Table 1.
Baseline data
| Placebo group (n = 354) | Dexmedetomidine group (n = 356) | ASD | |
|---|---|---|---|
| Age (year) | 71 ± 5 | 71 ± 5 | 0.042 |
| Male sex | 113 (31.9%) | 116 (32.6%) | 0.014 |
| Body mass index (kg/m) | 26.1 ± 3.5 | 26.0 ± 3.6 | 0.042 |
| Education (year) | 8.2 ± 4.5 | 8.3 ± 4.9 | 0.018 |
| Preoperative comorbidity | |||
| Stroke | 36 (10.2%) | 37 (10.4%) | 0.007 |
| Hypertension | 188 (53.1%) | 184 (51.7%) | 0.028 |
| Coronary heart disease | 35 (9.9%) | 29 (8.1%) | 0.064 |
| Arrhythmia | 15 (4.2%) | 9 (2.5%) | 0.109 |
| COPD | 1 (0.3%) | 1 (0.3%) | < 0.001 |
| Diabetes mellitus | 86 (24.3%) | 71 (19.9%) | 0.109 |
| History of surgery | 208 (58.8%) | 183 (51.4%) | 0.141 |
| Chronic smoking a | 32 (9.0%) | 37 (10.4%) | 0.044 |
| Alcoholism b | 23 (6.5%) | 27 (7.6%) | 0.041 |
| Preoperative medication | |||
| Calcium channel blockers | 99 (28.0%) | 95 (26.7%) | 0.029 |
| ACEI/ARB | 64 (18.1%) | 73 (20.5%) | 0.060 |
| Beta‐blockers | 26 (7.3%) | 24 (6.7%) | 0.024 |
| Insulin for diabetes mellitus | 24 (6.8%) | 18 (5.1%) | 0.079 |
| Chronic use of benzodiazepine | 8 (2.3%) | 11 (3.1%) | 0.048 |
| Preoperative laboratory tests | |||
| Hematocrit (%) | 40 ± 4 | 40 ± 4 | 0.064 |
| Albumin (g/L) | 42 ± 4 | 42 ± 4 | 0.048 |
| Creatinine (μmol/L) | 69.5 ± 16.8 | 69.3 ± 18.0 | 0.023 |
| Glucose < 4.0 or > 10.0 mmol/ L | 18 (5.1%) | 10 (2.8%) | 0.138 |
| Sodium < 135.0 or > 145.0 mmol/L | 25 (7.1%) | 27 (7.6%) | 0.020 |
| Potassium < 3.5 or > 5.5 mmol/L | 13 (3.7%) | 19 (5.3%) | 0.074 |
| Charlson Comorbidity Index (score) | 0 (0 to 1) | 0 (0 to1) | 0.041 |
| ASA classification | 0.031 | ||
| I | 8 (2.3%) | 3 (0.8%) | |
| II | 278 (78.5%) | 293 (82.3%) | |
| III | 67 (18.9%) | 60 (16.8%) | |
| IV | 1 (0.3%) | 0 (0.0%) | |
| Preoperative evaluation | |||
| MMSE (score) c | 26.1 ± 3.0 | 26.1 ± 2.9 | 0.003 |
| NRS of pain, at rest (score) d | 1 (0 to 2) | 0 (0 to 2) | 0.009 |
| NRS of pain, with movement (score) d | 5 (3 to 6) | 4 (3 to 6) | 0.105 |
| NRS of sleep quality (score) e | 2 (1 to 3) | 2 (1 to 3) | 0.083 |
| Hypnotics in preoperative night | 24 (6.7%) | 20 (5.6%) | 0.043 |
| Study site | 0.005 | ||
| Centre 1 | 210 (59.3%) | 212 (59.6%) | |
| Centre 2 | 144 (40.7%) | 144 (40.4%) | |
Data are mean ± SD, number (%) or median (interquartile range)
ASD absolute standardized difference (an ASD of ≥ 0.147 is considered imbalanced between the two groups), COPD chronic obstructive pulmonary disease, ACEI angiotensin converting enzyme inhibitor, ARB angiotensin receptor blocker, ASA American Society of Anesthesiologists, MMSE Mini-Mental Status Examination, NRS numeric rating scale
aSmoking half a pack of cigarettes per day for at least 2 years
bTwo drinks or more daily, or weekly consumption of the equivalent of 150 mL of alcohol
cScore ranges from 0 to 30, with higher score indicating better function
dAn 11-point scale where 0 indicates no pain and 10 the worst pain
eAn 11-point scale where 0 indicates the best possible sleep and 10 the worst possible sleep