Mechanical insufflation-exsufflation in prevention of post-extubation acute respiratory failure: most welcome but must be used cautiously in critically ill patients

Abstract

In a study published in the previous issue of Critical Care, Goncalves and colleagues [1] observed a 33% reduction in re-intubation rate in the study group, due to eff ective management of bronchial secretions. Current evidence favors early implementation of noninvasive mechanical ventilation (NIV) in the post-extubation period to reduce re-intubation, especially in patients with hypercapnic respiratory failure [2-4]. However, some important practical issues need to be considered before the use of mechanical insuffl ationexsufl ation (MI-E) in the post-extubation period can be generalized, especially in patients needing NIV: (a) MI-E application requires that the NIV mask be disconnected, resulting in positive pressure loss, alveolar collapse, and desaturation. (b) MI-E devices do not have entrained oxygen. Hence, any rapid desaturation episode will require immediate reconnection to NIV. (c) Assessment of the eff ective management of bronchial secretions can prove diffi cult because of the lack of an objective or specifi c scoring system. (d) In some situations requiring several MI-E sessions, frequent disconnection from NIV can lead to prolonged use of post-extubation NIV. (e) MI-E may be diffi cult to perform or may lead to poor compliance in cases of unplanned extubation, moderate to severe hypoxemic acute respiratory failure (ARF) after extubation, agitation/anxiety, and tachypnea. (f ) Th e eff ectiveness of MI-E should be studied beyond 48 hours, as late-onset extubation failures and post-extubation NIV failures are due mostly to ineff ective secretion clearance [5]. In conclusion, we believe that this original study could have an impact on the management and prevention of post-extubation ARF in a select group of patients. However, owing to the above-mentioned reasons, the use of MI-E cannot be generalized to all patient populations.