Subanesthetic ketamine for pain management in hospitalized children, adolescents, and young adults: a single-center cohort study

Kathy A Sheehy,1,* Caroline Lippold,1,* Amy L Rice,1 Raissa Nobrega,1 Julia C Finkel,1 Zenaide MN Quezado1,2 1Division of Anesthesiology, Pain, and Perioperative Medicine, The Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s Research Institute, Children’s National Health System, George Washington University School of Medicine and Health Sciences, 2Center for Neuroscience Research, Children’s Research Institute, Children’s National Health System, Washington, DC, USA *These authors contributed equally to this work Background: Subanesthetic doses of ketamine, an N-methyl-D-aspartate receptor antagonist used as an adjuvant to opioid for the treatment of pain in adults with acute and chronic pain, have been shown, in some instances, to improve pain intensity and to decrease opioid intake. However, less is known about the role of ketamine in pain management in children, adolescents, and young adults. Purpose: We examined the effects of subanesthetic ketamine on pain intensity and opioid intake in children, adolescents, and young adults with acute and chronic pain syndromes treated in an inpatient setting. Methods: This is a longitudinal cohort study of patients treated with subanesthetic ketamine infusions in regular patient care units in a tertiary pediatric hospital. Primary outcomes included changes in pain scores and morphine-equivalent intake. Results: The study cohort included 230 different patients who during 360 separate hospital admissions received subanesthetic ketamine infusions for pain management. Overall, ketamine infusions were associated with significant reductions in mean pain scores from baseline (mean pain scores 6.64 [95% CI: 6.38–6.90]) to those recorded on the day after discontinuation of ketamine (mean pain scores 4.38 [95% CI: 4.06–4.69]), p<0.001. Importantly, the effect of ketamine on pain scores varied according to clinical diagnosis (p=0.011), infusion duration (p=0.004), and pain location (p=0.004). Interestingly, greater reductions in pain scores were observed in patients with cancer pain and patients with pain associated with pancreatitis and Crohn’s disease. There were no records of psychotomimetic side effects requiring therapy. Conclusion: These data suggest that administration of subanesthetic ketamine for pain management is feasible and safe in regular inpatient care units and may benefit children, adolescents, and young adults with acute and chronic pain. This study is informative and can be helpful in determining sample and effect sizes when planning clinical trials to determine the role of subanesthetic ketamine infusions for pain management in pediatric patients. Keywords: cancer pain, sickle cell disease, CRPS, postoperative pain, chronic pain, acute pai