Anesthesia, or anaesthesia, traditionally meant the condition of having sensation (including the feeling of pain) blocked or temporarily taken away. It is a pharmacologically induced and reversible state of amnesia, analgesia, loss of responsiveness, loss of skeletal muscle reflexes or decreased fight-or-flight response, or all simultaneously.
Anesthesia controls pain during surgery or other medical procedures. It includes using medicines, and sometimes close monitoring, to keep you comfortable. It can also help control breathing, blood pressure, blood flow, and heart rate and rhythm, when needed.
At the heart of the practice of anesthesia is the decision to use a specific anesthetic technique in a given patient. This decision must take into account both the planned surgical procedure as well as the patient's physical condition and coexisting disease. Much of the research performed by anesthesiologists has improved our ability to make this decision wisely, as during the last fifteen years anesthetic mortality has decreased from 1 in 10,000 to 1 in 187,000.
Anesthesia is a state of unconsciousness induced in an animal. The three components of anesthesia are analgesia (pain relief), amnesia (loss of memory) and immobilization. The drugs used to achieve anesthesia usually have varying effects in each of these areas. Some drugs may be used individually to achieve all three. Others have only analgesic or sedative properties and may be used individually for these purposes or in combination with other drugs to achieve full anesthesia.
It is estimated that nearly 40 million anesthetics are administered each year in the United States. Anesthesiologists provide or participate in more than 90 percent of these anesthetics.
It is very common for anesthesiologists to provide expectant mothers with pain relief during labor and delivery. While many mothers choose to use natural childbirth techniques, the demand for epidural anesthesia for labor and delivery has increased dramatically over the last several years due to the proven safety and benefits of this resource.
General anesthesia affects the brain as well as the entire body. You may get it through a vein (intravenously, or IV), or you may breathe it in. With general anesthesia, you are completely unaware and do not feel pain during the surgery. General anesthesia often causes you to forget the surgery and the time right after it.
Local anesthesia numbs a small part of the body. You get a shot of medicine (anesthetic) directly into the surgical area to block pain. Sometimes the doctor will apply a numbing medicine to part of your body, such as your nose or mouth. Local anesthesia is used only for minor procedures. You may stay awake during the procedure, or you may get medicine to help you relax or sleep.
Regional anesthesia blocks pain to a larger part of your body. Anesthetic is injected around major nerves or the spinal cord. You may get medicine to help you relax or sleep.
On Oct. 16, 1846, William T.G. Morton, a Boston dentist, demonstrated the use of ether during surgery, ending the indescribable pain — and the overwhelming dread — that had been associated with the surgeon’s knife.
Using a specially designed glass inhaler containing an ether-soaked sponge, Morton administered the anesthetic to Gilbert Abbott, a printer who had come to the MGH for treatment of a vascular tumor on his jaw. After several minutes, Abbott was rendered unconscious. John Collins Warren, MD, one of the most widely recognized surgeons of that time, then surgically removed the tumor. Upon wakening, Abbott informed the curious and skeptical physicians and medical students in the theater that he had experienced no pain.
After the first demonstrations of general anesthesia with nitrous oxide or ether by Wells in 1845 and Morton in 1846, its use was rapidly adopted in Europe and the rest of the world. Initially there was some resistance from those who believed that it was "not moral" to eliminate pain, particularly in childbirth. This resistance was overcome when, in 1853, the English physician John Snow used chloroform to eliminate the pain of Queen Victoria at the birth of her eighth child, Prince Leopold. For many years, ether and chloroform, the latter introduced by the Scotsman James Young Simpson in 1847, were the drugs of choice, for both childbirth and surgical interventions.