A Reassessment of Needs and Practice Patterns in Pharmacologic Prophylaxis of Venous Thromboembolism Following Elective Major Surgery

Abstract

Objective: To provide an accurate account of venous thromboembolism (VTE) risk and rates in patients undergoing major elective surgery, as related to the use of pharmacologic prophylaxis. Background: Venous thromboembolism, comprising deep venous thrombosis and pulmonary embolus, has long been described in ill hospitalized patients as a silent killer. Elective major surgery, however, is a specialty scenario in which potential risks of pharmacologic prophylaxis are magnified by the surgical procedure itself. Methods: Following approval by the University of Louisville Institutional Review Board (HSPPO 08.0028), we queried the University HealthSystem Consortium database, which comprises data from 123 academic teaching hospitals, for 18 consecutive month periods in 2003/2004 and compared that with an identical period of observations in 2007/2008 for 4 elective major operations: colorectal resections, total hip replacement, total knee replacement, and hysterectomy. Results: Venous thromboembolism rates ranged from 0.6% to 3.2% and pulmonary embolism rates ranged from 0.28% to 1.09%. Use of pharmacologic prophylaxis increased for all procedures between 2003/2004 and 2007/2008, except for hysterectomy. Venous thromboembolism rates, however, were not significantly affected among patients who received pharmacologic prophylaxis and actually decreased among patients who did not receive any pharmacologic prophylaxis despite an absence of significant change of severity of illness of patient populations. This may represent remarkable judgment by treating surgeons in choosing patients who were candidates for pharmacologic prophylaxis. Conclusions: When combining the much lower incidence rate of VTE observed among non-prophylaxed patients undergoing elective major surgery with physicians' seemingly wise clinical judgment in determining patient susceptibility to VTE, the genuine risk of VTE and pulmonary embolus is very small and must be carefully balanced with the risks of pharmacologic prophylaxis.