Ketamine-precipitated syndrome of inappropriate antidiuretic hormone secretion in a patient with persistent lumbar pain: a case report

Abstract

Purpose: To report on an unusual case of ketamine-precipitated syndrome of inappropriate antidiuretic hormone secretion (SIADH) in an individual managed by an outpatient pain specialty team. Clinical features: A 78-yr-old male presented to the emergency department with lethargy, malaise, nausea, and abdominal bloating three days following intravenous ketamine infusion for intractable postsurgical lumbar radicular pain with neuropathic features. The patient had a history of resected prostate cancer, hyperlipidemia, chronic kidney disease, and spinal stenosis and the cause of his symptoms was investigated. He was found to be hyponatremic and the treating team excluded reversible surgical and medical causes. A Naranjo score of 7 was calculated, suggesting that the correlation between ketamine and hyponatremia was “likely.” Hence, a diagnosis of ketamine-precipitated SIADH was made. The patient was treated with fluid restriction and symptoms were controlled with antiemetics. He returned to baseline function with resolution of the hyponatremia within three days of discharge. Conclusion: This case is of clinical importance for providers using ketamine in the field of pain management as the effect of this medication reaction can be profound. Clinicians should develop an awareness that ketamine can potentiate adverse effects such as SIADH and they should monitor, detect, and manage as appropriate.