Clinical characteristics and risk factors associated with mortality in patients with severe community-acquired pneumonia in the intensive care unit.

Background: The mortality rate among patients in the intensive care units (ICUs) with severe community-acquired pneumonia (CAP) is high. Identification of severe CAP early in the course and transferring to appropriate setting seem favorable. This study aimed to identify clinical characteristics and the risk factors associated with mortality of severe CAP in the ICU (ICU-CAP). Methods: A multi-center, prospective study was conducted at 11 teaching hospitals in China from December 2017 to October 2021. Patients who met the inclusion criteria were assigned to the ICU group and the non-ICU group according to whether they were admitted to the ICU. Results: A total of 170 patients with severe CAP were included, 111 patients were admitted to the ICU and 59 patients were admitted to the ward. Among patients in the ICU, 91.9% of patients were with respiratory failure, 65.8% of patients with consciousness disturbance, 23.4% were in shock state, and 73.0% (81/111) of patients had at least one comorbidity. In-hospital mortality for ICU-CAP was 34.2% (38/111), 28-day mortality was 27.9% (31/111), and 7-day mortality was 10.8% (12/111). Mortality in patients with pneumonia severity index class V (PSI-V) was 40.0% (18/45), mortality in patients with invasive mechanical ventilation was 40.2% (33/82). In the ICU subgroup, invasive mechanical ventilation [odds ratio (OR) =3.35; 95% confidence interval (CI): 1.14-9.81; P=0.02] and age ≥60 years (OR =2.64; 95% CI: 1.07-6.53; P=0.03) were independently associated with in-hospital mortality. Conclusions: In this multicenter prospective cohort, severe CAP patients admitted to the ICU exhibited substantial disease severity, with high rates of treatment failure and mortality. Invasive mechanical ventilation and age ≥60 years were associated with in-hospital mortality in the ICU subgroup.