Anesthetic

An anesthetic is a drug that causes a reversible loss of sensation or awareness. It is used to prevent pain and enable medical procedures.

General anesthesia: A drug-induced state of unconsciousness and reduced responsiveness used for procedures. General anesthetics suppress awareness as well as sensation.
Analgesia: The reduction or absence of pain without necessarily causing unconsciousness. Pain relief is one effect anesthetics can produce, but it is not identical to anesthesia.
Regional anesthesia: Anesthesia that blocks sensation across a substantial region of the body while often preserving consciousness. Regional techniques use anesthetic drugs to numb areas such as a limb or lower body.
Ether: A volatile chemical historically used as an inhaled general anesthetic. Ether was an early surgical anesthetic, unlike most agents used today.
History of anesthesia: The development of methods and drugs that make surgery and other procedures tolerable. Reliable anesthetic drugs transformed the feasibility and scope of surgery.
Local anesthetic: A drug that temporarily blocks sensation in a limited region of the body. Local anesthetics prevent pain without necessarily changing awareness.
Sedation: A drug-induced reduction in alertness and responsiveness, ranging from calmness to deep sleep. Sedation can reduce awareness without providing the full effects of general anesthesia.
Spinal anesthesia: A regional technique in which anesthetic is injected into cerebrospinal fluid in the lower back. It is a specific route for producing dense anesthesia below the injection level.
Nitrous oxide: A colorless gas used for analgesia and, at higher concentrations, as an anesthetic adjunct. Its analgesic effects and limited anesthetic potency distinguish it from potent inhaled agents.
Anesthesia awareness: Unexpected conscious awareness during general anesthesia, sometimes accompanied by recall. It is a rare but serious failure of intended unconsciousness.

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PhencyclidineNarrower topic: PCP was first developed and tested for this purpose.