A randomized comparison of nitrous oxide plus hematoma block versus ketamine plus midazolam for emergency department forearm fracture reduction in children

Pediatrics. 2006 Oct;118(4):e1078-86. doi: 10.1542/peds.2005-1694. Epub 2006 Sep 11.


Objectives: Ketamine provides effective and relatively safe sedation analgesia for reduction of fractures in children in the emergency department. However, prolonged recovery and adverse effects suggest the opportunity to develop alternative strategies. We compared the efficacy and adverse effects of ketamine/midazolam to those of nitrous oxide/hematoma block for analgesia and anxiolysis during forearm fracture reduction in children.

Methods: Children 5 to 17 years of age were randomly assigned to receive intravenous ketamine (1 mg/kg)/midazolam (0.1 mg/kg; max: 2.5 mg) or 50% nitrous oxide/50% oxygen and a hematoma block (2.5 mg/kg of 1% buffered lidocaine). All of the children received oral oxycodone 0.2 mg/kg (max: 15 mg) at triage > or = 45 minutes before reduction. Videotapes were obtained before (baseline), during (procedure), and after (recovery) reduction and scored using the Procedure Behavioral Checklist by an observer blinded to study purpose. The primary outcome measure was the mean change in Procedure Behavioral Checklist score from baseline to procedure, with greater change indicating greater procedure distress. Other outcome measures of efficacy included recovery times and visual analog scale scores to assess patient distress, parent report of child distress, and orthopedic surgeon satisfaction with sedation. Adverse effects were assessed during the emergency visit and by telephone 1 day after reduction. Data were analyzed using repeated measures, that is, analysis of variance, chi2, and t tests.

Results: There were 102 children (mean age: 9.0 +/- 3.0 years) who were randomly assigned. There was no difference in age, race, gender, and baseline Procedure Behavioral Checklist scores between ketamine/midazolam (55 subjects) and nitrous oxide/hematoma block (47 subjects). Mean changes in Procedure Behavioral Checklist scores were very small for both groups. The mean change in Procedure Behavioral Checklist was less for nitrous oxide/hematoma block, and patients and parents reported less pain during fracture reduction with nitrous oxide/hematoma block. Recovery times were markedly shorter for nitrous oxide/hematoma block compared with ketamine/midazolam. Orthopedic surgeons were similarly satisfied with the 2 regimens. Of the ketamine/midazolam subjects, 11% had O2 saturations < 94%. Other adverse effects occurred in both groups, but more often in ketamine/midazolam both during the emergency visit and at 1-day follow-up.

Conclusions: In children who had received oral oxycodone, both nitrous oxide/hematoma block and ketamine/midazolam resulted in minimal increases in distress during forearm fracture reduction at the doses studied. The nitrous oxide/hematoma block regimen had fewer adverse effects and significantly less recovery time.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Analgesics / adverse effects
  • Analgesics / therapeutic use*
  • Analgesics, Non-Narcotic / adverse effects
  • Analgesics, Non-Narcotic / therapeutic use*
  • Anesthetics, Local / adverse effects
  • Anesthetics, Local / therapeutic use*
  • Anti-Anxiety Agents / adverse effects
  • Anti-Anxiety Agents / therapeutic use*
  • Child
  • Child, Preschool
  • Drug Therapy, Combination
  • Female
  • Fracture Fixation* / adverse effects
  • Fracture Fixation* / methods
  • Humans
  • Ketamine / adverse effects
  • Ketamine / therapeutic use*
  • Lidocaine / adverse effects
  • Lidocaine / therapeutic use*
  • Male
  • Midazolam / adverse effects
  • Midazolam / therapeutic use*
  • Nitrous Oxide / adverse effects
  • Nitrous Oxide / therapeutic use*
  • Oxycodone / administration & dosage
  • Pain / etiology
  • Pain / prevention & control
  • Pain Measurement
  • Prospective Studies
  • Radius Fractures / therapy
  • Stress, Psychological
  • Treatment Outcome
  • Ulna Fractures / therapy


  • Analgesics
  • Analgesics, Non-Narcotic
  • Anesthetics, Local
  • Anti-Anxiety Agents
  • Ketamine
  • Lidocaine
  • Oxycodone
  • Nitrous Oxide
  • Midazolam