Table 1.
Characteristics of the Cohorta
| Variable | Full Cohort (N = 727) | Included in Analysis (N = 619) | Not Included in Analysis (N = 108) |
|---|---|---|---|
| Age (years) | 62 ± 14 | 62 ± 14 | 62 ± 14 |
| Male sex | 458 (63%) | 396 (64%) | 62 (57%) |
| American Society of Anesthesiologists class | |||
| 2 | 25 (3%) | 14 (2%) | 11 (10%) |
| 3 | 261 (36%) | 222 (36%) | 39 (36%) |
| 4 | 434 (60%) | 378 (61%) | 56 (52%) |
| 5 | 7 (1%) | 5 (1%) | 2 (2%) |
| Age-adjusted Charlson index | 3 [2, 5] | 3 [2, 5] | 4 [2, 5] |
| Dementia | 4 (0.6%) | 4 (0.7%) | 0 (0%) |
| Coronary artery disease | 350 (48%) | 299 (48%) | 51 (47%) |
| Chronic obstructive pulmonary disease | 125 (17%) | 102 (16%) | 23 (21%) |
| Malignancy, excluding skin cancer | 120 (17%) | 87 (14%) | 33 (31%) |
| Sensory impairment (hearing or vision) | 142 (23%) | 117 (22%) | 25 (27%) |
| Home sedative use | 123 (17%) | 107 (17%) | 16 (15%) |
| Home opioid use | 160 (22%) | 128 (21%) | 32 (30%) |
| Alcohol use > 5 drinks per week | 65 (9%) | 57 (9%) | 8 (8%) |
| Surgery Type | |||
| Open cardiac | 479 (66%) | 410 (66%) | 69 (64%) |
| Coronary artery bypass grafting | 144 (20%) | 132 (21%) | 12 (11%) |
| Non-cardiac | 104 (14%) | 77 (13%) | 27 (25%) |
| Midazolam dose > 2mg | 121 (17%) | 100 (16%) | 21 (19%) |
| Nitrous oxide use | 63 (9%) | 52 (8%) | 11 (10%) |
| Intraoperative ketamine use | 221 (30%) | 190 (31%) | 31 (29%) |
| Intraoperative opioid dose (morphine equivalents per kg) | 1.1 [0.8, 1.6] | 1.1 [0.8, 1.5] | 1.3 [0.9, 1.8] |
| Intraoperative blood transfusion (units) | 1 [0, 3] | 1 [0, 3] | 1 [0, 4] |
| Mean end-tidal anesthetic concentration (age-adjusted MAC units)b | 0.91 ± 0.11 | 0.91 ± 0.11 | 0.90 ± 0.13 |
a
Values are mean ± standard deviation, number (%), or median [lower quartile, upper quartile].
b
MAC = Minimum alveolar concentration