Concordancia entre el gram y el cultivo del lavado broncoalveolar en pacientes con neumonía asociada al ventilador

Abstract

Ventilator associated pneumonia is an entity of growing incidence in intensive care units worldwide. Doing an appropriate diagnosis, specially when using cost effective tests, allows better clinical results and costs savings. Simple tests as the gram stain of respiratory samples, like the bronchoalveolar lavage are used, but the variability with the final diagnostic procedure, the culture of the respiratory sample, is high. The early use of appropriate antibiotics using the information from microbiological studies available has important impact in the clinical result. The aim of this study was to determine the overall agreement between the gram stain from a respiratory sample obtained through bronchoalveolar lavage and the final result from the culture. A retrospective analysis of 69 patients in a mixed intensive care unit of a single center, with a clinical diagnosis of ventilator associated pneumonia, and bronchoalveolar lavage obtained through fiberoptic bronchoscopy was made. The overall correlation between the gram stain and the culture of the respiratory sample from bronchoalveolar lavage was poor, with a kappa score of 0,16. It is possible that this deficient correlation is secondary to the previous use of antibiotics in 69% of the patients. The most frequent diagnoses in this group of patients were sepsis and neurological pathologies. Oxygenation abnormalities were more frequent at the diagnosis of the pneumonia. Mortality was 27,5% as of ICU stay, and 29% at the 29th day.