The association of excessive warfarin anticoagulation and postoperative ileus after total joint replacement surgery

Patients undergoing joint replacement who show signs of ileus in the postoperative period that require insertion of a nasogastric tube (NGT) must be monitored closely to avoid bleeding complications. The diagnosis of postoperative ileus was documented in 40 of 2,526 (1.6%) consecutive joint replacement operations between January 1, 1990, and March 1, 1998, at 1 hospital. Of the 40 patients with postoperative ileus, 34 received warfarin postoperatively. Of these 34 patients, 19 required a NGT for >48 hours, and 15 patients required a NGT for <48 hours or did not require a NGT. Of the 19 patients who required a NGT for >48 hours and who received warfarin anticoagulation, 17 had a prothrombin time of >20 seconds or an international normalized ratio (INR) of >2.0. None of the 15 patients who required a NGT for <48 hours and who received warfarin anticoagulation had a prothrombin time of >20 second or an INR of >2.0. This difference was highly satistically significant (P < .001).