Syndrome of Inappropriate Antidiuretic Hormone Release During Ketamine Infusion in Complex Regional Syndrome Patient Receiving Intrathecal Baclofen: A Case Report.

Complex regional pain syndrome (CRPS) is a severely disabling condition that typically develops after an inciting traumatic event. Ketamine infusion in subanesthetic dose provides sustained analgesia in selected cases of CRPS. In general, ketamine treatment does not significantly affect electrolyte or water balance. Here, we report a case of a CRPS patient on intrathecal baclofen pump developing syndrome of inappropriate antidiuretic hormone release (SIADH) during ketamine infusion. Prophylactic treatment with intravenous loop diuretics was successful in preventing the development of SIADH during ketamine infusion during subsequent infusions in this case.

Double Trouble - Severe Hypernatremia Secondary to Central Diabetes Insipidus Complicated by Hypercalcemic Nephrogenic Diabetes Insipidus: A Case Report.

BACKGROUND Patients with malignancies often have electrolyte abnormalities. We present a case of a patient with central diabetes insipidus secondary to metastatic pituitary invasion complicated by hypercalcemic nephrogenic diabetes insipidus. CASE REPORT We present a case of 40-year-old female with a history of stage IV breast cancer with skeletal and leptomeningeal metastasis, who was admitted with polyuria, polydipsia, and recent onset of confusion. The patient was found to have profound hypernatremia and severe hypercalcemia with normal parathyroid and vitamin D serum levels. Urine studies showed low urine osmolality and high urine output, despite the higher serum osmolality. The patient received 5% dextrose for rehydration, 1 dose of intravenous (IV) pamidronate, 1 dose of IV desmopressin, and 4 days of subcutaneous calcitonin 200 international units Q12H. Initially, her urine output in the hospital was in the range of 350-400 milliliters/hour, which responded well to 1 dose of 1-desamino-8d-arginine vasopressin (DDAVP). In the subsequent days, her confusion resolved with normalization of serum sodium and calcium, but she died because of the extensive malignancy. CONCLUSIONS Our case emphasizes the importance of identification of causes and complications of electrolyte abnormalities associated with metastatic cancers. These electrolyte abnormalities can be primary or paraneoplastic and should be actively pursued and treated in such cases.