Maximum inspiratory pressure: Can it be a helpful parameter for predicting successful weaning in chronic obstructive pulmonary disease patients?

Abstract

Objective: To evaluate the predictive value of maximum inspiratory pressure (MIP) besides rapid and shallow breathing index (RSBI) in the weaning of chronic obstructive pulmonary disease (COPD) patients. Material and Methods: Fifty-six COPD patients with acute exacerbation and type II respiratory failure requiring invasive mechanical ventilation for more than 24 hours were enrolled in this study. Extubation was planned if the patients tolerated pressure support mode for at least two hours and spontaneous breathing during a 30 minutes T-piece trial. Breathing frequency, exhaled tidal volume, rapid and shallow breathing index (RSBI), minute ventilation (Vmin), MIP and vital capacity measurements were recorded prior to extubation. Patients were divided into two groups according to weaning success (WS) and failure. WS was defined as 48 hours of independence from mechanical ventilation after extubation. Results: Although RSBI values between two groups were not significantly different, there were statistically significant differences between the two groups in terms of MIP (30 vs 18 cmH20; p=0.008) and Vmin (10.40 vs 8.25; p= 0.032). Patients with a MIP value greater than or equal to 25 cm H20 had greater WS when compared to those with values lower than 25 cm H20. Conclusion: RSBI alone seems not reliable enough to predict weaning outcome in COPD patients with type II respiratory failure due to acute exacerbation. Supported with MIP, better results may be achieved to predict weaning outcome. © 2010 by Türkiye Klinikleri.