-III, Signed informed consent. Exclusion Criteria: Lack of informed consent, ASA IV-V, Contra-indications to isoflurane anesthesia or other anesthetics included in the protocol, History of cardiac or respiratory disease, Alcohol or drug abuse, Psychiatric illness and/or medications.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Study intervention<br>Patient will be disconnected from the anesthetic circuit and connected to the resuscitation bag attached to the IH system. Ventilation will be assisted to maintain tidal volume of 8-10 mL/kg and respiratory rate of 20-25 breaths per minute to achieve minute ventilation of 15-20 L/min. Isocapnia manifold will maintain end-tidal PCO2 in range of 40-50 mm Hg. | Other: Isocapnic Hyperpnoea<br>* IH is a method of increasing alveolar ventilation (Va) while preventing the unwanted hypocapnia by addition of CO2 to the inhaled mixture.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time from the end of anesthesia (turning isoflurane vaporizer off) to the readiness for Post Anesthesia Care Unit (PACU) discharge. |  | Intraoperatively and Post Anesthetic Care Unit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Times from end of anesthesia to BIS exceeds 75, b) eye-opening to verbal command, c) extubation, d) readiness for leaving |  | Intraoperatively and Post Anesthetic Care Unit | 
| Sedation/Pain scores in the PACU. |  | Intraoperatively and Post Anesthetic Care Unit | 
| Change in exhaled isoflurane concentrations in the 1st hour postoperatively. |  | Intraoperatively and Post Anesthetic Care Unit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Isocapnic hyperpnoea, obesity, isoflurane, Recovery of obese patient from isoflurane anesthesia