Role of Internal Jugular Vein Collapsibility Index in Predicting Post-spinal Hypotension in Pregnant Women Undergoing Cesarean Section: A Prospective Observational Study.

Introduction Post-spinal hypotension (PSH) frequently occurs in women undergoing cesarean section. In recent studies, Ultrasound-guided measurements of the internal jugular vein (IJV) have been reported to predict fluid responsiveness. We planned to evaluate the correlation between the internal jugular vein collapsibility index (IJVCI) and PSH in cesarean section patients. Methods Ninety-one parturients who underwent elective lower segment cesarean section with a singleton pregnancy were recruited. Preoperatively, patients were placed in a supine position with a 15-degree left lateral tilt. Maximum (at the end of expiration) and minimum (at the end of inspiration) IJV diameters (mm) and IJVCI were assessed using M-mode imaging during spontaneous and deep breathing. Spinal anaesthesia was performed at the L3-4 or L4-5 level. Systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, respiratory rate, and SpO2 were recorded from baseline till the delivery of the baby. Results Among 91 patients, 40 (45.5%) patients had at least one episode of hypotension. Demographic variables and baseline vitals were comparable between the hypotensive and normotensive groups (p>0.05). In spontaneous and deep breathing, IJV diameter at the end-expiration (IJVdmax), end-inspiration (IJVdmin), and IJVCI amongst both hypotensive and non-hypotensive pregnant women were statistically similar. Receiver Operating Characteristic (ROC) curve analysis showed that during spontaneous breathing, using a cut-off point of 29.5%, IJVCI had a sensitivity and specificity of 70% and 23%, respectively, for predicting PSH; whereas during deep breathing, IJVCI had a sensitivity and specificity of 77% and 27%, respectively, for predicting the same using a cut-off value of 37.5%. Conclusion We conclude that internal jugular vein parameters such as maximum diameter, minimum diameter, and IJVCI during spontaneous and deep breathing cannot be used as reliable predictors of post-spinal hypotension in pregnant patients undergoing elective cesarean section.