IS THERE STILL AN AVOIDABLE FRACTION OF POSTOPERATIVE THROMBOEMBOLIC COMPLICATIONS WITH HEPARIN-PROPHYLAXIS - THE RESULTS OF A CASE-CONTROLSURVEILLANCE

A case-control multicenter study was set up in 68 general and speciali stic wards in Italian regional hospitals in order to assess whether un deruse of heparin prophylaxis may account for at least a fraction of t he thromboembolic events still occurring in surgical patients. 100 cas es with clinically relevant thromboembolic or hemorrhagic events occur ring during hospitalization for major surgery and 200 controls were id entified. Controls were selected among patients not presenting any of the events under study during the same period of observation and were matched with cases for age, sex, and type of surgery. The results of t he study suggest that heparin use in routine conditions of care closel y reflects the ''consensus'' knowledge, patients at higher risk (speci fically orthopedic surgical patients, those with varicose veins or wit h preoperative bed rest longer than 3 days) being treated more frequen tly with heparin. Absence of heparin prophylaxis does not appear to re present a specific risk factor for the occurrence of index events (OR 0.73, 95% CI = 0.42-1.26). Despite the higher rates of heparin exposur e, the presence of varicose veins is associated with a statistically s ignificant increase in the risk of postoperative complications (OR 2.2 3, 95% CI = 1.07-4.65). This study indicates that among known pre- and peri-operative risk factors only varicose veins may be unprotected by the current prophylaxis practice.