The role of short-term, low dose intravenous ketamine infusion in Calciphylaxis

Calciphylaxis is a small vessel vasculopathy causing subcutaneous ischemic necrosis. This condition is a recognized complication of end stage renal disease and is associated with severe pain. The mechanism of the pain generated by calciphylaxis is thought to be partly related to tissue ischemia, with a significant neuropathic component associated with neuronal hypoxic injury. The pain can be further exacerbated by the inflammatory process ensuing as a result of calciphylactic lesion infections which are commonly associated with this condition. Obtaining adequate pain relief is a challenging aspect of symptom control in calciphylaxis, and historically, patients suffering from calciphylaxis required high dose opioid medications to achieve satisfactory analgesia.This case report presents a multimodal pain management approach utilizing low dose ketamine infusion in an opioid-tolerant patient suffering from severe calciphylaxis-related pain. Ketamine is an anesthetic agent well established for its efficacy in the management of neuropathic pain in opioid-tolerant patients, and has been shown to prevent opioid-induced hyperalgesia and decrease opioid requirements. Prior published data studying pain control in calciphylaxis have mainly focused on subcutaneous ketamine administration which as noted in the literature, can be associated with infusion site complications. To the best of our knowledge, this report is first of its kind to describe successful use of ketamine infusion in treatment of acute calciphylaxis-related pain.Dose modification of ketamine is not required for patients with impaired renal function, and low dose intravenous ketamine infusion was associated with no reported adverse effects in our patient.