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.