The pathophysiological significance of prognostic factors for fatal outcome in lower respiratory tract infections

OBJECTIVE: The aim of this study was to determine prognostic factors for outcome in patients with lower respiratory tract infections (LRTI). LRTI are an heterogeneous group of disorders, including acute bronchitis, pneumonia, superinfection of chronic bronchitis and influenza. METHODOLOGY: A total of 616 patients with LRTI were retrospectively reviewed with regard to epidemiological, clinical, laboratory and radiographical data. Prognostic analysis included a univariate as well as a multivariate approach, in order to identify parameters associated with death. RESULTS: The parameters found to be significantly different between survivors and non-survivors in the univariate analysis, were respiratory rate, PaO2, heart rate, systolic and diastolic blood pressure, platelet count, urea, creatinine, previous admission to the hospital in the last year and cavitations visible on the chest radiograph. CONCLUSIONS: LRTI remain a widespread problem and have a significant impact on primary healthcare resources. The great variability seen in rates of hospital admission and lengths of stay in part reflects uncertainty among physicians in assessing the severity of the illness. According to our data, PaO2 and heart rate were most closely associated with patient death and are readily defined and available at presentation.