What are the common drugs and doses used in pediatric anesthesia?

Common Paediatric Anaesthetic Drugs and Doses

The following comprehensive dosing guide is based on the 2024 European Society for Paediatric Anaesthesiology (ESPA) guidelines, which provide the most current evidence-based recommendations for paediatric anaesthetic drug dosing. 1

Induction Agents

Sevoflurane (Inhalational)

• Induction concentration: 6-8% in oxygen/nitrous oxide (50:50) 2
• Maintenance concentration: 1-4% (age-dependent MAC values) 3, 4
• End-tidal concentration for intubation: 2-4% 3
• Note: 6% sevoflurane provides optimal balance between rapid induction and minimal airway irritation 2
• Priming technique: 8% sevoflurane achieves faster induction times 3, 5
• Always use with nitrous oxide during induction to reduce excitation (35% incidence without N₂O vs 5% with N₂O) 5

Remifentanil (IV)

• Induction bolus: 1 mcg/kg over 30-60 seconds (if intubation <8 minutes) 6
• Induction infusion: 0.5-1 mcg/kg/min 6
• Maintenance infusion: 0.05-0.3 mcg/kg/min 1
• Neonates (birth to 2 months): Start at 0.4 mcg/kg/min (may require up to 1.0 mcg/kg/min due to 2× higher clearance) 6
• Critical: Never use as sole induction agent due to high incidence of apnea and muscle rigidity 6

Intraoperative Opioids

Fentanyl

• Intraoperative: 1-2 mcg/kg 1
• PACU breakthrough pain: 0.5-1.0 mcg/kg, titrated to effect 1

Morphine (Age-Dependent Dosing)

• Intraoperative: 25-100 mcg/kg depending on age, titrated to effect 1
• PACU: 25-100 mcg/kg depending on age, titrated to effect 1
• Ward (IV):
  • <3 months: 25-50 mcg/kg every 4-6 hours 1
  • 3-12 months: 50-100 mcg/kg every 4-6 hours 1
  • 1-5 years: 100-150 mcg/kg every 4-6 hours 1
• Oral conversion: Increase daily dose by 2-3× when converting from IV to oral 1

Other Opioids

• Alfentanil: 10-20 mcg/kg 1
• Sufentanil bolus: 0.5-1 mcg/kg 1
• Sufentanil infusion: 0.5-1 mcg/kg/h 1
• Piritramide: 0.05-0.15 mg/kg 1
• Tramadol: 1-1.5 mg/kg, titrated to effect 1
• Nalbuphine: <3 months: 0.05 mg/kg; >3 months: 0.1-0.2 mg/kg 1

Ketamine/S-Ketamine

• Intraoperative bolus: 0.5 mg/kg (reduce to 0.25-0.5 mg/kg for S-ketamine) 1
• Continuous infusion: 0.1-0.2 mg/kg/h (max 0.4 mg/kg/h) 1
• PACU breakthrough: 0.5 mg/kg (0.25-0.5 mg/kg for S-ketamine), titrated to effect 1
• Sedation (bronchoscopy): 0.25-0.5 mg/kg intermittent IV bolus 1

Non-Opioid Analgesics

Paracetamol (Acetaminophen)

• IV loading dose: 15-20 mg/kg 1
• IV maintenance: 10-15 mg/kg every 6-8 hours 1
• Oral: 10-15 mg/kg every 6 hours (max daily dose: 60 mg/kg) 1
• Rectal loading: 20-40 mg/kg (15 mg/kg if <10 kg) - higher dose due to poor bioavailability 1

NSAIDs

Oral:

• Ibuprofen: 10 mg/kg every 8 hours 1
• Diclofenac: 1 mg/kg every 8 hours 1
• Naproxen: 5-7.5 mg/kg every 12 hours 1

Intravenous:

• Ketorolac: 0.5-1 mg/kg (max 30 mg) single intraoperative dose; 0.15-0.2 mg/kg (max 10 mg) every 6 hours (max 48 hours) 1
• Ketoprofen: 1 mg/kg every 8 hours 1
• Ibuprofen: 10 mg/kg every 8 hours 1

