RESULTS: The median age was 76 yr (range, 65-93 yr; IQR, 71-83), and 70.9% of the patients were male. There were 25 cases of severe community acquired pneumonia, 43 severe hospital acquired pneumonia and 18 severe healthcare-associated pneumonia. 6 patients required exclusively non-invasive ventilation, 57 required exclusively invasive ventilation, 15 required both non-invasive and invasive ventilation, and 8 required only oxygen therapy. The median level of NT-pro-BNP on ICU admission was 3,839.5 pg/mL (range, 63.9-236,823.0 pg/mL; IQR, 1,243.3-9,623.3pg/mL), and the median APACHE II score was 23 (range, 13-43). The 28-day mortality rate was 61.6%. The 28-day survivors did show significantly decreased levels of NT-pro-BNP from non-survivors (3,058.0 pg/mL [range, 63.9-47,305.0 pg/mL] vs. 5,252.0 pg/mL [range, 428.0-236,823.0 pg/mL], Z=−2.216, P=0.027). In prediction of 28-day mortality, the area under the curve (AUC) for APACHE II score was 0.67 (95% CI, 0.56-0.79) and AUC for NT-pro-BNP was 0.64 (95% confidence interval [CI], 0.52-0.76). AUC was 0.68 (95%CI, 0.57-0.80) when NT-pro-BNP was combined with APACHE II score.