Negative predictive value Of Point-of-care ultrasound normal exam to exclude PneumoniA (NO-PNA)

Abstract

AbstractPneumonia is one of the most common causes of hospital admission in the United States. Worldwide, the majority of antibiotics are prescribed for upper respiratory infections, much of which could be avoided with highly accurate methods of diagnosing or excluding pneumonia at the bedside. Despite the high prevalence of infectious pneumonia and decades of medical progress, accurately diagnosing or ruling out pneumonia without the use of computed tomography (CT) scanners and distinguishing between viral or bacterial etiologies remains challenging. We enrolled 61 patients in a prospective, blinded study to determine the sensitivity of lung ultrasound (LUS) using a handheld ultrasound probe in patients who had a computed tomography (CT) scan of their chest for any reason. The sensitivity of lung ultrasound to detect patients with evidence of pneumonia as compared to a CT scan was 94.4% (72.7 - 99.9) with a negative predictive value of 96.2% (80.4 - 99.9) when the scan was normal. Due to our broad inclusion criteria and the high prevalence of of non-infectious lung disease at the site of this study, the specificity was 61% (44.5 - 75.8) and positive predictive value was 51.5% (33.5 - 69.2). This simple lung ultrasound scan can be incorporated into the physical exam, has very high sensitivity to detect patients with pneumonia, and can be effectively used to rule out pneumonia if the lung exam is normal.