What is the recommended dosage and administration of ketamine for acute pain management and sedation in pediatric patients?

Ketamine Dosing and Administration for Pediatric Acute Pain Management and Sedation

Recommended Dosing Regimens

For pediatric procedural sedation and analgesia, administer ketamine at 1.5-2 mg/kg IV or 4 mg/kg IM, with continuous vital sign monitoring throughout the procedure. 1

Intravenous Administration

• The optimal IV dose is 1.5-2 mg/kg, which requires supplemental dosing in only 5.5% of patients compared to 54% when using the inadequate 1 mg/kg dose 1, 2
• Onset of adequate sedation occurs within 30-96 seconds, allowing rapid procedural intervention 1, 3
• Average total sedation time is 75-78 minutes, with recovery averaging 84 minutes (range 22-215 minutes) 4, 1
• Procedural completion success rate reaches 98.9% with appropriate dosing 3

Intramuscular Administration

• Administer 4 mg/kg IM when IV access is unavailable or impractical, with onset of action within 3-4 minutes 1, 3
• Repeat doses of 2-4 mg/kg may be given after 5-10 minutes if needed 1
• IM administration combined with 0.01 mg/kg atropine provides faster onset (3 minutes vs 18 minutes) and shorter discharge time compared to alternative sedatives 1
• Average recovery time with IM ketamine is approximately 90 minutes (range 60-130 minutes) 4, 1

Essential Adjunctive Medications

Atropine Co-administration

• Administer atropine 0.01 mg/kg (minimum 0.1 mg, maximum 0.5 mg) with ketamine to prevent hypersalivation and potentially reduce post-procedural vomiting 1, 3
• The combination demonstrates superior efficacy with faster onset and shorter discharge times 3

Midazolam Considerations

• Consider adding midazolam 0.05-0.1 mg/kg IV to reduce emergence reactions, particularly in children over 10 years old 1, 3
• Midazolam reduces recovery agitation in patients >10 years from 35.7% to 5.7% 1
• However, midazolam does not decrease overall sedation time or recovery agitation in younger children 4
• The combination provides 100% procedure completion rates 1

Monitoring Requirements

Continuous monitoring is mandatory and must include: 1, 3

• Pulse oximetry with oxygen saturation maintained >93% on room air 1
• Heart rate monitoring (expect 18% increase from baseline) 4
• Blood pressure monitoring
• Capnography when available 1
• Vital signs documented at least every 5 minutes during deep sedation 1

Expected Adverse Effects and Management

Common Side Effects

• Emesis occurs in 6.7-19.4% of patients, associated with increasing age 4, 1, 3
• Recovery agitation occurs in 7.1-17.6% of patients, more common in younger children and higher ASA status 4, 1
• Increased salivation in 17.6% (prevented by atropine) 4
• Nausea in 4-5% of patients 3

Respiratory Complications

• Hypoxemia occurs in 1.6-7.3% of patients, typically transient and responsive to supplemental oxygen 1, 3
• Laryngospasm occurs in 0.9-1.4% of cases 3
• Bag-valve-mask ventilation required in approximately 2% of cases 1
• No episodes of clinically significant respiratory depression requiring intubation have been reported in large pediatric series 1

Critical Pitfalls to Avoid

The most common error is underdosing ketamine, particularly using 1 mg/kg IV instead of the recommended 1.5-2 mg/kg, which results in inadequate sedation requiring supplemental doses in over 50% of patients 1, 3, 2

Contraindications

Avoid ketamine in patients with: 1, 3

• Active psychosis
• Ischemic heart disease or uncontrolled cardiovascular disease
• Cerebrovascular disease
• Uncontrolled hypertension
• Elevated intracranial or intraocular pressure
• Severe hepatic dysfunction

Age-Specific Dosing Considerations

• Younger children require higher doses per kilogram to achieve adequate sedation 5, 6
• Recovery agitation is inversely associated with age (more common in younger children) 1
• Emesis risk increases with age 1
• Consider midazolam co-administration specifically for children >10 years to reduce emergence reactions 1