A case of severe stenosis of the internal carotid artery that was diagnosed by monitoring cerebral regional oxygen saturation

Abstract

A 61-year-old male with chronic kidney disease due to diabetic nephropathy received hemodialysis (HD) therapy 3 times per week. Recently, he had frequently experienced intradialytic hypotension, but we judged that his body fluid status was well controlled based on a physical assessment, his cardiothoracic ratio, and monitoring of his circulating blood volume. After obtaining informed consent for an observational study, we monitored cerebral regional oxygen saturation (rSO₂). The patient’s mean blood pressure gradually decreased, and about 120 minutes after starting HD his right cerebral rSO₂ had markedly decreased. We suspected brain ischemia, and therefore, we performed magnetic resonance imaging and found severe stenosis of the right internal carotid artery. On single photon emission computed tomography, his cerebral blood flow appeared to be stable, and no interventions were conducted. Monitoring of cerebral rSO₂ could help to diagnose cerebral ischemia-related diseases in HD patients in the future.