Spinal and general anaesthesia in total hip replacement: frequency of deep vein thrombosis

Abstract

Subarachnoid block (SAB) or general anaesthesia (GA) was induced in 85 patients undergoing total hip replacement. The frequency of deep vein thrombosis (DVT), assessed by fibrinogen uptake studies and venography, was 29 % in those patients receiving SAB and 54 % in the GA group. Total blood loss (intra-operative and post-operative wound suction drainage) in SAB group was 66 % and total transfusion volume 52 % of that of GA group. No morbidity attributable to SAB or to the associated arterial hypotension was detected. The frequency of total hip arthroplasty is increas-ing steadily in the U.K., and is likely to increase further (Morris, 1975). The operation is associated with a high frequency of deep venous thrombosis (DVT) (Kakkar et al., 1972) and considerable blood loss (Murray, 1973). Prophylaxis against DVT has been disappointingly ineffective, and has produced conflicting results (Kakkar et al., 1972; Hampson et al., 1974; Morris, Henry and Prestow, 1974; Rogers et al., 1978). However, blood loss during operation is decreased following sub-arachnoid block (SAB) (Sculco and Ranawat, 1975), and general anaesthesia (GA) with induced arterial hypotension (Davis, Jennings and Harris, 1974; Lawson et al., 1976). This study was undertaken to compare the effects of SAB associated with moderate hypoten-sion with those of GA, on the frequency of DVT, blood loss and transfusion volumes and to detect any morbidity attributable to SAB. PATIENTS AND METHODS Eighty-five patients undergoing total hip replacement were studied. Forty-three received general anaesthesia, and 38 spinal anaesthesia. Patients suffering from thyroid disease, taking oral anti-coagulants or with a neurological spinal dis-ease were excluded from the study. Assessment before operation included physical examination, e.c.g., chest x-ray, determination o