TABLE 2.
Anal canal resting pressure per study condition and per anesthetics used
| N | Pressure in mmHg, median (IQR) | Change in pressure, *median (IQR) | P value compared to awake | |
|---|---|---|---|---|
| Awake | 34 | 70 (59–85) | n/a | n/a |
| Under general anesthesia | 34 | 46 (36–65) | 21.5 (3 to 40) | <0.001 |
| Sevoflurane | 32 | 46 (37–66) | 20.5 (2 to 38) | <0.001 |
| Propofol | 26 | 42 (31–60) | 29.5 (9 to 45) | <0.001 |
| Induction with propofol | 20 | 42 (36–63) | 29.5 (6 to 46) | 0.001 |
| Nitrous oxide | 19 | 53 (38–68) | 8 (–2 to 20) | 0.080 |
| Fentanyl | 11 | 42 (39–56) | 20 (1 to 32) | 0.062 |
| Anesthesia with propofol and sevoflurane | 9 | 40 (20–59) | 46 (22 to 55) | |
| Anesthesia with propofol, sevoflurane, and nitrous oxide | 6 | 57 (36–78) | 4 (–11.5 to 30) | |
| Anesthesia with propofol, sevoflurane, nitrous oxide, and fentanyl | 6 | 42 (31–47) | 25.5 (–0.6 to 34) | |
| Anesthesia with sevoflurane and nitrous oxide | 5 | 54 (53–69) | 6 (1 to 9) | |
| Anesthesia with propofol, sevoflurane, and fentanyl | 2 | 50 (40–60) | 21.5 (3 to 40) | |
| Anesthesia with sevoflurane, nitrous oxide, and fentanyl | 2 | 53 (37–68) | –13.5 (–35 to 8) | |
| Anesthesia with propofol only | 2 | 39 (25–53) | 40.5 (36 to 45) | |
| Anesthesia with sevoflurane and fentanyl | 1 | 51 | 34 | |
| Anesthesia with propofol, sevoflurane, nitrous oxide, dexmedetomidine, and rocuronium | 1 | 56 | 21 |
*
Anal canal resting pressure awake minus anal canal resting pressure under general anesthesia. Bold P values denote statistical significance at the P < 0.05 level.