Table 1.
Preoperative Patient Characteristics by Status of AKIa.
| Characteristics | All patients (n = 624) | Non-AKI (n = 540) | AKI (n = 84) | P value |
|---|---|---|---|---|
| Age, years | 50 (40, 60) | 50 (40, 59) | 54 (39, 65) | 0.056 |
| Gender (male), n (%) | 283 (45.4) | 244 (45.2) | 40 (46.4) | 0.831 |
| BMI, kg/m2 | 22.5 (20.0, 25.2) | 22.3(19.9, 25.2) | 22.8 (20.1, 24.6) | 0.845 |
| Preexisting clinical conditions, n (%) | ||||
| Hypertension | 91 (14.6) | 79 (14.6) | 12 (14.3) | 0.934 |
| Diabetes mellitus | 34 (5.4) | 28 (5.2) | 6 (7.1) | 0.440 |
| CKD | 12 (1.9) | 6 (1.1) | 6 (7.1) | 0.002 |
| Cerebrovascular disease | 32 (5.1) | 27 (5.0) | 5 (6.0) | 0.789 |
| Hyperlipidemia | 20 (3.2) | 15 (2.8) | 5 (6.0) | 0.171 |
| CAD | 9 (1.4) | 6 (1.1) | 3 (3.6) | 0.108 |
| Prior neurological surgery, n (%) | 54 (8.7) | 45 (8.3) | 9 (10.7) | 0.470 |
| Emergency surgery, n (%) | 54 (8.7) | 40 (7.4) | 14 (16.7) | 0.005 |
| ASA classification, n (%) | 0.018 | |||
| I | 431 (69.1) | 382 (70.7) | 49 (58.3) | |
| II | 118 (18.9) | 101 (18.7) | 17 (20.2) | |
| III | 27 (4.3) | 23 (4.3) | 4 (4.8) | |
| IV | 42 (6.7) | 30 (5.6) | 12 (14.3) | |
| V | 6 (1.0) | 4 (0.7) | 2 (2.4) | |
| Preoperative hemoglobin, g/L | 130 (119, 141) | 130 (119, 141) | 129 (119, 141) | 0.761 |
| Baseline serum creatinine, mg/dl | 0.69 (0.59, 0.84) | 0.69 (0.59, 0.84) | 0.68 (0.53, 0.91) | 0.704 |
| Baseline eGFR, ml/min/1.73 m2 | 106.5 (94.8, 117.3) | 106.5 (95.1, 117.3) | 106.7 (87.4, 120.3) | 0.488 |
| Preoperative medication, n (%) | ||||
| Nephrotoxic drugsb | 18 (2.9) | 15 (2.8) | 3 (3.6) | 0.723 |
| Radiographic contrast | 26 (4.2) | 22 (4.1) | 4 (4.8) | 0.768 |
| Mannitol | 102 (16.3) | 86 (15.9) | 16 (19.0) | 0.472 |
| Diagnostic group, n (%) | 0.169 | |||
| Spine disease | 32 (5.1) | 31 (5.7) | 1 (1.2) | |
| Hydrocephalus | 22 (3.5) | 19 (3.5) | 3 (3.6) | |
| Intracranial tumor | 461 (73.9) | 399 (73.9) | 62 (73.8) | |
| Traumatic brain injury | 16 (2.6) | 12 (2.2) | 4 (4.8) | |
| Intracranial aneurysm/AVM | 27 (4.3) | 22 (4.1) | 5 (6.0) | |
| Hypertensive cerebral hemorrhage | 10 (1.6) | 7 (1.3) | 3 (3.6) | |
| Others | 56 (9.0) | 50 (9.3) | 6 (7.1) | |
aContinuous variables were expressed as mean ± SD or median (25th percentile–75th percentile, IQR). Categorical variables were expressed as a number (%). bIncludes any of the following medications administered within 5 days before operation: nonsteroidal anti-inflammatory drug, angiotensin-converting enzyme inhibitor, angiotensin receptor blocker, immunosuppressant, aminoglycoside, vancomycin, acyclovir, amphotericin. Abbreviations: AKI, acute kidney injury; BMI, body mass index; CKD, chronic kidney disease; CAD, coronary artery disease; ASA classification, American Society of Anesthesiologists classification; eGFR, estimated glomerular filtration rate; AVM, arteriovenous malformation.