Focused sonography of the heart, lungs, and deep veins identifies missed life-threatening conditions in admitted patients with acute respiratory symptoms

Abstract

Background: Patients with acute respiratory symptoms still remain a diagnostic challenge. The aim of the study was to evaluate whether focused sonography could potentially diagnose life-threatening conditions missed at the primary assessment in a patient population consisting of admitted patients with acute respiratory symptoms.

Methods: A prospective blinded observational study was conducted in a medical ED. Inclusion criteria were the presence of one or more of the following: respiratory rate > 20/min, oxygen saturation < 95%, oxygen therapy initiated, dyspnea, cough, or chest pain. After the initial assessment, focused sonography of the heart, lungs, and deep veins was performed by a physician blinded to patient history and the results of the primary assessment.

Results: One hundred thirty-nine patients were included. The focused sonographic examinations could be performed in 134 patients (96%). Focused sonography identified 19 patients (14%) with an acute life-threatening condition missed at the primary assessment. Diagnostic performance of focused sonography for the diagnosis of an acute life-threatening condition, when using audit as gold standard, was as follows: sensitivity, 100% (95% CI, 85.2%-100%); specificity, 93.3% (95% CI, 86.7%-97.3%); positive predictive value, 76.7% (95% CI, 57.7%-90.1%); and negative predictive value, 100% (95% CI, 96.3%-100%).

Conclusions: Focused sonography of the heart, lungs, and deep veins is fast, highly feasible, and able to diagnose life-threatening conditions missed at the primary assessment in admitted patients with acute respiratory symptoms. In an ED setting sonography can be used both for ruling in and ruling out acute life-threatening conditions in these patients.