Features of severe pneumonia in patients with undiagnosed pulmonary tuberculosis in an intensive care unit.

Abstract

Early antituberculosis (anti-TB) therapy in hospitalized, severely ill patients with pulmonary tuberculosis (PTB) diminishes the mortality and morbidity rate and also reduces nosocomial transmission. However, delayed diagnosis of PTB is common in the respiratory intensive care unit (RICU), especially in patients with respiratory failure. This retrospective study evaluated the clinical features of RICU patients with severe pneumonia and undiagnosed active PTB, in order to determine which specific features might help in the screening of these patients. Patients with severe pneumonia with undiagnosed active PTB and those without active PTB on admission to the RICU, from March 1, 2000 to August 31, 2002, were compared. The 2 groups of patients were matched for age, gender, and Acute Physiology and Chronic Health Evaluation (APACHE) II score prior to the analysis. Data on clinical course, chest radiographic patterns, and laboratory findings were collected. Thirty five patients in the case group were matched with 35 controls who were similar with regard to age, gender, smoking history, acute lung injury score, and the presence of underlying disease. The duration of symptoms before admission was significantly longer in the case group than in the control group (15.1 +/- 13.9 vs 7.8 +/- 7.6 days, p = 0.012). The mean interval from admission to the RICU to the initiation of anti-TB therapy was 10.0 +/- 9.8 days. Small nodular lesions (p = 0.044) and cavitary lesions (p = 0.013) predominated on the chest radiograph in the case group. The mortality rates at discharge were not significantly different between the case group and the control group. These data suggest that when a patient developing severe pneumonia has a history of a sub-acute or chronic illness longer than 2 weeks in duration, and predominant small nodular or cavitary patterns on chest radiograph, active PTB should be considered.