Patient characteristics stratified by the difficulty of intubation
| Patient characteristics | Non-difficult intubation (n=1733) | Difficult intubation (n=276) | P value |
| Gestational age (GA) at birth, weeks, median (25%, 75%) | 29 (25, 35) | 28 (25, 34) | 0.08 |
| Birth weight, g, median (25%, 75%) | 1090 (710, 2515) | 904 (680, 2020) | 0.005 |
| Day of life at time of intubation, median (25%, 75%) | 14 (1, 50) | 10 (1, 41) | 0.09 |
| Corrected GA at time of intubation, weeks, median (25%, 75%) | 34 (29, 39) | 31 (28, 37) | <0.001 |
| Weight at time of intubation, g | 1870 (1000, 3050) | 1326 (830, 2600) | <0.001 |
| Sex* (male), n (%) | 1024 (59) | 158 (57) | 0.75 |
| Comorbidities, n (%) | |||
| Acute respiratory failure | 1003 (58) | 171 (62) | 0.2 |
| Chronic respiratory failure | 412 (24) | 66 (24) | 0.9 |
| Congenital anomaly requiring surgery | 176 (10) | 19 (7) | 0.1 |
| Neurological impairment (eg, HIE, seizures and stroke) | 125 (7) | 21 (8) | 0.4 |
| Cardiac disease (excluding isolated patent ductus arteriosus) | 124 (7) | 19 (7) | 1.0 |
| Airway or craniofacial anomaly | 110 (6) | 20 (7) | 0.6 |
| Sepsis | 106 (6) | 28 (10) | 0.02 |
| Surgery/procedure for acquired disorder | 7 (<1) | 3 (1) | 0.2 |
| Indication for intubation, n (%) | |||
| Ventilation failure | 664 (38) | 94 (34) | 0.2 |
| Oxygenation failure | 550 (32) | 71 (29) | 0.3 |
| Frequent apnoea and desaturations | 343 (20) | 54 (20) | 1.0 |
| Surfactant administration | 299 (17) | 64 (23) | 0.02 |
| Intubation for procedure | 194 (11) | 20 (7) | 0.06 |
| Upper airway obstruction | 87 (5) | 23 (8) | 0.03 |
| Unstable haemodynamics | 37 (2) | 3 (1) | 0.3 |
| Absent protective reflexes | 8 (<1) | 4 (2) | 0.07 |
| Neuromuscular weakness | 4 (<1) | 1 (<1) | 0.5 |
*Sex was unknown in four neonates.
HIE, hypoxic–ischaemic encephalopathy.