Patient characteristics
| Survivors (n=120) | Deaths (n=35) | p Value | |
| Birth weight (g) | 1176 (868–1479) | 872 (730–942) | <0.0001 |
| Gestation (weeks) | 29 (26–30) | 27 (25–27) | <0.0001 |
| Male sex | 77 (64) | 28 (80) | 0.08 |
| Caesarean section | 68 (57) | 18 (51) | 0.58 |
| Antenatal steroids | 97 (81) | 32 (91) | 0.20 |
| Apgar score at 5 min | 9 (1–10) | 7 (2–10) | 0.002 |
| Surfactant | 120 (100) | 35 (100) | 1.0 |
| Patient trigger ventilation | 10 (8) | 0 | 0.12 |
| Max PIP (cm H2O) | 22 (19–26) | 32 (24–38) | <0.0001 |
| Max PEEP (cm H2O) | 4 (4–4) | 4 (4–5) | 0.001 |
| Max MAP (cm H2O) | 10.4 (8.9–12.6) | 16.4 (12.0–19.5) | <0.0001 |
| Max Paco 2 (mm Hg) | 48 (41–53) | 55 (47–73) | 0.0001 |
| Max Fio 2 | 0.68 (0.46–0.86) | 1.0 (0.98–1.0) | <0.0001 |
| Max A-aDo 2 (mm Hg) | 364 (205–494) | 633 (584–645) | <0.0001 |
| Min a/A ratio | 0.14 (0.09–0.24) | 0.05 (0.03–0.08) | <0.0001 |
| Max OI | 10.0 (5.6–19.1) | 38.8 (22.0–98.9) | <0.0001 |
Data are expressed as median (interquartile range) or n (%).
PIP, peak inspiratory pressure; PEEP, peak end expiratory pressure; MAP, mean airway pressure; A-aDo 2, alveolar-arterial oxygen tension difference; a/A ratio, ratio of arterial to alveolar oxygen tension; OI, oxygenation index.