Hypercapnic Spontaneous Hyperpnoea and Recovery From Sevoflurane Anesthesia

Study Overview
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Brief Summary
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The rate of elimination of inhalation agent is directly proportional to the degree of alveolar ventilation. Using Isocapnic Hyperpnoea (IH) device, it is possible to maintain constant end-tidal CO2 with increased minute ventilation. This is achieved by passively adding a flow of CO2 to the inspirate in proportion to increases in ventilation above the baseline. In animal and human studies IH shortens the time of awakening from isoflurane and sevoflurane anesthesia when manual positive pressure ventilation is applied. IH device could be used for spontaneous hyperpnoea as well. The investigators want to compare recovery times from sevoflurane anesthesia in patients with application of hypercapnic spontaneous hyperpnoea (HSH) versus the standard anesthesia protocol (controls). 44 patients ill be randomized to either HSH facilitated recovery, or conventional recovery (controls).The time intervals from the end of anesthesia (turning off the vaporizer) until recovery milestones will be recorded.

Official Title
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Hypercapnic Spontaneous Hyperpnoea and Recovery From Sevoflurane Anesthesia

Conditions
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Anesthesia, Surgery

Intervention / Treatment
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* Other: Standard Anesthesia management for post surgical patients
* Device: Hypercarbic Spontaneous Hyperpnoea


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: elective gynecological surgery age 18-80 ASA I-III informed consent Exclusion Criteria: ASA IV-V, contra-indications to sevoflurane anesthesia or other anesthetics included in the protocol history of cardiac or respiratory disease intracranial pathology 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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Female

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: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Control Arm<br>The O2 flow on the anesthetic machine will be set at 15 L/min. Ventilatory assistance will be performed to maintain O2 saturation >97% and end tidal CO2 at 35-45mmHg. | Other: Standard Anesthesia management for post surgical patients<br>* The O2 flow on the anesthetic machine will be set at 15 L/min. Ventilatory assistance will be performed to maintain O2 saturation >97% and end tidal CO2 at 35-45mmHg.<br>|
| Active Comparator: HSH Group<br>Patient will be disconnected from the anesthetic circuit and connected to the resuscitation bag attached to the IH system. With O2 flow of 2 L/min patient will be gently ventilated until recovery of the spontaneous ventilation. After starting spontaneous ventilation basal O2 flow will be adjusted to keep ETCO2 in range of 50-60 mm Hg or minute ventilation of 15-17 L/min, whichever occurs first. | Device: Hypercarbic Spontaneous Hyperpnoea<br>* Patient will be disconnected from the anesthetic circuit and connected to the resuscitation bag attached to the IH system. With O2 flow of 2 L/min patient will be gently ventilated until recovery of the spontaneous ventilation. After starting spontaneous ventilation basal O2 flow will be adjusted to keep ETCO2 in range of 50-60 mm Hg or minute ventilation of 15-17 L/min, whichever occurs first.<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 to the readiness for post-anesthesia care unit (PACU) discharge. |  | End of anesthesia (turning off the vaporizer) until readiness for PACU discharge, approximately 30 minutes to 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of pain and sedation scores |  | End of anesthesia (turning off the vaporizer) to PACU discharge, approximately 30 minutes to 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Isocapnic hyperpnoea (IH), Anesthesia, Accelerate elimination of inhalation agents, Recovery from anesthesia