Table 2.
Characteristics of study patients, stratified by delirium status. Univariate comparison was only performed for BIS versus ETAC group because of the randomized design of the BAG-RECALL parent trial; no further univariate “prescreening” tests were performed as discussed in the Methods section.
| Descriptor | Delirious (n=73) | Nondelirious (n=237) | P value | |
|---|---|---|---|---|
| Age | 63.3±12.4 | 61.0±14.5 | ||
| Female sex | 32 (44%) | 84 (35%) | ||
| Duration of surgery | 350±83 | 305±90 | ||
| Type of surgery | Aorta | 15 | 25 | |
| CABG only | 13 | 65 | ||
| Valve only | 15 | 61 | ||
| >1 CABG, Valve, Maze | 8 | 22 | ||
| Other Heart | 17 | 30 | ||
| Thoracic | 5 | 34 | ||
| BIS group | 28 (38%) | 121 (51%) | 0.058(1) | |
| ASAPS 4 | 66 (90%) | 162 (68%) | ||
| EuroSCORE | 6 (4-7) | 4 (2-6) | ||
| Units pRBCs | 2 (1-4) | 1 (0-2) | ||
| Average ETAC during maintenance | 0.79±0.12 | 0.85±0.11 | ||
| Norepinephrine dose (mcg/kg/min) | 0.05 (0.01 - 0.09) | 0.02 (0-0.05) | ||
| Fentanyl dose (mcg/kg/hr) | 2.40±1.83 | 1.93±1.30 | ||
| Daily alcohol use | 5 (6.8%) | 27 (11%) | ||
| Preoperative hemoglobin | 11.7±2.1 | 12.7±2.0 | ||
| Midazolam dose (mcg/kg/hr) | 6.2 (2.6-12.5) | 4.8 (1.0-8.8) | ||
| Duration of MAP<75mmHg, BIS<45, & ETAC<0.7 MAC | 13 (3.5-42.5) | 10 (2-23) | ||
| Minutes of cardiopulmonary bypass | 115±63 | 89±65 | ||
| Duration of MAP<75 | 175±88 | 155±80 | ||
| Duration of BIS<45 | 212±99 | 202±102 | ||
| Proportion of intraoperative time with BIS <20 | 0 (0-0.034) | 0 (0-0.026) | ||
| Ever experienced BIS<20 | 33 (45.2%) | 100 (42.2%) | ||
(1)
Chi square.
Abbreviations: CABG, coronary artery bypass grafting. BIS, Bispectral Index. ASAPS, American Society of Anesthesiologists Physical status. pRBCs, packed red blood cells. ETAC, end-tidal anesthetic concentration. MAP, mean arterial blood pressure. MAC, age-adjusted minimum alveolar concentration.