Principles: Midregional proadrenomedullin (proADM) is a novel biomarker with potential prognostic utility in patients with community-acquired pneumonia. The aim of this study was to investigate the value of proADM levels for severity assessment and outcome prediction in severe sepsis and septic shock due to CAP.
Methods: Prospective observational study including 49 patients admitted to ICU with both a clinical and radiologic diagnosis of pneumonia and fulfilling criteria for severe sepsis or septic shock. The prognostic accuracy of proADM levels was compared with those of pneumonia severity index and of procalcitonin (PCT) and C-reactive protein (CRP).
Results: 49 patients with severe sepsis or septic shock due to CAP were included in the study. Mortality was 24.5% for ICU and 34.7% for hospital mortality. In all cases proADM values at ICU admission were pathological (considering normal proADM levels <4 nmol/L). ProADM consistently rose as PSI class advanced from II to V (p = 0.02). Median proADM levels were higher (p <0.01) in hospital non-survivors 5.0 (1.9-10.1) nmol/L vs. survivors 1.7 (1.3-3.1) nmol/L. These differences were also significant with respect to ICU mortality. The receiver-operating characteristic curve for proADM yielded an AUC of 0.72; better than the AUC for PCT and CRP (0.40 and 0.44 respectively) and similar to PSI (0.74).
Conclusions: In our study MR-proADM levels correlate with increasing severity of illness and death. High MR-proADM levels offer additional risk stratification in high-risk CAP patients.