Determining if the prognostic nutritional index can predict outcomes in community acquired bacterial pneumonia

Background: The Prognostic Nutritional Index (PNI) uses albumin levels and total lymphocyte count to predict the relationship between immune-nutritional state and prognosis in a variety of diseases, however it has not been studied in community acquired bacterial pneumonia (CABP). We conducted a historical cohort study to determine if there was an association between PNI and clinical outcomes in patients with CABP. Methods: We reviewed 204 adult patients with confirmed CABP, and calculated admission PNI and Neutrophil-toLymphocyte Ratio (NLR). A comparative analysis was performed to determine the association of these values, as well as other risk factors, with the primary outcomes of 30-day readmissions and death. Results: Of the 204 patients, 56.9% (116) were male, 48% (98) were black/African American and the mean age was 63.2 +/- 16.1 years. The NLR was neither associated with death nor 30-day readmission. The mean PNI in those who survived was 34.7 +/- 4.5, compared to 30.1 +/- 6.5, in those who died, p < 0.001. From multivariable analysis after controlling for the Charlson score and age, every one-unit increase in the PNI decreased the risk of death by 13.6%. The PNI was not associated with readmissions. Conclusions: These findings suggest that poor immune and nutritional states, as reflected by PNI, both contribute to mortality, with a significant negative correlation between PNI and death in CABP. PNI was predictive of mortality in this patient cohort; NLR was not. Monitoring of albumin and lymphocyte count in CABP can provide a means for prevention and early intervention.