Article: Lee JH, Lee SH, Yun SJ. Comparison of 2-point and 3-point point of care ultrasound techniques for deep vein thrombosis at the emergency department. Medicine. 2019 May; 98:22. doi: 10.1097/MD.0000000000015791

Overview: Lower extremity deep vein thrombosis (DVT) is a life-threatening vascular condition that requires rapid diagnosis in the emergency department. Although the gold standard for diagnosis of DVT is contrast venography, 2 or 3-point point of care ultrasound (POCUS) can be used at bedside in a timely manner. Whether or not the addition of the 3rd point in evaluation of a DVT improves this exam.

Study: A meta-analysis was performed using 16 original research articles obtained by keyword searches of the PubMed and EMBASE databases. Inclusion criteria were 1) patients with a suspected DVT 2) 2 or 3 point POCUS performed by emergency physician 3) reference standard reported such as contrast venography, follow-up, or formal radiology ultrasound 4) sufficient data to create a 2x2 contingency table and 5) classified as an original article. The researchers excluded articles in which duplex, not compression POCUS, was performed, and the 3rd point was not the superficial femoral vein. The final 17 sets of data were then analyzed to determine differences in sensitivity, specificity, and false-negative rate between 2 and 3 point POCUS.

Results: 2 point POCUS demonstrated a sensitivity, specificity, and false-negative rate pooled proportion of 91%, 98%, and 4.2% respectively, compared to 90%, 95%, and 4.1% for 3 point POCUS. Both methods had significant heterogeneity between studies with Q values of 8.4, P=.008 and 18.3, P<.01 for 2 and 3 point POCUS respectively.

Takeaway: POCUS is a reliable bedside procedure for the diagnosis of DVT in an emergency department. The use of the superficial femoral vein as a 3rd point in this study does not significantly change the sensitivity, specificity, or false-negative rate in the detection of DVT. Heterogeneity in results was attributed to better outcomes when the test was performed with an attending physician, rather than a resident alone, and when separate POCUS training had been previously provided. In conclusion, 2-point POCUS is recommended for the initial evaluation of a DVT by an emergency physician.

Post by Cody Yokubaitis, MS4