A Nomogram for Predicting the Risk of Spinal Anesthesia-Induced Hypotension in Older Patients.

Background

Hypotension is a common complication following spinal anesthesia, and it is particularly prevalent in older patients. The study aimed to develop and validate a nomogram integrating echocardiographic and clinical predictors for spinal anesthesia-induced hypotension (SAIH) in older patients.

Methods

This was an observational cohort study conducted at Peking University People's Hospital. A total of 865 older patients (age ≥ 65), enrolled from 1 January 2023 to 31 December 2024, were randomly split into a training set (70%) and an internal validation set (30%). For temporal external validation, 349 patients from January to March 2025 were enrolled. LASSO, univariable, and multivariate logistic regression analyses were used to identify predictive factors. A nomogram was subsequently developed based on the results of multivariate logistic regression, and its predictive efficacy was evaluated via both internal and temporal external validation.

Results

SAIH occurred in 271 patients (44.8%) in the training set, 110 patients (42.3%) in the internal validation set, and 173 patients (49.6%) in the external validation set. Age, body mass index (BMI), bupivacaine dose, sensory block level, baseline systolic blood pressure (SBP), history of hypertension, interventricular septum thickness at end-diastole (IVSd), early diastolic mitral annular velocity (e'), and E/e' ratio were significant predictors of SAIH on multivariate analysis. The diagnostic performance of the nomogram was favorable (AUC = 0.885, 95% CI: 0.859-0.911). The AUC values of the internal validation set and temporal external validation set were 0.856 (0.811-0.901) and 0.895 (0.863-0.927).

Conclusions

This study identifies age, BMI, bupivacaine dose, sensory block level, baseline SBP, history of hypertension, and IVSd as predictors of SAIH with good discrimination and clinical utility. We present a predictive nomogram that accurately predicts SAIH in older patients. The external validation illustrates its generalizability.