Rectal:

• Ibuprofen: 10 mg/kg every 8 hours 1
• Diclofenac: 0.5-1 mg/kg every 8 hours 1

Metamizole

• IV/Oral: 10-15 mg/kg every 8 hours 1
• Continuous infusion: 2.5 mg/kg/h (following loading dose) 1
• Critical warning: Short-term hospital use only due to agranulocytosis risk 1

Adjuvant Medications

Dexmedetomidine

• IV bolus: 0.5-1 mcg/kg 1
• Alternative bolus: 1-3 mcg/kg 1
• Continuous infusion: 0.2-0.7 mcg/kg/h until end of procedure 1

Corticosteroids

• Dexamethasone: 0.15-0.25 mg/kg (max 0.5 mg/kg) 1
• Methylprednisolone: 1 mg/kg 1

Lidocaine (Systemic)

• IV bolus: 1.5 mg/kg 1
• Continuous infusion: 1.5 mg/kg/h until end of procedure 1

Local Anaesthetics for Regional Blocks

Ropivacaine

• Concentration: 0.2% for most applications 7
• Maximum dose with epinephrine: 3 mg/kg 7
• Maximum dose without epinephrine: 2 mg/kg 7
• Infants <6 months: Reduce dose by 30% 7

Volume by Block Type:

• Peripheral nerve blocks/wound infiltration: 1.5 mL/kg (max) 7
• Caudal block: 1.0 mL/kg 7
• Lumbar epidural: 0.5 mL/kg (max 15 mL initially) 7
• Thoracic epidural: 0.2-0.3 mL/kg 7
• Truncal blocks (TAP/Rectus Sheath/Paravertebral): 0.2-0.5 mL/kg per side 7

Bupivacaine

• Concentration: 0.25% 1
• Maximum dose: 2.5 mg/kg (1 mL/kg of 0.25% solution) 1

Lidocaine (Local Infiltration)

• Maximum dose without epinephrine: 4.5 mg/kg 8
• Maximum dose with epinephrine: 7.0 mg/kg 8
• Infants <6 months: Reduce all amide local anaesthetic doses by 30% 8
• Critical: Calculate maximum allowable dose before starting procedure 8

Sedation Agents (for Procedures)

Midazolam

• Anxiolysis: 75-300 mcg/kg IV 1
• Amnesia: 0.5-2 mg/kg IV 1
• Onset: 1-5 minutes; Duration: 90 minutes 1
• Antagonist: Flumazenil 0.01 mg/kg 1

Propofol

• Intermittent bolus: 0.5-1 mg/kg 1
• Continuous infusion: 100 mcg/kg/min 1
• Onset: <1 minute; Duration: 30 minutes 1

Critical Safety Considerations

Age-Specific Dosing Adjustments

• Neonates (<6 months): Reduce amide local anaesthetic doses by 30% 7, 8
• Neonates (remifentanil): Clearance 2× higher than adults; may require increased infusion rates 6
• Elderly (>65 years): Reduce remifentanil starting dose by 50% 6

Monitoring Requirements

• Document vital signs every 5 minutes initially, then every 10-15 minutes once stable when using high-dose local anaesthetics 8
• Have 20% lipid emulsion immediately available for local anaesthetic systemic toxicity (LAST) treatment 7
• Aspirate frequently before injection to avoid intravascular administration 7, 8

Common Pitfalls to Avoid

• Never use remifentanil as sole induction agent - high risk of apnea and muscle rigidity 6
• Never use sevoflurane without nitrous oxide for induction - 35% incidence of excitement 5
• Never use ropivacaine for IV regional anaesthesia (Bier block) - excessive cardiac toxicity risk 7
• Always calculate maximum local anaesthetic dose before starting to prevent cumulative dosing errors 7, 8
• Use atropine pretreatment to blunt bradycardia with remifentanil in neonates 6