Ten hours later, respiratory parameters were as follows: synchronized intermittent mandatory ventilation (SIMV) with a tidal volume (VT) of 20 ml (5 ml/kg); rate, 30/min; PEEP, 5 cm H 2 O; and FiO 2 , 50%. Measured parameters (stable for 2 hours) included a SpO 2 of 91%, a mean airway pressure of 10 cm H 2 O, and a peak inspiratory pressure of 30 cm H 2 O (other parameters are also shown in Table 1 ). The OSI was 5.5. A chest X-ray showed poorly ventilated lungs with diffuse infiltrates. Since the child was agitated, the options for care were to increase sedation, or to attempt ventilation using NAVA. A brief test was undertaken to validate the use of NAVA, which proved successful. We chose to commence NAVA after a short period of decreased sedation (morphine was decreased to 8 μg/kg/h). Initial NAVA settings were PEEP, 5 cm H 2 O; NAVA level, 1 cm H 2 O/μV; and FiO 2 , initially 50% was then decreased by nurses to SpO 2 > 90%.