Prediction of spinal anesthesia-induced hypotension in cesarean delivery

Spinal anesthesia-induced hypotension is a common complication in cesarean delivery that can negatively impact maternal and fetal welfare by impeding uteroplacental blood flow. However, there is currently no simple and effective prediction score for spinal hypotension. In our study, we developed and internally validated a risk scoring scheme using a prospective cohort design. The parturients who underwent cesarean delivery under spinal anesthesia were included. The outcome was spinal anesthesia-induced hypotension. Predictors included patients’ baseline characteristics, pregnancy details, and preoperative hemodynamic results. Multivariable logistic regression was used for score derivation. Model discrimination and calibration were assessed. Among 712 parturients who underwent cesarean delivery, The risk score, derived from four predictors in Model A: elective surgery, baseline heart rate > 80 bpm, stroke volume index, and level of spinal blockade at 1 minute. This model achieved a predictive performance of 72.76%. Recognizing the limitations of stroke volume index measurement, we also developed a stroke volume-free model, Model B, which included elective surgery, underlying DM/GDM, obesity, baseline heart rate, and level of spinal blockade at 1 minute. Model B achieved a predictive performance of 71.02%. In Model A, the SIH prediction score ranged from 0 to 7.5. Model A classified risk as high (score > 5.5), intermediate (3-5.5), and low (< 3). The likelihood ratio for a positive result increased from 0.27 (low-risk) to 6.13 (high-risk). In Model B, the SIH prediction score ranged from 0 to 10, while risk classification was high (score > 6.5), intermediate (4-6.5), and low (< 4). The likelihood ratio for a positive result increased from 0.37 (low-risk) to 3.37 (high-risk) in Model B. The risk score can aid in individualizing prophylactic treatment and identifying high-risk patients who would benefit from such therapy, particularly in settings where routine prophylactic vasopressor therapy is not commonly practiced.