Elevated Blood Urea Nitrogen Is a Predictive Factor for Intensive Care Unit Admission in Legionella Pneumonia

Abstract

Background : Legionella pneumonia (L. pneumonia) is a serious disease among patients with community-acquired pneumonia (CAP). Appropriate initial assessment of severity and admission to intensive care unit (ICU) can reduce mortality due to L. pneumonia. Here, the efficacy of using the current CAP scoring for recommending admission to ICU and other variables for initial management were evaluated. Methods : The clinical characteristics of 11 patients diagnosed with L. pneumonia at Maebashi Red Cross Hospital from November 1999 to July 2010 were examined. The scoring systems of A-DROP (A : Age, D : Dehydration, R : Respiration, O : Orientation, and P : Blood Pressure) and CURB-65 (C : Confusion, U : Urea, R : Respiratory rate, B : Blood pressure, and Age) were used. Results : Of the 11 L. pneumonia patients, 6 were admitted to the ICU. By A-DROP and CURB-65 scoring systems, 4 cases were assessed as not severe. Among the parameters used in the scores, only elevated blood urea nitrogen (BUN) had significantly predictive potential for ICU admission (sensitivity=100%, specificity=80%, P< 0.02). Both A-DROP and CURB-65 scoring systems underestimated the severity of CAP caused by L. spp .. Conclusions : In the case of L. pneumonia, elevated BUN level is important for assessing CAP severity and making ICU admission recommendations.