Table 2.
Intra- and postoperative variables and postoperative delirium (univariate analysis)
| Postoperative Delirium Status | ||||
|---|---|---|---|---|
| Total n = 716 (%) | Yes n = 127 (17.7) | No n = 589 (82.3) | P-value | |
| Intraoperative variables | ||||
| Invasiveness *, n (%) | ||||
| Tier 1 and 2 | 255 (35.6) | 23 (9.0) | 232 (91.0) | |
| Tier 3 and 4 | 461 (64.4) | 104 (22.6) | 357 (77.4) | <0.0012 |
| Type of anesthesia, n (%) | ||||
| TIVA | 98 (13.7) | 26 (26.5) | 72 (73.5) | |
| TIVA + Volatile | 285 (39.8) | 58 (20.4) | 227 (79.6) | |
| Volatile | 333 (46.5) | 43 (12.9) | 290 (87.1) | 0.0032 |
| BIS monitoring, n (%) | ||||
| No | 273 (38.1) | 28 (10.3) | 245 (89.7) | |
| Yes | 443 (61.9) | 99 (22.3) | 344 (77.7) | <0.0012 |
| Estimated blood loss, n (%), n = 693 | ||||
| < 500 ml | 600 (86.6) | 92 (15.3) | 508 (84.7) | |
| 501–999 ml | 45 (6.5) | 15 (33.3) | 30 (66.7) | |
| > 1000 ml | 48 (6.9) | 18 (37.5) | 30 (62.5) | <0.0012 |
| Transfusion of blood products, n (%) | ||||
| No | 659 (92.0) | 106 (16.1) | 553 (83.9) | |
| Yes | 57 (8.0) | 21 (36.8) | 36 (63.2) | <0.0012 |
| Length of surgery, min median [25th-75th] | 129.0 [97.0–187.2] | 162.0 [120.5–233.0] | 124 .0 [95.0–178.0] | <0.0013 |
| Intraoperative MEA median [25th-75th] | 15.6 [12.4–24.0] | 18.0 [12.8–27.6] | 14.4 [12.4–24.0] | 0.0093 |
| Postoperative variables | ||||
| Mean pain score on postoperative day 1 median [25th-75th], n = 697 | 4.6 [3.3–6.0] | 5.5 [4.0–6.8] | 4.5 [3.3–5.7] | <0.0013 |
| MEA on postoperative day 1, median [25th-75th] | 22.2 [12.0–33.4] | 23.0 [13.8–38.2] | 22.0 [12.0–32.4] | 0.0543 |
TIVA: Total Intravenous Anesthesia, BIS: Bispectral Index; MEA: morphine equivalents amount
*
Invasiveness: Tier 1, microdiscectomy, lumbar laminectomy or anterior cervical procedures, minimally invasive fusions; Tier 2, lumbar fusion, trauma, or posterior cervical fusion procedures, tumor, infection, deformity, or combined anterior and posterior cervical procedures.
1
T-tests were used.
2
Chi-square tests were used
3
Wilcoxon rank sum tests were used
4
Fisher’s exact tests were used