Ketamine
Description: Ketamine is a nonbarbiturate, sedative hypnotic used parenterally to provide anesthesia for short diagnostic and surgical procedures. It is also used as an inducing agent, as an adjunct to supplement low-potency anesthetics such as nitrous oxide, and as a supplement to local and regional anesthesia. Ketamine can be used concomitantly with muscle relaxants without complication because it does not provide muscle relaxation of its own. It is a fairly short-acting agent that provides a profound, rapid, dissociative state and a short recovery time. Mechanism: Although the exact mechanism of action is not known, ketamine appears to be an agonist at CNS muscarinic acetylcholine-receptors and opiate-receptors. Ketamine
Similarly, ketamine is relatively contraindicated in patients with increased intracranial pressure, space-occupying intracranial lesions, or CNS hemorrhage because it has been reported to increase the CSF pressure. Ketamine is relatively contraindicated in patients with psychiatric disorders, such as schizophrenia or acute psychosis, because it may exacerbate these conditions. Patients with a history of thyrotoxicosis or taking thyroid hormones because they are at an increased risk of developing tachycardia and hypertension. With proper administration, serious side effects in children are uncommon. Respiratory depression and apnea have been reported but are most likely to occur following rapid administration or high doses of ketamine. In patients receiving ketamine, CNS and psychological adverse effects can occur in as many as 12% of adult patients and include visual hallucinations, nightmares or illusions, and post-anesthesia emergence delirium (often consisting of dissociative or floating sensations). These reactions, however, occur mostly in adult patients and typically last only a few hours. Costs and Monitoring
Relative Drug Costs
• generic available
• Monitoring Parameters
• laboratory monitoring not necessary
Total Cost of Therapy • Because it is relatively safe, ketamine is used regularly in operating rooms in developing countries, with a single physician often both performing