The rate of bleeding complications after pharmacologic deep venous thrombosis prophylaxis: a systematic review of 33 randomized controlled trials.

HYPOTHESIS Major bleeding complications from pharmacologic deep venous thrombosis (DVT) prophylaxis are infrequent. DESIGN Systematic review of the MEDLINE database from 1965 to August 2005, using the terms DVT, prophylaxis, general surgery, and heparin. SETTING AND PATIENTS Randomized controlled trials evaluating pharmacologic DVT prophylaxis in patients undergoing general surgery. MAIN OUTCOME MEASURES Eight complication categories: injection site bruising, wound hematoma, drain site bleeding, hematuria, gastrointestinal tract bleeding, retroperitoneal bleeding, discontinuation of prophylaxis, and subsequent operation. RESULTS Fifty-two randomized controlled trials studied DVT prophylaxis; 33 randomized controlled trials with 33 813 patients undergoing general surgery evaluated pharmacologic prophylaxis and quantified bleeding complications. Of the minor complications, injection site bruising (6.9%), wound hematoma (5.7%), drain site bleeding (2.0%), and hematuria (1.6%) were most common. Major bleeding complications, such as gastrointestinal tract (0.2%) or retroperitoneal (<0.1%) bleeding, were infrequent. Discontinuation of prophylaxis occurred in 2.0% of patients and subsequent operation in less than 1% of patients. When analyzed by high- vs low-dose unfractionated heparin, the lower dose had a smaller rate of discontinuation of prophylaxis (P = .02) and subsequent operation (P = .06). CONCLUSIONS Knowledge of bleeding complication rates is important for surgeons because DVT prophylaxis may soon be implemented by Medicare as a quality measure. This level 1 evidence report shows that bleeding complications requiring a change in care occur less than 3% of the time and seem reduced with lower-dose prophylaxis. Given these findings, most patients undergoing general surgery could receive pharmacologic prophylaxis safely.