PREDICTION OF HYPOTENSION USING INFERIOR VENA CAVA COLLAPSIBILITY INDEX TO GUIDE FLUID MANAGEMENT AFTER SPINAL ANAESTHESIA

Abstract

BACKGROUND: Assessing the inferior vena cava collapsibility index (IVCCI) through ultrasonography can provide important information on intravascular volume status and the effectiveness of volume resuscitation. The IVCCI's calculation, sensitivity, and specificity make it a reliable indicator of volume responsiveness, offering potential for predicting perioperative hypotensive events and the need for perioperative fluid. OBJECTIVE: To assess the degree of relationship between preoperative IVCCI and incidence of hypotension post SA. MATERIAL AND METHOD: The observational single group prospective clinical study conducted at R. L. Jalappa Hospital in Kolar from September 2022 to December 2023 focused on ASA 1&2 non-obstetric patients undergoing spinal anesthesia for elective surgeries. Informed consent was obtained. IVC measurements performed in the supine position right before shifting into operation theatres using an ultrasonography machine. The maximum and minimum anteroposterior diameters of the IVC at the end of expiration and inspiration noted during the same respiratory cycle. The IVCCI calculated. Changes in vital parameters were observed during and after SA. A decrease of more than 30% in blood pressure or a recorded MAP <60 mmHg after SA was considered as hypotension. A P value of 0.05 was considered statistically significant. RESULTS: Study participants were with an average age of 44 years, balanced distribution between males and females, an average BMI of 25 kg/m2, and falling into ASA grades 1 and 2 in similar numbers. Their vital signs were normal and comparable. Overall hypotension following spinal anesthesia was found in 49% of cases which was xiii directly correlating with IVCCI values. Hypotension observed in 46% and 9% of cases based on SBP and MAP drop respectively. The research showed that IVCCI is a highly effective test with a sensitivity of 98% and a specificity of 77% to 79% (P< 0.05). CONCLUSION: The study suggests that pre-spinal anesthesia IVCCI measurements are highly predictive of post-spinal hypotension. Increased IVCCI values are strongly associated with hypotension, making IVCCI a valuable tool for identifying high-risk patients for post-spinal hypotension. These findings are consistent with previous research showing that IVCCI can anticipate hemodynamic fluctuations and indicate intravascular volume status.