Point-of-Care Ultrasonographic Deep Venous Thrombosis Evaluation After Just Ten Minutes' Training: Is This Offer Too Good to Be True?

Deep venous thrombosis (DVT) diagnostics: gleaning insights from point-of-care ultrasound (PoCUS) techniques in emergencies: a systematic review and meta-analysis

BACKGROUND

The assessment of deep venous thrombosis (DVT) is clinically difficult diagnosis. The "gold standard test" for DVT diagnosis is venography; however, various point-of-care ultrasound (POCUS) protocols have been suggested for DVT evaluation in the emergency department.

AIMS

This review evaluated the role of different POCUS protocols in diagnosing DVT in the emergency department.

METHODS

A systematic review and meta-analysis was conducted based of PRISMA guideline and registered on PROSEPRO (CRD42023398871). An electronic database search in Embase, PubMed, ScienceDirect, and Google scholar and a manual search were performed to identify eligible studies till February 2023. Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) was used to assess the risk of bias in included studies. Quantitative analysis was carried out using STATA 16 and Review Manager software (RevMan 5.4.1). Sensitivity, specificity of POCUS protocols for DVT diagnosis compared to reference standard test was calculated.

RESULTS

Heterogeneity was identified between 26 included studies for review. The pooled sensitivity, specificity, PPV, and NPV for the 2-point POCUS protocol were 92.32% (95% CI: 87.58-97.06), 96.86% (95% CI: 95.09-98.64), 88.41% (95% CI: 82.24-94.58) and 97.25% (95% CI: 95.51-98.99), respectively. Similarly, the pooled sensitivity, specificity, PPV, and NPV for 3-point POCUS were 89.15% (95% CI: 83.24-95.07), 92.71% (95% CI: 89.59-95.83), 81.27% (95% CI: 73.79-88.75), and 95.47% (95% CI: 92.93-98). The data pooled for complete compression ultrasound, and whole-leg duplex ultrasound also resulted in a sensitivity and specificity of 100% (95% CI: 98.21-100) and 97.05% (95% CI: 92.25-100), respectively. On the other hand, the time from triage to DVT diagnosis was significantly shorter for emergency physician-performed POCUS than diagnostic tests performed by radiologists.

CONCLUSION

The diagnostic performance of POCUS protocols performed by emergency physicians was excellent. Combined with the significant reduction in time to diagnosis. POCUS can be used as the first-line imaging tool for DVT diagnosis in the emergency department. We also recommended that attending emergency physicians with POCUS training are present during DVT diagnosis to improve diagnostic performance even though high diagnostic performance is observed even with the minimum training.

Two-point compression ultrasonography: Enough to rule out lower extremity deep venous thrombosis?

BACKGROUND

Deep venous thrombosis (DVT) is a major cause of morbidity and is a common presenting complaint to the emergency department (ED). Point-of-care two-point compression ultrasonography has evolved as a quick and effective way of diagnosing DVT. The purpose of this study is to validate the prevalence and distribution of venous thrombi isolated to proximal lower extremity veins, other than common femoral and popliteal veins in patients with DVT.

METHODS

This is a single-center retrospective study that looked at patients presenting to the ED of a tertiary care hospital between January 2014 and August 2018. The clinical presentation and laboratory and imaging results were obtained using the hospital's electronic medical record.

RESULTS

A total of 2,507 patients underwent a lower extremity duplex ultrasound during the study period. Among them, 379 (15%) were included in the study. The percentages of isolated thrombi to the femoral vein and deep femoral vein were 7.92% and 0.53%, respectively. When the patients were stratified into the two groups of isolated DVT and two-point compression DVT, there were no statistically significant differences in the laboratory results between both groups. However, immobilized patients and patients with recent surgeries were more likely to have an isolated DVT.

CONCLUSIONS

Thrombi isolated to proximal lower extremity veins other than the common femoral and popliteal veins make up 8.45% of DVTs. Given this significant number of missed DVTs, the authors recommend the addition of the femoral and deep femoral veins to the two-point compression exam.

The Use of Point-of-Care Ultrasound (POCUS) in the Diagnosis of Deep Vein Thrombosis

Acute lower extremity proximal deep venous thrombosis (DVT) requires accurate diagnosis and treatment in order to prevent embolization and other complications. Point-of-care ultrasound (POCUS), a clinician performed, and clinician interpreted bedside ultrasound examination has been increasingly used for DVT evaluation mainly in the urgent and critical care setting, but also in the ambulatory clinics and the medical wards. Studies have demonstrated that POCUS has excellent diagnostic accuracy for acute proximal DVT when performed by well-trained users. However, there is significant heterogeneity among studies on the necessary extent of training and universally acceptable standardized education protocols are needed. In this review, we summarize the evidence that supports the use of POCUS to diagnose acute proximal DVT and focus on methodology and current technology, sensitivity and specificity, pre-test probability and the role of D-dimer, time and resources, education, limitations, and future directions.

Diagnostic accuracy of point-of-care ultrasound for catheter-related thrombosis in children

BACKGROUND

Compared with consultative US performed by the radiology department, point-of-care US performed by non-radiology physicians can accurately diagnose deep venous thrombosis in adults.

OBJECTIVE

In preparation for a multicenter randomized controlled trial, we determined the accuracy of point-of-care US in diagnosing central venous catheter-related thrombosis in critically ill children.

MATERIALS AND METHODS

Children <18 years old with a central venous catheter who were admitted to the intensive care unit were enrolled. Consultative and point-of-care compression ultrasounds with Doppler were done on the vein where the catheter was inserted within 24 h after insertion. Repeat US was obtained within 24 h of removal of the catheter. All images were centrally, blindly and independently adjudicated for thrombosis by a team of pediatric radiologists. Chance-corrected agreement between readings was calculated.

RESULTS

From 84 children, 152 pairs of consultative and point-of-care ultrasounds were analyzed. A total of 38 (25.0%) consultative and 17 (11.2%) point-of-care ultrasounds were positive for thrombosis. The chance-corrected agreement between consultative and point-of-care ultrasounds was 0.17 (standard error: 0.07; P = 0.008). With consultative US as a reference, the sensitivity of point-of-care US was 28.1% (95% confidence interval: 13.7%-46.7%) with a specificity of 91.8% (95% confidence interval: 84.4%-96.4%). A catheter in the subclavian vein was associated with discordant readings (adjusted odds ratio: 4.00; 95% confidence interval: 1.45-13.94).

CONCLUSION

Point-of-care US, when performed by non-radiology physicians and centrally adjudicated by pediatric radiologists in the setting of a multicenter randomized controlled trial, may not accurately diagnose catheter-related thrombosis in critically ill children.

Point-of-Care Ultrasound for a Deep Venous Thrombosis

Patients presenting to the emergency department with lower extremity symptoms suggestive of venous thromboembolic disease require a diagnostic evaluation. Although contrast venography was the diagnostic standard, this has largely been replaced by duplex ultrasound as the first-line imaging modality. This review presents a summary of the literature on the evolution and performance of B-mode point-of-care compression ultrasound as an alternative to duplex ultrasound evaluation. The 2-point compression and 2-region compression techniques are described. The limitations of point-of-care ultrasound of the lower extremity as a diagnostic modality for this disease entity, the role of a D-dimer assay in the emergency department evaluation and future directions for this diagnostic modality are discussed.