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Abstract

Background: Post-spinal hypotension (PSH) is a common complication seen during the intra-operative period in women posted for caesarean section under spinal anaesthesia. It poses risks to both mother and foetus. The Inferior Vena Cava Collapsibility Index (IVCCI) has emerged as a non-invasive tool for assessing volume status and may predict PSH.
Methods: In this prospective observational study, 123 term pregnant women scheduled for elective lower segment caesarean section under spinal anaesthesia were enrolled. Preoperative ultrasound was done to measure minimum and maximum IVC diameters, and IVCCI was calculated. Hemodynamic parameters were recorded every 5 minutes for 30 minutes post-spinal anesthesia. The primary outcome was the incidence of PSH and its association with IVCCI. ROC curve analysis was performed to determine predictive thresholds.
Results: PSH occurred in 58.5% of participants. IVCCI was significantly higher in patients who developed hypotension. An IVCCI >26.5% yielded a sensitivity of 94.4% and specificity of 27.5%, while a threshold of >36.5% improved specificity to 60.8% with sensitivity of 83.3%. ROC analysis demonstrated an AUC of 0.745 (p < 0.001), confirming moderate predictive accuracy. Heart rate and mean arterial pressure trends also differed significantly between hypotensive and normotensive groups.
Conclusion: IVCCI is a reliable, non-invasive predictor of post-spinal hypotension in parturients. Incorporating bedside IVC ultrasound into preoperative assessment may improve early identification and targeted management of high-risk patients