Anaesthesia is that area of medicine concerned with inducing temporary loss of sensation or awareness in a patient – either through general anaesthetic (which causes loss of consciousness) or local anaesthetic (which causes loss of sensation in an isolated part of the body only). The development of anaesthetics revolutionized the field of surgery, allowing for procedures all but impossible on a patient who was not desensitized.
Chloroform and cocaine
In 1846 James Young Simpson, a Scottish obstetrician, showed that chloroform (which had been invented in 1831) could be used to put people to sleep, and he promptly began employing it with the expectant mothers under his care. By 1853, it was sufficiently established that Dr John Snow felt confident enough to treat Queen Victoria with chloroform during the birth of Prince Leopold. Meanwhile, another Englishman, Benjamin Ward Richardson, built upon Simpson’s suggestion that a local anaesthetic might be even more beneficial than a general one and pioneered the use of ether spray to numb specific regions of the body. Then, in the 1880s, the Austrian ophthalmologist Karl Koller promoted cocaine as a local anaesthetic, although by the mid-20th century lidocaine was the preferred local anaesthetic for most medics. By then, spinal and epidural anaesthesia had also been developed, blocking the transmission of pain by injections directly into the spinal cord.
Before the 18th century, anaesthesia was usually crude in the extreme. The first recorded use of it was by the Chinese physician Hua Tuo (140–208), who dosed up his patients with herbal solutions prior to operating on them. In antiquity, ethanol was another trusted means of knocking out a patient, along with a quick blow to the head and compression of the carotid artery – all highly risky measures with the potential to cause unforeseen side effects and even death.
There was markedly little progress in the story until the late 18th century. In England in 1784, James Moore used nerve compression to desensitize a patient prior to an amputation, although this appears to have been a one-off. Of greater import was the publication in 1799 of chemist and inventor Humphrey Davy’s Researches, Chemical and Philosophical: Chiefly Concerning Nitrous Oxide, in which the author suggested the use of laughing gas during surgical procedures. Although there was scarcely any practical adoption of this idea, it sowed the seeds of an idea. Michael Faraday investigated the anaesthetic properties of ether, while a general practitioner called Henry Hill Hickman argued the case for carbon dioxide inhalation to create a state of suspended animation.
In America, the gauntlet was taken up by a dentist, Horace Wells. Struck by the effects of nitrous oxide he had seen demonstrated in a travelling show, he attempted to use it on a volunteer prior to a tooth extraction. It had limited success (the patient screamed out in pain though could remember little of the experience afterwards) so one of Wells’s students, William Morton, decided to find a more efficient anaesthetic agent. He plumped for ether vapour, which he successfully demonstrated at Massachusetts General Hospital in 1846 – an event that ushered in the modern age of anaesthesia.
The field of anaesthesia continues to evolve as more efficient and less dangerous drugs are developed and improved for use in ever more complex operations.