Dai Yimin, Han Chang, Weng Xisheng
Peking Union Medical College, Eight-year MD program, Chinese Academy of Medical Sciences, Beijing, China.
Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Front Surg. 2022 Jun 9;9:849761. doi: 10.3389/fsurg.2022.849761. eCollection 2022.
The loss of blood is a significant problem in Total Knee Arthroplasty (TKA). Anemia often occurs after such surgeries, leading to serious consequences, such as higher postoperative infection rates and longer hospital stays. Tools for predicting possible anemia can provide additional guidance in realizing better blood management of patients.
2,165 patients who underwent TKA from 2015 to 2019 in the same medical center were divided into training and validation cohorts. Both univariate and multivariate logistic regression analyses were performed to identify independent preoperative risk factors for anemia. Based on these predictors, a nomogram was established using the area under the curve (AUC), calibration curve (AUC), and the area under the curve (AUC). The model was then applied to the validation cohort, and decision curve analyses (DCA) were also plotted.
Through analysis of both univariate and multivariate logistic regression, five independent predictors were found in the training cohort: female, relatively low BMI, low levels of preoperative hemoglobin, abnormally high levels of ESR, and simultaneously two sides of TKA in the same surgery. The AUCs of the nomogram were 74.6% (95% CI, 71.35%-77.89%) and 68.8% (95% CI, 63.37%-74.14%) of training and the validation cohorts separately. Furthermore, the calibration curves of both cohorts illustrated the consistency of the nomogram with the actual condition of anemia of patients after TKA. The DCA curve was higher for both treat-none and treat-all, further indicating the relatively high practicality of the model.
Female, lower BMI, lower levels of preoperative Hb, simultaneous bilateral TKA, and high levels of preoperative ESR were figured out as five independent risk factors for postoperative anemia (<9.0 g/dL) in patients undergoing TKA. Based on the findings, a practical nomogram was constructed to predict risk of postoperative anemia. The evidence level should be level 4 according to guideline.
失血是全膝关节置换术（TKA）中的一个重要问题。此类手术后常出现贫血，会导致严重后果，如术后感染率升高和住院时间延长。预测可能发生贫血的工具可为实现更好的患者血液管理提供额外指导。
将2015年至2019年在同一医疗中心接受TKA手术的2165例患者分为训练组和验证组。进行单因素和多因素逻辑回归分析，以确定贫血的独立术前危险因素。基于这些预测因素，使用曲线下面积（AUC）、校准曲线（AUC）和曲线下面积（AUC）建立了列线图。然后将该模型应用于验证组，并绘制决策曲线分析（DCA）图。
通过单因素和多因素逻辑回归分析，在训练组中发现了五个独立的预测因素：女性、相对较低的体重指数、术前血红蛋白水平低、血沉异常高以及同一手术中同时进行双侧TKA。列线图在训练组和验证组的AUC分别为74.6%（95%CI，71.35%-77.89%）和68.8%（95%CI，63.37%-74.14%）。此外，两组的校准曲线均表明列线图与TKA术后患者贫血的实际情况一致。DCA曲线在不治疗和全部治疗时都较高，进一步表明该模型具有较高的实用性。
女性、较低的体重指数、术前较低的血红蛋白水平、同时进行双侧TKA以及术前血沉水平高被确定为TKA患者术后贫血（<9.0 g/dL）的五个独立危险因素。基于这些发现，构建了一个实用的列线图来预测术后贫血风险。根据指南，证据级别应为4级。
