Minimal Alveolar Concentration of Sevoflurane Inducing Isoelectric Electroencephalogram

General Anesthesia Clinical Trial

Official title:

Minimal Alveolar Concentration of Sevoflurane Inducing Isoelectric Electroencephalogram

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01662622
• Other study ID #: TJMZK20120301
• Status: Completed
• Phase: Phase 4
• First received: August 8, 2012
• Last updated: August 12, 2012
• Start date: March 2012
• Est. completion date: July 2012

Study information

• Verified date: August 2012
• Source: Huazhong University of Science and Technology
• Contact: n/a
• Is FDA regulated: No
• Health authority: China: Ministry of Health
• Study type: Interventional

Clinical Trial 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.

Description:

Patients received sevoflurane for anesthesia induction and maintenance at preselected concentrations according to an 'up and down' design, with 0.2% as a stepsize. General anesthesia was induced and maintained with sevoflurane, tracheal intubation was facilitated with cisatracurium. After a steady-state period of 30min without surgical stimulation, the state of isoelectric EEG was considered as significant when a burst suppression ratio of 100% last for more than 1 min. The haemodynamic responses to skin incision and the vasopressor requirement to maintain cardiovascular system were also analysed according to the EEG state.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 31
• Est. completion date: July 2012
• Est. primary completion date: May 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 45 Years to 65 Years

Eligibility

Inclusion Criteria:

• 45-65yr

• upper abdominal surgery in general anaesthesia

• ASA physical status classification of I or II

Exclusion Criteria:

• 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

Study Design

Endpoint Classification: Pharmacodynamics Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• General Anesthesia
• Middle Aged Patients
• Sevoflurane

Intervention

Drug:
• Sevoflurane
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.

Locations

Country	Name	City	State
China	Department of Anaesthesiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology	Wuhan	Hubei

Sponsors (3)

Lead Sponsor	Collaborator
Huazhong University of Science and Technology	Ministry of Health, China, National Natural Science Foundation of China

Country where clinical trial is conducted

China, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Hemodynamic parameters	Hemodynamic parameters 2 min before and 3 min after skin incision	3 min	Yes
Other	Use of phenylephrine	Use of phenylephrine during induction and maintenance of anesthesia with sevoflurane.	30 min	Yes
Primary	MACie	Minimal Alveolar Concentration of sevoflurane inducing isoelectric electroencephalogram (EEG) in 50% of the subjects (MACie)	30min	Yes
Secondary	MACbs	Minimal Alveolar Concentration of sevoflurane inducing inducing burst suppression EEG (MACbs) in middle aged adults.	30 min	Yes