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

Single centre, randomized crossover physiological study to assess effort of breathing anddyssynchrony burden associated with different modes of assisted ventilation in children.We hypothesize that patients on optimized pressure support ventilation (PSV) will 1) nothave higher effort of breathing and 2) have a reduced rate of dyssynchronous effortcompared to pressure control ventilation (PCV) or synchronized intermittent mandatoryventilation pressure control/pressure support (SIMV PC/PS) that is the current standardof care.An esophageal catheter will be inserted and calibrated for measuring esophageal pressure(Pes) swings to quantify breathing effort and diagnose dyssynchronies. During passivebreathing, the chest wall compliance will be measured. When the patients are in theventilation weaning phase and triggering consistently in SIMV mode, a 30 min recording ofrespiratory signals will be performed (clinical mode) followed by exposure to two modesof 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 withineach participant. PSV optimization: If the PS breath is too short (< 0.2 sec), theinspiratory rise time will be increased to 0.15 sec and the cycling % reduced to 20, 15or 10% to ensure an adequate size breath (approx 1/3 of the patient's respiratory cycle).