Table 2.
Characteristics of infants born at <32 weeks' GA and mechanically ventilated for >2 consecutive days who did and did not receive an opioid whilst ventilated.
| All infants | Received opioid | Did not receive opioid | p-value | |
|---|---|---|---|---|
| Number of infants | 24,815 | 20,561 | 4254 | |
| Gestational age in weeks, median (IQR) | 27 (25–28) | 26 (25–28) | 27 (26–29) | <0.0001 |
| Birth weight in grams, median (IQR) | 890 (710–1160) | 880 (700–1150) | 946 (760–1200) | <0.0001 |
| Birth weight z-score, median (IQR) | −0.10 (−0.80 to 0.50) | −0.10 (−0.80 to 0.40) | −0.10 (−0.80 to 0.50) | 0.27 |
| Sex, n (%) | ||||
| Female | 10,503 (42.3) | 8620 (41.9) | 1883 (44.3) | 0.0049 |
| Male | 14,312 (57.7) | 11,941 (58.1) | 2371 (55.7) | |
| Multiple birth, n (%) | 6100 (24.6) | 4948 (24.1) | 1152 (27.1) | 0.00011 |
| Any antenatal steroid, n (%)a | 22,132 (89.7) | 18,291 (89.4) | 3841 (91.1) | 0.00086 |
| Caesarean delivery, n (%)a | 12,906 (53.9) | 10,573 (53.2) | 2333 (57.3) | <0.0001 |
| Early onset sepsis, n (%) | 15,199 (61.3) | 13,150 (64.0) | 2049 (48.2) | <0.0001 |
| Surfactant given on day 1, n (%)a | 21,143 (88.2) | 17,768 (88.7) | 3375 (85.7) | <0.0001 |
| Mechanical ventilation on day 1, n (%) | 21,636 (87.2) | 17,966 (87.4) | 3670 (86.3) | 0.49 |
| Received inotropes whilst ventilated, n (%) | 12,745 (51.4) | 11,707 (56.9) | 1038 (24.4) | <0.0001 |
| Number of days mechanical ventilation, median (IQR) | 10 (5–25) | 12 (6–27) | 6 (4–11) | <0.0001 |
| Major congenital anomaly requiring early surgical intervention, n (%) | 1125 (4.5) | 1005 (4.9) | 120 (2.8) | <0.0001 |
| Any painful/surgical condition in first 2 days of mechanical ventilation, n (%) | 3007 (12.1) | 2786 (13.5) | 221 (5.2) | |
| NMR-2000 score, categorised as risk of in-hospital mortality, n (%)a | ||||
| Low risk | 717 (3.2) | 606 (3.2) | 111 (3.2) | <0.0001 |
| Medium risk | 16,785 (75.1) | 13,891 (73.7) | 2894 (82.5) | |
| High risk | 4842 (21.7) | 4341 (23.0) | 501 (14.3) | |
| Level of care of first admitting unit, n (%) | ||||
| Neonatal Intensive Care Unit | 16,021 (64.6) | 12,740 (62.0) | 3281 (77.1) | <0.0001 |
| Local Neonatal Unit | 7265 (29.3) | 6448 (31.4) | 817 (19.2) | |
| Special Care Baby Unit | 1527 (6.2) | 1372 (6.7) | 155 (3.6) | |
| Length of hospital stay in days, median (IQR) | 81 (52–108) | 84 (52–111) | 73 (49–94) | <0.0001 |
| Death before discharge, n (%) | 3836 (15.5) | 3395 (16.5) | 441 (10.4) | <0.0001 |
a
Missing data: Birth weight z-score, 4 (<0.01%); Caesarean delivery, 879 (3.5%); antenatal steroids, 131 (0.5%); surfactant given, 850 (3.4%); NMR-2000 score, 2471 (10.0%).