Ketamine anesthesia in children--exploring infusion regimens

Area of Science:

• Pediatric Anesthesiology
• Pharmacokinetics
• Drug Infusion Regimens

Background:

• Establishing safe and effective anesthetic protocols for pediatric patients is crucial.
• Racemic ketamine is a widely used anesthetic agent, but specific infusion regimens for children require optimization.
• Understanding age-related pharmacokinetic differences is essential for accurate drug dosing.

Purpose of the Study:

• To design a manual ketamine infusion regimen for children aged 1.5-12 years.
• To achieve and maintain a steady-state blood concentration of ketamine associated with anesthesia.
• To simulate and predict ketamine blood concentrations during infusions in this pediatric population.

Main Methods:

• Literature review to identify ketamine concentrations associated with anesthesia in humans.
• Utilized pharmacokinetic parameter estimates from published pediatric infusion studies.
• Employed pharmacokinetic simulation software to predict ketamine blood concentrations.
• Incorporated a 10% variability allowance around the target concentration.

Main Results:

• A target concentration of 3 mg/L was selected for simulation.
• A specific loading dose and tiered infusion rate regimen was determined for children (1.5-12 years).
• Simulated steady-state concentrations reached the 3 mg/L target.
• Anticipated arousal approximately 3 hours and 47 minutes after a 2-hour infusion in a 6-year-old.
• Shorter context-sensitive half-times were observed in children compared to adults.

Conclusions:

• Children require higher ketamine infusion rates than adults to achieve similar steady-state concentrations.
• Age-related pharmacokinetic variations influence ketamine dosing and recovery profiles in children.
• Prolonged infusions may lead to delayed return to consciousness, suggesting potential benefits of lower target concentrations with adjuvant anesthetics.