Frequency, clinical characteristics, and outcomes of pneumonia in patients with out-of-hospital cardiac arrest undergoing extracorporeal cardiopulmonary resuscitation

Aim: This study aimed to describe the frequency, clinical characteristics, and outcomes of pneumonia in OHCA patients treated with ECPR in a multicenter setting. Methods: This is a secondary analysis of the SAVE-J II study, which was a multicenter, retrospective cohort of OHCA patients treated with ECPR. Age, sex, comorbidities, presence of witnessed CA, presence of bystander CPR, initial rhythm, cause of CA, low-flow time, initiation of targeted temperature management, details of sputum culture, pneumonia, and prophylactic antibiotic use were recorded. Pneumonia was diagnosed when the patients met all the clinical, radiologic, and microbiologic criteria acquired after hospitalization. Results: In total, 1,986 patients were included in the analysis, and 947 (48%) died during the first 2 days of admission. A prophylactic antibiotic was used in 712 (35.9%) patients. Overall, the hazard of death was high on days 1 and 2 of admission, exceeding 20% on both days; 251 (12.6%) patients developed pneumonia during hospitalization, and the hazard of pneumonia development remained high (>2%) in the first 7 days of admission.Staphylococcus aureus and Klebsiella species were commonly identified in the sputum culture. Among patients who survived the first 7 days, the odds ratio (OR) of those with pneumonia and unfavorable neurological outcomes defined by cerebral performance category 3–5 was approximately 1. In those who survived the first 10 days, the OR was greater than 1 with a wide confidence interval. Conclusions: This is the first study describing details of pneumonia in OHCA patients treated with ECPR using a large dataset.