Sensitivity and specificity of three-point compression ultrasonography performed by emergency physicians for proximal lower extremity deep venous thrombosis

Comparison of Two-Point Compression Ultrasonography Performed by Emergency Medicine Doctors and Radiologists in Detection of Deep Vein Thrombosis

Venous thromboembolism (VTE) is a serious coagulation disorder that includes deep vein thrombosis (DVT) and pulmonary embolism and is an important cause of hospitalization and death. This study aimed to evaluate the compliance of the emergency doctor and radiologist in diagnosing DVT in the emergency department using the two-point compression ultrasonography (USG) method.

Patients and Methods This prospective cross-sectional study was performed between February and July 2022 in the Emergency Medicine Clinic of a tertiary university hospital with patients who were thought to have DVT and had lower extremity venous USG indication. Demographic information of patients, clinical markers used in the Wells score, and USG results of the emergency doctors and radiologists were recorded in the study form.

Results A total of 400 patients were included in the study. The mean age of the study patients was 59.8 ± 18.0 years, and 54.4% (n = 217) of the patients were male. There was a significant difference in the incidence of DVT between those with a Wells score of 2 or less and those above 2 (n = 67, 21.8% vs. n = 41, 47.1%; p < 0.001). Regarding interobserver agreement in the evaluation of DVT by emergency medicine doctor and radiologist, kappa values were 0.81 (95% confidence interval [CI]: 0.71–0.91) for the right femoral vein, 0.89 (95% CI: 0.81–0.97) for the left femoral vein. It was found to be 0.81 (95% CI: 0.76–0.86) for all lower extremity vein USGs.

Conclusions There is a very good level of agreement between the emergency department and the radiologist in diagnosing DVT with USG.

EFSUMB Clinical Practice Guidelines for Point-of-Care Ultrasound: Part One (Common Heart and Pulmonary Applications) LONG VERSION

AIMS

 To evaluate the evidence and produce a summary and recommendations for the most common heart and lung applications of point-of-care ultrasound (PoCUS).

METHODS

 We reviewed 10 clinical domains/questions related to common heart and lung applications of PoCUS. Following review of the evidence, a summary and recommendation were produced, including assignment of levels of evidence (LoE) and grading of the recommendation, assessment, development, and evaluation (GRADE). 38 international experts, the expert review group (ERG), were invited to review the evidence presented for each question. A level of agreement of over 75 % was required to progress to the next section. The ERG then reviewed and indicated their level of agreement regarding the summary and recommendation for each question (using a 5-point Likert scale), which was approved if a level of agreement of greater than 75 % was reached. A level of agreement was defined as a summary of "strongly agree" and "agree" on the Likert scale responses.

FINDINGS AND RECOMMENDATIONS

 One question achieved a strong consensus for an assigned LoE of 3 and a weak GRADE recommendation (question 1). The remaining 9 questions achieved broad agreement with one assigned an LoE of 4 and weak GRADE recommendation (question 2), three achieving an LoE of 3 with a weak GRADE recommendation (questions 3-5), three achieved an LoE of 3 with a strong GRADE recommendation (questions 6-8), and the remaining two were assigned an LoE of 2 with a strong GRADE recommendation (questions 9 and 10).

CONCLUSION

 These consensus-derived recommendations should aid clinical practice and highlight areas of further research for PoCUS in acute settings.

Correlation Between D-Dimer Level and Deep Venous Thrombosis in Patients With Acute Spinal Cord Injuries

Supplemental digital content is available in the text.

Objective

Venous thromboembolism is a serious life-threatening complication of S SCI. Measurement of D-dimer levels is used as a screening test for deep vein thrombosis. However, trauma, surgery, and motor weakness are known as factors that affect D-dimer levels. Thus, the aim of this study was to examine the correlation between D-dimer levels and deep vein thrombosis in relation to the comorbidities in acute spinal cord injury.

Design

A retrospective observational study was conducted at a hospital’s rehabilitation department. Forty-five patients without pharmacologic thromboembolic thromboprophylaxis 5−90 days after the onset of injury were enrolled.

