World Anesthesia Day Is celebrated annually on October 16. It commemorates the first successful demonstration of ether anesthesia on October 16, 1846, by Boston dentist William Thomas Green Morton Who gave the correct dose of diethyl ether to medical students at the Massachusetts General Hospital in Boston. Morton, who was unaware of Long’s previous work, was invited to the Massachusetts General Hospital to demonstrate his new technique for painless surgery. After Morton had induced anesthesia, surgeon John Collins Warren removed a tumor from the neck of Edward Gilbert Abbott. This occurred in the surgical amphitheater now called the Ether Dome. The previously skeptical Warren was impressed and stated, “Gentlemen, this is no humbug.” In a letter to Morton shortly thereafter, physician and writer Oliver Wendell Holmes, Sr. proposed naming the state produced “anesthesia”, and the procedure an “anesthetic”.
At first Morton tried to hide the actual nature of his anesthetic substance, referring to it as Letheon. He received a US patent for his substance, but news of the successful anesthetic spread quickly by late 1846. Respected surgeons in Europe including Liston, Dieffenbach, Pirogov, and Syme quickly undertook numerous operations with ether. An American-born physician, Boott, encouraged London dentist James Robinson to perform a dental procedure on a Miss Lonsdale. This was the first case of an operator-anesthetist. On the same day, 19 December 1846, in Dumfries Royal Infirmary, Scotland, a Dr. Scott used ether for a surgical procedure.The first use of anesthesia in the Southern Hemisphere took place in Launceston, Tasmania, that same year. However Drawbacks with ether such as excessive vomiting and its explosive flammability led to its replacement in England with chloroform.Nevertheless this ranks as one of the most significant events in the history of medicine and took place at the Massachusetts General Hospital, home of the Harvard School of Medicine. The discovery made it possible for patients to obtain the benefits of surgical treatment without the pain associated with an operation. The date (16 October) is now globally recognised as World Anaesthesia Day in respect of the importance of this event.
Anesthesia or anaesthesia (from Greek “without sensation”) is a state of controlled, temporary loss of sensation or awareness that is induced for medical purposes. It may include analgesia (relief from or prevention of pain), paralysis (muscle relaxation), amnesia (loss of memory), or unconsciousness. A patient under the effects of anesthetic drugs is referred to as being anesthetized. Anesthesia enables the painless performance of medical procedures that would otherwise cause severe or intolerable pain to an unanesthetized patient. Three broad categories of anaesthesia exist:
- General anesthesia which suppresses central nervous system activity and results in unconsciousness and total lack of sensation.
- Sedation suppresses the central nervous system to a lesser degree, inhibiting both anxiety and creation of long-term memories without resulting in unconsciousness.
- Regional anesthesia and local anesthesia, block transmission of nerve impulses from a specific part of the body, causing loss of sensation in the targeted body part only.
Depending on the situation, this may be used either on its own (in which case the patient remains conscious), or in combination with general anaesthesia or sedation. There are two broad forms:
- Peripheral blockade inhibits sensory perception in an isolated part of the body, such as numbing a tooth for dental work, or using a nerve block to inhibit sensation in an entire limb.
- Central, or neuraxial, blockade administers the anesthetic in the region of the central nervous system itself, suppressing incoming sensation from nerves outside the area of the block. Examples include epidural anaesthesia and spinal anaesthesia.
In preparing for a medical procedure, the health care provider giving anesthesia chooses and determines the doses of one or more drugs to achieve the types and degree of anesthesia characteristics appropriate for the type of procedure and the particular patient. The types of drugs used include general anesthetics, local anesthetics, hypnotics, sedatives, neuromuscular-blocking drugs, narcotics, and analgesics. There are both major and minor risks of anesthesia. Examples of major risks include death, heart attack and pulmonary embolism whereas minor risks can include postoperative nausea and vomiting and hospital readmission. The likelihood of a complication occurring is proportional to the relative risk of a variety of factors related to the patient’s health, the complexity of the surgery being performed and the type of anesthetic used. Of these factors, the person’s health prior to surgery (stratified by the ASA physical status classification system) has the greatest bearing on the probability of a complication occurring. Patients typically wake within minutes of an anesthetic being terminated and regain their senses within hours. One exception is a condition called long-term postoperative cognitive dysfunction, characterized by persistent confusion lasting weeks or months, which is more common in those undergoing cardiac surgery and in the elderly.