Intraoperative variables.
| Variables | Normal (n = 91) | Prolonged (n = 38) | P Value |
| Median fusion levels (IQR) | 12.0 (11.0–13.0) | 12.0 (12.0–13.0) | 0.447 |
| Osteotomies performed, n (%) | 15 (16.5) | 5 (13.2) | 0.792 |
| Estimated blood loss, mL | |||
| Mean ± SD | 1042.0 ± 502.0 | 1087.0 ± 494.0 | 0.745 |
| RBC transfusion, n (%) | |||
| Autologous | 33 (36.3) | 12 (31.6) | 0.252 |
| Nonautologous | 16 (17.6) | 5 (13.2) | 0.319 |
| Units of RBC transfused, n (%) | 0.509 | ||
| 0 | 42 (46.2) | 14 (36.8) | |
| 1 | 20 (22.0) | 8 (21.1) | |
| >1 | 29 (31.9) | 16 (42.1) | |
| Platelets/fresh frozen plasma transfusion, n (%) | 4 (4.4) | 3 (7.9) | 0.420 |
| Cell saver, n (%) | 91 (100.0) | 37 (97.4) | 0.295 |
| Albumin transfusion, n (%) | 54 (59.3) | 27 (71.1) | 0.292 |
| Tranexamic acid used, n (%) | 80 (87.9) | 27 (71.1) | 0.039 |
| Aminocaproic acid used, n (%) | 10 (11.0) | 9 (23.7) | 0.114 |
| Procedure time, h | 0.009 | ||
| Mean ± SD | 6.6 ± 1.2 | 7.2 ± 1.3 | |
| Median (IQR) | 6.5 (5.9–7.4) | 7.0 (6.4–8.1) | |
| Spinal cord injury, n (%) | 1 (1.1) | 0 (0.0) | >0.99 |
| Durotomy, n (%) | 0 (0.0) | 1 (2.6) | 0.295 |
| Neuromonitoring changes, n (%) | 4 (4.4) | 2 (5.3) | >0.99 |
| Plastic surgery closure, n (%) | 13 (14.3) | 5 (13.2) | >0.99 |
| Drain use, n (%) | 85 (93.4) | 38 (100.0) | 0.178 |
| Intrathecal opioid administration, n (%) | 79 (86.8) | 31 (86.1) | >0.99 |
Abbreviations: IQR, interquartile range; RBC, red blood cell.
Note: Bold indicates a statistically significant P value.