Ketamine and Propofol

Ketamin

Phencyclidine, which shares pharmacological similarities with the hallucinogen, causes dissociative anesthesia, a state in which a person feels cut off from both their own body and their surroundings.

Mechanism of Action

• It inhibits NMDA receptors, affecting the binding of glutamate, an excitatory neurotransmitter.

Indication

• Mainly in children & adult of short operation.
• Inducing agent before general anaesthesia.
• Maintenance of anaesthesia.

Dose

• Induction total dose of 0.5-2 mg/kg and maintenance dose 20-80 mcg/min
• IV Ketamine: Induction: Ketamine 1- 2mg / k * g Atropine 10-20mcg/kg and Diazepam 0.1mg / k * g
• There are several options for maintenance :Intermittent boluses of IV Ketamine 0.5mg / k * g given according to patient's response - pupil size, heart rate, blood pressure, movement etc
• IM Ketamine: Induce anaesthesia with IM Ketamine 5 - 10mg / k * g and Atropine 20mcg/kg and Diazepam 0.1mg/kg.

Contraindication

• Hypertension, history of chronic alcoholism, history of CVA, history of psychatric disorder.

Side Effects

• Emergence reactions, hypertension, increased cardiac output, increased ICP, tachycardia, tonic-clonic movements, visual hallucination, vivid dreams, increased salivation.

Nursing Consideration:

• It is also known as dissociative anesthesia. It means that the person experiencing it feels alienated from their surroundings.
• Rapid induction takes place, and within 10 to 15 minutes, emergence begins.
• Unpleasant psychological responses may occur when recovering.
• It can take many hours for a full recovery.
• The patient has to be kept in a calm environment.
• The primary use is for simple surgical operations.

Propofol

It is an intravenous general anesthetic that is a hindered phenolic chemical. It is the preferred anesthetic for daycare facilities.

Mechanism of Action

It is a diisoprophylphenol, an IV hypnotic, which induces anaesthesia quickly and with little excitatory activity.

Indication

• Induction & maintenance of general anaesthesia.
• It is drug of choice for sedating intubated patient in ICU.

Dose

• 2mg/kg bolus IV for induction 9mg/kg/hr for maintenance.

Contraindication

• Poor respiratory status, children under 3 years, labor & delivery.

Side Effects

• Hypotension, dystonic or choreiform movement, apnea, arrhythmia, bradycardia, tachycardia, pruritus, hyperlipidemia, respiratory acidosis, myocardial dysfunction, 
• Burning, stinging, pain at the site of injection.