Interventions
All neonates were monitored using a Philips monitor (IntelliVue MX450) that displayed the real-time peripheral oxygen saturation (SpO2) and heart rate prior to, during, and after the procedure.
The patients were divided into two groups: the NIPPV group and the standard care group. In the NIPPV group, NIPPV was implemented during the entire intubation process (pre-intubation to intubation to the end of successful intubation). Appropriately-sized short binasal prongs (Fisher & Paykel, New Zealand) were placed prior to laryngoscopy as interface for NIPPV implementation. NIPPV was implemented using Leoni Plus (Löwenstein Medical, Bad Ems, Germany) mechanical ventilator. Non-synchronized NIPPV was implemented. NIPPV was initiated prior to intubation, with the peak inspiratory pressure set to 16–20 cmH2O (selected according to the infant’s birth weight and chest wall expansion), positive-end expiratory pressure (PEEP) set to 6 cmH2O, breathing rate set to 40–50 breaths/min, inspiratory time set to 0.40–0.45 s, and flow rate set to 8–12 L/min. After the first successful intubation attempt, NIPPV was discontinued. Prior to laryngoscopy, the fraction of inspired oxygen (FiO2) was adjusted to maintain SpO2above 90%. In the standard care group, the intubation attempt proceeded without NIPPV or supplemental oxygen. In the event of failure in the intubation attempt, SpO2 was increased above 90%, and the heart rate was increased above 120/min by applying positive pressure ventilation using a face mask prior to initiating the next intubation procedure.
If the infant was crying or agitated, midazolam was administered as pre-medication. No medication other than midazolam was used for sedation or premedication. The size of the intubation tube was determined based on the baby’s body weight.13 Stylet was not used during intubation.
Endotracheal intubations were performed either by pediatric research assistants or a neonatologist. A conventional laryngoscope with a straight blade was used for the intubation. Video laryngoscope was not used. Data accuracy was ensured by videotaping the monitor-displayed heart rate and SpO2 during the intubation procedure. After intubation, an independent assessor who was not part of the intubation team reviewed all recorded videos to document the obtained data on a case report form.