Adequate preoperative hemoglobin level in patients with thoracic and lumbar tuberculosis: A single center retrospective cohort study

Abstract

Abstract Objective: This study aimed to find out the risk factors of postoperative moderate anemia (PMA) to develop a scoring scale for predicting the occurrence of PMA and to determine the recommended preoperative hemoglobin level in spinal tuberculosis (STB) patients.Methods: A total of 223 STB patients who underwent focus debridement from January 2012 to March 2020 were enrolled in the study. The study cohort was divided into two groups owing to the occurrence of PMA. Moderate anemia was defined as a hemoglobin level of < 90 g/L. The clinical characteristics of STB patients who developed PMA were evaluated, and a scale was developed by logistic regression analysis. The performance of this scoring scale is prevalidated.Results: Of the 223 patients, 76 developed PMA. Multivariate binary logistic regression analysis showed that body mass index, diabetes, low preoperative hemoglobin level, long operation time, and posterior approach were independent risk factors for PMA in STB patients. These significant items were assigned scores to create a scoring scale as to predicting PMA, and receiver operating characteristic (ROC) curve analysis implicated that the optimal cutoff score was 4 points. On the basis of the scoring scale, patients with scores within 0–3 points were defined as the low-risk group; those with scores within 4–6 points were defined as the moderate-risk group; and those with scores within 7–10 points were defined as the high-risk group. The perioperative decrease in hemoglobin level was 20.07 ± 10.47 g/L in the low-risk group, 24.44 ± 12.67 g/L in the moderate-risk group, and 29.18 ± 10.34 g/L in the high-risk group.Conclusion: According to the scoring scale, patients with STB with a score of 0–3 points have a low risk of PMA, those with a score of 4–6 have a moderate risk, and those with a score of 7–10 have a high risk. The recommended preoperative hemoglobin levels for the low-, moderate-, and high-risk groups are 110, 115, and 120 g/L, respectively.