The basic introduction of ketamine

Ketamine, commonly known as Aberdeen, K powder. Ketamine is a very dangerous psychotropic drug, belonging to the Department of non-opiate anesthesia drugs. Ketamine products are mainly found in ketamine hydrochloride, the chemical formula is C13H16ClNO · HCl, molecular weight is 274.19. It is a white powder at room temperature and pressure under the solid material. The melting point of 266 degrees, non-flammable. PH value of 3.5 ~ 5.5, acidic aqueous solution.

Ketamine is a derivative of phencyclidine. Ketamine used clinically is a racemate of the two enantiomers of dextroketamine and L-ketamine. Ketamine is an intravenous general anesthetic, used clinically as anesthesia or anesthesia inducer, has a certain spirit-dependent potential. Selective inhibition of medial thalamus, blocking the spinal cord reticular structure of the uplink conduction, excitement of the limbic system. Ketamine can produce an isolated state of anesthesia, characterized by stiffness-like, shallow sedation, forgetting and significant analgesia, and can enter the dream, hallucinations. Since 1999, ketamine has flowed into Japan, Thailand and Hong Kong.

History of ketamine development

Ketamine was developed by Professor Craig of Wayne State University. Was developed in 1962 by Parke-Davis (now Pfizer's subsidiary) as a safer anesthetic to replace phencyclidine (PCP), a side effect of the year, Hallucinations, neurological intoxication and seizures. For the first time widely used is distributed to the United States soldiers to participate in the Vietnam War. In addition to anesthetic effects, ketamine is also strong analgesic effect, until now is still widely used. Veterinarians are also currently using the drug extensively and are being used as anesthetic in developing countries.

Ketamine was widely used as a psychotropic drug and research object in the 1970s. Until the peak in 1978, scientists began to report on the toxic effects of ketamine, including John C. Lilly. Near the end of the century, the application of ketamine began to deteriorate, it became a wild party and other similar activities commonly used in hallucinogenic drugs. States began to tighten their application and list them as dangerous psychotropic drugs to strengthen monitoring. Including the United States, Britain and Canada.

Chemical structure of ketamine

Ketamine Ketamine is found in ketamine hydrochloride, the main component of ketamine, which is not flammable. PH value of 3.5 ~ 5.5, acidic aqueous solution.

As pharmacological with DXM, PCP is very similar to the human side effects are relatively large, usually for veterinary use for anesthesia. In recent years, some dance halls and other entertainment venues found signs of abuse of K powder. May 9, 2001, K powder by the People's Republic of China State Drug Administration in the second category of psychotropic drugs to be managed in 2007, promoted to the first category of psychotropic drugs.

The use of ketamine and adverse effects

Basic anesthesia can be 4 to 6 mg / kg ketamine intramuscular injection or 1 to 2 mg / kg intravenous injection, maintenance of 15 to 30 minutes. Can also be used for nerve block anesthesia and spinal anesthesia adjuvant therapy, 0.5 ~ 1 mg / kg by intravenous or intramuscular injection.

Ketamine main adverse reactions in the recovery of anesthesia hallucinations, restlessness, nightmares and delirium and other psychiatric symptoms, followed by intraoperative often tears, increased saliva secretion, blood pressure, intracranial pressure and increased intraocular pressure; occasional transient Respiratory depression or pause, laryngeal spasm and tracheal spasm, mostly in the amount of larger, increased secretion occurs.

Precautions for ketamine

Preoperative use of antipsychotic drugs can reduce intraoperative and wakefulness during adverse reactions.

Induction of common muscle tremors and muscle involuntary movements, occasional limbs without movement and myoclonus, this situation is easy to mistakenly believe that anesthesia is too shallow and excessive administration. Recovery of muscle tension first returned to normal, then there is a stage of patients do not care about their surroundings, and the surrounding people and things completely restored contact may be sudden, this may occur in patients with signs of recovery after a few minutes to several hours. Occasionally there are diplopia or other visual impairment, occasional blindness or speech difficulties, mostly transient, and quickly restored.

Injection of ketamine, the tears, saliva secretion increased, the performance of autonomic nervous excitement, occasional laryngospasm and tracheal spasm, preoperative anticholinergic drugs can be avoided or reduced.

Although the ketamine respiratory inhibition is slight, but if the dose is too large or intravenous drug injection too fast, or combined with narcotic analgesics, can cause significant inhibition of breathing, and even respiratory arrest. In addition, the infant or the elderly respiratory depression is more obvious. Ketamine dilates the bronchus and can antagonize the contraction of the trachea and bronchus by histamine, acetylcholine, and serotonin. Has been confirmed that the drug is the treatment of asthma, one of the most satisfied with the drug, a clinical value.

Ketamine can enhance myocardial contractility, resulting in increased myocardial oxygen consumption, so patients with severe coronary heart disease should not use this drug.

Ketamine increased uterine muscle tension, contraction intensity and frequency, usually no pathological effect. However, when abnormal uterine activity increases, such as ankylosing uterine contraction, placental abruption and umbilical cord prolapse, routine use of clinical doses of ketamine harmful dose should be reduced to 25 mg or less. Intramuscular injection of ketamine, the fetal muscle tension increased.

Ketamine increased cerebral blood flow and cerebral oxygen consumption, cerebrospinal fluid pressure increased with the increase in cerebral blood flow. Control of respiration caused by hypocapnia to eliminate ketamine on cerebral blood flow, cerebrospinal fluid pressure and intracranial pressure increased response.

Ketamine has a strong drug abuse potential, should be strictly in accordance with relevant state regulations and use.