Predictors of development and outcome in patients with acute respiratory distress syndrome due to tuberculosis

Abstract

Objective: To study the predictors of development and determinants of outcome in patients with acute respiratory distress syndrome (ARDS) due to tuberculosis (TB). Methods: Retrospective case-control study of demographic, clinical and laboratory data of hospitalised adult patients with active TB. RESULTS: Of 2733 TB patients treated during 1980-2003, 29 (1.06%; 1.21 patients/year; mean age 31.6 ± 10.9 years; 16 males) developed ARDS (cases). Seven had pulmonary TB and 22 had miliary TB (MTB); 298 (mean age 32.0 ± 14.2 years; 110 males) who did not develop ARDS constituted controls. Presence of MTB (OR 4.6, 95%CI 1.2-17.8; P = 0.02), duration of illness beyond 30 days at presentation (OR 177.9, 95%CI 39-811.7; P < 0.001), absolute lymphocyte count <1625/mm³ (OR 4.5, 95%CI 1.1-19.3; P = 0.04) and serum ALT > 100 IU (OR 15.7, 95%CI 3.0-81.1, P < 0.001) were independent predictors of ARDS development. Twelve cases died (41.4%). Patients with APACHE II score >18; those with APACHE II score < 18 in the presence of hyponatraemia and PaO₂/FIO₂ ratio < 108.5 were likely to die. Conclusions: In patients with TB, prolonged illness, MTB, absolute lymphocytopaenia and elevated ALT are independently associated with ARDS development. APACHE II score, serum sodium and PaO₂/FIO₂ ratio are determinants of outcome.