It remains unknown whether bacteremia and rapid radiologic progression of pulmonary infiltrates increase the risk of shock and mortality in ICU patients with community-acquired pneumonia (CAP). The objective of this study was to investigate the relative importance of these two factors in the outcome of patients with severe CAP (sCAP).
A secondary analysis in a multicenter observational study was conducted in 457 patients with CAP admitted to the ICU. Patients were classified into four groups: group RB, rapid radiographic spread of pulmonary infiltrates and bacteremia (n = 48); group R, rapid radiographic spread but no bacteremia (n = 183); group B, bacteremia but without rapid radiographic spread (n = 39); and group C, neither rapid radiographic spread nor bacteremia (n = 187).
Logistic regression analysis showed that group RB and group R had a greater risk for shock than group C (adjusted odds ratio [aOR], 8.9; 95% confidence interval [CI], 4.0 to 19.7; and aOR, 3.8; 95% CI, 2.5 to 5.9; respectively), while patients in group B had no increased risk. In addition, compared to group C, group RB and group R had an increased risk of ICU death (aOR, 3.4; 95% CI, 1.4 to 8.1; and aOR, 3.1; 95% CI, 1.7 to 5.7, respectively), while patients in group B had none.
In this cohort of patients with severe CAP, radiologic progression of pulmonary infiltrates in the first 48 h is a significant adverse prognostic feature. In contrast, bacteremia does not affect outcomes.