The purpose of<unk>  can be distilled down to three basic goals or endpoints: * hypnosis (a temporary loss of consciousness and with it a loss of memory. In a pharmacological context, the word hypnosis usually has this technical meaning, in contrast to its more familiar lay or psychological meaning of an altered state of consciousness not necessarily caused by drugs—see hypnosis). * analgesia (lack of sensation which also blunts autonomic reflexes) * muscle relaxation Different types of<unk>  affect the endpoints differently. Regional<unk> , for instance, affects analgesia; benzodiazepine-type sedatives (used for sedation, or "twilight<unk> ") favor amnesia; and general<unk> thetics can affect all of the endpoints. The goal of<unk>  is to achieve the endpoints required for the given surgical procedure with the least risk to the person. The<unk> thetic area of an operating room To achieve the goals of<unk> , drugs act on different but interconnected parts of the nervous system. Hypnosis, for instance, is generated through actions on the nuclei in the brain and is similar to the activation of sleep. The effect is to make people less aware and less reactive to noxious stimuli. Loss of memory (amnesia) is created by action of drugs on multiple (but specific) regions of the brain. Memories are created as either declarative or non-declarative memories in several stages (short-term, long-term, long-lasting) the strength of which is determined by the strength of connections between neurons termed synaptic plasticity. Each<unk> thetic produces amnesia through unique effects on memory formation at variable doses. Inhalational<unk> thetics will reliably produce amnesia through general suppression of the nuclei at doses below those required for loss of consciousness. Drugs like midazolam produce amnesia through different pathways by blocking the formation of long-term memories. Nevertheless, a person can have dreams during<unk> thetic or have consciousness of the procedure despite having no indication of it under<unk> thetic. It is estimated that 22% of people dream during general<unk>  and 1 - 2 cases per 1000 have some consciousness termed "awareness during general<unk> ".
Anesthesia
Sedoanalgesia
Neuraxial blockade
Spinal anaesthesia
Sedation
Decompensation
Local anesthesia
Neurosurgical anesthesia