Introduction: The Clinical Pulmonary Infection Score (CPIS) has received much attention recently. Advocates have touted its use for the diagnosis and duration of therapy in patients with ventilator-associated pneumonia (VAP). However, little has been written about its utility in trauma patients. The clinical, physiologic, and radiologic components of the CPIS may be difficult to differentiate from the systemic effects of injury. Quantitative cultures of the lower airway have been shown to be efficacious in differentiating VAP from the systemic inflammatory response syndrome (SIRS). In this study, we evaluated the potential use of CPIS as the sole means for diagnosis of VAP in critically injured patients.
Methods: Patients were identified from the VAP database maintained in our Level I trauma center. Only those who had CPIS calculated at the time of bronchoscopy with BAL were included. VAP required >or=10 colonies/mL on quantitative BAL for diagnosis. Antibiotic therapy was based on quantitative BAL results. Patients with <10 colonies/mL were diagnosed with SIRS. Sensitivity and specificity of a CPIS>6 for VAP diagnosis (confirmed by BAL) were calculated.
Results: In all, 158 patients underwent 285 BALs. The overall incidence for VAP was 42%. Patients with episodes of VAP and SIRS were well matched for age, Injury Severity Score, APACHE II score, and Glasgow Coma Scale score. The average CPIS was 6.8 in patients with SIRS and 6.9 for those with VAP. Using a CPIS>6 as the threshold for VAP only yielded a sensitivity of 61% and a specificity of 43%.
Conclusions: CPIS cannot differentiate VAP from SIRS in critically injured patients. Using CPIS to initiate antibiotic therapy in trauma patients could be harmful. Whether CPIS is useful to determine duration of antibiotic therapy is unknown.