Korean J Anesthesiol.  2001 Sep;41(3):280-283. 10.4097/kjae.2001.41.3.280.

The Effect of Inhaled Desflurane Concentrations on the Bispectral Index

• Kil HY
• Hong SJ
• Chae BS
• Park H
• Han TH
• Lee HH

• KMID: 2031878
• DOI: http://doi.org/10.4097/kjae.2001.41.3.280

Abstract

BACKGROUND
The bispectral index (BIS) has been designed to objectively measure the degree of sedation and hypnosis for several anesthetics. The aim of this study was to evaluate the changes of the BIS during desflurane-N2O-O2 anesthesia.
METHODS
With Institutional Review Board approval and informed consent, forty premedicated (atropine 0.5 mg, IM) male and female adult patients (ASA class 1 or 2, 18 55 yrs) scheduled for elective surgery were studied. After intubation with the aid of propofol (2.0 mg/kg) and vecuronium (0.15 mg/kg), anesthesia was maintained with desflurane in combination with 50% N2O and 50% O2. Several transitions between 3.0 and 12.0 vol% were performed. During anesthesia, the BIS was checked at least 30 min after induction to avoid the residual effect of propofol and after 15 min maintenance of a certain inhaled concentration for equilibration.
RESULTS
The values of BIS were correlated closely with the desflurane concentrations (r = 0.88). Steep changes in the BIS were shown between 1.5 6.0 vol% and a ceiling effect regarding the BIS over 6.0 vol% was observed.
CONCLUSIONS
The BIS is valuable for measuring the degree of sedaton and hypnosis in desflurane anesthesia. Above 6.0 vol%, desflurane showed a ceiling effect regarding the BIS.

Keyword

Anesthetics; desflurane; bispectral index

MeSH Terms

Adult
Anesthesia
Anesthetics
Ethics Committees, Research
Female
Humans
Hypnosis
Informed Consent
Intubation
Male
Propofol
Vecuronium Bromide
Anesthetics
Propofol
Vecuronium Bromide