A novel nomogram model to predict hypotension during the induction of anesthesia in preeclampsia women

Background ​ Hypotension during anesthesia induction for cesarean section is a common concern in women with preeclampsia, posing risks to both maternal and fetal health. However, predictive tools specifically for this population are lacking. This study aimed to develop and validate a novel nomogram to predict the risk of hypotension during the induction of anesthesia in pregnant women with preeclampsia. Methods ​ A retrospective, non-randomized observational study was conducted on 1208 preeclamptic women undergoing cesarean section. Patients were randomly divided into a training cohort (n = 861) and a validation cohort (n = 347). Hypotension was defined as a systolic blood pressure < 90 mmHg or a 30% decrease from baseline during anesthesia induction until 20 minutes post-induction. Univariate and multivariate logistic regression analyses were performed on numerous preoperative and intraoperative variables to identify independent risk factors. These factors were then integrated into a nomogram. Results ​ Multivariate analysis identified six independent predictors of hypotension: anesthesia method (Combined lumbar-epidural, Epidural, General), HELLP syndrome, preoperative systolic blood pressure (SBP), preoperative heart rate (HR), emergency status, and preoperative serum potassium level (K⁺). The nomogram constructed from these factors demonstrated good discrimination, with area under the curve (AUC) values of 0.753 in the training cohort and 0.758 in the validation cohort. Calibration curves indicated good agreement between predicted and observed probabilities, and decision curve analysis confirmed the clinical utility of the model. Conclusions ​ This study successfully developed and validated a practical nomogram for predicting hypotension during anesthesia induction in preeclamptic women. The model incorporates six readily available clinical factors, allowing for individualized risk assessment prior to cesarean section. This tool can assist anesthesiologists in implementing early interventions to reduce the incidence of hypotension, thereby potentially improving outcomes for both mother and fetus.