Intraoperative Dexmedetomidine-Induced Polyuric Syndrome

A 23-year-old male trauma patient with a cervical spine fracture underwent an anterior and posterior discectomy and spinal fusion surgery. The patient presented to the operating room with a stabilizing halo fixation device in place, and a fiberoptic intubation was performed with dexmedetomidine for sedation. During the surgical procedure, general anesthesia was maintained with a propofol and remifentanil infusion as the patient was monitored using somatosensory and motor evoked potentials. The patient's urine output increased gradually during the nine-hour surgical procedure from 150 mL/hour to over 700 mL/hour in the eighth hour of the procedure, where it remained until the end of the procedure. Postoperatively, the patient's laboratory values and urine output returned to baseline levels the following day. A search of the literature revealed few case reports of polyuria under similar conditions. Dexmedetomidine, being an alpha-2 agonist that blocks arginine-vasopressin release, may be responsible for inducing the polyuria noted in this patient case.