Resident Performed Compression Ultrasound for the Evaluation of Proximal Lower Extremity Deep Vein Thrombosis: Fast, Accurate, and Timely

OBJECTIVES: To prospectively examine if emergency medicine residents could quickly perform accurate compression ultrasonography (CUS) for the detection of proximal lower extremity DVTs (PLEDVT) with minimal training. METHODS: A prospective, observational study using a convenience sample of patients presenting with signs/symptoms of PLEDVT. Vascular laboratory and department of radiology studies were considered "gold standard." Resident CUS was done of the femoral vessels down to the popliteal fossa. An area of incompressibility or thrombus was considered "positive". RESULTS: 70 patients were enrolled and examined by 8 residents without prior experience with DVT US. Their average scan time was 11.7 minutes (95% CI, 9.4-14). The average patient age was 54 years. EM resident CUS was considered positive in 26 of the 70 patients. Confirmatory testing was positive in 22 patients for PLEDVT. None of the 44 patients which were considered negative for PLEDVT by EM-resident CUS were found to have PLEDVT by confirmatory testing: Test characteristic for PLEDVT sensitivity 100% (95% CI, 81.5-100) specificity 91.7% (95% CI, 79.1-97.3) PPV 84.6% (95% CI, 64.3-95.0) NPV 100% (95% CI, 90.0-100) 42 patients (60%) were evaluated "after hours." 11 patients were admitted and subsequently diagnosed with DVT by diagnostic imaging done an average of 1385 minutes (95% CI, 850-1920) after EM resident-CUS. 13 patients were diagnosed with DVT prior to being admitted (2 with distal peroneal vein DVT). Their diagnostic imaging was obtained an average of 512 minutes (95% CI, 374-650) after EM resident-CUS. 23 patients were diagnosed as "without DVT" prior to disposition with an average time from EM resident-CUS to diagnostic imaging of 388 minutes (95% CI, 221-555). CONCLUSION: EM residents with limited US experience can quickly perform CUS for the detection of PLEDVT with high sensitivity. This leads to a significant decrease in time to diagnostic imaging.