Effort of Breathing and Dyssynchrony Burden During Assisted Ventilation in Paediatric Patients

Single centre, randomized crossover physiological study to assess effort of breathing and dyssynchrony burden associated with different modes of assisted ventilation in children. We hypothesize that patients on optimized pressure support ventilation (PSV) will 1) not have higher effort of breathing and 2) have a reduced rate of dyssynchronous effort compared to pressure control ventilation (PCV) or synchronized intermittent mandatory ventilation pressure control/pressure support (SIMV PC/PS) that is the current standard of care.

An esophageal catheter will be inserted and calibrated for measuring esophageal pressure (Pes) swings to quantify breathing effort and diagnose dyssynchronies. During passive breathing, the chest wall compliance will be measured. When the patients are in the ventilation weaning phase and triggering consistently in SIMV mode, a 30 min recording of respiratory signals will be performed (clinical mode) followed by exposure to two modes of assisted ventilation (PCV or PSV) in a randomized crossover manner for 30 min each. Level of support (the pressure above the PEEP) and sedation will remain stable within each participant. PSV optimization: If the PS breath is too short (< 0.2 sec), the inspiratory rise time will be increased to 0.15 sec and the cycling % reduced to 20, 15 or 10% to ensure an adequate size breath (approx 1/3 of the patient's respiratory cycle).