Point-of-Care Multi-Organ Ultrasound Improves Diagnostic Accuracy in Adults Presenting to the Emergency Department with Acute Dyspnea

Abstract

Introduction: Determining the etiology of acute dyspnea in emregency department (ED) patients is often difficult. Point-of-care ultrasound (POCUS) holds promise for improving immediate diagnostic accuracy (after history and physical), thus improving use of focused therapies. We evaluate the impact of a three-part POCUS exam, or "triple scan" (TS) - composed of abbreviated echocardiography, lung ultrasound and inferior vena cava (IVC) collapsibility assessment - on the treating physician's immediate diagnostic impression.

Methods: A convenience sample of adults presenting to our urban academic ED with acute dyspnea (Emergency Severity Index 1, 2) were prospectively enrolled when investigator sonographers were available. The method for performing components of the TS has been previously described in detail. Treating physicians rated the most likely diagnosis after history and physical but before other studies (except electrocardiogram) returned. An investigator then performed TS and disclosed the results, after which most likely diagnosis was reassessed. Final diagnosis (criterion standard) was based on medical record review by expert emergency medicine faculty blinded to TS result. We compared accuracy of pre-TS and post-TS impression (primary outcome) with McNemar's test. Test characteristics for treating physician impression were also calculated by dichotomizing acute decompensated heart failure (ADHF), chronic obstructive pulmonary disease (COPD) and pneumonia as present or absent.

Results: 57 patients were enrolled with the leading final diagnoses being ADHF (26%), COPD/asthma (30%), and pneumonia (28%). Overall accuracy of the treating physician's impression increased from 53% before TS to 77% after TS (p=0.003). The post-TS impression was 100% sensitive and 84% specific for ADHF.

Conclusion: In this small study, POCUS evaluation of the heart, lungs and IVC improved the treating physician's immediate overall diagnostic accuracy for ADHF, COPD/asthma and pneumonia and was particularly useful to immediately exclude ADHF as the cause of acute dyspnea.

Figure 1

Typical findings on “triple scan” (TS) in acute decompensated heart failure (ADHF) and chronic obstructive pulmonary disease (COPD)/asthma. Images a-c show typical findings of ADHF: dilated left ventricle with poor mitral valve opening (a); vertical b-line artifacts in this case indicating excess lung water (b); dilated inferior vena cava (IVC [lacking respiratory variation]) (c). Images d-e show typical findings in COPD/asthma: normal left ventricle (often hyperdynamic) (d), horizontal a-line artifacts indicating hyperinflation (e) and normal IVC (f).

Figure 2

Case level data showing final diagnosis in each case. ADHF, acute decompensated heart failure; COPD, chronic obstructive pulmonary disease; TS, triple scan