Hollywood has a tendency to take a reasonable concept and blow it out of proportion, citing artistic license, and more importantly, revenue maximization.
Unless it's a documentary, we're generally ready to write off the content of any film as "only a movie." The 30,000 people who fall victim to anesthesia every year say the film Awake has terrifyingly strong elements of truth. While experts have dismissed the dramatizations as exaggerations, Carol Weihrer, founder of the Anesthesia Awareness Campaign, says she screamed while sitting in the theater. Seeing the film brought back memories of her own eye-removal surgery during which she awoke. Completely paralyzed from the powerful general anesthetics, she was unable to move or notify the surgeons that she was awake.
Anesthetics come in two forms: general and local. Local anesthetics selectively block sensory feedback from a part of the body; procaine (Novacaine) at the dentist's office is a good example. General anesthetics induce a deep sleeplike state in which patients cannot be woken, even from otherwise extraordinarily painful events. Of course, each form can further be subclassified many more times into their methods of administration, strength, and chemical base. Furthermore, other drugs are often used in conjunction with anesthetics, such as muscle relaxants, in order to aid surgeons in handling the patient.
For the most part, anesthetics are used conservatively. Local anesthetics are typically used in very minor procedures, such as drilling cavities or removing foreign bodies or small abnormalities from the skin. They are sometimes utilized in higher-risk scenarios when the patient should be awake, such as with epidurals used during childbirth, sometimes known as regional anesthesia. General anesthetics tend to be used in major surgical operations in which the pain or psychological effects of witnessing the operation are too great. Again, further criteria may be applicable based on the individual case.
The history of anesthetics is both long and convoluted. Opium was long known for its narcotic properties; ancient Sumerians carried opium capsules more than 6,000 years ago.
Later, it was used as an anesthetic throughout the Egyptian, Greek, Roman, and Persian empires. It did not reach the Far East until much later, but in the meantime, the Chinese empire experimented with cannabis, incense, and various herbal techniques. These ancient means of anesthesia were used until the recent prevalence of morphine and aspirin, which were discovered less than 200 years ago. Beginning in the 19th century, gaseous means of anesthetizing patients were investigated. At first, carbon dioxide was used, followed by nitrous oxide, and finally diethyl ether in 1842. Today's inhaled general anesthetics are far superior to ether, leaving the patient with few to no side effects.
Nitrous oxide is still used, along with a host of newer compounds. Surpisingly, despite the frequency of surgery, the mechanisms behind anesthetics were not fully explored until about 30 years ago. Prior to 1980, the mortality rate among patients given general anesthesia was one in 10,000. Those figures have improved roughly tenfold since then due to a public outcry after the original figures were revealed.
While the exact mechanisms vary from drug to drug, all anesthetics work by blocking nerve signals in one way or another. In fact, patients under general anesthesia show brainwave patterns indicative of a very relaxed state. Just as their mechanisms vary, their potency and half-lives also vary considerably. Some drugs have a lasting effect, while others do not. Some require a reversal drug to bring the patient out of anesthesia, while others cease functioning naturally.
In some cases, usually due to unforeseen biological factors, but also possibly due to human error, an anesthetic effect can wear off before it is intended to do so.
Genetic factors seem to play a role, as well as instable body chemistry. Trauma patients, for instance, undergo rapid fluctuations in blood chemistry, making dosage determination incredibly difficult. If the anesthetic was mixed with a muscle relaxant, which is rather common, the effect of the anesthetic can wear off and the patient could regain consciousness prematurely and still be fully paralyzed. Many of the reported cases involve patients who claim to have experienced intense, excruciating pain as well as sensory input from all of their other senses. In a normal situation, if something causes pain, we do our best to eliminate the source. Victims of anesthesia awareness, however, cannot; they lie helpless while surgeons cut through their tissues, believing the patient is anesthetized.
Fortunately, anesthesiologists acknowledge that anesthesia awareness does happen, although they claim it is very rare and question the patients' memory of the events. Several companies are now creating special sensors to monitor brain wave activity in an attempt to better anesthetize patients. Most anesthesiologists approve of these devices because it helps them better determine proper dosages while ensuring that the patients' worst fear does not become a reality. Hospitals balk at them, however, because they cost quite a lot and aren't 100 percent accurate.
In any event, nothing can replace a good, experienced, and qualified anesthesiologist. If you're planning major surgery in the future, it would be beneficial to know your anesthesiologist's background for your own protection.
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