Short answers, pulled from the story.
Anesthesia is a state of controlled, temporary loss of sensation or awareness induced for medical or veterinary purposes. It may include analgesia, paralysis, amnesia and unconsciousness, in some or all combinations. A person under anesthetic drugs is described as anesthetized.
The three broad categories of anesthesia are general anesthesia, sedation, and regional and local anesthesia. General anesthesia suppresses the central nervous system to produce unconsciousness and total lack of sensation. Sedation dials the nervous system down less, while regional and local anesthesia block nerve impulses from a specific part of the body.
On the 14th of November 1804, the Japanese doctor Hanaoka Seishu became the first person to successfully perform surgery using general anesthesia. He used a formula he named tsusensan, which combined Korean morning glory with other herbs. Japan's national isolation policy kept his achievement from the wider world until 1854.
The rate of death attributed to anesthesia alone is 1:185,056, compared with 1:870 for deaths attributed to the patient's health and 1:2,860 for surgical factors. The patient's own health is the single greatest driver of anesthetic mortality. A 1954 study reported death from anesthesia alone at 1:2,680, indicating safety has improved by an uncertain degree.
The physician and writer Oliver Wendell Holmes Sr. proposed the name anesthesia in a letter to William Thomas Green Morton shortly after Morton's successful ether demonstration on the 16th of October 1846. Holmes suggested calling the state produced anesthesia and the procedure an anesthetic.
Alice Magaw, born in November 1860, was the personal anesthesia provider for William and Charles Mayo and is often called the Mother of Anesthesia. In one publication she reviewed more than 14,000 surgical anesthetics with no anesthetic-related death. Her records helped establish that nurses could deliver anesthesia safely.
During emergence, nausea and vomiting are reported at 9.8%, airway support is needed in 6.8% of cases, and hypotension occurs in 2.7%. Hypothermia, shivering and confusion are common because little body heat is produced during surgery. Postoperative cognitive dysfunction, a disturbance in cognition that can last weeks or months, may also follow, especially after cardiac surgery.