Definitions
An attempt was defined as an airway maneuver, which commenced with the insertion of the laryngoscope blade (conventional) into the mouth of the patient and ended with the removal of the blade.11Successful airway management was defined as the placement of an endotracheal tube in the trachea via orally, confirmed based on chest elevation, auscultation, second independent laryngoscopy, carbon dioxide detection, and/or chest radiography.11 First-attempt success was defined as successful intubation by the first practitioner on the first attempt. Multiple-attempt success was defined as the requirement of over two attempts (≥3) for successful intubation. The requirement for single, double, or multiple attempts for successful intubation was defined as all intubation attempts. Severe oxygen desaturation during intubation was defined as a decrease of ≥20% in oxygen saturation relative to the highest level of oxygen saturation recorded prior to the first attempt.11 Bradycardia was defined as a heart rate of <100 beats per minute. Physiological instability was defined as severe desaturation (a decrease of to pre-laryngoscopy) or bradycardia (a heart rate of <100 beats per minute) during the intubation attempts. Hatch et al.12 defined practitioners as experienced if they had performed more than 40 previous intubations. Based on this knowledge and our NICU conditions, those who performed >35 previous intubations were considered experienced practitioners.