Patient characteristics (N = 48).
| Factor | n (%) |
| Patient characteristics | |
| Age, y, mean ± SD (range) | 74.7 ± 9.2 (60–96) |
| Body mass index, mean ± SD (range) | 31.9 ± 8.3 (19–58.5) |
| Male sex | 42 (87.5) |
| Preoperative risk factors | |
| Coronary artery disease | 20 (41.6) |
| Congestive heart failure | 7 (14.6) |
| Chronic obstructive pulmonary disease | 5 (10.4) |
| Diabetes mellitus | 22 (45.8) |
| Hypertension | 40 (83.3) |
| Prior cervical/thoracic spine surgery | 5 (10.4) |
| Anticoagulation therapy | 15 (31.3) |
| Preoperative American Society of Anesthesiologists score | |
| 1 | 0 (0) |
| 2 | 4 (8.3) |
| 3 | 30 (62.5) |
| 4 | 14 (29.2) |
| Charlson Comorbidity Index, mean ± SD (range) | 5.14 ± 1.71 (2–10) |
Note: Values are presented as n (%) unless otherwise indicated.