Prediction of spinal anesthesia–induced hypotension using the internal jugular vein collapsibility index in transurethral resection surgery

Hypotension is a common consequence of spinal anesthesia and is mainly related to sympathetic blockade, venous pooling, and reduced venous return. We investigated whether the preoperative right internal jugular vein collapsibility index (RIJV-CI) could help identify patients at risk of hypotension after spinal anesthesia during transurethral resection surgery. This prospective observational study included 60 patients aged 18–65 years with ASA physical status I–II who underwent elective transurethral resection surgery (TUR-P and TUR-M) under spinal anesthesia. Before intravenous fluid administration and spinal anesthesia, inspiratory (dI) and expiratory (dE) diameters of the right internal jugular vein were measured using M-mode ultrasonography during spontaneous breathing. RIJV-CI was calculated as [(dE − dI) / dE] × 100. Hypotension was defined as a ≥20% decrease in systolic blood pressure (SBP) from baseline. The ability of RIJV-CI to discriminate between patients who did and did not develop hypotension was assessed using receiver operating characteristic (ROC) curve analysis. Hypotension occurred in 30 of the 60 patients (50%). Preoperative RIJV-CI was higher in patients who developed hypotension than in those who did not (37.7 ± 9.5% vs. 27.5 ± 6.7%, p<0.001). RIJV-CI showed good discrimination for post-spinal hypotension, with an AUC of 0.826 (95% CI, 0.724–0.929; p<0.001). A cohort-derived cutoff value of 32.5% yielded 80% sensitivity and 70% specificity. In the exploratory multivariable model, higher RIJV-CI remained significantly associated with hypotension (OR 1.239 per 1-percentage-point increase; 95% CI, 1.075–1.428; p=0.003). Higher preoperative RIJV-CI was associated with hypotension after spinal anesthesia in patients undergoing transurethral resection surgery and demonstrated good discriminative performance in this cohort. RIJV-CI may have potential as a simple, non-invasive bedside marker for identifying patients at increased risk of hypotension. However, the cutoff identified in this study is preliminary and requires validation in larger, independent cohorts before clinical application.