Objective To construct a dynamic nomogram model for predicting hypotension after combined spinal-epidural anesthesia during cesarean section.

Methods A total of 262 parturients who underwent combined spinal-epidural anesthesia for cesarean section were selected. Baseline and perioperative data of parturients were collected, and independent risk factors were screened through LASSO regression and multivariate Logistic regression. Based on the screened variables, a static nomogram model for predicting the risk of hypotension was constructed, and further developed into an online interactive dynamic nomogram. The discrimination of the model was evaluated by the area under the receiver operating characteristic curve, and the calibration and clinical practicability of the model were evaluated by the analysis of the calibration curve and decision curve, respectively.

Results The incidence of hypotension after combined spinal-epidural anesthesia during cesarean section was 62.5%. Multivariate logistic regression analysis indicated that the BMI ≥ 28 kg/m² (compared with ＜28 kg/m²), prenatal hemoglobin ＜110 g/L (compared with ≥110) g/L), epidural additional local anesthetic (compared with no additional), multiple pregnancies and anesthesia level exceeding T₆ (compared with no additional) were the independent risk factors of hypotension after combined spinal-epidural anesthesia during cesarean section (OR = 6.506, 4.050, 8.317, 3.938, 4.633, P ＜ 0.01). The areas under the ROC curves of the training set and validation set were 0.887 and 0.853, respectively. The calibration curve showed that the predicted probability of the model was highly consistent with the actual incidence rate. The decision curve analysis indicated that the model coulld provide clinical net benefits within a wide range of risk thresholds. The column chart visualization was the dynamic nomogram of hypotension after combined spinal-epidural anesthesia during cesarean section (https://shengxinfenxi135.shinyapps.io/PeripartumHypotension/).

Conclusions Based on BMI ≥ 28 kg/m², prenatal hemoglobin ＜110 g/L, additional epidural local anesthetics, multiple pregnancies and anesthesia plane exceeding T₆, this study constructs a dynamic histogram prediction model for hypotension risk after combined spinal-epidural anesthesia in cesarean section parturients, which can provide anesthesiologists with an intuitive and quantitative individualized risk assessment tool. It helps to identify high-risk pregnant women at an early stage, and implement targeted preventive measures, providing decision support tools for reducing the risk of maternal and infant complications related to hypotension.