Factors Affecting the Effective End-tidal Concentration of Desflurane Anaesthesia

Study Overview
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Brief Summary
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There is accumulating evidence that inappropriate depth of anaesthesia is associated with increased risk of postoperative complications including risk of death. The aim of this study was to identify factors determining the effective end-tidal concentration (EEtC) of desflurane, duration of wash in and wash out phase, and to estimate the risk of perioperative awareness in patients undergoing elective neurosurgical procedure.

Detailed Description
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All patients with American Society of Anesthesiologists (ASA) physical status I-III scheduled for elective neurosurgical procedure under general anaesthesia are studied. In each individual, the manufacturer recommended age-corrected end-tidal concentrations of desflurane is set and achieved initially. Individual effective end-tidal concentration (EEtC) of desflurane is then defined according to entropy parameters and maintained in the targeted range of static and response entropy 40-50. Effective analgesia is maintained according to surgical plethysmographic index (SPI) and dose of muscle relaxants according to neuromuscular transmission monitoring (TOF). Comorbidity, regular intake of alcohol and medication, smoking, sex, weight, height, and age are recorded. Postoperative questionnaire is used to reveal the intraoperative awareness.

Official Title
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Factors Affecting the Effective End-tidal Concentration of Desflurane Anaesthesia

Conditions
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General Anesthetic Drug Adverse Reaction

Intervention / Treatment
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* Drug: desflurane - oxygen in air
* Drug: desflurane - oxygen in nitric oxide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA I-III elective neurosurgical procedure under general anaesthesia Age between 18 and 78 elective procedures with estimated duration 1 - 3 hours Exclusion Criteria: Glasgow coma scale GCS below 14 other rhythm than sinus pacemaker stimulation planned postoperative ventilation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 78 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: desflurane - oxygen in air<br>The manufacturer recommended age-corrected end-tidal concentrations of desflurane in air should be set and achieved initially. Concentration of oxygen should be 50%. | Drug: desflurane - oxygen in air<br>* The manufacturer recommended age-corrected end-tidal concentrations of desflurane in air should be set and achieved initially. Individual EEtC of desflurane will be defined according to entropy parameters and maintained in the targeted range of static and response entropy 40-50<br>* Other names: suprane;|
| Experimental: desflurane - oxygen in nitric oxide<br>The manufacturer recommended age-corrected end-tidal concentrations of desflurane with nitric oxide - oxygen should be set and achieved initially.Concentration of oxygen should be 50%. | Drug: desflurane - oxygen in nitric oxide<br>* The manufacturer recommended age-corrected end-tidal concentrations of desflurane with nitric oxide - oxygen should be set and achieved initially. Individual EEtC of desflurane will be defined according to entropy parameters and maintained in the targeted range of static and response entropy 40-50<br>* Other names: suprane;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| end tidal concentration of desflurane according to age |  | from the start of procedure up to 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to spontaneous ventilation |  | from end of anesthesia up to 1 hour | 
| Time to extubation |  | from the end of anesthesia up to 1 hour | 
| Time to reaction to command |  | from the end of anesthesia up to 1 hour | 
| Wash in phase | sec | up to achievement of manufacturer age-corrected end-tidal concentrations of desflurane up to 10 minutes | 
| Wash out phase |  | from the end of procedure up to 1 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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age, Desflurane, end tidal concentration, anesthesia