EFFICACY OF INFERIOR VENA CAVA COMPRESSIBILITY INDEX IN PREDICTING POST-SPINAL HYPOTENSION AND ITS CORRELATION WITH PERFUSION INDEX AND PLETH VARIABILITY INDEX IN INFRAUMBILICAL SURGERIES.

Abstract

: Following infraumbilical surgery under spinal anaesthesia, post-spinal hypotension (PSH) is a frequent and important clinical consequence. It arises mainly from sympathetic blockade, causing peripheral vasodilation, venous pooling, and reduced cardiac output. Prompt identification of patients at higher risk enables timely preventive measures. This study examined the predictive efficacy of Inferior Vena Cava Collapsibility Index (IVC-CI) for PSH as well as the correlation between Pleth Variability Index (PVI), Perfusion Index (PI), and occurrence of hypotension. This prospective, double-blind, randomized observational study involved 100 ASA I–II patients between the ages of 18 and 60 who were under spinal anaesthesia for elective infraumbilical surgeries. Using preoperative ultrasound, patients were grouped as Group A (IVC-CI <40%) or Group B (IVC-CI ≥40%). Baseline PI, PVI, and haemodynamic parameters were recorded. The capacity of IVC-CI to predict PSH, as evaluated through sensitivity ,specificity and receiver operating characteristic (ROC) analysis, was primary result. Secondary outcomes were correlations between PI, PVI, and hypotension, as well as vasopressor use.

Results: Hypotension occurred in 64% of Group B compared with 12% of Group A (p <0.001). An IVC-CI >40% predicted PSH with 84.21% sensitivity and 70.97% specificity (AUC = 0.867). Higher baseline PI (>3.5) and elevated PVI were significantly linked to hypotension. Vasopressor (ephedrine) requirement was also notably greater in Group B (p <0.01).

Conclusion: Preoperative IVC-CI is reliable and non-invasive predictor of PSH. Both PI and PVI show a significant association with hypotension, supporting their use as adjuncts in perioperative risk assessment.