Short (low-dose) ketamine infusion for managing acute pain in the ED: case-report series

A convenience sample of 14 patients received an analgesic dose of ketamine infusion for acute pain in the emergency department (ED). Low-dose ketamine (LDK) was defined as the administration of 0.2 to 0.4 mg/kg of ketamine, and infusion was defined as a drip of ketamine diluted in 50 to 100 mL of normal saline piggyback administered over 10 to 15 minutes. Pain intensity was measured using validated numeric rating scale in 8 of the 14 cases, 5 were documented nonquantitatively, and 1 case was not documented. Fourteen cases in which patients received LDK infusion in the ED were identified. Doses ranged from 10 to 35 mg. Patients received opioids in the ED before LDK infusion in 12 of the 14 cases. Significant improvement in pain was observed in 11 of the 14 cases. None of the patients required rescue analgesia. Two patients reported mild adverse reactions. The administration of analgesic dose of ketamine infusion in the ED may be a safe and effective analgesic modality for ED patients with acute painful conditions who have a history of chronic opioid use or who are refractory to opioid pain medications. More prospective randomized controlled trials are needed before widespread use of LDK infusion for analgesia in the ED can be recommended.