Placental blood flow during caesarean section under lumbar extradural analgesia.

The effect on intervillous blood flow of lumbar extradural analgesia for Caesarean section was studied in nine healthy women using xenon-133. Extradural anaesthesia was performed with lignocaine 1 1/2% 16--20 ml with adrenaline 5 microgram ml-1. Impairment of placental blood flow during the block was observed in seven patients, but the mean decrease (13% from the control value) was not statistically significant. The most notable decrease in intervillous blood flow occurred in two patients with simulateous arterial hypotension.