ObjectiveTo 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).MethodsThe 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.ResultsEighty 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.ConclusionIn 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