Fig. 1
Effect of ketamine infusions on pain scores (numeric rating scale) in children and adolescents with chronic pain. The box plots show the data’s median and interquartile range and the whiskers the 5th and 95th percentiles. a Box plots of pain scores at baseline (white) and after ketamine infusions (gray) in all patients. Subanesthetic ketamine infusions in an outpatient setting significantly reduced pain scores (p <0.001). b Effect of ketamine infusions on pain scores according to pain diagnoses of complex regional pain syndrome (CRPS) or other chronic pain syndromes. The reductions in pain scores after ketamine infusions were significantly greater in patients with CRPS than in patients with other chronic pain syndromes (p = 0.029). c Box plots of pain scores at baseline (white) and after ketamine infusion (gray) for patients with history of trauma, postural orthostatic tachycardia syndrome (POTS), chronic headache (HA), malignancy (CA), and other associated condition (sickle cell, diabetes). The reductions in pain scores after ketamine infusions were the greatest in trauma and POTS patients and the lowest in patients with chronic headache (p = 0.007 for overall difference)