Conduction anaesthesia, blood pressure and haemorrhage.

Forty-five patients received lumbar epidural block for major vaginal surgery. Twentyfive of them had, in addition,', light general anaesthesia (halothane, oxygen and spontaneous respiration). Measurements of blood loss and mean (integral) operative blood pressure were made. The group receiving halothane had a significantly lower mean integral operative blood pressure dian the group receiving lumbar epidural block alone. The mean volume of haemorrhage in the two groups was not significantly different. The possible mechanism whereby conduction anaesthesia causes a relatively bloodless operating field for vaginal surgery is discussed.