Clinical question: Is low molecular weight heparin (LMWH) safe for deep vein thrombosis (DVT) prophylaxis in patients with severe renal insufficiency?

Background: LMWH is avoided in patients with severe renal insufficiency due to concerns about increased bleeding risk caused by delayed renal excretion.

Study design: Multi center, prospective, single-arm trial.

Setting: Several Canadian intensive-care units (ICUs).

Synopsis: 138 critically ill patients with a creatinine clearance lower than 30 mL/min received open-labeled dalteparin, 5,000 IU once daily for DVT prophylaxis for a median duration of seven days. Peak and trough anti-Xa levels were measured to assess for efficacy and evidence of bioaccumulation, respectively. Patients were monitored for DVT development, heparin-induced thrombocytopenia (HIT), and bleeding. None of the patients (0%, CI, 0%-3%) had evidence of bioaccumulation. Seven patients (5.1%) developed DVT and only two patients (1.4%) developed HIT. Of the 10 patients who bled (7.2%), two died.

Of note, 62% of patients in this study had acute renal failure and their improvement in renal function during their ICU stay might have contributed to lack of bioaccumulation. Another limitation is the lack of comparison with other DVT prophylaxis strategies, especially unfractionated heparin.

Bottom line: Using dalteparin for DVT prophylaxis is unlikely to increase bleeding risk in patients with severe renal insufficiency. However, this finding cannot be generalized to dialysis-dependent patients or those with chronic kidney disease.

Citation: Arch Intern Med. 2008;168(16):1805-1812

—Reviewed by Rebecca Allyn, MD, Smitha Chadaga, MD, Mary Dedecker, MD, Vignesh Narayanan, MD, Eugene S. Chu, MD, Division of Hospital Medicine, Denver Health and Hospital Authority