Abnormal peri-operative haemorrhage in asymptomatic patients is not predicted by laboratory testing.

The pre-operative identification of individuals at high risk of bleeding during major elective surgery is obviously important. Extensive haemostatic screening is, however, expensive and may be inappropriate in low-risk groups. Accordingly, we undertook two studies to determine whether it could be justified in patients without a history of abnormal bleeding. In the first of these, 45 of 159 patients were excluded because of aspirin ingestion and a further 3 because of positive bleeding history so that prothrombin time, activated partial thromboplastin time, bleeding time and platelet count were measured in 111 asymptomatic patients about to undergo major surgery. A single patient had mild thrombocytopenia, and 8 had a prolonged partial thromboplastin time; none showed abnormal peri-operative haemorrhage. In the second study, over a 4-month period, 49 patients out of 1,872 required larger peri-operative blood transfusions than anticipated; on investigation, none of these patients was shown to have disturbances in haemostatic mechanism, the transfusion having been indicated for technical reasons. Patients undergoing elective surgery should be asked about medication and previous bleeding and if they have no history thereof and a physical examination is negative, pre-operative screening for coagulation defects would appear to be unnecessary.