Department of Pediatric Intensive Care Unit, National Center for Cardiovascular Disease and Fuwai Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China.
Pediatr Cardiol. 2021 Jan;42(1):47-58. doi: 10.1007/s00246-020-02451-7. Epub 2020 Sep 4.
To develop and internally validate nomogram predicting postoperative blood loss risk among pediatric patients with pulmonary atresia (PA) undergoing cardiopulmonary bypass (CPB). All patients aged from 6 months to 6 years with PA who underwent surgery at Fuwai Hospital from June 2015 to December 2019 were selected. And the prediction nomogram model was developed in the training set based on the selected patients. The demographic characteristics and laboratory data from each enrolled patient were gathered. Postoperative blood loss was defined as a blood loss exceeding 20.0 ml/kg within the first 24 postoperative hours. The least absolute shrinkage and selection operator (LASSO) method was used to optimize feature selection for multivariate logistic regression analysis that was applied to build a nomogram composed of all the features selected in the LASSO algorithm. The concordance index (C-index), calibration plot, and decision curve analysis (DCA) were used to evaluate the discrimination, calibration, and clinical net benefit of the nomogarm, respectively. Finally, internal validation was performed using the bootstrap technique. Of the 66 pediatric patients in the training set, 21 (31.82%) and 45 (68.18%) patients were assigned into bleeding group and non-bleeding group, respectively. The first postoperative 24-h blood loss in the bleeding group was significantly higher than that in the non-bleeding group during ICU stay (P = 0.000). Multivariate logistic regression analysis showed that, the immediate postoperative prothrombin time (odds ratio = 1.419, 95% confidence interval: 1.094-1.841, P = 0.008), the immediate postoperative platelet count (odds ratio = 0.985, 95% confidence interval: 0.973-0.997, P = 0.015) and the immediate postoperative red blood cell (RBC) count (odds ratio = 0.335, 95% confidence interval: 0.166-0.667, P = 0.002) were independent predictors of postoperative blood loss risk. The model presented favorable calibration and good discrimination with satisfactory calibration curve and a C-index of 0.858 (95% confidence interval: 0.758-0.958). High C-index value of 0.837 was achieved in the internal validation. The DCA revealed that the nomogram was great clinical effect when intervention was decided among nearly the entire range of threshold probabilities. We developed and internally validated an accurate nomogram to assist in the clinical decision-making concerning the presence of postoperative blood loss in pediatric patients with PA undergoing CPB. However, the nomogram should be endorsed by external validation before it can be recommended for routine practice.
建立并内部验证预测小儿法洛四联症（PA）体外循环（CPB）术后出血风险的列线图。
选取 2015 年 6 月至 2019 年 12 月在阜外医院接受手术的年龄 6 个月至 6 岁的 PA 患儿，根据术后 24 小时内出血量（>20.0ml/kg）分为出血组和非出血组，采用最小绝对收缩和选择算子（LASSO）法对多变量逻辑回归分析进行特征选择，建立列线图。采用一致性指数（C-index）、校准图和决策曲线分析（DCA）分别评估模型的判别、校准和临床净获益。最后，采用 bootstrap 技术进行内部验证。
在训练集中，66 例患儿中 21 例（31.82%）和 45 例（68.18%）患儿分别被分为出血组和非出血组。出血组患儿 ICU 期间术后 24 小时内首次出血量明显高于非出血组（P=0.000）。多变量逻辑回归分析显示，术后即刻凝血酶原时间（比值比=1.419，95%置信区间：1.094-1.841，P=0.008）、术后即刻血小板计数（比值比=0.985，95%置信区间：0.973-0.997，P=0.015）和术后即刻红细胞计数（比值比=0.335，95%置信区间：0.166-0.667，P=0.002）是术后出血风险的独立预测因素。该模型具有良好的校准和良好的判别能力，校准曲线满意，C-index 为 0.858（95%置信区间：0.758-0.958）。内部验证的 C-index 值为 0.837。DCA 显示，在几乎整个阈值概率范围内进行干预时，列线图具有较好的临床效果。
我们建立并内部验证了一种准确的列线图，以帮助临床决策是否存在 CPB 术后出血风险。然而，在推荐用于常规实践之前，该列线图需要通过外部验证。
