Venous duplex in the intensive care unit: Misuse, overuse, or both?

Background. - Venous duplex scan (VD) is a frequently used test for the diagnosis of deep vein thrombosis (DVT) but has a high negative rate, adding to the burden on health care resources and personnel. Intensive care patients frequently undergo a duplex scan to rule out DVT for a variety of indications, such as fever, leg swelling, leg pain, and shortness of breath. This study examines the value of duplex scan in patients in the intensive care unit (ICU) relative to several indications and cost. Methods.- AII VDs performed in the ICUs (surgical, cardiovascular, medical, and pulmonary) at St. Vincent Hospital over a 24-month period (January 1999-January 2001) were retrospectively reviewed. Demographic data, indications, and results of the VD study were tabulated and analyzed. A positive study was defined as the presence of an acute thrombus in the iliac, femoral, or popliteal veins of the lower extremity. Clots detected in the infrapopliteal venous system were considered negative studies. Results. - Over the study period, a total of 211 venous duplex scans were performed in the ICUs at our hospital. The average age of the patients having the study was 65.2 years, and 51.1% were women. Thirty of the 211 (14.2%) studies were positive for a DVT. Of these, 12 (40%) were performed for an indication for leg swelling. Cost per positive study was $3,791; fever of unknown origin (FUO) had a 4.7% positive rate, with a cost of $11,588 per DVT diagnosed. Conclusions. - VDs are overused for liberal indications in the ICU setting. Risk assessment profiles should be used to discriminate patients for the study. FUO is a very poor indication for ordering a VD. These changes can potentially result in significant cost savings.