noun, plural: general anaesthetics
(pharmacology) An agent that produces a reversible loss of sensation as well as loss of consciousness
Anaesthetics are agents that are used to induce anaesthesia. They are causing reversible loss of sensation and also capable of providing relief from or prevention of pain (analgesic effect). Thus, they are often used to facilitate surgery.
There are two major categories of anaesthetics: (1) general anaesthetics and (2) local anaesthetics. General anaesthetics are drugs that produce loss of sensation associated with loss of consciousness. Local anaesthetics, in contrast, result in a small region of anaesthesia particularly at the region of the tissue wherein the anaesthetic is injected into.
General anaesthetics may be classified according to the mode of administration: (1) inhalational anaesthetics and (2) injectable anaesthetics. Inhalational anaesthetics are volatile liquids or gases that are delivered to the patient through an anaesthesia machine whereas injectable anaesthetics are administered intravenously or intramuscular. Examples of inhalational anaesthetics are desflurane, isoflurane, and sevoflurane. They are often combined with nitrous oxide. Injectable anaesthetics include propofol, etomidate, barbiturates, benzodiazepines, and ketamine. There are instances that inhalational and injectable anaesthetics are administered together, i.e. an injectable anaesthetic is introduced to induce anaesthesia and an inhalational anaesthetic to maintain it.
- general anesthetic