Anesthesia (AE), also anaesthesia (BE), is the process of blocking the perception of pain and other sensations. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience. There are several forms of anesthesia:
regional anesthesia — with reversible loss of sensation and possibly movement in a region of the body by selective blockade of sections of the spinal cord or nerves supplying the region.
Doctors specialising in the administration of anesthetics are known as anesthesiologists (AE) or anaesthetists (BE).
The first herbal anaesthesia was administered in prehistory. Opium and hemp were two of the most important herbs used. They were ingested or burned and the smoke inhaled. Alcohol was also used, its vasodilatory properties being unknown. In China, Taoist medical practitioners developed anaesthesia by means of acupuncture. In South America preparations from datura, effectively scopolamine, were used as was coca. In Medieval Europe various preparations of mandrake were tried as was henbane (hyoscyamine).
Another dentist, William E. Clarke, performed an extraction in January, 1842 using a different chemical, ether (discovered in 1540). In March, 1842 in Danielsville, Georgia, Dr. Crawford Williamson Long was the first to use anaesthesia during an operation; giving it to a boy before excising a cyst from his neck. In October 1846 yet another dentist, William Thomas Green Morton, removed a tumour from an patient under ether. Despite Morton's claims of a new gas called 'Letheon' the use of ether spread to Europe in late 1846. Here respected surgeons including Liston, Dieffenbach, Pirogoff, and Syme undertook numerous operations with ether.
Ether had a number of drawbacks and was quickly replaced with chloroform. Discovered in 1831 its use in anaesthesia is usually linked to James Young Simpson. Who, in a wide-ranging study of organic compounds, found chloroform's efficacy in 1847. Its use spread quickly and gained royal approval in 1853 when John Snow gave it to Queen Victoria during the birth of Prince Leopold.
The first effective local anaesthetic was cocaine. Isolated in 1859 it was first used by Karl Koller in ophthalmic surgery in 1884. Halsted. Prior to that doctors had used a salt and ice mix for the numbing effects of cold - which could only have limited application. Similar numbing was also induced by a spray of ether or ethyl chloride. Cocaine soon produced a number of derivatives and safer replacements, including procaine (1905), Eucaine (1900), Stovaine (1904), lidocaine (1943).
