Minimal Alveolar Concentration of Sevoflurane Inducing Isoelectric Electroencephalogram

NCT01662622 | Completed Phase 4 DMC

• 1 other identifier: TJMZK20120301
• Study Type: interventional
• Target: 31
• Locations: 1 country
• Sites: 1

Brief Summary

Sevoflurane can abolish movement or adrenergic response to noxious stimulus. In order to investigate the effect of sevoflurane on cerebral electrical activity, we determined the MAC of sevoflurane inducing isoelectric electroencephalogram (EEG) in 50% of the subjects (MACie) in middle aged subjects.

Conditions

Middle Aged Patients; Sevoflurane; General Anesthesia

Keywords

anaesthesia; middle aged; minimal alveolar concentration; sevoflurane; isoelectric EEG

Outcome Measures

Primary Outcomes (1)

• MACie

  Minimal Alveolar Concentration of sevoflurane inducing isoelectric electroencephalogram (EEG) in 50% of the subjects (MACie)

  30min

Secondary Outcomes (1)

• MACbs

  30 min

Other Outcomes (2)

• Hemodynamic parameters

  3 min

• Use of phenylephrine

  30 min

Study Arms (1)

Sevoflurane

EXPERIMENTAL

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.

Drug: Sevoflurane

Interventions

Sevoflurane DRUG

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.

Sevoflurane

Eligibility Criteria

• Age: 45 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• upper abdominal surgery in general anaesthesia
• ASA physical status classification of I or II

You may not qualify if:

• neurological disease
• received central nervous system-active drugs
• cardiac ejection fraction less than 40%
• history of difficult intubation or anticipated difficult intubation
• daily alcohol consumption
• obesity, defined as a body-mass index of more than 30
• without informed consent

Sponsors & Collaborators

• Huazhong University of Science and Technology: lead
• Ministry of Health, China: collaborator
• National Natural Science Foundation of China: collaborator

Study Sites (1)

Department of Anaesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology

Wuhan, Hubei, 430030, China

Location

MeSH Terms

Interventions

Sevoflurane

Intervention Hierarchy (Ancestors)

Methyl Ethers; Ethers; Organic Chemicals; Hydrocarbons, Fluorinated; Hydrocarbons, Halogenated; Hydrocarbons

Study Officials

• Yuke Tian, MD.

  Department of Anaesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: AssociateProfessor

Study Record Dates

• First Submitted: August 8, 2012
• First Posted: August 10, 2012
• Study Start: March 1, 2012
• Primary Completion: May 1, 2012
• Study Completion: July 1, 2012
• Last Updated: August 14, 2012

Record last verified: 2012-08

Locations

CN (1)