This study estimated the incidence of pulmonary aspiration during general a
naesthesia for obstetric procedures performed in the peripartum period (Cae
sarean sections were not studied). The records of 1870 patients anaesthetis
ed without tracheal intubation were reviewed retrospectively. The diagnosis
of aspiration was based on the anaesthetist's written remarks and the post
operative course. Eighty per cent of patients received ketamine and a benzo
diazepine, and the remaining 20% received methohexital or thiopental and fe
ntanyl. No cricoid pressure or tracheal intubation was performed. A single
case of mild aspiration was detected in a woman anaesthetised with methohex
ital (an incidence of 0.053%). These results suggest that the risk of aspir
ation during general anaesthesia without tracheal intubation, during and im
mediately after delivery, may not be higher in obstetric patients in the pe
ripartum period, as has been reported previously.