Participant demographics and clinical characteristics
| Nasal prongs first n=25 | Nasal mask first n=25 | Total n=50 | |
| PMA at study (completed weeks) | |||
| Median (IQR) | 33 (31–38) | 33 (32–38) | 33 (32–38) |
| Range | 29–41 | 28–42 | 28–42 |
| PNA at study (days) | |||
| Median (IQR) | 1 (0–3.5) | 1 (0.5–4.5) | 1 (0–4) |
| Range | 0–52 | 0–74 | 0–74 |
| Weight (g) | |||
| Median (IQR) | 2012 (1496–3708) | 1844 (1551–3202) | 1948 (1517–3442) |
| Gender, n (%) | |||
| Female | 8 (32) | 13 (52) | 21 (42) |
| Male | 17 (68) | 12 (48) | 29 (58) |
| Delivery method, n (%) | |||
| C-section | 14 (56) | 12 (48) | 26 (52) |
| Vaginal | 11 (44) | 13 (52) | 24 (48) |
| CPAP level (cm H2O) | |||
| Median (IQR) | 4.0 (4–4) | 4.0 (4–5) | 4.0 (4–4) |
| Range | 3–5 | 2–6 | 2–6 |
| SpO2 (%) | |||
| Mean (SD) | 98 (4) | 97 (3) | 97 (3) |
| FiO2 (%) | |||
| Median (IQR) | 21 (21–21) | 21 (21–22.5) | 21 (21–21.3) |
| Previous surfactant treatment, n (%) | |||
| Yes | 2 (8) | 7 (28) | 9 (18) |
| No | 23 (92) | 18 (72) | 41 (82) |
| Previous mechanical ventilation, n (%) | |||
| Yes | 1 (4) | 3 (12) | 4 (8) |
| No | 24 (96) | 22 (88) | 46 (92) |
| CPAP duration (h) | |||
| Median (IQR) | 18.0 (8.5–78) | 48.0 (12.5–132) | 31.0 (9.8–96.8) |
| PMA at study, n (%) | |||
| <34 weeks | 13 (52) | 14 (56) | 27 (54) |
| ≥34 weeks | 12 (48) | 11 (44) | 23 (46) |
| Nasogastric tube, n (%) | |||
| Yes | 24 (96) | 24 (96) | 48 (96) |
| No | 1 (4) | 1 (4) | 2 (4) |
PMA, postmenstrual age; PNA, postnatal age.