Ketamine Complete Drug Review
- Ketamine is also called as dissociative anesthesia, It can be given by Oral, IV and IM routes .
- Ketamine causes sympathetic stimulation which leads to feeling of excitement.
- Ketamine was first used by Domino and corsen.
- Ketamine causes profound analgesia.
IV Dose of ketamine is : 1-2 mg/kg body weight
IM Dose of Ketamine is : 5-10 mg/kg body weight
Onset of action of ketamine : 10 min (IM) and 60 second (IV)
Half life of ketamine : 2-3 hours
Effects of Ketamine in different Systems
- Ketamine increases the Bronchial secretions, it also stimulates respiration , Ketamine can be used for the full stomach patients because pharyngeal and laryngeal reflexes are preserved.
Central Nervous System
- Ketamine is the strongest analgesic among all the intravenous anesthetics, it is also called as the dissociative anesthesia because it creates the feeling of dissociated from the environment after the induction by stimulating the limbic system and inhibiting the Cortical and thalamus function .
- Ketamine also causes the vivid dream and hallucinations which can be reduced by injecting 1-2 mg of midazolam before injecting the ketamine.
- Ketamine also increases the cerebral blood flow & intracranial pressure so ketamine is contraindicated in the head injury patients .
- Ketamine also causes increase in the cerebral oxygen consumption.
- Ketamine is contraindicated in Hypertensive patients because it increases both systolic and diastolic blood pressure.
- Ketamine increases both blood pressure and pulse rate after induction so Ketamine is the drug of choice for IV anesthetic in shock patients.
- Ketamine increases the intra ocular pressure so this is contraindicated in glaucoma patients .
- Ketamine produces not purposeful muscle movements.
Uses of Ketamine
- Ketamine is the safest anesthetics for the non experienced hands in the rural hospitals because does not depress the respiration .
- Ketamine can be used as the IV anesthetic of choice for the shock patients .
- Ketamine can be used as the solo anesthetic for the minor surgeries cases.
- Ketamine can also be used in case of full stomach patients because it preserves laryngeal reflexes.
- Because of the strong analgesic property Ketamine is the drug of choice for the burn dressings.
- Ketamine is contraindicated for the infants below 3 month but can be used safely in children’s above 3 month.
- Ketamine causes bronchospasm so it should be injected very slowly.
Side effects of Ketamine
- Ketamine increases the bronchial secretions so premedication of atropine is needed before induction.
- Ketamine causes Hallucinations in 40-50 % of the patients and Delirium and vivid dreams in 10 to 30 % of patients, to prevent this short acting benzodiazepines are used before the injection of ketamine.
- Ketamine increases muscle tone, Blood pressure , pulse rate causing tachycardia , intra ocular pressure, Intragastric pressure and intra cranial pressure .