Background: Whether proadrenomedullin (ProADM) improves the performance of the Risk of Early Admission to ICU (REA-ICU) score in predicting early, severe community-acquired pneumonia (ESCAP) has not been demonstrated.
Methods: Secondary analysis was completed of the original data from 877 consecutive patients with community-acquired pneumonia (CAP) enrolled in the Procalcitonin-Guided Antibiotic Therapy and Hospitalization in Patients With Lower Respiratory Tract Infections (ProHOSP) study, a multicenter trial in EDs of six tertiary-care hospitals in Switzerland. ESCAP was defined by either the requirement for mechanical ventilation or vasopressive drugs or occurrence of death within 3 days of ED presentation.
Results: Eighty patients (9.1%) developed ESCAP (47 required mechanical ventilation, 19 vasopressive drugs, and 16 died) within 3 days of ED presentation. They had a higher median ProADM value (2.18 nmol/L vs 1.15 nmol/L, P < .001). Combining ProADM testing with the REA-ICU score improved the area under the curve (0.81) compared with either parameter (ProADM [0.73] or REA-ICU score [0.76], P < .001) and resulted in a net reclassification improvement of 0.20 (P < .001). A ProADM value ≥ 1.8 nmol/L or assignment to REA-ICU risk classes III-IV predicted ESCAP with a sensitivity of 76.3% and a negative predictive value of 96.7%. Excluding 21 patients with major criteria of severe CAP on presentation showed similar results.
Conclusion: These study findings demonstrate that the addition of ProADM to the REA-ICU score improves the classification of a substantial proportion of patients in the ED at intermediate or high risk for ESCAP, which may translate into better triage decisions.