Results

Fourteen patients (31%) were diagnosed with deep vein thrombosis using duplex ultrasonography. The mean ± SD D-dimer levels were 2.15 ± 2.74 and 6.98 ± 7.46 μg/ml in the deep vein thrombosis–negative and deep vein thrombosis–positive groups, respectively. The lower limb motor index scores significantly correlated with D-dimer levels regardless of the time between the onset of spinal cord injury and D-dimer testing. Patients with trauma had significantly increased D-dimer levels compared with patients without trauma.

Conclusion

Although D-dimer levels have limitations with regard to the positive prediction of acute spinal cord injury, it is a useful screening parameter for deep vein thrombosis. Trauma and lower limb motor weakness should be considered when analyzing D-dimer levels.

Point-of-care ultrasound in primary care: a systematic review of generalist performed point-of-care ultrasound in unselected populations

BACKGROUND

Both the interest and actual extent of use of point-of-care ultrasound, PoCUS, among general practitioners or family physicians are increasing and training is also increasingly implemented in residency programs. However, the amount of research within the field is still rather limited compared to what is seen within other specialties in which it has become more established, such as in the specialty of emergency medicine. An assumption is made that what is relevant for emergency medicine physicians and their populations is also relevant to the general practitioner, as both groups are generalists working in unselected populations. This systematic review aims to examine the extent of use and to identify clinical studies on the use of PoCUS by either general practitioners or emergency physicians on indications that are relevant for the former, both in their daily practice and in out-of-hours services.

METHODS

Systematic searches were done in PubMed/MEDLINE using terms related to general practice, emergency medicine, and ultrasound.

RESULTS

On the extent of use, we identified 19 articles, as well as 26 meta-analyses and 168 primary studies on the clinical use of PoCUS. We found variable, but generally low, use among general practitioners, while it seems to be thoroughly established in emergency medicine in North America, and increasingly also in the rest of the world. In terms of clinical studies, most were on diagnostic accuracy, and most organ systems were studied; the heart, lungs/thorax, vessels, abdominal and pelvic organs, obstetric ultrasound, the eye, soft tissue, and the musculoskeletal system. The studies found in general either high sensitivity or high specificity for the particular test studied, and in some cases high total accuracy and superiority to other established diagnostic imaging modalities. PoCUS also showed faster time to diagnosis and change in management in some studies.

CONCLUSION

Our review shows that generalists can, given a certain level of pre-test probability, safely use PoCUS in a wide range of clinical settings to aid diagnosis and better the care of their patients.

Accuracy of three-point compression ultrasound for the diagnosis of proximal deep-vein thrombosis in emergency department

Background:

This study aimed to assess the accuracy of three-point compression ultrasonography (3PCUS) performed for the diagnosis of proximal deep-vein thrombosis (DVT) in Emergency Department (ED) compared with the results of duplex US (DUS) (whole-leg compression ultrasound).

Materials and Methods:

The current prospective cross-sectional study with diagnostic test assessment was conducted on adult patients who were referred to the ED of a general teaching hospital in Shiraz, southern part of Iran (September 2016–May 2017), suspected of lower-extremity DVT, using a convenience sampling. The results of 3PCUS performed by ED residents were compared with the results of DUS performed by the radiology residents, which was considered as a criterion standard.

Results:

A total of 240 patients were enrolled, with a mean (standard deviation) age of 59.46 (16.58). 3PCUS has a sensitivity and a specificity of 100% (95% confidence interval [CI], 96.55%–100%) and 93.33% (95% CI, 87.72%–96.91%), respectively, in comparison with DUS (whole-leg compression ultrasound). Negative predictive value and positive predictive value were 100% and 92.11% (95% CI, 86.12%–95.64%), respectively, with an accuracy of 96.25% (95% CI, 93%–98.27%).

Conclusion:

The results of this study showed that 3PCUS of the lower extremities with a portable US machine, performed by the ED's residents, can accurately identify the presence or absence of lower-extremity DVT.

