Korean J Anesthesiol.  2007 Feb;52(2):143-149. 10.4097/kjae.2007.52.2.143.

Effect of Administration Method of Isoflurane on Bispectral Index Values in the Early Period of Cesarean Section: A Comparison of End-Tidal or Vaporizer Concentration using Overpressure

• Lee HJ
• Kim JB
• Choi HJ

• KMID: 2236615
• DOI: http://doi.org/10.4097/kjae.2007.52.2.143

Abstract

BACKGROUND
Patients undergoing a cesarean section under general anesthesia are at risk of intraoperative awareness due to the use of low concentration of volatile anesthetics used. This study investigated the effect of different methods for administering isoflurane on the anesthetic adequacy using bispectral index (BIS) in the early period of cesarean section.
METHODS
Eighty-two parturients undergoing a cesarean section were randomly assigned to receive 1 vol% isoflurane (Group EQ), 1.5 vol% isoflurane for the first 5 minutes and 1 vol% for the next 5 minutes (Group CO), 0.6 vol% end-tidal isoflurane immediately after intubation (Group ET). Thiopental 4 mg/kg was used to induce anesthesia. The bispectral index value, systolic and diastolic arterial pressure, heart rate and end-tidal concentration of isoflurane were recorded every minute for 10 minutes after intubation.
RESULTS
There were no significant differences in the systolic and diastolic pressure, and heart rate between the groups. The BIS values from 1 to 8 minutes after intubation were significantly lower in the ET group than in the EQ group. BIS values from 4 to 8 minutes after intubation were significantly lower in the CO group than in the EQ group.
CONCLUSIONS
The administration of volatile anesthetics using the end-tidal concentration after thiopental induction shows the best anesthetic efficacy in the early period of cesarean section. This method may further reduce the level of intraoperative awareness.

Keyword

awareness; bispctral index; cesarean section; general anesthesia; isoflurane; thiopental

MeSH Terms

Anesthesia
Anesthesia, General
Anesthetics
Arterial Pressure
Blood Pressure
Cesarean Section*
Female
Heart Rate
Humans
Intraoperative Awareness
Intubation
Isoflurane*
Nebulizers and Vaporizers*
Pregnancy
Thiopental
Anesthetics
Isoflurane
Thiopental