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Dissociative Anaesthetic / Procedural Sedation Pregnancy: Avoid in pregnancy unless essential

Ketamine

Brand names: Ketalar

Adult dose

Dose: 1-2 mg/kg IV or 4-6 mg/kg IM
Route: IV / IM
Frequency: Single dose for induction; titrate for sedation
Max: As per anaesthetic protocol
IV: give slowly over 60 seconds; IM: suitable when IV access unavailable

Paediatric dose

Dose: 1-2 mg/kg IV; 4-6 mg/kg IM mg/kg
Route: IV / IM
Frequency: Single dose; may supplement with 0.5-1 mg/kg IV
Max: See protocol; typically 500 mg total
Procedural sedation: 1-2 mg/kg IV over 1 min or 4-6 mg/kg IM. Onset IV 60 sec, IM 5 min. Duration 10-15 min IV, 15-30 min IM. Use with atropine to reduce hypersalivation; consider midazolam to reduce emergence phenomena in older children

Dose adjustments

Renal

Use with caution; consider dose reduction

Hepatic

Use with caution in severe hepatic impairment

Paediatric weight-based calculator

Procedural sedation: 1-2 mg/kg IV over 1 min or 4-6 mg/kg IM. Onset IV 60 sec, IM 5 min. Duration 10-15 min IV, 15-30 min IM. Use with atropine to reduce hypersalivation; consider midazolam to reduce emergence phenomena in older children

Clinical pearls

  • Ketamine is a dissociative NMDA receptor antagonist — preserves airway reflexes and maintains haemodynamic stability, making it preferred for paediatric procedural sedation
  • Unique advantage: bronchodilator properties make it useful in severe asthma with respiratory failure
  • Emergence phenomena more common in adults and older adolescents; benzodiazepine pre-medication reduces risk
  • Controlled Drug (CD) — Schedule 4 Part I in UK
  • Sub-anaesthetic doses (0.1-0.3 mg/kg IV) used for acute pain management in paediatric ED

Contraindications

  • Conditions where hypertension is hazardous
  • Raised intracranial pressure (relative)
  • Psychosis
  • Uncontrolled thyroid disease (relative)

Side effects

  • Hypertension
  • Tachycardia
  • Laryngospasm (rare)
  • Hypersalivation
  • Emergence phenomena (hallucinations, nightmares — less common in children under 10)
  • Raised intraocular pressure
  • Nausea and vomiting

Interactions

  • Benzodiazepines (reduce emergence phenomena, extend sedation)
  • Atropine (co-prescribed to reduce hypersalivation)
  • Halothane (cardiac sensitisation)

Monitoring

  • Continuous SpO2
  • Heart rate
  • Blood pressure
  • Level of consciousness
  • Airway patency

Reference: BNF for Children; RCEM Guideline on Procedural Sedation in Children; NICE CG132. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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