Intraoperative polyuria with lactic acidosis in a patient undergoing cervical spine surgery- A case report

Postoperative diabetes insipidus is a common complication noted in neurosurgical procedures involving the pituitary gland or hypothalamus, but intraoperative diabetes insipidus during cervical spine surgery is rare. We report a case of a 43-year-old male who was undergoing transoral C2-C3 discectomy, posterior foramen magnum decompression, C1 posterior arch excision, and occipito-C3-C4 fusion and C3 laminectomy under general anesthesia. The patient developed polyuria with concurrent hyperlactatemia intraoperatively, and diabetes insipidus was suspected. Although we could not ascertain the diagnosis of diabetes insipidus intraoperatively, due to the lack of facilities for intraoperative measurements of urine osmolality and urine sodium, the clinical course strongly suggested central diabetes insipidus. Polyuria started resolving with the administration of vasopressin intraoperatively. Still, a gradual rise in serum sodium and persistent hyperlactatemia with mild acidosis were noted during the intraoperative period, requiring overnight ventilation and management in the critical care unit postoperatively. Postoperative administration of desmopressin, along with left-ventricular outflow tract velocity time integral and pulse pressure variation-guided fluid management, corrected the polyuria. He was weaned off all support and extubated the next day and discharged to the ward without any further events. The case highlights the importance of considering intraoperative diabetes insipidus in patients presenting with intraoperative polyuria who are undergoing extensive cervical spine surgeries. The timely administration of vasopressin plays a crucial role in managing suspected diabetes insipidus diabetes insipidus.