Unexpectedly frequent acute pulmonary lesions on chest CT in patients with subarachnoid hemorrhage during the COVID-19 pandemic: a retrospective observational study

Background/Objective : Pulmonary complications of subarachnoid hemorrhage (SAH) are a major cause of unfavorable outcomes; however, detailed studies on acute pulmonary complications immediately after SAH have seldom been reported. We report the frequency of acute pulmonary lesions and their correlation with outcomes using chest computed tomography (CT), principally performed in patients with SAH at admission for screening during the coronavirus disease pandemic. Methods : We conducted a retrospective study of 99 patients who underwent chest CT on admission from among 132 with SAH treated between March 2020 and May 2023. The clinical features, laboratory data, imaging findings, and outcomes at discharge were analyzed. Results : Acute chest CT abnormalities were identified in 84 of the 99 (84.8%) patients, which included inadequate inspiration in 43 patients, aspiration in 38, consolidation in 29, In 37 (44.0%) of the 84 patients with acute lesions on chest CT, chest radiography could not detect acute abnormalities. Multivariate analysis showed smoking history (p=0.033, odds ratio [OR] 11.1 [2.2–100.0]) and World Federation of Neurosurgical Societies grade (p<0.001, OR 2.6 [1.6–4.3]) as independent risk factors for chest CT abnormality. Patients showing acute lung lesions on chest CT on admission had unfavorable outcomes more frequently compared to those without chest CT abnormalities (p<0.001). Conclusion : Patients with SAH were frequently complicated by acute lung lesions, which resulted in unfavorable outcomes. Chest CT at admission in patients with a poor SAH grade and/or smoking history might allow for the early detection of acute respiratory diseases, which could potentially improve outcomes.