Throughout the centuries, there have been many attempts to relieve pain during medical procedures, from blows to the head to induce unconsciousness, to ingestion of herbal mixtures, and even hypnotism. Nowadays, we rely on anesthesia – a medical treatment that prevents patients from feeling pain during procedures such as surgery.
Up until the mid-1800s, doctors could only offer patients opium, alcohol, and a bullet or rope to bite on to deal with the excruciating pain of surgery, which was only performed as a last resort. One of the very few accounts describing the pain of surgery is that of Fanny Burney, an English novelist who had to undergo a mastectomy in 1811, and recounted her experience as “terror that surpasses all description.”
The Discovery of Gases
During the Enlightenment in the mid-1700s, gases like carbon dioxide and nitrous oxide were discovered, which were also explored for their therapeutic and anesthetic properties. In 1779, Sir Humphry Davy, a British chemist who discovered several chemical elements and compounds, suggested the use of nitrous oxide – known today as laughing gas – to produce pain relief, which he first tested on himself.
In the early 1820s, British doctor and surgeon Henry Hickman, in his efforts to alleviate pain during surgery for his patients, experimented on animals using carbon dioxide gas while operating on them. The animals seemingly felt no pain and recovered fully from what he called a state of ‘suspended animation.’ Hickman though was unsuccessful in publishing his research and died shortly after.
In 1844, an American dentist called Horace Wells was the first to use nitrous oxide for a tooth extraction of one of his patients, but it didn’t work as adequate pain relief. Wells took this failure to heart and didn’t experiment further.
The Discovery of General Anesthesia
In the late 18th and early 19th centuries, chemists and doctors experimented with various gases to provide pain relief during surgeries, but their efforts weren’t successful enough to be established. However, in the mid-1840s, a young American dentist named William Morton was committed to discovering an effective pain relief and settled on sulfuric ether. Morton experimented on small animals and discovered that, when they inhaled ether, they passed out and became unresponsive.
On 16th, October 1846, Morton performed the first general anesthesia on a patient in a public demonstration at Massachusetts General Hospital. A surgeon then performed a tumor excision on the patient’s neck without any distress. Much to everyone’s surprise, ether had successfully worked as an anesthetic, hailing a new era in the field of medical surgery. The operating theater where the above occurred is known as the Ether Dome and is still preserved at the Massachusetts General Hospital, and the 16th of October is celebrated as World Anesthesia Day.
The successful use of ether as a general anesthetic in the U.S. led to the discovery of chloroform in 1947 in England by James Simpson who was a Professor of Midwifery and had pioneered inhalational analgesia for women in labor. English doctor John Snow popularized the use of chloroform by using it on Queen Victoria for the birth of her 8th child in 1853. Eventually, chloroform became the most commonly used anesthetic in England, and, by the end of the 19th century, anesthesia had become commonplace in surgical procedures.
Chloroform, however, was a very toxic compound and was also unpredictable, which made maintenance of anesthesia very difficult. It was eventually associated with a substantially high death rate due to cardiac arrest, the first one occurring in 1848 and witnessed by Simpson himself. In other cases, it caused delayed poisoning due to liver damage, and, by the beginning of the 20th century, the need for other, better substances was becoming evident.
During the 1860s, the use of nitrous oxide made a return with doctors experimenting with it on both sides of the Atlantic as it was more pleasant to inhale than ether, and less risky than chloroform. However, nitrous oxide on its own was safe only for brief procedures and was mostly used for tooth extractions.
Joseph Clover, an English surgeon who became one of England’s leading anesthesiologists, was the first to consider combining nitrous oxide with another gas, thus starting the trend of using a combination of several drugs, rather than a larger, more toxic, dose of one. Clover realized that mixing nitrous oxide with ether would induce anesthesia much faster and also safely make it last longer for more complex surgical procedures.
James Simpson, the English Professor of Midwifery who discovered chloroform in 1847, also suggested that ‘local’ anesthesia would be equally useful as general anesthesia. He suggested ‘cooling’ as a method, which led another doctor named Benjamin Richardson to develop the ether spray. Rapid evaporation of ether produced the cooling effect, hence the term ‘freezing’, which is still being used today.
In 1884, Austrian ophthalmologist Carl Koller was experimenting with different substances to find one that would be safe and effective as a local anesthetic for use during eye surgery. In pharmaceutical circles, the numbing effect of cocaine had already been recognized, and so Koller decided to try placing a few drops of cocaine solution to the cornea. His experiment proved a huge success as cocaine produced insensibility and complete numbing of the eye.
News of this success traveled quickly and so cocaine became a favorite among doctors as a local anesthetic. This led to the development of the peripheral nerve block, spinal anesthesia in 1898, and epidural block in 1921.
Anesthesia Developments in the 20th Century
The late 1930s saw the introduction of pentothal or sodium thiopentone, a barbiturate, making general anesthesia much more pleasant for patients compared to nitrous oxide and ether. In 1942, doctors in Montreal introduced ‘curare’ as a muscle relaxant. ‘Curare’, which had first been observed in South American arrows, allowed a lighter depth of general anesthesia than previously possible. This was essential for thorax and abdomen surgery and required anesthetists to learn how to insert a tube through the trachea to allow mechanical ventilation of the lung and ‘control’ breathing.
Halogenated hydrocarbons, which were highly potent, non-flammable anesthetic agents, were introduced in the 1950s replacing ether and chloroform in most operating theatres.
In the 1960s, new drugs and new monitoring equipment were developed, allowing surgery to be extended to increasingly complex procedures, and today inhaled anesthetics are combined with intravenous anesthetics for ultimate patient comfort and overall surgical success.
Evolution of Anesthesia Devices
The first anesthesia device was the ether inhaler used in 1946 by American dentist William Morton in the first ever general anesthesia to be performed. This was then further developed in 1877 by Joseph Clover who invented an inhaler that combined nitrous oxide with ether and dispersed the mix to the patient with a face mask.
During the 1940s, another piece of equipment was being perfected – the hollow needle, which allowed easier administration of opium as pain management. Intravenous anesthetics were widely used during WWI as inhaled versions were too instable to use in the battlefield.
In 1917, Henry Edmund Gaskin Boyle invented the first continuous flow anesthetic machine, known as the ‘Boyle Apparatus.’ The Boyle Apparatus ensured patients safely received oxygen while enabling ventilation, accurately mixing oxygen with a stable level of anesthetic gas.
The Boyle Apparatus was the dominant anesthetic machine for much of the 20th century, and today contemporary anesthesia devices retain many of the key characteristics found in the original.
The Future of Anesthesia
Today, ongoing research into how a person’s genetic makeup affects their response to certain anesthetics will hopefully allow for a more tailor-made, personalized approach for patients with safer and more effective results during and after anesthesia.
Furthermore, scientists are hoping that, with new advancements in research, understanding how anesthesia affects pain and consciousness could lead to new treatments for conditions such as epilepsy and even coma, and also help in further understanding consciousness itself.
Finally, recent technological advancements are enabling further research into the field of anesthesia and are also changing the practice of anesthesiology. The integration of new technologies has improved the process of anesthesia delivery and overall patient care, while the experimental application of artificial intelligence has been showing potential to further transform the field.