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Anesthesia
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Anesthesia

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: Doctors specialising in the administration of anesthetics are known as anesthesiologists (AE) or anaesthetists (BE). Nurses specialising in the administration of anesthetics are known as nurse anesthetists (AE).

Table of contents
1 History
2 Choice of anesthetic technique
3 Related topics
4 External links

History

Non pharmacological methods

Hypnotism and Acupuncture have a long history of use as anaesthetic techniques.

Herbal derivatives

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).

Early gases and vapours

The development of effective anaesthetics in the 19th century was, with Listerian techniques, one of the keys to successful surgery. Henry Hill Hickman experimented with
carbon dioxide in the 1820s. The anaesthetic qualities of nitrous oxide (isolated by Joseph Priestley) were discovered by the British chemist Humphry Davy about 1795 when he was an assistant to Thomas Beddoes and reported in a paper in 1800. But initially the medical uses of laughing gas were limited - its main role was in entertainment. It was used in December 1844 for painless tooth extraction by American dentist Horace Wells. Demonstrating it the following year, at Massachusetts General Hospital, he made a mistake and the extractee suffered considerable pain. This lost Wells any support.

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.

Local anaesthetics

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).

Early opioids

Opioids were first used by Racoviceanu-Pitesti, who reported his work in 1901.

The twentieth century

Choice of anesthetic technique

The choice of anesthetic technique is a complex one, requiring consideration of both patient and surgical factors.

However, when either technique is possible, regional anesthesia is about 30% safer than general anesthesia. Neuraxial blockade reduces the risk of deep vein thrombosis, pulmonary embolism, transfusion, pneumonia, respiratory depression, myocardial infarction and renal failure[1].

Related topics

External links


Health science - Medicine
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General surgery; - Cardiothoracic surgery; - Neurosurgery - Ophthalmology - Orthopedic surgery; - Otolaryngology (ENT) - Plastic surgery; - Urology - Vascular surgery;