The science of anesthesiology has enabled incredible medical breakthroughs. Being able to take away the pain and the memory of a medical procedure is one of the most satisfying aspects of being an anesthesiologist. When anesthesiologists are choosing the right gases to sedate their patients, there are many factors to take into consideration. Subrata Chakravarty, an experienced anesthesiologist, and physician, examines the different types of gases or inhalational anesthetics that are used during procedures and states how each gas has different effects.
Perhaps the best-known anesthetic gas, nitrous oxide does not produce general anesthesia, but it is an important supplement to existing gases or intravenous methods of sedation. Nitrous oxide is frequently used in dental applications where it is combined with injectable anesthesia.
Nitrous oxide has been used since the 18th century. The gas was first created in a lab in 1794 and was at first used primarily for recreation. It was not until 1844 when the drug was first used in a surgical setting. It was adopted first by dentists. By the time of the Civil War, the drug had gained popularity in the American market.
Nitrous oxide has three primary effects on the body. The first is the euphoric effect. Nitrous oxide stimulates reward pathways in the brain by activating dopamine release. This brings about the possibility of misuse for recreational purposes. Another effect of nitrous oxide is the anxiolytic effect, or the reduction of anxiety. Even low doses of nitrous oxide can help to reduce anxiety, which is a valuable property of this gas. The third and final effect is the analgesic, or pain relief, effect. The gas interacts with the body’s own endogenous opioid system and provides some analogous effects.
Nitrous oxide does have some dangerous side effects. It results in manual and mental impairment while the gas is being inhaled and until it fully wears off. Patients who are being treated with nitrous oxide should be monitored carefully to avoid falls. In the long term, vitamin B12 deficiencies have been observed, as well as harmful prenatal effects.
Desflurane belongs to the category of methyl ethyl ethers. It is often used because it both takes effect and wears off at the fastest rate among comparable gases. It is more often used to maintain general anesthesia because it can cause airway irritability and tachycardia.
Desflurane has been in use since the 1960s, along with its related gases. These drugs were developed in hopes of providing more stable and safer anesthetic gases.
Desflurane has a strong aroma, which makes it less attractive to patients. The administration can be controlled precisely, and the drug is less expensive than many other alternatives. This makes it especially useful in disadvantaged areas. The best benefit of desflurane is that it wears off quickly and causes fewer lingering effects than other drugs in its class.
Isoflurane is a general anesthetic related to desflurane. It was first approved for use in the United States in 1979. It is one of the World Health Organization’s Essential Medicines as one of the safest and most effective drugs used in a health system.
Isoflurane has an anesthetic effect and reduces a patient’s sensitivity to pain. It also relaxes muscles. While the exact mechanism by which isoflurane works is not clear, it may bind to glycine, glutamate, and GABA receptors in the body.
It does have serious side effects when used in the elderly. It can enhance the formation of amyloid plaques in the brain which cause Alzheimer’s Disease. Otherwise, the medication is generally well-tolerated.
Related to isoflurane and desflurane, sevoflurane replaced the ether compounds that were used before the 1970s. It is generally given in a mixture of oxygen and nitrous oxide. It was first used in clinical practice in Japan in 1990. It is frequently used to put children to sleep, but it can cause delirium and agitation.
It may have significant neurotoxic effects when used in children, and studies are being performed to make sure the drug is safe for use.
Xenon works differently than the flurane gases. It is a noble gas that does not interact with any other compounds in the body. It occurs in nature.
The first medical publication to report xenon’s anesthetic use was a 1946 paper by John Lawrence. It was first used in surgery in 1951. It has the advantage of not causing neurotoxicity. It inhibits the toxicity of nitrous oxide and ketamine. It has potential for misuse, especially in sports doping. It may increase the production of red blood cells and enhance athletic performance when inhaled with oxygen. Unfortunately, there is no reliable doping test for xenon or for argon, a closely related gas.
Xenon is an expensive anesthetic, but it is well-regarded by the medical community thanks to its lower risk of side effects.
Anesthesia and Surgery
Many types of surgeries and treatments are possible with advanced anesthetic gases such as nitrous oxide, desflurane, isoflurane, sevoflurane, and xenon. The medical science of anesthesia is constantly in development. Subrata Chakravarty encourages all anesthesiologists and interested patients to research the drugs they are being given before and during surgery.