Bispectral index values in patients undergoing cesarean section under general anesthesia at Nopparatrajathanee Hospital

Abstract

Background: Cesarean section at Nopparatrajathanee Hospital is usually per - formed under general anesthesia, in spite of high risk for intraoperative awareness and recall. Assessment depth of anesthesia by clinical factors and hemodynamic variability may not be sensitive and specific. Bispectral index monitoring could provide reliable assessment.

Objectives: To evaluate Bispectral index values during operation and anesthesia. Methods: Thirty ASA classification 1 parturients under - going elective cesarean section under general anesthesia using routine anesthetic drugs, doses and technique were studied prospectively. Intraoperative BIS index values and hemodynamic variability were measured every 1 minute before delivery, then every 3 minute and 12 specific events during the operation. All patients were interviewed for any awareness and recall before leaving the recovery room and 24 hours post - operative.

Results: BIS index values were 96.63 2.04, 49.37  12.86, 51.87  12.43, 68.23  9.80, 69.90  8.09, 64.50  12.60, 60.27  6.86, 66.83  4.09, 68.30  4.12, 73.10  5.12, 79.40  5.20 and 82.20  5.17 at baseline, induction, intubation, skin incision, uterine incision, delivery, uterine suture, subcutaneous tissue suture, skin closure, reverse muscle relaxant, eye opening and extubation respectively. Hemodynamic profiles and Apgar score were satisfactory. There was no case of uterine atony, nor were reported of intraoperative awareness and recall.

Conclusions: Although BIS index values of more than 60 was discovered at most events during operation and anesthesia, no report of intraoperative awareness and recall were found.