Patient characteristics
| Esketamine 0mg ml−1 (n=30) | Esketamine 0.2 mg ml−1 (n=30) | Esketamine 0.3 mg ml−1 (n=30) | Esketamine 0.4 mg ml−1 (n=30) | Esketamine 0.5 mg ml−1 (n=30) | |
| Age (years) | 29.7±3.6 | 29.5±3.3 | 31.0±4.1 | 30.3±3.2 | 30.5±3.5 |
| Height (cm) | 161.1±4.7 | 162.1±6.3 | 162.2±4.7 | 162.5±4.7 | 161.9±4.7 |
| Weight (kg) | 70.7±8.5 | 68.6±8.3 | 68.4±10.0 | 67.3±7.8 | 67.8±6.0 |
| Gestational age (weeks) | 39.4 (38.8, 40.0) | 39.4 (38.9, 40.0) | 39.6 (39.3, 40.1) | 39.4 (38.8, 40.0) | 39.0 (38.4, 39.4) |
| Pain visual analogue scale score (0–100 mm)* | 82 (71, 92) | 89 (80, 100) | 83 (75, 100) | 90 (78,100) | 85 (80, 90) |
| Cervical dilation (cm)* | 3.0 (2.0, 3.0) | 3.0 (3.0, 3.0) | 3.0 (2.0, 3.0) | 3.0 (3.0, 3.0) | 3.0 (3.0, 3.0) |
| Number of gravidities | 1 (1, 2） | 1 (1, 2） | 1 (1, 1） | 1 (1, 2） | 1 (1, 2） |
| Number of parturitions | 0 (0, 0） | 0 (0, 0） | 0 (0, 0） | 0 (0, 0） | 0 (0, 0） |
| Oxytocin | 12 (40.0） | 14 (46.7） | 13 (43.3） | 15 (50.0） | 12 (40.0） |
Data are presented as mean±SD or median (IQR).
*Pain visual analogue scale score and cervical dilation were assessed at the time of request for analgesia.