Table 3.
Perioperative parameters of the patients and results of Pearson correlation analysis for hidden blood loss
| Parameters | n (%) or mean±SD | Pearson’s r | P-value |
|---|---|---|---|
| Age (years), mean (range) | 82.3±5.7 (70–96) | 0.086 | 0.213 |
| Gender (men/women) | 155/57 | 0.165 | 0.016 |
| BMI category (kg/m2) | 0.079 | 0.253 | |
| BMI<18.5 | 54 (25.5) | ||
| 18.5≤BMI<30 | 130 (61.3) | ||
| ASA classification | 0.232 | 0.001 | |
| II | 70 (33.0) | ||
| III | 129 (60.9) | ||
| IV | 13 (6.1) | ||
| Type of anesthesia | 0.176 | 0.010 | |
| General | 36 (17.0) | ||
| Spinal | 176 (83.0) | ||
| Comorbid conditions | |||
| Hypertension | 175 (82.6) | 0.093 | 0.178 |
| Diabetes mellitus | 55 (25.9) | 0.100 | 0.148 |
| Cerebrovascular disease | 39 (18.4) | 0.064 | 0.355 |
| Cardiovascular disease | 35 (16.5) | 0.079 | 0.254 |
| Pulmonary disease | 36 (17.0) | 0.088 | 0.204 |
| Renal insufficiency | 7 (3.3) | 0.053 | 0.446 |
| Liver disease | 10 (4.7) | 0.093 | 0.175 |
| Chronic anticoagulation preoperatively | 59 (27.8) | 0.153 | 0.026 |
| Perioperative gastrointestinal bleeding/ulcer | 13 (6.1) | 0.179 | 0.009 |
| Blood parameters | |||
| Preoperative hematocrit | 0.36±0.04 | 0.010 | 0.884 |
| Preoperative hemoglobin (g/L) | 118.8±15.1 | −0.040 | 0.563 |
| Preoperative albumin (g/L) | 37.1±11.3 | −0.018 | 0.797 |
| Time to surgery (days) | 3.0±2.0 | 0.057 | 0.409 |
| Surgical time (minutes) | 71.6±17.8 | 0.089 | 0.196 |
| Intraoperative blood loss (mL) | 182±96 | −0.046 | 0.506 |
| Wound drainage (mL) | 162±112 | 0.048 | 0.486 |
| Transfusion | 63 (29.7) | 0.393 | 0.000 |
| Postoperative length of stay (days) | 9.0±3.6 | 0.085 | 0.216 |
Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index.