Surgery before anesthesia

(via)
 It would take a little while for surgeons to discover that the use of anesthesia allowed them time to be meticulous. Despite the advantages of anesthesia, Liston, like many other surgeons, proceeded in his usual lightning-quick and bloody way. Spectators in the operating-theater gallery would still get out their pocket watches to time him. The butler's operation, for instance, took an astonishing 25 seconds from incision to wound closure.
(Liston operated so fast that he once accidentally amputated an assistant's fingers along with a patient's leg, according to Hollingham. The patient and the assistant both died of sepsis, and a spectator reportedly died of shock, resulting in the only known procedure with a 300% mortality.)

One reason why all fantasy novels include healing magic, this.