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Anaesthetic Pregnancy: B — use with caution in first trimester

Ketamine

Brand names: Ketalar

Adult dose

Dose: Induction: 1–2mg/kg IV. Sub-dissociative analgesia: 0.1–0.3mg/kg IV
Route: IV / IM
Frequency: Single induction dose; titrated doses for analgesia
RSI induction: 1.5–2mg/kg IV. IM (field/pre-hospital): 4–6mg/kg. Analgesia (adjunct): 0.1–0.3mg/kg IV over 15 min. Pre-treat with midazolam 0.05mg/kg to reduce emergence reactions.

Paediatric dose

Dose: 1.5 mg/kg
Route: IV
Frequency: Single induction dose
Max: 200mg
Concentration: 10 mg/ml
Paediatric weight-based calculator

Clinical pearls

  • Haemodynamic stability: ideal RSI induction agent in hypotensive/shocked patients — maintains BP and HR via sympathomimetic effect.
  • Bronchodilator: drug of choice for intubating patients with severe bronchospasm or status asthmaticus.
  • Sub-dissociative ketamine (0.1–0.3mg/kg IV over 15 min) provides excellent analgesia for fractures, burns, and dislocations without full dissociation.
  • Always have pre-drawn midazolam available to manage emergence reactions.
  • Paed IM route (4mg/kg): reliable when IV access unavailable — onset 3–5 min.

Contraindications

  • Severe or uncontrolled hypertension (SBP >180 mmHg — relative)
  • History of psychosis (relative)
  • Acute porphyria
  • Ischaemic heart disease where tachycardia/hypertension is hazardous (relative)

Side effects

  • Emergence reactions — hallucinations, vivid dreams (reduced by co-administered midazolam)
  • Increased salivation — consider glycopyrrolate 200mcg IV
  • Elevated BP and HR (bronchodilator — beneficial in asthma)
  • Elevated intracranial pressure (may be overstated — not a contraindication in head injury per current evidence)

Interactions

  • Benzodiazepines: reduce emergence reactions and prolong recovery
  • Theophylline: increased seizure risk
  • Volatile anaesthetic agents: enhanced hypotension

Monitoring

  • HR
  • BP
  • SpO₂
  • level of consciousness
  • emergence phenomena

Reference: BNFc; NICE BNF 84; DAS RSI Guidelines 2015; Annals EM Ketamine Review 2019. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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