Conversion From Total Intravenous Anesthesia Technique to Desflurane Anesthesia for Long Duration Neurosurgery

Study Overview
=================
Brief Summary
-----------------
Since neurological testing during neurosurgery, such as somato-sensory evoked potentials, motor-evoked potentials, auditory evoked potentials and visual evoked potentials are well maintained their wave-form reactivity with total intravenous anaesthesia technique better than inhalational anesthetic techniques, the standard anesthesia method for neurosurgery is usually total intravenous anaesthesia technique. Nonetheless, after finishing recording the evoked potential responses during surgery, facilitation of recovery from general anesthesia is getting important, because the real neurological physical examination is much more sensitive than above electrical evoked potentials to evaluate the results of surgical operation. We propose to evaluate the recovery parameters after conversion from total intravenous anaesthesia technique to Desflurane anesthesia during long term neurosurgery procedures. The conversion will be initiated upon completion of the neurophysiological electric evoked potentials assessment. Based on the pharmacological properties of desflurane, we hypothesize that recovery after conversion to Desflurane will be faster compared to recovery after total intravenous anaesthesia alone.

Official Title
-----------------
Conversion From Total Intravenous Anesthesia Technique to Desflurane Anesthesia for Long Duration Neurosurgery: A Pilot Study for Assessment of Recovery Parameters

Conditions
-----------------
Patients Undergoing Elective Craniotomy

Intervention / Treatment
-----------------
* Drug: Propofol
* Drug: Desflurane


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients undergoing elective craniotomy American Society of Anesthesiology Physical Status Ⅰ, II and III Age: between 20 to 65 years Sex: male or female Patients who are postmenopausal or surgically sterilized Expected Operation time is longer than 4 hours. Exclusion Criteria: -

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Propofol<br>Propofol target-controlled infusion will be kept 2-4μg /ml plasma concentration throughout procedure. | Drug: Propofol<br> <br> * Other names: Diprivan;|
| Experimental: Desflurane<br>After taking off the electrophysiological monitoring from the patients, discontinue propofol and start desflurane from 6% (dialed concentration) at flow rate of 4L/min for 2 minutes in desflurane group. When achieve end tidal concentration of 4-5%, decrease the flow rate to 2L/min. | Drug: Desflurane<br> <br> * Other names: Suprane;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time from the discontinuation of anesthesia to extubation |  | Patients will be followed in the operation room, an expected average of 30 minutes. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time from the discontinuation of anesthesia to eye opening |  | At the end of surgery, duration time from the discontinuation of anesthesia to the eye opening will be measured, averaged expected time is 30 minutes | 
| Cognitive function | Cognitive function will be measured by Mini-Mental state examination at baseline (preoperatively) 5 minutes and 24 hours after extubation. Postoperative recovery function will be also measured by Post-operative Quality Recovery Scale (PQRS scale) at 5 minutes and 24 hours after extubation. | Up to 24 hours | 
| Time from the discontinuation of anesthesia to orientation | Time from the discontinuation of anesthesia to orientation (State name, state the date of birth) | Up to 24 hours | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Desflurane, Propofol, Total intravenous anesthesia, Neurosurgery