Adverse events.
| Adverse Event | No ITM (n = 115) | ITM (n = 65) | P |
| Urinary retention | 11 (9.6) | 9 (13.8) | 0.528 |
| Respiratory depression | 33 (28.7) | 21 (32.3) | 0.715 |
| Oversedation | 1 (0.9) | 3 (4.6) | 0.267 |
| Itching | 8 (7.0) | 16 (24.6) | 0.002 |
| Nausea | 44 (38.3) | 28 (43.1) | 0.635 |
Abbreviation: ITM, intrathecal morphine.
Note: P values < 0.05 in bold. Data are expressed as mean ± SD or n (%).