Effects of anaesthetic technique on deep vein thrombosis. A comparison of subarachnoid and general anaesthesia.

Forty patients with fractured neck of femur were allocated randomly to undergo surgery under general anaesthesia (GA) or subarachnoid anaesthesia (SAB). After operation, the incidence of deep vein thrombosis (DVT), assessed by venography, was found to be 40% in the SAB group, which was significantly lower than the incidence (76.2%) in the GA group. These observations may account for the previously reported effect of SAB, in comparison with GA, in reducing early postoperative mortality in this category of patient.