Comparison of intraoperative and postoperative outcomes of patients between the low-hematocrit and the high-hematocrit groups
| Characteristic | Hematocrit <30% (n=86) | Hematocrit ≥30% (n=86) | P value |
| Operation time (min) | 486 (396 – 611) | 444 (341 – 569) | 0.25 |
| Urgency | 1 | ||
| Elective | 39 (45%) | 40 (47%) | |
| Emergent | 47 (55%) | 46 (54%) | |
| Types of procedure | 0.016 | ||
| CABG | 7 (8%) | 18 (21%) | |
| Valve surgery | 20 (23%) | 8 (9%) | |
| CABG and valve surgery | 9 (11%) | 5 (6%) | |
| Aortic surgery | 48 (56%) | 51 (59%) | |
| Others | 2 (2%) | 4 (5%) | |
| Duration of cardiopulmonary bypass (min) | 223 (181 – 278) | 219 (156 – 283) | 0.43 |
| Amount of bleeding during surgery (mL) | 2000 (1386 – 2728) | 1920 (1321 – 2958) | 0.92 |
| Amount of transfusion during surgery (mL) | 3645 (2598 – 5295) | 3450 (2128 – 5380) | 0.58 |
| Amount of urine output during surgery (mL) | 1270 (655 – 1903) | 1340 (636 – 2183) | 0.34 |
| Hemoglobin on ICU admission (g/L) | 8.8 (8.2 – 9.3) | 10.7 (10.1 – 11.5) | |
| Hematocrit on ICU admission (g/dL) | 27.4 (25.4 – 28.7) | 33.0 (31.3 – 35.5) | |
| Maximum serum creatinine after operation (mg/dL) | 2.00 (1.10 – 3.91) | 1.63 (1.16 – 2.80) | 0.82 |
| Duration of mechanical ventilation (hours) | 192 (120 – 360) | 144 (120 – 258) | 0.13 |
| Reintubation | 11 (13%) | 12 (14%) | 1 |
| Reoperation for bleeding | 18 (21%) | 6 (7%) | 0.014 |
| Complications | |||
| Stroke | 17 (20%) | 9 (11%) | 0.14 |
| Paraparesis | 4 (5%) | 3 (4%) | 1 |
| Renal failure | 23 (27%) | 24 (28%) | 1 |
| Dialysis | 14 (16%) | 15 (17%) | 1 |
| Myocardiac infarction | 3 (4%) | 3 (4%) | 1 |
| Heart block requiring pacemaker implantation | 2 (2%) | 3 (4%) | 1 |
| Arrest | 6 (7%) | 3 (4%) | 0.5 |
| Tamponade | 8 (10%) | 5 (6%) | 0.4 |
| Atrial fibrillation | 32 (37%) | 24 (28%) | 0.26 |
| Mediastinitis | 5 (6%) | 1 (1%) | 0.21 |
| Pulmonary embolism | 1 (1%) | 0 (0%) | 1 |
| Pneumonia | 26 (30%) | 21 (24%) | 0.49 |
| Length of ICU stay (days) | 10.5 (6.3 – 20.5) | 9.5 (5.3 – 14) | 0.18 |
| Thirty-day mortality | 5 (6%) | 3 (4%) | 0.72 |
| One-year mortality | 17 (22%) | 13 (18%) | 0.54 |
Quantitative data are expressed as medians (first to third IQRs), and categorical data are expressed as frequencies (percentages).
CABG, coronary artery bypass grafting; ICU, intensive care unit.