Maximal expiratory pressure compared with maximal expiratory pressure during induced cough as a predictor of extubation failure.

Objective: To compare the diagnostic performance of maximal expiratory pressure with maximal expiratory pressure during induced cough for predicting extubation failure within 72 hours in patients who completed a spontaneous breathing trial (SBT).

Methods: The study was conducted between October 2018 and September 2019. All patients aged over 18 years admitted to the intensive care unit who required invasive mechanical ventilation for over 48 hours and successfully completed a spontaneous breathing trial were included. The maximal expiratory pressure was assessed with a unidirectional valve for 40 seconds, and verbal encouragement was given. The maximal expiratory pressure during induced cough was measured with slow instillation of 2mL of a 0.9% saline solution. The primary outcome variable was extubation failure.

Results: Eighty patients were included, of which 43 (54%) were male. Twenty-two patients [27.5% (95%CI 18.9 - 38.1)] failed extubation within 72 hours. Differences were observed in the maximal expiratory pressure during induced cough between the group who failed extubation, with a median of 0cmH2O (P25-75: 0 - 90), and the group without extubation failure, with a median of 120cmH2O (P25-75: 73 - 120); p < 0.001.

Conclusion: In patients who completed a spontaneous breathing trial, the maximal expiratory pressure during induced cough had a higher diagnostic performance for predicting extubation failure within 72 hours.Clinicaltrials.gov Registry: NCT04356625.