IVC Collapsibility Index (IVC-CI) Guided Preloading to Reduce Hypotension Following Spinal Block in Lower Limb Surgery

Background: Hypotension following spinal anesthesia is a common and serious complication during lower limb surgeries. Traditional fluid preloading strategies can lead to fluid overload, especially in patients with co-morbid conditions. The inferior vena cava collapsibility index (IVC-CI) offers a non-invasive method to guide fluid management more precisely. Objective: The primary objective was to compare the incidence of hypotension following spinal anesthesia between Group A with IVC-CI-guided fluid management, and Group B with standard fluid administration. Secondary objectives included comparisons of the total amount of fluids administered, vasopressor use, and perioperative complications between the two groups. Materials and Methods: The present study was a prospective, comparative clinical trial involving 83 patients undergoing lower limb surgery under spinal anesthesia. Patients were randomly divided into two groups with Group A, in which ultrasound was used to measure the IVC-CI before spinal anesthesia, with an index of 36% or higher considered as responsive to fluid administration, and Group B, the standard group, which did not undergo IVC-CI assessment and received standard fluid administration. Results: In the ultrasound-guided IVC-CI group, Group A, which included 41 patients, nine patients (21.95%) experienced hypotension, compared to eight patients (20%) in the standard care group, Group B, of 42 patients (p=0.829, 95% CI –15.77 to 19.68). There were no clinically significant differences between the groups in the total volume of fluids administered and in the use of vasopressor or inotropic drugs between the groups. Additionally, no severe postoperative complications occurred in either group. Conclusion: The use of ultrasound to monitor IVC-CI of 36% or greater, as a guide for fluid administration prior to spinal anesthesia in patients undergoing lower limb surgery did not reduce the incidence of hypotension when compared to standard fluid administration, in patients aged 18 to 75 years without cardiovascular disease.