Editing General anaesthetic (section)

==Mode of administration==
General anaesthetics can be administered either as gases or vapours ([[inhalational anaesthetic]]s), or as injections ([[intravenous]] or even [[Intramuscular injection|intramuscular]]). All of these agents share the property of being quite hydrophobic (i.e., as liquids, they are not freely [[miscible]]—or mixable—in water, and as gases they dissolve in oils better than in water).<ref name=":16" /><ref name=":52">{{Cite book|title=Rang & Dale's pharmacology|last=M.|first=Dale, M.|date=2007|publisher=Churchill Livingstone|others=Rang, H. P., Dale, Maureen M.|isbn=978-0443069116|edition= 6th|location=[Edinburgh]|oclc=76798115}}</ref> It is possible to deliver anaesthesia solely by inhalation or injection, but most commonly the two forms are combined, with an injection given to induce anaesthesia and a gas used to maintain it.<ref name=":52" />

===Inhalation===

[[File:US Navy 030513-N-1577S-001 Lt. Cmdr. Joe Casey, Ship's Anesthetist, trains on anesthetic procedures with Hospital Corpsman 3rd Class Eric Wichman aboard USS Nimitz (CVN 68).jpg|thumb|General anesthetics are frequently administered as volatile liquids or gases.]]
Inhalational anaesthetic substances are either [[Volatility (chemistry)|volatile]] [[liquid]]s or [[gas]]es, and are usually delivered using an [[anaesthesia machine]]. An anaesthesia machine allows composing a mixture of oxygen, anaesthetics and ambient air, delivering it to the patient and monitoring patient and machine parameters. Liquid anaesthetics are vapourised in the machine.<ref name=":52" />

Many compounds have been used for inhalation anaesthesia, but only a few are still in widespread use. [[Desflurane]], [[isoflurane]] and [[sevoflurane]] are the most widely used [[volatile anaesthetic]]s today. They are often combined with [[nitrous oxide]]. Older, less popular volatile anaesthetics include [[halothane]], [[enflurane]], and [[methoxyflurane]]. Researchers are also actively exploring the use of [[xenon]] as an anaesthetic.<ref name=":52" />

===Injection===

Injectable anaesthetics are used for the induction and maintenance of a state of unconsciousness. Anaesthetists prefer to use [[intravenous injection]]s, as they are faster, generally less painful and more reliable than [[Intramuscular injection|intramuscular]] or [[subcutaneous injection]]s. Among the most widely used drugs are:
* [[Propofol]]
* [[Etomidate]]
* [[Barbiturate]]s such as [[methohexital]] and [[thiopentone]]/[[thiopental]]
* [[Benzodiazepine]]s such as [[midazolam]]
* [[Ketamine]] is used in the UK as "field anaesthesia", for instance in road traffic incidents or similar situations where an operation must be conducted at the scene or when there is not enough time to move to an operating room, while preferring other anaesthetics where conditions allow their use. It is more frequently used in the operative setting in the US.<ref name=":52" />
Benzodiazepines are sedatives and are used in combinations with other general anaesthetics.<ref name=":04" /><ref name=":52" />