Table 2.
Characteristics of patients with postoperative delirium according to the anesthetic methods
| General anesthesia (n = 19) | Regional anesthesia (n = 21) | P | |
|---|---|---|---|
| Occurrence rate, delirium No./total No. | 19/47 | 21/31 | 0.02a |
| Number of occurrence, No. (%) | 0.06c | ||
| POD 1 | 5 (26.4) | 9 (42.8) | |
| POD 2 | 3 (15.8) | 6 (28.6) | |
| POD 3 | 4 (21.1) | 4 (19.0) | |
| POD 4 | 5 (26.3) | 1 (4.8) | |
| POD 5 | 2 (10.5) | 1 (4.8) | |
| POD 6 | 0 (0.0) | 0 (0.0) | |
| POD 7 | 0 (0.0) | 0 (0.0) | |
| Onset day, median (min ~ max) | 3 (1 ~ 5) | 2 (1 ~ 5) | 0.07d |
| Days of duration, median (min ~ max) | 4 (2 ~ 13) | 3 (2 ~ 33) | 0.39d |
| Severity: K-DRS scores on the onset day, mean (SD) | |||
| Total | 19.8 (4.7) | 18.3 (5.0) | 0.34e |
| Cognitive | 10.8 (2.9) | 9.5 (3.2) | 0.18e |
| Non-cognitive | 8.9 (2.5) | 8.8 (2.8) | 0.87e |
| Difference in MMSE scores: the onset day minus pre-op day, median (min ~ max) | -6.5 (-25 ~ -3) | -4 (-21 ~ -1) | 0.45d |
| Days of hospitalization, median (min ~ max) | 11 (7 ~ 36) | 9 (7 ~ 45) | 0.39d |
| Preoperative comorbidity, No. (%) | |||
| COPD | 0 (0.0) | 0 (0.0) | - |
| Cerebrovascular disease | 4 (21.1) | 0 (0.0) | 0.04b |
| CABG/MI/CAD | 4 (21.1) | 3 (14.3) | 0.69b |
| Chronic renal insufficiency | 0 (0.0) | 0 (0.0) | - |
| Preoperative medication, No. (%) | |||
| Opiates | 0 (0.0) | 0 (0.0) | - |
| Benzodiazepines | 3 (15.8) | 5 (23.8) | 0.70b |
| Antidepressants | 6 (31.6) | 3 (14.3) | 0.27b |
| Anticholinergics | 2 (10.5) | 3 (14.3) | 0.72b |
| Other psychotics | 2 (10.5) | 1 (4.8) | 0.60b |
| ASA PS, No. (%) | 0.80c | ||
| 2 | 3 (15.8) | 4 (19.0) | |
| 3 | 15 (78.9) | 16 (76.2) | |
| 4 | 1 (5.3) | 1 (4.8) | |
| Anesthetic drugs | |||
| Propofol dose, median (min ~ max), mcg/kg/min | 11.7 (4.5 ~ 33.3) | - | - |
| Fentanyl use, No. (%) | 19 (100.0) | 5 (23.8) | 0.00a |
| Fentanyl dose, median (min ~ max), mcg/kg | 17.5 (0.5 ~ 22.8) | 0.00 (0.00 ~ 2.7) | 0.00d |
| Midazolam use, No. (%) | 1 (5.3) | 2 (9.5) | 0.61b |
| Midazolam dose, median (min ~ max), mg/kg | 0.00 (0.00 ~ 0.02) | 0.00 (0.00 ~ 0.06) | 0.83d |
Abbreviations: POD postoperative day, IQR interquartile range, COPD chronic obstructive pulmonary disease, CABG coronary artery bypass graft, MI myocardial infarction, CAD coronary artery disease, ASA PS American Society of Anesthesiology Physical Status, K-DRS Korean-Delirium Rating Scale-R-98, SD standard deviation, MMSE mini-mental state examination
aPearson’s chi-square test
bFisher test
cscore test for trend
dMann-Whitney U test
eStudent t-test