Predictors of need of mechanical ventilation and reintubation in patients with acute respiratory failure secondary to chronic obstructive pulmonary disease

Background and Aims: To identify predictors of need of mechanical ventilation (MV) and that of reintubation, after a planned extubation, among the patients with exacerbation of chronic obstructive pulmonary disease. Materials and Methods: Prospectively collected data of 82 patients with exacerbation of COPD over a one-year period were reviewed. Clinical and demographic profile, APACHE II score, blood gas parameters and serum biochemistry, recorded at the time of admission, were compared between patients who required MV and those who did not. Parameters were also compared between the groups formed on the basis of requirement of reintubation. Results: Sixty-nine patients (84.1%) required invasive MV. Independent predictors of need of MV were pH<7.26 ( adjusted OR, 95% CI) (4.9, 1.1-21.3; P=0.03) and SA < 3.5 g/dL (6.3, 1.4-27.7; P=0.01). Reintubation was required in 8 patients out of 45, who were extubated (17.8%). PaCO2 rise 12 hours after extubation (1.25, 1.0-1.5; P=0.01) and APACHE II score (1.33, 1.0-1.7; P=0.03) were independent predictors for need of reintubation. A cut off level of 7.2 mmHg for PaCO2 rise had sensitivity of 100% and specificity of 84%, for need of reintubation. Conclusions: Presence of acidemia and hypoalbuminemia at admission are predictors of need of MV, whereas APACHE II score at baseline and PaCO2 rise in the initial 12 hours after extubation, predict need of reintubation.