Maternal awareness and neonatal outcome after ketamine induction of anaesthesia for Caesarean section

Abstract

Ketamine was used as the sole anaesthetic during the induction-to-delivery interval in 20 full-term patients undergoing elective Caesarean section. The intravenous administration of ketamine 1.5 mg · kg-1 was followed by succinylcholine 1.5 mg · kg-1 and tracheal intubation. The mother's lungs were then ventilated using 100 per cent oxygen until the baby was delivered. Intraoperative maternal awareness was assessed by the isolated forearm technique. The Apgar scores of the newborn at one and five minutes, as well as their umbilical vein blood gases were also evaluated and correlated with the induction-to-delivery (1-D) and the uterine incision-to-delivery (U-D) intervals. In 13 patients (Group A) the 1-D interval was < 10 min and U-D interval < 90 sec, while in seven (Group B) the 1-D interval was ≥ 10 min and the U-D interval ≥ 90 sec. The isolated arm test was negative in all patients having an 1-D interval < 10 min, and was positive in three patients when the 1-D interval exceeded ten minutes. The newborns of group A showed higher Apgar scores atone minute, as well as higher umbilical vein PO2 than was achieved in Group B. It was concluded that the technique used was not associated with maternal awareness or neonatal depression, provided that the 1-D interval was < 10 min and the U-D interval was < 90 sec. © 1990 Canadian Anesthesiologists.