Thiopental--ketamine association and low dose priming with rocuronium for rapid sequence in duction of anaesthesia for elective cesareum section.

ABSTRACT

Obstetric patients undergoing caesarean section under general anaesthesia require rapid induction due to high risk of aspiration. Rocuronium provides the shortest onset of action of nondepolarizing blocking agents. Onset time can be shortened by the priming principle. Ketamine has been shown to improve intubating conditions when used in association with rocuronium. Even if ketamine crosses the placenta rapidly, it does not produce neonatal depression unless used in doses above 1-1.5 mg x kg(-1). We present a case of elective caesarean section due to pelvic disproportion managed in general anaesthesia. Following 5 min of preoxygenation, a priming dose of 0.04 mg x kg(-1) of rocuronium was administered. The patient was maintained on spontaneous breathing with 100% oxygen by face mask for 3 min and then induced in rapid sequence with thiopental 2 mg x kg(-1), ketamine 1 mg x kg(-1) and 0.4 mg x kg(-1) or rocuronium. Intubation was performed 30 s after induction (twitch tension 17%) with an excellent clinical intubating score. No adverse events such as muscle weakness or patient discomfort were observed or reported by the patient. Time from injection of the intubating does of rocuronium to recovery of 25% of single twitch was 26 min. Recovery index (T25-75) was, instead, of 3 min and 25 s. The combination of the induction agents thiopental and ketamine, associated with low dose priming with rocuronium, have guaranteed excellent intubating conditions in this clinical context.