Effects of Hypercapnia on Emergence From General Anesthesia Under Propofol

Study Overview
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Brief Summary
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Hypercapnia derives increase of cerebral blood flow and cardiac output. It means that the rate of propofol elimination from the brain and the blood will be increased and the patient will awake more quickly. There has been no study about the effects of hypercapnia. The investigators will evaluate hypercapnia's effects on the recovery time from propofol anesthesia.

Official Title
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Effects of Hypercapnia on Emergence From General Anesthesia Under Propofol: a Pilot Study

Conditions
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Anesthesia, Intravenous, Anesthesia Recovery Period

Intervention / Treatment
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* Procedure: Rebreathing tube
* Procedure: No rebreathing tube (Nothing)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists physical status (ASA PS) I-II Age 20 - 60 years male and female Elective schedule with minor surgery under general anesthesia Exclusion Criteria: Body mass index (BMI) >= 30 (kg/m2) Patient with pulmonary, cardiac, endocrinal, neuromuscular and neurological diseases or past history Patient with medication affecting on this study Patient with general anesthesia history within one month

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 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

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Hypercapnia group<br>Respiratory rate will be 10/min and the rebreathing tube will be connected between the y-piece of corrugated tube and the tracheal tube to maintain the partial pressure of the end-tidal carbon dioxide at around 50 mmHg during emergence after propofol anesthesia. | Procedure: Rebreathing tube<br>* 750 ml rebreathing tube will be connected between the corrugated tube and the tracheal tube of a patient. Target partial pressure of the end-tidal carbon dioxide is 50 mmHg.<br>|
| Experimental: Hypocapnia group<br>No rebreathing tube (Nothing) will be connected. Respiratory rate will be 10/min and the tidal volume will be modulated to maintain the partial pressure of the end-tidal carbon dioxide at around 30 mmHg during emergence after propofol anesthesia. | Procedure: No rebreathing tube (Nothing)<br>* 750 ml rebreathing tube will not be connected between the corrugated tube and the tracheal tube of a patient. Target partial pressure of the end-tidal carbon dioxide is 30 mmHg.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to open eyes under investigator's command | After stopping propofol infusion, every 30 seconds, the investigator (caregiver) will command the patient, Open your eyes. When the patient opens eyes, the time will be recorded. The patients will be followed for an expected average of 10 minutes. | From cessation of propofol infusion to patient's eye opening (seconds) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to breath spontaneously | The time from cessation of propofol infusion to patient's spontaneous breaths will be recorded. The patients will be followed for an expected average of 10 minutes. | From cessation of propofol infusion to patient's spontaneous breathing (sec) | 
| Change of bispectral index (BIS) | After stopping propofol infusion, the BIS and time (seconds) will be recorded and reviewed. These will be recorded for an expected average of 15 minutes. | From the cessation of propofol infusion to extubation, BIS and time (seconds) will be recorded. | 
| Time to open mouth under investigator's command | After the patient opens the eyes, every 10 seconds, the investigator command the patient, Open your mouth.. When the patient opens mouth, the time will be recorded. The patients will be followed for an expected average of 12 minutes. | From cessation of propofol infusion to patient's mouth opening (seconds) | 
| Time to extubation | After stopping propofol infusion, When the patient breaths spontaneously with adequate tidal volume and respiratory rates, the trachea will be extubated and the time will be recorded. The patients will be followed for an expected average of 15 minutes. | From cessation of propofol infusion to extubation (sec) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypocapnia, Emergence, Hypercapnia, Propofol