Diagnostic accuracy of focused deep venous, lung, cardiac, and multiorgan ultrasound in suspected pulmonary embolism: a systematic review and meta-analysis

Abstract

ObjectiveTo determine the diagnostic accuracy of point-of-care ultrasound in suspected pulmonary embolism. DesignSystematic review and meta-analysis.Data sources MEDLINE, Embase, CINAHL, and Cochrane library was searched on the 2 nd of July, 2020 with no restrictions on date of publication. Subject headings or subheadings combined with text words for the concepts of pulmonary embolism, ultrasound, and diagnosis were used. Eligibility criteria and data analysisEligible studies reported sensitivity and specificity of deep venous, lung, cardiac, or multiorgan ultrasound in patients with suspected pulmonary embolism, using an adequate reference-test. Prospective, crosssectional and retrospective studies were considered for eligibility. No restrictions were made on language. Studies were excluded if a control group consisted of healthy volunteers or if transesophageal or endobronchial ultrasound was utilized. Risk of bias was assessed using quality assessment of diagnostic accuracy studies 2 (QUADAS-2). Meta-analysis of sensitivity and specificity was performed by construction of hierarchical summary receiver operator curves. I 2 was used to assess study heterogeneity. Main outcome measuresThe primary outcome was overall sensitivity and specificity of reported ultrasound signs, stratified by organ approach (deep venous, lung, cardiac, and multiorgan). Secondary outcomes were stratum specific sensitivity and specificity within subgroups defined by pretest probability of pulmonary embolism. Results6378 references were identified, and 70 studies included. The study population comprised 9664 patients with a prevalence of pulmonary embolism of 39.9% (3852/9664). Risk of bias in at least one domain was found in 98.6% (69/70) of included studies. Most frequently, 72.8% (51/70) of studies reported more than 24 hours between ultrasound examination and reference test or did not disclose time interval at all. Level of heterogeneity ranged from 0% to 100%. Most notable ultrasound signs were bilateral compression of femoral and popliteal veins (22 studies; 4708 patients; sensitivity 43.7% (36.3% to 51.4%); specificity 96.7% (95.4% to 97.6%), presence of at least one hypoechoic pleural based lesion (19 studies; 2,134 patients; sensitivity 81.4% (73.2% to 87.5%); specificity 87.4% (80.9% to 91.9%)), D-sign (13 studies; 1,579 patients; sensitivity 29.7% (24.6% to 35.4%); specificity 96.2% (93.1% to 98.0%)), visible right ventricular thrombus (5 studies; 995 patients; sensitivity 4.7% (2.7% to 8.1%); specificity 100% (99.0% to 100%)), and McConnell's sign (11 studies; 1,480 patients; sensitivity 29.1% (20.0% to 40.1%); specificity 98.6% (96.7% to 99.4%)). ConclusionSeveral ultrasound signs exhibit a high specificity for pulmonary embolism, suggesting that implementation of ultrasound in the initial assessment of patients with suspected pulmonary embolism may improve the selection of patients for radiation imaging. Study registration: PROSPERO CRD42020184313. Data extraction and quality assessmentTwo reviewers (CF and NJ) used a predes...

Diagnostic Accuracy of a Bespoke Multiorgan Ultrasound Approach in Suspected Pulmonary Embolism

“…If this approach were applied to our ultrasound protocol, the false-negative patient with intermediate probability would be referred to further diagnostic imaging, as no other explanation for his dyspnea, Wells score of 6, and D-dimer of 5.1 mg/L could be determined. When considering the ability of our selected single-organ ultrasound signs to confirm PE suspicion, our findings support the results of a recent meta-analysis 9 . The presence of a DVT, at least two hypoechoic pleural lesions, D-sign, 60/60-sign, and a visible RV thrombus all had a specificity of 100%, which also applied to the McConnell’s sign in the absence of COPD, ILD, known PH, or pulmonary valve stenosis.…”

“…PE research often excludes patients with known illnesses which might affect findings during heart ultrasound. Our decision not to exclude these patients but rather incorporate possible consequences increases the generalizability 9 . The several ultrasound signs with high specificity raise the possibility that some PEs may be confirmed without further diagnostic workup.…”

“…As recent studies report a prevalence of PE in patients referred to CTPA of 20–30% in Europe and as low as 5–10% in the United States, improvement of the clinical assessment of PE probability and refining of the selection of patients for radiation imaging are warranted 7 8 . Use of point-of-care ultrasound (PoCUS) in the diagnostic algorithm could reduce the need for CTPA or V/Q scan by confirming or dismissing PE suspicion in selected cases 9 . It is noninvasive, can be performed bedside, and reduces time, radiation exposure, and costs 10 .…”

“…While several previous studies have evaluated the diagnostic accuracy of a PoCUS investigation, only three have utilized a multiorgan approach, encompassing heart, lung, and deep venous ultrasound 13 14 15 . To further the body of evidence and confirm the existing literature, we developed a bespoke multiorgan ultrasound approach, combining the ultrasound signs with the highest sensitivities and specificities, based on a recent meta-analysis on the diagnostic accuracy of ultrasound in suspected PE, including 70 descriptive studies 9 . Prospective validation of a bespoke approach via a diagnostic accuracy study is an important prerequisite for assessing its impact in a randomized controlled trial.…”

Clinical Characteristics and Risk Factors for Early versus Late Pulmonary Embolism in Trauma Patients: A Retrospective, Observational Study

“…Contemporary studies have identified that PE could occur without documented DVT and could be considered as a distinct entity. 14,27,28 An earlier study by Velmahos et al 22 demonstrated that most PE patients did not have evidence of DVT screened by CT venography of the pelvis and proximal lower extremity veins. PE could occur de novo within the lungs.…”