Diagnostic Accuracy of a Three-point Compression Ultrasonography Performed by Emergency Medicine Resident for the Diagnosis of Deep Vein Thrombosis: a Prospective Diagnostic Study

Introduction:

Deep vein thrombosis (DVT) is a common cause of admission to the emergency departments (ED). Doppler ultrasonography of the entire lower limb is the first-line imaging modality. But most EDs do not access to full-time radiologists which can lead to delayed diagnosis.

Aim:

The aim of this study was to evaluate the diagnostic accuracy of three-point compression ultrasonography performed by emergency medicine resident for diagnosis of DVT.

Methods:

This prospective diagnostic study was carried out at Imam Khomeini Hospital in Sari from March 2018 to November 2018. For all patients with suspected lower extremity DVT, first bedside 3-point compression ultrasound were performed by a third year emergency medicine resident at ED. Then Doppler ultrasonography were performed by a radiologist in the radiology department, as a reference test. Sensitivity, specificity, and positive predictive value of the three-point compression ultrasound performed by emergency medicine resident was calculated.

Results:

Of the 72 patients enrolled in our study, 50% of the patients were male, with an average age of 36±19 years. The mean of patient admission time to perform ultrasonography by an emergency medicine resident and radiologist were 14.05±19 and 216±140.1 minutes, respectively. The two groups had a statistically significant difference (P<0.0001). In ultrasonography performed by emergency medicine resident and doper ultrasonography by radiologist, 91.67% and 36.1% of patients were diagnosed with DVT, respectively. Although the ultrasonography performed by emergency medicine resident has a relatively low sensitivity (53.8%), it has a good specificity (85.7%). The positive and negative predictive value was 70 and 75%, respectively.

Conclusion:

Although the results of this study indicate insufficient sensitivity of bedside three-point compression ultrasound performed by emergency medicine resident in diagnosis of lower limb DVT, the specificity, positive and negative predictive values and positive likelihood ratio were almost appropriate.

Diagnostic value of whole-body-focused ultrasonography in high-acuity patients in the emergency department: a prospective single-center cross-sectional study

BACKGROUND

A fast and diagnostic accurate tool to assess the unselected category of high-acuity patients, in whom the underlying pathology is not always obvious, is needed in the emergency departments (ED). We aim to describe the feasibility, validity and diagnostic yield of a routine whole-body-focused ultrasonography (wbf-us) in an unselected group of high-acuity ED patients.

METHODS

In a prospective observational study, a convenience sample of ED patients (≥ 18 years) with a high-acuity score or systolic blood pressure < 100 mmHg received a routine wbf-us of the heart, lungs, abdomen and deep veins by two non-expert sonographers. Final diagnosis was established by experienced auditors. Investigators were blinded to the patients' medical history and emergency physicians and auditors were blinded to the investigators assessments. Diagnostic accuracy was assessed by comparing the investigators' ultrasonography findings to a structured double-blinded clinical audit of patient files.

RESULTS

We included 171 patients, initiated a whole-body-focused ultrasonography examination (wbf-us) in 160 and completed it in 128 patients with an average time of a full examination of 28 min. We found pathology in 65/171 (38%) of the patients whose most frequent symptoms upon arrival were cardiopulmonary. Among the patients who received wbf-us, we found the majority of pathology by wbf-us of the lungs (n = 50, 31%), the heart (n = 26, 16%), few in the abdomen (n = 5, 3%) and none in the deep veins. The overall sensitivity was 50-100%, specificity 84-94%, positive predictive value 11-44% and negative predictive value 94-100%.

CONCLUSION

Focused cardiopulmonary ultrasonography might be considered for routine use in high-acuity ED patients with cardiopulmonary symptoms whereas focused ultrasonography of the abdomen and deep veins performed by non-expert sonographers only seems indicated in selected patients. Trial registration Danish Data Protection Agency (ID 13/12076). Committee on Biomedical Research Ethics for the Region of Southern Denmark (ID S-20130047).

Comparison of 2-point and 3-point point-of-care ultrasound techniques for deep vein thrombosis at the emergency department: A meta-analysis

BACKGROUND

To our knowledge, so far, no studies have comprehensively examined the performance of 2-point and 3-point point-of-care compression ultrasound (POCUS) in the diagnosis of lower extremity deep vein thrombosis (DVT). The aim of this meta-analysis was to compare the performance of 2-point and 3-point POCUS techniques for the diagnosis of DVT and evaluate the false-negative rate of each POCUS method.

