- Prophylaxis against deep vein thrombosis in critically ill patients with severe renal insufficiency with the low-molecular-weight heparin dalteparin: an assessment of safety and pharmacodynamics: the DIRECT study. Douketis, J., Cook, D., Meade, M., Guyatt, G., Geerts, W., Skrobik, Y., Albert, M., Granton, J., Hébert, P., Pagliarello, G., Marshall, J., Fowler, R., Freitag, A., Rabbat, C., Anderson, D., Zytaruk, N., Heels-Ansdell, D., Crowther, M. Arch. Intern. Med. (2008)