Extensive Ketamine Flashcards
Ketamine
Drug Class & Pharmacology
Q: What class of drug is ketamine?
A: Anaesthetic and analgesic .
Q: What is the mechanism of action of ketamine?
A: NMDA receptor antagonist → produces analgesia & dissociation. At low doses: analgesia with preserved airway reflexes & respiratory drive. At higher doses: induction of anaesthesia .
Q: How does ketamine affect haemodynamics compared to other anaesthetics?
A: Minimal haemodynamic compromise; acts as a sympathomimetic → can cause transient hypertension & tachycardia .
Q: How is ketamine metabolised and excreted?
A: Extensive hepatic metabolism; ~90% excreted in urine as metabolites .
Indications
Q: What are the QAS indications for ketamine?
A:
Severe traumatic pain (with prior opioid use) associated with:
Fracture reduction & splinting
Multiple/significant fractures needing extrication
Splinted fractures requiring ongoing analgesia during transport
Severe traumatic pain associated with burns (with opioid + midazolam)
Ongoing traumatic pain unresponsive to narcotics
Induction of anaesthesia
Acute behavioural disturbance (SAT ≥ 2) unresponsive to droperidol
Contraindications
Q: What are the contraindications for ketamine (analgesia use)?
A:
Allergy/adverse drug reaction
Age <1 year
GCS ≤ 12
Uncontrolled hypertension (SBP ≥ 180 or DBP ≥ 110 mmHg)
Suspected ACS or acute heart failure
Known hydrocephalus or raised intraocular pressure
Q: What is the contraindication for ketamine use in induction of anaesthesia?
A: Allergy/adverse drug reaction
Precautions
Q: What precautions must be considered with ketamine?
A:
Age >65 years
Concomitant midazolam or other CNS depressants
Significant hypovolaemia
Globe or complex facial injuries
Impaired respiratory function
Psychotic symptoms
Side Effects
Q: What are the side effects of ketamine?
A:
Dissociation, trance-like state
Transient hypertonicity, nystagmus
Disinhibition, emergence reactions
Hypertension, tachycardia
Depression of consciousness
Hypersalivation
Nausea/vomiting
Laryngospasm
Rare respiratory depression
Onset, Duration & Half-life
Q: What is the IV onset of ketamine?
A: ~30 seconds
Q: What is the IV duration of ketamine?
A: 5–20 minutes
Q: What is the half-life of ketamine?
A: 10–15 minutes
Presentation
Q: How is ketamine presented for QAS use?
A: Ampoule, 200 mg/2 mL ketamine hydrochloride
Schedule
Q: What schedule drug is ketamine?
A: Schedule 8 (S8 – Controlled drug)
Routes of Administration
Q: What routes can ketamine be given by QAS?
A: IV, IO, IM
Adult Doses
Q: What is the IV dose of ketamine for severe traumatic pain?
A: 10–30 mg IV, repeated every 2–3 min. Max 1 mg/kg
Q: What is the IV/IO dose of ketamine for induction of anaesthesia?
A: 0.25–2 mg/kg IV/IO, single dose only. Max 150 mg (adult)
Q: What is the IM dose of ketamine for acute behavioural disturbance (≥16 yrs)?
A: 200 mg IM, single dose only
Q: What is the IM dose of ketamine for acute behavioural disturbance (12–15 yrs)?
A: 2 mg/kg IM, single dose only
Paediatric Doses
Q: What is the IV ketamine dose for paediatric traumatic pain (>1 year)?
A: 0.1–0.3 mg/kg IV, repeated every 2–3 min. Max 1 mg/kg
Q: What is the IV/IO ketamine dose for paediatric induction of anaesthesia?
A: 0.25–2 mg/kg IV/IO, single dose only. Max 100 mg
Q: What is the IM ketamine dose for paediatric burns (with opioid + midazolam)?
A: 0.1–0.3 mg/kg IV (or IO), repeated every 2–3 min. Max 1 mg/kg
Special Notes
Q: What must be done after max analgesia dose (1 mg/kg) of ketamine?
A: QAS Clinical Consultation and Advice Line must be consulted before further administration
Q: When can midazolam be given with ketamine?
A: Only if patient displays significant emergence reactions not resolved by reassurance
Q: How should ketamine be prepared for IV analgesia (adult)?
A: Mix 200 mg (2 mL) with 18 mL NaCl 0.9% → 10 mg/mL solution
Q: How should ketamine be prepared for paediatric IV analgesia?
A: Dilute further to 1 mg/mL for accurate weight-based dosing