Table 4.
Comparison of laboratory values and comorbidities among patients
| Preoperative laboratory tests and comorbidities | BMI (kg/m2) | p value | |||
|---|---|---|---|---|---|
| 18.5–25 | 25–30 | 30–35 | > 35 | ||
| White blood cell count | |||||
| Mean | 7 | 7 | 7 | 7 | < 0.001 |
| SD | 2 | 3 | 2 | 3 | |
| Creatinine | |||||
| Mean | 0.9 | 1.0 | 1.0 | 1.0 | < 0.001 |
| SD | 0.4 | 0.6 | 0.4 | 0.7 | |
| Hematocrit | |||||
| Mean | 40 | 40 | 41 | 41 | < 0.004 |
| SD | 4 | 5 | 4 | 4 | |
| International normalized ratio | |||||
| Mean | 1.1 | 1.1 | 1.1 | 1.0 | 0.611 |
| SD | 0.3 | 0.5 | 0.3 | 0.3 | |
| Albumin | |||||
| Mean | 4.1 | 4.1 | 4.1 | 4.0 | 0.009 |
| SD | 0.5 | 0.4 | 0.4 | 0.4 | |
| Wound classification (%) | |||||
| Clean | 99 | 98 | 99 | 99 | 0.301 |
| Not clean | 1 | 2 | 1 | 1 | |
| ASA class (%) | |||||
| 1 or 2 | 56 | 57 | 52 | 35 | < 0.001 |
| 3 | 42 | 41 | 46 | 61 | |
| 4 | 2 | 2 | 2 | 4 | |
| Diabetes (%) | 8 | 12 | 18 | 27 | < 0.001 |
| Hypertension (%) | 56 | 65 | 80 | 69 | < 0.001 |
| Congestive heart failure (%) | 1 | < 1 | < 1 | 1 | 0.050 |
| Dyspnea (%) | |||||
| At rest | 1 | < 1 | 1 | 1 | 0.001 |
| Moderate exertion | 5 | 6 | 6 | 11 | |
| No | 94 | 94 | 93 | 88 | |
| Cardiac surgery or stent (%) | 5 | 6 | 5 | 5 | 0.441 |
| Chronic obstructive pulmonary disease (%) | 6 | 5 | 5 | 6 | 0.453 |
| Peripheral vascular disease (%) | 0 | 1 | 1 | < 1 | 0.479 |
| Cerebrovascular accident or transient ischemic attack (%) | 10 | 6 | 4 | 6 | 0.004 |
| Ascites (%) | <1 | 0 | <1 | 0 | 0.425 |
| Bleeding disorder (%) | 3 | 3 | 3 | 3 | 0.629 |
| Steroid use (%) | 7 | 4 | 5 | 4 | 0.008 |
| Chemotherapy (%) | 0 | < 1 | 0 | < 1 | 0.602 |
| Radiation (%) | 0 | 0 | 0 | 0 | – |
ASA = American Society of Anesthesiologists.