It is metabolized by the liver and has one major metabolite, norketamine, which is 33% potency of the parent compound. Ketamine is a schedule III drug, defined as a drug with a lower potential for abuse than illegal schedule I drugs, or controlled schedule II narcotics, with currently accepted medical use, with potential for abuse that may lead to low-moderate physical dependence or high psychological dependence. It modulates the opioid receptors and causes that dissociative state which may lead to psychological and potentially physical dependence. Additional precautions are applied to its use overall, and include airway complication in the form of cardiovascular effects, laryngospasms, CNS depression, dependence, emergence reactions. Absolute contraindications for its use include hypersensitivity to ketamine, and in any medical condition that increased blood pressure would be hazardous, cause end-organ damage or acute decompensation. This is due to transient sympathetic stimulation of the heart, which transiently increases blood pressure, heart rate, and cardiac output. The exact mechanism is unknown. Relative contraindications for ketamine are reasoned based on the precautions for use. Again, for its sympathomimetic effects on the heart, increased intracranial, intraocular and cerebrospinal fluid pressures, porphyria, and hyperthyroidism are relative contraindications for ketamine’s use. For the risk of …show more content…
Given examples include fracture reduction, laceration repair and abscess drainage, burn debridement, central line placement, and tube thoracostomy. Levels of sedation are also detailed in the guidelines. In these guidelines ketamine is described in terms of procedural, dissociative and deep sedation. Procedural sedation involves administering sedatives or dissociative agents with or without analgesics to intentionally suppress a patient’s level of consciousness. Dissociative sedation is reserved for ketamine, reaching that cataleptic state with immobilization and loss of sensation, but with retention of cardiopulmonary function and stability. Deep sedation is a level of sedation in which a patient cannot be easily aroused but will respond purposefully to repeated or painful stimulation. Usually agents such as midazolam, propofol and etomidate are used but carry the risk of respiratory depression seen that are dose-dependent. The 2011 update to the specific ACEP guidelines for use of ketamine reports the dissociative effects and sedation are observed in doses of 1.0 to 1.5 mg/kg IV bolus over 30-60 seconds, or a 3 to 4 mg/kg IM injection4. IV is preferred over IM for faster recovery to normal mentation.