Table 1 Patient demographics
|  | A | B | O | AB | F/χ2 | P |
|---|---|---|---|---|---|---|
Number of patients | 20 | 20 | 20 | 20 | Â | Â |
Age (yr) | 53.45 ± 5.29 | 53.55 ± 5.9 | 54 ± 5.52 | 54.95 ± 6.68 | 0.272 | 0.845 |
Sex (n) | Â | Â | Â | Â | 0.158 | 0.984 |
 Male | 8 | 8 | 7 | 8 |  |  |
 Female | 12 | 12 | 13 | 12 |  |  |
BMI (kg/m2) | 21.48 ± 1.98 | 22.47 ± 1.38 | 21.79 ± 1.78 | 21.8 ± 1.7 | 1.178 | 0.324 |
Tumor type (n) | Â | Â | Â | Â | 5.348 | 0.803 |
 Rectal cancer | 3 | 2 | 3 | 3 |  |  |
 Colon cancer | 8 | 6 | 9 | 11 |  |  |
 Gastric cancer | 8 | 11 | 8 | 6 |  |  |
 Esophageal cancer | 1 | 1 | 0 | 0 |  |  |
Treatment history (n) | Â | Â | Â | Â | 0.213 | 0.975 |
 No | 8 | 7 | 7 | 8 |  |  |
 Chemoradiation | 12 | 13 | 13 | 12 |  |  |
Preoperative hemoglobin (g/L) | 83.95 ± 8.42 | 84.45 ± 10.2 | 83.25 ± 8.74 | 83.55 ± 7.88 | 0.690 | 0.976 |
Operative time (min) | 200 ± 30.96 | 213.7 ± 40.98 | 218.95 ± 25.9 | 226.55 ± 29.57 | 2.394 | 0.075 |
Operative technique (n) | Â | Â | Â | Â | 0.595 | 0.898 |
 Laparotomy | 8 | 6 | 8 | 7 |  |  |
 Peritoneoscopy | 12 | 14 | 12 | 13 |  |  |
Blood transfusion volume (ml) | ||||||
 RBC | 425.0 ± 99.9 | 456.0 ± 113.1 | 440.0 ± 96.9 | 450.5 ± 113.3 | 0.331 | 0.803 |
 Plasma | 474.5 ± 154.5 | 442.0 ± 140.1 | 506.0 ± 167.4 | 514.0 ± 165.9 | 0.872 | 0.460 |