What is the recommended dose of ketamine (intravenous anesthetic) for procedural sedation in pediatric patients undergoing wrist fracture reduction?

Ketamine Dosage for Pediatric Wrist Fracture Reduction

For pediatric wrist fracture reduction, intravenous ketamine should be administered at a dose of 1-1.5 mg/kg, while intramuscular administration requires 4 mg/kg. 1, 2

Route-Specific Dosing

Intravenous (IV) Administration

• Initial dose: 1-1.5 mg/kg IV
• Onset of action: 1-2 minutes (average 1.7 minutes) 3
• Duration of optimal sedation: 20-30 minutes 2, 3
• Consider lower initial dose (1 mg/kg) for older children/adolescents 1, 4

Intramuscular (IM) Administration

• Dose: 4 mg/kg IM 1, 5
• Onset of action: 4-8 minutes (average 8.6 minutes) 3
• Duration of optimal sedation: 35-40 minutes 3
• Consider when IV access is difficult or unavailable

Clinical Considerations

Efficacy

• Both IV and IM ketamine provide excellent sedation for fracture reduction with 100% adequacy of sedation in high-quality studies 1
• IV ketamine at 1.5 mg/kg requires fewer additional doses compared to 1 mg/kg (median 1 vs 2 doses) 4
• Patients receiving 1 mg/kg IV ketamine more frequently require a third dose to complete sedation (18.5% vs 7.6% with 1.5 mg/kg) 4

Safety Profile

• Respiratory complications are rare (1.4% incidence) 2
• Emesis occurs in approximately 6.7-19.4% of pediatric cases 2
• Emergence reactions occur in about 17.6% of pediatric cases, with 1.6% being moderate to severe 2
• Hypoxemia (SpO₂ <90%) occurs in approximately 1.6% of cases with ketamine alone 1

Recovery and Monitoring

• Average recovery time: 60-90 minutes 2
• Time to discharge: 65-85 minutes (range 22-215 minutes) 1, 2, 3
• Monitor continuously with pulse oximetry, vital signs, airway patency, and respiratory effort throughout procedure and recovery 2

Adjunctive Medications

Anticholinergics

• Consider glycopyrrolate (5 μg/kg IV) or atropine (0.01 mg/kg IV, minimum 0.1 mg, maximum 0.5 mg) to reduce secretions 1

Benzodiazepines

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

Common Pitfalls and Caveats

1. Dosing errors: Using adult doses in children can lead to inadequate sedation. Pediatric patients typically require higher mg/kg doses than adults 2

2. Inadequate initial dosing: Starting with 1 mg/kg IV often requires additional doses. Consider 1.5 mg/kg IV for more reliable single-dose sedation 4

3. Insufficient monitoring: Always maintain continuous monitoring of vital signs and oxygen saturation throughout the procedure and recovery period 2

4. Premature discharge: Recovery time varies widely (22-215 minutes); ensure full recovery before discharge 1, 2

5. Failure to prepare for adverse events: Have airway equipment and reversal agents immediately available 2

By following these evidence-based dosing recommendations and monitoring protocols, ketamine provides safe and effective procedural sedation for pediatric wrist fracture reduction with minimal complications.