Internal Jugular Vein Collapsibility Index in prediction of hypotension after spinal anesthesia in transurethral resection operations

Aim: Hypotension is one of the most frequent complications associated with neuraxial anesthesia. Various predictive methods have been developed to reduce its incidence and severity. This study aimed to evaluate the predictive value of the internal jugular vein collapsibility index (IJV-CI) for post-spinal hypotension in patients undergoing transurethral resection of the bladder (TUR-B) or prostate (TUR-P). Method: In this prospective observational study, 60 patients aged between 18 and 65 years, classified as ASA (American Society of Anesthesiologists) physical status I–II, who underwent elective TUR-M or TUR-P operations under spinal anesthesia at the Department of Anesthesiology and Reanimation of Balıkesir University Health Practice and Research Hospital, were included. Patients with contraindications to spinal anesthesia, those in whom jugular venous ultrasonography could not be performed, obese patients (Body Mass Index >30 kg/m²), patients with failed spinal anesthesia, and those who did not consent to participate were excluded from the study. Prior to spinal anesthesia and after surgery, ultrasonographic assessment of the right internal jugular vein (IJV) was performed at the intersection of the sternocleidomastoid muscle and thyroid cartilage. Using motion mode, IJV diameters during inspiration (dI) and expiration (dE) were measured, and the IJV collapsibility index (IJV-CI) was calculated using the following formula: [IJV-CI = (dE - dI) / dE × 100]. A decrease of more than 20% in systolic blood pressure compared to the baseline value was defined as hypotension during intraoperative measurements. Patients were then divided into two groups: those who did not develop hypotension (Group 1) and those who did (Group 2). The primary outcome measure of the study was the development of hypotension following spinal anesthesia and the identification of contributing factors. The secondary outcome measure was to determine the predictive value of the IJV-CI. Results: Hypotension did not develop in 30 patients (50%) following spinal anesthesia (Group 1), while it developed in 30 patients (50%) (Group 2). The preoperative and postoperative IJV-CI values were significantly lower in Group 1 compared to Group 2 (27.47 ± 6.65 vs. 37.73 ± 9.47; 21.16 ± 5.65 vs. 29.46 ± 7.44, respectively; p < 0.05). In univariate analysis, preoperative IJV inspiratory diameter, IJV-CI, pre-spinal systolic arterial pressure, mean arterial pressure, and sensory block level were found to be significant factors associated with the development of hypotension (p < 0.05). Receiver operating characteristic (ROC) curve analysis demonstrated that IJV-CI was an independent predictor of hypotension [AUC: 0.826 ± 0.052; p = 0.000]. The threshold value for IJV-CI was determined as 32.5%, with a sensitivity of 80% and specificity of 70%. Conclusion: In our study, it was concluded that the preoperatively measured IJV-CI is a useful parameter for predicting hypotension following spinal anesthesia