METHODS

A computerized search of the PubMed, EMBASE, and Cochrane library databases was performed to identify relevant original articles. Bivariate modeling and hierarchical summary receiver operating characteristic modeling were performed to compare the diagnostic performance of 2-point and 3-point POCUS. The pooled proportions of the false-negative rate for each POCUS method were assessed using a DerSimonian-Laird random-effects model. Meta-regression analyses were performed according to the patient and study characteristics.

RESULTS

Seventeen studies from 16 original articles were included (2-point, 1337 patients in 9 studies; 3-point, 1035 patients in 8 studies). Overall, 2-point POCUS had similar pooled sensitivity [0.91; 95% confidence interval (95% CI), 0.68-0.98; P = .86) and specificity (0.98; 95% CI, 0.96-0.99; P = .60) as 3-point POCUS (sensitivity, 0.90; 95% CI, 0.83-0.95 and specificity, 0.95; 95% CI, 0.83-0.99). The false-negative rates of 2-point (4.0%) and 3-point POCUS (4.1%) were almost similar. Meta-regression analysis showed that high sensitivity and specificity tended to be associated with an initial POCUS performer (including attending emergency physician > only resident) and separate POCUS training for DVT (trained > not reported), respectively.

CONCLUSION

Both 2-point and 3-point POCUS techniques showed excellent performance for the diagnosis of DVT. We recommend that POCUS-trained attending emergency physicians perform the initial 2-point POCUS to effectively and accurately diagnose DVT.

Low Rate of Intrahospital Deep Venous Thrombosis in Acutely Ill Medical Patients: Results From the AURELIO Study

OBJECTIVE

To evaluate the effect of hospitalization on deep venous thrombosis (DVT) rate by the cumulative incidence of DVT in the proximal venous tract of the lower limbs at admission and discharge.

METHODS

The AURELIO (rAte of venoUs thRombosis in acutEly iLl patIents hOspitalized in internal medicine wards) multicenter observational study was carried out in hospital-university internal medicine wards including consecutive acutely ill medical patients. Patients underwent compression ultrasonography (CUS) of proximal lower limb veins at admission and discharge. The occurrence of DVT was the primary end point of the study.

RESULTS

Among 1340 patients, 26 (1.9%; 95% CI, 1.3%-2.8%) had asymptomatic DVT at admission and were excluded. During the follow-up, 144 patients were excluded because of hospitalization less than 5 days. The remaining 1170 patients underwent a CUS at discharge. Two hundred fifty (21%) underwent prophylaxis with parenteral anticoagulants; the remaining 920 (79%) were not treated with anticoagulants. The mean length of hospitalization was 13±8 days. Compared with patients without prophylaxis, those treated with parenteral anticoagulants had a higher incidence of active cancer, heart and respiratory failure, pneumonia, renal failure, previous venous thromboembolism, reduced mobility, and elderly age. During the hospital stay, 3 patients with a negative CUS at admission experienced DVT in the proximal tract (0.025%, rate of 1 per 5017 patient-days); 2 of them were in prophylaxis with parenteral anticoagulants.

CONCLUSION

We provide evidence that in the real world acutely ill medical patients display more than 90% (1.9%) asymptomatic DVT at admission, whereas the intrahospital DVT occurrence is very low. This suggests a novel diagnostic workup and a careful reanalysis of anticoagulant prophylaxis.

Comparison of the Accuracy of Emergency Department-Performed Point-of-Care-Ultrasound (POCUS) in the Diagnosis of Lower-Extremity Deep Vein Thrombosis

BACKGROUND

Compression ultrasonography is the most effective diagnostic tool in the emergency department (ED) for the diagnosis of deep vein thrombosis (DVT). It has been demonstrated to be highly accurate and cost-effective.

OBJECTIVE

The objective of this study was to determine the accuracy of emergency physicians who performed three-point compression ultrasound (US) for suspected above-knee DVT within the context of using Wells score and D-dimer.

