Population and Study Design
This prospective, observational study was conducted in our
medical/surgical PICU between March and December 2021, with the approval
of our institutional review board (2022/03-10). Written informed consent
was obtained from the parents at the time we enrolled the patient.
Children between 1 month and 10 years of age who were mechanically
ventilated for more than 48 hours via an endotracheal tube in the PICU
were screened for inclusion. The patients were assessed daily for
ventilator weaning and extubation according to our institutional weaning
protocol. Patients who met the following criteria were recruited: 1)
recovery from primary disease-causing mechanical ventilation, 2)
adequate spontaneous breathing and effective coughing, 3) increasing
consciousness, 4) hemodynamic stability with minimal vasoactive support,
5) oxygenation index <6, 6) lack of excessive tracheal
secretion (less need for endotracheal suctioning), 7) adequate gas
exchange with positive end-expiratory pressure (PEEP) <8 cm
H2O and fractional oxygen concentration (fiO2) <60%. The
exclusion criteria were as follows: 1) detected diaphragm paralysis, 2)
underlying neuromuscular disease and chronic respiratory failure, 3) a
current tracheostomy, 4) pleural effusion, pneumothorax or
pneumomediastinum.