| Placebo group (n = 354) | Dexmedetomidine group (n = 356) | P value |
---|---|---|---|
Bradycardia a | 1 (0.3%) | 1 (0.3%) |  > 0.999 |
 Bradycardia with intervention b | 1 (0.3%) | 1 (0.3%) |  > 0.999 |
Hypotension c | 3 (0.8%) | 2 (0.6%) | 0.686 |
 Hypotension with intervention d | 1 (0.3%) | 0 (0.0%) | 0.499 |
Tachycardia e | 0 (0.0%) | 2 (0.6%) | 0.499 |
 Tachycardia with intervention b | 0 (0.0%) | 1 (0.3%) |  > 0.999 |
Hypertension f | 5 (1.4%) | 3 (0.8%) | 0.504 |
 Hypertension with intervention b | 2 (0.6%) | 1 (0.3%) | 0.628 |
Hypoxemia g | 1 (0.3%) | 1 (0.3%) |  > 0.999 |
 Hypoxemia with intervention h | 1 (0.3%) | 1 (0.3%) |  > 0.999 |
PCA modified due to adverse events | Â | Â | 0.896 |
 None | 343 (96.9%) | 347 (97.5%) |  |
 Stopped temporarily i | 5 (1.4%) | 4 (1.1%) |  |
 Stopped permanently i | 6 (1.7%) | 5 (1.4%) |  |
Postoperative nausea and vomiting | 101 (28.5%) | 81 (22.8%) | 0.078 |