Contributing factors to mortality rates of pulmonary tuberculosis in intensive care units

Background: Tuberculosis (TB) remains an important health problem worldwide. TB patients sometimes require intensive care unit (ICU) treatment. The aim of this study is to establish special features and mortality rates of pulmonary TB patients in ICUs and identify the factors contributing to ICU mortality.

Methods: Medical records of adult patients (>18 years) with a diagnosis of TB who were admitted to the ICU of a referral hospital for chest diseases between 2004 and 2010 were reviewed retrospectively. Demographic characteristics, comorbidities, APACHE II scores, symptoms, radiologic appearance of the disease, bacteriological and laboratory investigations, need and type of mechanical ventilation support (invasive, non-invasive), characteristics related to ICU stay, length of ICU stay, mortality and factors affecting mortality were recorded and analysed.

Results: Forty patients (33 male) with active pulmonary TB with a median age of 55 years (43-63 years) and a median APACHE II score of 22 (17-26) were followed up in the ICU. Patients who needed invasive mechanical ventilation had significantly longer ICU stays than patients who were treated with non-invasive ventilation or medical therapy (Log rank p = 0.014). Mortality was 72.5%. The only independent risk factor for mortality was having an APACHE II score ≥18.

Conclusion: The mortality of TB patients who needed ICU support remains high. This higher mortality rate seems related to multi-organ failure, requiring invasive mechanical ventilation and high APACHE II scores.