Table 2.
Haemodynamic data and dose of ephedrine. Data are median (range) or number (percentage). SBP: systolic blood pressure. †: significantly different from the control group. *: significantly different from the 40 Hz group.
| Control (n = 14) | 2 Hz (n = 14) | 10 Hz (n = 13) | 20 Hz (n = 13) | 40 Hz (n = 13) | P | |
|---|---|---|---|---|---|---|
| Intensity of TENS (mA) | — | 13 (9–17) | 12 (9–15) | 13 (9–15) | 13 (9–15) | 0.721 |
| Baseline SBP (mmHg) | 130 (104–150) | 135 (115–145) | 130 (110–145) | 130 (114–145) | 132 (116–158) | 0.994 |
| Lowest SBP (mmHg) | 84 (74–110)* | 96 (62–116)* | 100 (68–110) | 96 (64–115)* | 104 (75–140) | 0.004 |
| Baseline HR (beats min−1) | 72 (56–98) | 76 (56–105) | 70 (60–85) | 70 (54–85) | 75 (55–105) | 0.343 |
| HR at lowest SBP (beats min−1) | 62 (45–80) | 64 (40–76) | 61 (44–86) | 55 (45–75) | 65 (50–95) | 0.522 |
| Incidence of hypotension (n) | 11 (78%) | 6 (43%) | 5 (38%) | 5 (38%) | 1 (8%)† | 0.008 |
| Ephedrine (mg) | 0 (0–16) | 8 (0–20) | 0 (0–8) | 0 (0–12) | 0 (0–8)† | 0.013 |