NONINVASIVE VENOUS TESTING IN THE DIAGNOSIS OF PULMONARY-EMBOLISM - THE IMPACT ON DECISION-MAKING

Purpose: To characterize the use and utility of lower extremity noninv asive venous testing (NIVT) in the diagnosis of pulmonary embolism (PE ). Methods: The study is a retrospective case series of consecutive pa tients in whom PE was suspected who were referred to a large, urban te rtiary care center for NIVT. The main outcome measures of the study we re the rate of positive results of NIVT, the amount of new information provided by NIVT, and the frequency of management changes that were a ttributable to NIVT. Results: Forty-one of 450 patients (9%) had deep venous thrombosis (DVT) by NIVT. The prevalence of DVT by NIVT among p atients not evaluated by ventilation/perfusion (V/Q) scanning was 8%. The prevalence of DVT by NIVT among patients with a high-probability V /Q scan result before NIVT was 39%, but no management decisions in thi s group were based on a positive NIVT result and only two decisions we re based on negative NIVT results. The prevalence of DVT according to NIVT among patients who had a negative ''diagnostic'' (low, or very lo w probability, or normal) result of V/Q scan before NIVT was 2%. The o verall frequency of management changes attributed to NIVT was only 2.5 %. In the remaining 97% of patients, management was determined by the result of V/Q scanning or of subsequent pulmonary arteriography. Concl usions: In patients in whom PE is suspected, results of NIVT are usual ly negative for acute DVT. Management decisions are almost always base d on V/Q scan or results of pulmonary arteriography and not on NIVT. T he utility of NIVT to identify DVT in these patients appears limited, and a more selective approach to its application for the diagnosis of PE should be considered.