In this blog post, we will look at the impact of anesthesia on the development of medicine from the time when medieval barbers performed surgery to the era of modern surgeons.
Yong Pal, White Tower, New Heart, and The Good Doctor. Surgeons in the popular Korean medical dramas of today are almost like gods in the operating room. They impress the public by successfully completing complex surgeries and saving patients’ lives. This image has helped to make surgeons heroes, but in the real medical field, it involves thorough preparation, collaboration, and numerous trials and errors. It is difficult to accept the fact that such a wonderful and important surgery was performed by barbers in the past, back in the Middle Ages. In less than 200 years, thanks to the development of sterilization, blood transfusion, hemostasis, treatment of bacterial infections, and anesthesia, the field of surgery has developed remarkably.
What kind of doctor is a competent surgeon? There may be various standards in the modern age, but in the past, the most competent surgeon was the one who finished the surgery as quickly as possible. In fact, there were doctors who had the skill to cut off a leg in three minutes. Since there was no anesthesia, the surgery had to be done quickly to reduce pain, and time was also important to prevent complications such as infection. What is interesting here is that these early surgeons had to exert tremendous concentration and physical abilities to simply win the battle against time. The fact that their skills were not limited to physical abilities is also linked to the development of anesthetics that would follow.
In the past, there were no anesthetics, but there were methods that produced anesthesia-like effects. In some cases, they would knock people out before performing surgery, but of course, there were more advanced forms of this. The doctors of ancient Egypt and Assyria performed surgery by pressing down on the two carotid arteries in the neck at the same time to reduce the amount of blood flowing to the brain, cutting off the supply of oxygen and causing the patient to lose consciousness. The Egyptians also discovered that a type of drug, opium, could relieve pain, and the Assyrians used a unique painkiller made from a mixture of belladonna, cannabis, and mandrake root. In medieval Arabia, they even developed inhaled anesthetics.
It was thanks to the knowledge accumulated by so many ancient civilizations that we began to gain a deeper understanding of anesthesia. However, at the time, there was a lack of understanding of why these methods were effective or exactly how they worked. When did anesthetics in the modern sense first appear? A typical example is nitrous oxide, also known as laughing gas. In the late 18th century, Joseph Priestley first isolated nitrogen dioxide, and Sir Humphrey Davy discovered that this gas had an anesthetic effect along with drowsiness. However, at the time, it was considered more of a fun pastime than a medically significant invention. However, the introduction of anesthetics in various fields was activated when a dentist in the United States used laughing gas to painlessly extract patients’ teeth. Following nitrogen dioxide, various anesthetics such as diethyl ether and chloroform appeared one after another.
However, not all anesthetics are safe. In the case of chloroform, although it has the advantage of being less flammable than ether, it has many potential problems. In addition, because there are many narcotics, if not used in the right amount, it can lead to addiction or death. If we go back in history, the discovery of anesthetics seems to have been quite accidental. The fact that such an important discovery sometimes comes from experimental curiosity is a good example of how science develops. So, how does anesthesia work?
Currently, various methods of anesthetizing multiple areas with various types of anesthetics are being practiced, and this article will discuss general anesthesia. When general anesthesia is administered, the main target of the anesthetic is the reticular activating system of the brain. The medulla oblongata is the part of the brain that connects the brain and the spinal cord, and it is directly related to life because it supports the movements that are directly related to survival, such as breathing and circulation. Among them, the reticular activating system is the pathway that transmits sensory information from the outside to the brain, and it acts like a filter that filters out what the brain should feel. It also acts like a stimulant that keeps consciousness clear. Anesthetics also have the function of blocking the transmission of information to the reticular activating system. Stimuli from the outside are not transmitted to the brain, and the patient cannot remain awake, so when anesthesia is administered, the patient loses consciousness and cannot feel anything.
To explain in detail how information is blocked from being transmitted to the reticular activating system, we must first understand the process by which stimuli are transmitted along the nerves. Like all other cells, nerve cells have a lipid membrane, which is fat-soluble. They also have a very long shape compared to normal cells. Within a single neuron, electrical impulses travel along the membrane and signals are transmitted. Signal transmission between adjacent neurons occurs through the secretion of signaling molecules (chemicals) through the synapse, which is the space between adjacent neurons, and then the absorption of these molecules by the cells. At this time, the secretion of these molecules is regulated by ion channels on the cell membrane.
Anesthetics dissolve in the lipid layer of the cell membrane and increase the fluidity of the membrane, thereby changing the structure of the ion channels present in the cell membrane. The outflow and inflow of ions through the altered channels is not efficient, so the nerve cells become relatively less receptive to electrical stimuli. This state in which the ability of nerve cells to transmit stimuli is reduced is called anesthesia.
Because they act on cell membranes, anesthetics are closely related to whether or not they are fat-soluble. Nitrous Oxide, Halothane, Ethrane, and Forane are among the anesthetics commonly used in recent clinical trials. Desflurane, Sevoflurane is being introduced. Interestingly, these anesthetics are selectively used according to the individual patient’s condition and the characteristics of the surgery, and they are being continuously studied to improve their effectiveness and safety.
It is questionable how anesthesia will develop in the future, and there have been many cases of abuse of narcotic anesthetics such as propofol, which is called the “milk injection,” so it is better to use it with caution. At the same time, it is expected that the safety and effectiveness of anesthesia will be further improved as future anesthetics become more sophisticated and customized treatment methods tailored to individual patients are developed.
