Minimal Alveolar Concentration of Sevoflurane Inducing Isoelectric Electroencephalogram
|ClinicalTrials.gov Identifier: NCT01662622|
Recruitment Status : Completed
First Posted : August 10, 2012
Last Update Posted : August 14, 2012
|Condition or disease||Intervention/treatment||Phase|
|Middle Aged Patients Sevoflurane General Anesthesia||Drug: Sevoflurane||Phase 4|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||31 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Official Title:||Minimal Alveolar Concentration of Sevoflurane Inducing Isoelectric Electroencephalogram|
|Study Start Date :||March 2012|
|Primary Completion Date :||May 2012|
|Study Completion Date :||July 2012|
Anaesthesia was induced by 8% sevoflurane. Cisatracurium 0.15mg kg-1 was administered after loss of the lash reﬂex, then ventilated manually until the amplitude of T1 decreased to 0. Intubation was performed and switched to mechanical ventilation with a fresh gas flow 2L min-1. Gas concentrations were analysed using a gas analyser.The end-tidal concentration of carbon dioxide was maintained at 4.7kPa; an esophageal temperature probe was inserted and a warming unit was used if necessary to maintain normothermia (35.5°-38.5°). The surgical incision was performed at least 30min after tracheal intubation. When arterial blood pressure (MAP) decrease exceeding 20% of baseline values. Phenylephrine 0.1mg was administered intravenously if necessary to maintained MAP and recorded.
The design of experiment is referred to the "Dixon up-and-down" method. The first subject was designed to receive end-tidal sevoflurane concentration of 1.7%. For each subject, 30 min interval time was given. The isoelectric EEG was considered as significant when the isoelectric state last for more than 1min. The maximal burst suppression rate was recorded if isoelectric EEG was not reached. Heart rate and MAP, were recorded 2 and 1min before and 3 min after skin incision. Adrenergic reflexes positive cases were counted.
- MACie [ Time Frame: 30min ]Minimal Alveolar Concentration of sevoflurane inducing isoelectric electroencephalogram (EEG) in 50% of the subjects (MACie)
- MACbs [ Time Frame: 30 min ]Minimal Alveolar Concentration of sevoflurane inducing inducing burst suppression EEG (MACbs) in middle aged adults.
- Hemodynamic parameters [ Time Frame: 3 min ]Hemodynamic parameters 2 min before and 3 min after skin incision
- Use of phenylephrine [ Time Frame: 30 min ]Use of phenylephrine during induction and maintenance of anesthesia with sevoflurane.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01662622
|Department of Anaesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology|
|Wuhan, Hubei, China, 430030|
|Study Chair:||Yuke Tian, MD.||Department of Anaesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology|