Pulmonary embolism in surgical patients: 1959-79

The Edinburgh surgical statistics (audit) have been analysed for the years 1959, 1964, 1969, 1974, and 1979 to determine the trends in pulmonary embolism in surgical patients who died. There was a total of 61,038 operations, 1528 postoperative deaths, 804 necropsies, and 158 reported pulmonary emboli. The incidence of embolism diagnosed clinically and at necropsy fell throughout the period. This fall held good after corrections for necropsy rates, prognosis, and proportions of major operations. Although the overall necropsy rate fell from 58% to 40%, in patients expected to have a good prognosis the rate rose from 68% to 75%. Necropsy-proved embolism in "good prognosis" patients fell from 0.5% to 0.15% per 100 major operations. The main reduction has taken place since most surgeons in the area adopted methods of prophylaxis against venous thrombosis, but a direct relationship is not proved by this study.