Point-of-care ultrasound of the internal jugular vein for the prediction of spinal anesthesia-induced hypotension in elderly dehydrated patients.

Background and Aims: This prospective, observational study investigated the performance of internal jugular vein (IJV) point-of-care ultrasonography in the prediction of spinal anesthesia-induced hypotension in aged, dehydrated patients. Material and Methods: Fifty-five elderly, dehydrated patients (blood urea-to-creatinine ratio >20) with a hip fracture were recruited. The 2-dimensional ultrasound area of each IJV was evaluated to determine which vein produced the dominant outflow from the brain. The IJV with the greatest measured area was considered the dominant outflow vein. The following measurements of both veins were obtained: the maximum and minimum area (during spontaneous breathing), the IJV collapsibility index, and the internal jugular maximum area-to-collapsibility index ratio. Receiver operating curve characteristics and gray zone analysis of ultrasound indices were performed to evaluate their prognostic utility in identifying patients with post-spinal anesthesia hypotension. Results: Thirty-four patients (61.8%) manifested a hypotension incident. The right and the left IJV provided dominant flow in 42 (76%) and 13 (24%) cases, respectively. A collapsibility index of > 0.35 and a maximum area-to-collapsibility index ratio of <2.73 of the non-dominant vein demonstrated moderate diagnostic performance (area under the curve: 0.71 and 0.72, respectively) and were the most predictive indices of post-spinal anesthesia hypotension. However, these two indices were associated with a high number of inconclusive cases, thereby contributing to a prognostic uncertainty (gray zone analysis). Conclusions: IJV ultrasound measurements are not strong predictors of post-spinal anesthesia hypotension in elderly patients. Anesthesiologists should pursue the prediction of post-spinal anesthesia hypotension by using additional monitoring methods.