METHOD

This was a prospective diagnostic test assessment of three-point ultrasound conducted in a district general hospital of patients who presented to the ED with suspected DVT of the lower limb. The accuracy of three-point ultrasound carried out by the emergency physicians was assessed by comparison of the Doppler ultrasound carried out by the Radiology Department as reference standard. The study incorporated ultrasound alongside the Wells score and D-dimer.

RESULTS

A total of 109 patients (66.1%) had a three-point compression point-of-care ultrasound in the ED and a second ultrasound performed by the Radiology Department. Bedside three-point compression ultrasound of the lower extremity performed by physicians in the ED had a sensitivity of 93.2% (95% confidence interval [CI] 83.8-97.3%) and a specificity of 90.0% (95% CI 78.6-95.7%), with an accuracy of 91.7% (95% CI 85-95.6%).

CONCLUSIONS

Emergency physicians can obtain a level of competence equivalent to that of radiologists, but it requires substantial training and practice to achieve and maintain this performance. Providers should be aware of their limitations and maintain regular training with ultrasound applications.

Clinical Value of Ultrasonography in Diagnosis of Pulmonary Embolism in Critically Ill Patients

Pulmonary embolism (PE) is a clinical emergency that will increase the mortality if complicated with unstable hemodynamics. Because of its nonspecific clinical symptoms, it's a great challenge to make a PE diagnosis. The golden standard to diagnose PE is computed tomography of pulmonary artery (CTPA), but a diagnosis of PE also composed of evaluation of PE risk factors, possibilities, and risk stratification. Ultrasonography may detect right ventricle strain related to hemodynamic change, intravascular thrombosis, thrombosis in right heart or pulmonary arteries, pulmonary infarction, and local pleural effusion. Combination of ultrasound and traditional PE possibility evaluation score may further improve the pretest probability of CTPA. A comprehensive ultrasonography may sometimes rule out PE and may disclose other causes for the clinical situations. A heart-lung-vessel-integrated multiorgan ultrasonography can help with the diagnosis of PE and so should be a necessary weapon for the physicians.

Interrater reliability of emergency physician-performed ultrasonography for diagnosing femoral, popliteal, and great saphenous vein thromboses compared to the criterion standard study by radiology

PURPOSE

To assess the interrater reliability and test characteristics of lower limb sonographic examination for the diagnosis of deep venous and proximal great saphenous vein thrombosis when performed by Emergency Physicians (EPs) as compared to that by the Department of Radiology (Radiology). The secondary objective was to assess the effects of patient body mass index and EP satisfaction with bedside ultrasound on sensitivity and specificity.

METHODS

A prospective study was conducted for patients with clinical suspicion for lower extremity thrombus. EPs evaluated for venous thrombosis in the common femoral vein, femoral vein of the thigh, popliteal vein, and proximal great saphenous vein. Subsequently, all patients received ultrasounds by Radiology, the criterion standard.

RESULTS

One hundred ninety-seven patients (257 individual legs) were evaluated. There was 90-95% agreement between EP and Radiology, moderate kappa agreement for common femoral vein, and femoral vein of the thigh and fair kappa agreement for great saphenous vein and popliteal vein. The sensitivity and specificity of EP ultrasounds compared with criterion standard were lower than previously reported. There was no trend in patient body mass index or provider satisfaction influencing the test characteristics.

CONCLUSIONS

Our study suggests that point-of-care sonography should not replace Radiology-performed scans. The required amount of training for EPs to be competent in this examination needs further investigation. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:360-367, 2016.

Deep venous thrombosis in patients with chronic spinal cord injury

CONTEXT/OBJECTIVE

Deep venous thrombosis (DVT) is a well-known complication of an acute spinal cord injury (SCI). However, the prevalence of DVT in patients with chronic SCI has only been reported in a limited number of studies. The aim of our study was to examine the prevalence of DVT in patients with SCI beyond three months after injury.

DESIGN

Cross-sectional study.

SETTING

Rehabilitation Department at the Bydgoszcz University Hospital in Poland.

