Lung parenchymal and pleural findings on computed tomography after out-of-hospital cardiac arrest

Lung injury and the acute respiratory distress syndrome (ARDS) are common after out-of-hospital cardiac arrest (OHCA), but the imaging characteristics of lung parenchymal and pleural abnormalities in these patients have not been well-characterized. We aimed to describe the incidence of lung parenchymal and pleural findings among patients who had return of spontaneous circulation (ROSC) and who underwent computed tomography (CT) of the chest after OHCA.

This was a retrospective cohort study conducted at two academic hospitals from 2014 to 2019. We included adults successfully resuscitated from OHCA who received a head-to-pelvis or dedicated chest CT scan. The composite primary outcome was the incidence of lung parenchymal and pleural abnormalities. CT scans were overread by attending radiologists and lung parenchymal and pleural findings were categorized based on predefined criteria. Data are presented as absolute numbers and percentages. We examined the associations between CPR duration, time to successful intubation, and outcome using multivariable analyses.

We evaluated 204 eligible patients. Mean age was 54 years and 33 % were women. An initial shockable rhythm was found in 27 % and in 72 patients (36 %) the presumed etiology of OHCA was cardiac. A total of 133 patients underwent head-to-pelvis CT and 71 patients had dedicated chest CT. The median time from 911 call to CT scan was 2.5 (IQR 2.0-3.4) hours. A total of 160 (78 %) of patients had abnormal lung parenchyma or pleural findings. Patients with longer CPR duration or longer time to successful intubation had a higher incidence of abnormal lung findings on CT.

Over three-quarters of patients who survived to the hospital post OHCA and received a chest CT had lung parenchymal or pleural abnormalities, the most common of which were aspiration, pulmonary edema, and consolidation/pneumonia. Future planned research will characterize the clinical impact of these findings and whether early chest CT could identify patients at risk for ARDS or other pulmonary complications.