Home Ketamine

Ketamine

Details

Presentation:

200 mg / 2 mL glass ampoule

Route:

  • IV (dilute ketamine 200 mg / 2 mL to 20 mL with 18 mL of Normal Saline (10 mg/mL).
  • Administer IV doses slowly (over at least 1 minute); rapid administration may result in respiratory depression and enhanced hypertensive response
  • IM (do not dilute)
  • IN (add 0.1 mL to required volume to account for dead space in the MAD)

Onset of action:

  • IV 30 seconds (anaesthesia)
  • IM 3 – 4 minutes
  • IN 5 minutes

Peak:

  • IN 20 minutes

Duration:

  • IV 5 – 10 minutes (anaesthesia)
  • IM 12 – 25 minutes
  • IN 45 minutes
Mode of action

Anaesthetic agent with analgesic properties at lower doses.

Exact mechanism of action is unclear, but primarily works as an antagonist at N-methyl-D-aspartate (NMDA) receptors. Ketamine may also interact with opioid, muscarinic and other receptors. Produces a trance-like dissociative state with amnesia, with preservation of laryngeal and pharyngeal reflexes.

  • Intubation
  • Analgesia
  • Sedation:
    • Agitation
    • Patient movement during CPR
  • Suspected non-traumatic brain injury with severe hypertension (SBP > 180)
  • May exacerbate cardiovascular conditions (e.g. uncontrolled hypertension, stroke, recent MI, cardiac failure) due to effects on HR and BP
  • CV: hypertension, tachycardia
  • CNS: emergence reactions (e.g. vivid dreams, restlessness, confusion, hallucinations, irrational behavior); increased skeletal muscle tone (may resemble seizures)
  • Respiratory: transient respiratory depression and apnoea (rare)
  • GI: nausea and vomiting
  • Other: injection site pain, lacrimation, hypersalivation, diplopia, nystagmus
Significant interactions
  • Nil
Pregnancy
  • Considered safe to use
Breastfeeding
  • Monitoring required – observe the infant for potential adverse effects (drowsiness, poor feeding, sleeping pattern changes) (*NB. Unlikely scenario in context of emergency indications)
Notes
  • Ketamine is managed as a restricted medication in AV
  • Emergence reactions associated with ketamine administration for analgesia in adult patients may be managed with midazolam. Consultation with the RCH is required to administer midazolam to paediatric patients
Infusion
  • AAV only: Ketamine 50mg added to make 50 mL with Dextrose 5% or Normal Saline to make 1 mg/mL dilution

Quiz