Venous air embolism during cesarean delivery.

Recent reports have indicated that subclinical venous air embolism (VAE) may occur in 50-65% of patients during cesarean delivery, with a potential for life-threatening embolic events. We attempted to confirm this incidence using precordial Doppler monitoring and to examine the occurrence of correlative signs thought to accompany embolic events. Doppler changes, oxygen saturation (SaO2), and ECG were monitored in 63 patients during cesarean delivery; 60 received regional anesthesia, and three, general anesthesia. Six of 63 (10%) had Doppler changes consistent with VAE. Nineteen patients (30%) had small decreases in SaO; most of these were not associated with Doppler changes or any other finding. Two patients had transient S-T segment depression. Fourteen of the 60 patients receiving regional anesthesia (23%) reported chest pain or discomfort at some point during the procedure. This incidence of Doppler changes was significantly smaller than previously reported and was not significantly correlated with other signs reported to accompany VAE. Positive signs of VAE were more frequent when the uterus was exteriorized than when it was maintained within the abdomen during surgical repair.