Agreement between emergency physicians and radiologists for the diagnosis of deep venous thrombosis with compression ultrasound: a prospective study

Emergency medicine residents' learning curve in diagnosing deep vein thrombosis with 3-point venous point-of-care ultrasound

BACKGROUND

Many cases of deep vein thrombosis (DVT) are diagnosed in the emergency department, and abbreviated lower extremity venous point-of-care ultrasound (POCUS) has already shown an accuracy comparable to that of specialists. This study aimed to identify the learning curve necessary for emergency medicine (EM) residents to achieve expertise-level accuracy in diagnosing DVT through a 3-point lower extremity venous POCUS.

METHODS

This prospective study was conducted at an emergency department between May 2021 and October 2022. Four EM residents underwent a one-hour POCUS training session and performed DVT assessments in participants with DVT symptoms or confirmed pulmonary embolism. POCUS was performed at three proximal lower extremity sites to evaluate the thrombi presence and vein compressibility, with results validated by specialized radiology ultrasound. Cumulative sum (CUSUM) and the Bush and Mosteller models were used to analyze the learning curve, while generalized estimating equations were used to identify factors affecting diagnostic accuracy.

RESULTS

91 POCUS scans were conducted in 49 patients, resulting in 22% DVT confirmed by specialized venous ultrasound. In the CUSUM analysis, all four EM residents attained a 90% success rate at the common femoral vein, whereas only half achieved this rate when all three sites were considered. According to Bush and Mosteller models, 13-18 cases are required to attain 90-95% diagnostic accuracy. After 10-16 cases, the examination time for each resident decreased, and a 20% increase in examiner confidence was linked to a 2.506-fold increase in the DVT diagnosis accuracy.

CONCLUSION

EM residents generally required 13-18 cases for 90-95% DVT diagnostic accuracy, but proficiency varied among individuals, particularly requiring more cases for regions outside the common femoral vein.

Point-of-care ultrasound: impact on emergency department length of stay for suspected lower extremity DVT

BACKGROUND

Point-of-care ultrasound (POCUS) has demonstrated excellent sensitivity and specificity for the diagnosis of DVT in the emergency department (ED). Before POCUS became widespread, patients underwent radiology department comprehensive lower extremity venous duplex ultrasounds (RADUS) which may be associated with a prolonged length of stay.

OBJECTIVES

The goal of this study is to evaluate the impact of POCUS on ED arrival to disposition (ATD) time for patients presenting to the ED with suspected lower extremity DVT.

METHODS

This is a retrospective chart analysis of ED visits to an urban, university-affiliated community hospital from January 2019 to December 2020. This study compared ATD between patients who underwent POCUS by an emergency medicine physician and RADUS by the radiology department.

RESULTS

In total, 1204 patients underwent POCUS, and 1582 patients were evaluated with RADUS. The POCUS mean ATD was 313 ± 16.8 min compared to the RADUS arm average of 323 ± 57.9 min (p = 0.56). Order to disposition time (OTD) was prolonged among the RADUS group relative to POCUS. ATD was significantly reduced in the POCUS subgroup of patients presenting during night shift when RADUS was not available, 326 ± 28.2 min versus 630 ± 109 min (p < 0.05).

CONCLUSION

ED POCUS scans decrease the amount of time between order placement and disposition when compared to RADUS. POCUS significantly decreases length of stay in the ED when RADUS is not available.

Multi-organ point-of-care ultrasound for detection of pulmonary embolism in critically ill COVID-19 patients - A diagnostic accuracy study

Purpose

Critically ill COVID-19 patients have an increased risk of developing pulmonary embolism (PE). Diagnosis of PE by point-of-care ultrasound (POCUS) might reduce the need for computed tomography pulmonary angiography (CTPA), while decreasing time-to-diagnosis.

Materials & methods

This prospective, observational study included adult ICU patients with COVID-19. Multi-organ (lungs, deep vein, cardiac) POCUS was performed within 24 h of CTPA, looking for subpleural consolidations, deep venous thrombosis (DVT), and right ventricular strain (RVS). We reported the scan time, and calculated diagnostic accuracy measures for these signs separately and in combination.

Results

70 consecutive patients were included. 23 patients (32.8%) had a PE. Median scan time was 14 min (IQR 11–17). Subpleural consolidations' diagnostic accuracy was: 42.9% (95%CI [34.1–52.0]). DVT's and RVS' diagnostic accuracy was: 75.6% (95%CI [67.1–82.9]) and 74.4% (95%CI [65.8–81.8]). Their sensitivity was: 24.0% (95%CI [9.4–45.1]), and 40.0% (95%CI [21.3–61.3]), while their specificity was: 88.8% (95%CI [80.8–94.3]), and: 83.0% (95%CI [74.2–89.8]), respectively. Multi-organ POCUS sensitivity was: 87.5% (95%CI [67.6–97.3]), and specificity was: 25% (95%CI [16.9–34.7]).

Conclusions

Multi-organ rather than single-organ POCUS can be of aid in ruling out PE in critically ill COVID-19 and help select patients for CTPA. In addition, finding RVS can make PE more likely, while a DVT would preclude the need for a CTPA.

Registration: www.trialregister.nl: NL8540.