PARTICIPANTS

Sixty-three patients with SCI that were more than 3 months post injury. The patients, ranging in age from 13 to 65 years, consisted of 15 women and 48 men; the mean age of the patients was 32.1 years. The time from injury varied from 4 to 124 months.

OUTCOME MEASURES

Clinical assessment, D-dimer and venous duplex scan.

RESULTS

The venous duplex scan revealed DVT in 5 of the 63 patients. The post-injury time in four of the patients varied between 4 and 5 months; one patient was 42 months post-injury.

CONCLUSION

DVT occurred in patients with chronic SCI, mainly by the 6th post injury month.

Mistakes and Pitfalls Associated with Two-Point Compression Ultrasound for Deep Vein Thrombosis

Introduction

Two-point compression ultrasound is purportedly a simple and accurate means to diagnose proximal lower extremity deep vein thrombosis (DVT), but the pitfalls of this technique have not been fully elucidated. The objective of this study is to determine the accuracy of emergency medicine resident-performed two-point compression ultrasound, and to determine what technical errors are commonly made by novice ultrasonographers using this technique.

Methods

This was a prospective diagnostic test assessment of a convenience sample of adult emergency department (ED) patients suspected of having a lower extremity DVT. After brief training on the technique, residents performed two-point compression ultrasounds on enrolled patients. Subsequently a radiology department ultrasound was performed and used as the gold standard. Residents were instructed to save videos of their ultrasounds for technical analysis.

Results

Overall, 288 two-point compression ultrasound studies were performed. There were 28 cases that were deemed to be positive for DVT by radiology ultrasound. Among these 28, 16 were identified by the residents with two-point compression. Among the 260 cases deemed to be negative for DVT by radiology ultrasound, 10 were thought to be positive by the residents using two-point compression. This led to a sensitivity of 57.1% (95% CI [38.8–75.5]) and a specificity of 96.1% (95% CI [93.8–98.5]) for resident-performed two-point compression ultrasound. This corresponds to a positive predictive value of 61.5% (95% CI [42.8–80.2]) and a negative predictive value of 95.4% (95% CI [92.9–98.0]). The positive likelihood ratio is 14.9 (95% CI [7.5–29.5]) and the negative likelihood ratio is 0.45 (95% CI [0.29–0.68]). Video analysis revealed that in four cases the resident did not identify a DVT because the thrombus was isolated to the superior femoral vein (SFV), which is not evaluated by two-point compression. Moreover, the video analysis revealed that the most common mistake made by the residents was inadequate visualization of the popliteal vein.

Conclusion

Two-point compression ultrasound does not identify isolated SFV thrombi, which reduces its sensitivity. Moreover, this technique may be more difficult than previously reported, in part because novice ultrasonographers have difficulty properly assessing the popliteal vein.

Addressing requests for emergency ultrasonographic examinations when implementing teleradiology services

PURPOSE

To prospectively assess how to address requests for ultrasonographic examinations when setting up an on-call teleradiology service.

MATERIALS AND METHODS

An analytical prospective study was performed from January 2012 to December 2012 inclusively. All requests received for after-hours ultrasonographic examinations during this period were analyzed. Ultrasound requests were classified as being postponable until working hours, replaceable by an alternate cross-sectional imaging modality, or urgent and needing to be performed after hours.

RESULTS

A total of 176 requests for ultrasonographic examinations were analyzed. They predominantly included requests for abdominal and pelvic ultrasonographic examinations (63%). Thirty-nine requests (22.2%) were considered as postponable, 49 (27.8%) as replaceable and 64 (36.4%) as both postponable and replaceable. Twenty-four requests (13.6%) were considered as urgent; they consisted of 10 requests for venous duplex Doppler ultrasonographic examinations of the lower limbs, eight requests for testicular ultrasonographic examinations, five for pelvic ultrasonographic examinations and one for soft-tissue ultrasonographic examination. In these urgent cases, realistic options were either to transfer the patient to another institution or to train emergency department physicians in ultrasonography for local handling.

CONCLUSION

Although the need for addressing requests for ultrasonographic examinations should be taken into account when setting up an on-call teleradiology service, it should not impede such plans.