Lung ultrasound in the diagnosis of stroke-associated pneumonia

Abstract

Pneumonia is a common complication in stroke patients; it is associated with an adverse outcome, prolonged hospital stay and increased health costs. The aim of this study was to assess the ability of lung ultrasound to rule in or rule out pneumonia in patients with stroke. Patients with ischemic or hemorrhagic stroke were included in the study if they had a clinical suspicion of pneumonia. Lung ultrasound imaging and chest X-ray studies were performed within 24 h from the onset of symptoms of pneumonia; the sonographer and radiologists were unaware of the chest X-ray study and ultrasound imaging results, respectively. In case of discordant results, lung computed tomography (CT) was performed if a definitive diagnosis was required to optimize clinical management. Seventy patients were included in the study. Among 24 patients with unilaterally positive chest X-ray studies, the ultrasound imaging was unilaterally positive in 19 cases (79.2 %), bilaterally positive in 3 cases (12.5 %) and negative in 2 cases (8.3 %). Among 44 patients with negative chest X-ray studies, ultrasound imaging was unilaterally positive in 17 cases (38.6 %), bilaterally positive in 2 cases (4.6 %), negative in 19 cases (43.2 %) and non-conclusive in 6 cases (13.6 %). A lung CT scan was performed in 9 of the 21 discordant cases, and it always confirmed the ultrasound imaging results. Ultrasound imaging and chest X-ray studies were concordant in 42 out of 63 cases, 66.7 % (Pearson χ(2) = 11.97, p = 0.001). In conclusions, this study shows the utility of LUS imaging to rule in or rule out pneumonia in patients with stroke. We believe that lung ultrasound imaging can help clinicians in the diagnosis of stroke-associated pneumonia.