What is the recommended dose of ketamine (intravenous anesthetic) for pediatric wrist fracture reduction?

Ketamine Dosage for Pediatric Wrist Fracture Reduction

The recommended dose of ketamine for pediatric wrist fracture reduction is 1-1.5 mg/kg IV or 4 mg/kg IM, with consideration of a lower initial dose (1 mg/kg) for older children/adolescents. 1

Dosing Guidelines

Intravenous (IV) Administration

• Standard dose: 1-1.5 mg/kg IV 1
• Initial dose considerations:
  • Consider 1 mg/kg for older children/adolescents 1
  • Lower doses (0.5-1.0 mg/kg) may be effective in many cases 2
  • 88% of pediatric patients can be successfully sedated with 1 mg/kg or less 2
• Administration technique:
  • Administer slowly over 60 seconds to prevent respiratory depression 3
  • Can be given as an IV infusion at 0.5 mg/kg/min for induction 3

Intramuscular (IM) Administration

• Standard dose: 4 mg/kg IM 1
• Onset of action: 3-4 minutes (vs. 30 seconds for IV) 3
• Duration of effect: 12-25 minutes 4

Efficacy and Timing Considerations

• IV ketamine:

  • Onset of action: approximately 1.7 minutes 5
  • Duration of optimal sedation: 20.6 minutes 5
  • Time to discharge: 65.3 minutes 5

• IM ketamine:

  • Onset of action: approximately 8.6 minutes 5
  • Duration of optimal sedation: 37.2 minutes 5
  • Time to discharge: 72.2 minutes 5

Adjunctive Medications

• Consider antisialagogue administration prior to ketamine:

  • Glycopyrrolate (5 μg/kg IV) or
  • Atropine (0.01 mg/kg IV, minimum 0.1 mg, maximum 0.5 mg) 1

• Midazolam considerations:

  • Adding midazolam (0.05-0.1 mg/kg IV) does not decrease recovery agitation in children under 10 years
  • May increase risk of desaturation (7.3% vs 1.6% with ketamine alone)
  • May decrease emesis (9.6% vs 19.4% with ketamine alone) 1

Monitoring Requirements

• Continuous monitoring with:

  • Pulse oximetry
  • Vital signs
  • Airway patency assessment
  • Respiratory effort evaluation 1

• Emergency airway equipment must be immediately available 3

Adverse Events to Anticipate

• Hypoxemia (SpO₂ <90%): occurs in approximately 1.6% of cases 1
• Emesis: occurs in approximately 6.7-19.4% of pediatric cases 1
• Emergency reactions: reported in 17.6% of pediatric cases, with 1.6% being moderate to severe 1
• Respiratory complications: low incidence (1.4%) 1

Special Considerations

• Higher doses may be needed for younger children compared to adolescents 1
• Allow sufficient time between doses to assess effect (2-5 minutes) 1
• Ketamine preserves protective airway reflexes, which may be beneficial in patients with high aspiration risk 1
• Patients with cardiovascular dysfunction or volume depletion may require dose adjustment 1

Clinical Pearls

• Purposeless and tonic-clonic movements may occur during ketamine anesthesia but do not indicate a light plane or need for additional doses 3
• Recovery is typically complete within 60-90 minutes 1
• Rapid administration technique (≤5 seconds) can be effective with lower doses (0.7-0.8 mg/kg) for short procedures 6