Extensive Ketamine Flashcards

What class of drug is ketamine?

Anaesthetic and analgesic.

What is the mechanism of action of ketamine?

NMDA receptor antagonist → produces analgesia & dissociation; at low doses: analgesia with preserved airway reflexes & respiratory drive; at higher doses: induction of anaesthesia.

How does ketamine affect haemodynamics compared to other anaesthetics?

Minimal haemodynamic compromise; acts as a sympathomimetic → can cause transient hypertension & tachycardia.

How is ketamine metabolised and excreted?

Extensive hepatic metabolism; ~90% excreted in urine as metabolites.

What are the QAS indications for ketamine?

Severe traumatic pain (with prior opioid use), severe pain with burns (with opioid + midazolam), ongoing traumatic pain unresponsive to narcotics, induction of anaesthesia, acute behavioral disturbance (SAT ≥ 2) unresponsive to droperidol.

What are the contraindications for ketamine (analgesia use)?

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.

What is the contraindication for ketamine use in induction of anaesthesia?

Allergy/adverse drug reaction.

What precautions must be considered with ketamine?

Age >65 years, concomitant midazolam or other CNS depressants, significant hypovolaemia, globe or complex facial injuries, impaired respiratory function, psychotic symptoms.

What are the side effects of ketamine?

Dissociation, trance-like state, transient hypertonicity, nystagmus, disinhibition, emergence reactions, hypertension, tachycardia, depression of consciousness, hypersalivation, nausea/vomiting, laryngospasm, rare respiratory depression.

What is the IV onset of ketamine?

~30 seconds.

What is the IV duration of ketamine?

5–20 minutes.

What is the half-life of ketamine?

10–15 minutes.

How is ketamine presented for QAS use?

Ampoule, 200 mg/2 mL ketamine hydrochloride.

What schedule drug is ketamine?

Schedule 8 (S8 – Controlled drug).

What routes can ketamine be given by QAS?

IV, IO, IM.

What is the IV dose of ketamine for severe traumatic pain?

10–30 mg IV, repeated every 2–3 min. Max 1 mg/kg.

What is the IV/IO dose of ketamine for induction of anaesthesia?

0.25–2 mg/kg IV/IO, single dose only. Max 150 mg (adult).

What is the IM dose of ketamine for acute behavioural disturbance (≥16 yrs)?

200 mg IM, single dose only.

What is the IM dose of ketamine for acute behavioural disturbance (12–15 yrs)?

2 mg/kg IM, single dose only.

What is the IV ketamine dose for paediatric traumatic pain (>1 year)?

0.1–0.3 mg/kg IV, repeated every 2–3 min. Max 1 mg/kg.

What is the IV/IO ketamine dose for paediatric induction of anaesthesia?

0.25–2 mg/kg IV/IO, single dose only. Max 100 mg.

What is the IM ketamine dose for paediatric burns (with opioid + midazolam)?

0.1–0.3 mg/kg IV (or IO), repeated every 2–3 min. Max 1 mg/kg.

What must be done after max analgesia dose (1 mg/kg) of ketamine?

QAS Clinical Consultation and Advice Line must be consulted before further administration.

When can midazolam be given with ketamine?

Only if patient displays significant emergence reactions not resolved by reassurance.

How should ketamine be prepared for IV analgesia (adult)?

Mix 200 mg (2 mL) with 18 mL NaCl 0.9% → 10 mg/mL solution.

How should ketamine be prepared for paediatric IV analgesia?

Dilute further to 1 mg/mL for accurate weight-based dosing.