Venous thromboembolism prophylaxis in medical inpatients: a retrospective chart review

BACKGROUND: Venous thromboembolic disease (VTE) is a major cause of morbidity and mortality in hospitalized patients. Most hospitalized patients with a fatal pulmonary embolism are medical patients who do not have a history of recent surgery [BMJ 302 (1991) 709; J. R. Soc. Med. 82 (1989) 198]. There is evidence suggesting that VTE prophylaxis is indicated in many high risk medical patients [Chest 119 (2001) 132S; NEJM 341 (1999) 793]. However, previous studies have shown that only about one third of high risk medical patients receive VTE prophylaxis [Ann. Intern. Med. 115 (1991) 591; Chest 106 (1994) 13; Chest 107 (1995) 296]. The objective of this study was to determine the frequency of use of VTE prophylaxis in medical inpatients at two teaching hospitals in Hamilton, Ontario. METHODS: A retrospective chart review of consecutive patients admitted to medical wards at two acute care sites of McMaster University affiliated teaching hospitals between October 10, 2001 and December 11, 2001 was performed. For each patient, demographic data, risk factors for VTE, method of VTE prophylaxis and contraindications to VTE prophylaxis were recorded. RESULTS: 756 patient charts were reviewed and 310 (41%) were excluded because the primary diagnosis required anticoagulation, the patients were being treated with anticoagulation (warfarin or heparin) before admission or the patient was admitted to the intensive care unit. Of the remaining 446 patients, 146 (33%) received some form of VTE prophylaxis. Of the patients receiving prophylaxis, 4% had early ambulation, 9% wore anti-embolic stockings (AES), 1% used intermittent pneumatic compression, 23% used unfractionated heparin and 3% used low molecular weight heparin. Two hundred five (46%) patients had one identifiable VTE risk factor and 63 (14%) had two or more risk factors. Patients with more VTE risk factors were more likely to receive prophylaxis. INTERPRETATION: One third of medical inpatients at two teaching hospitals in Hamilton received some form of VTE prophylaxis.