The use of antiseptics:

It is widely known today that getting a cut requires treatment with antiseptic to prevent dirt getting on the wound and infection occurring. This knowledge is only a recent development in history though. In the 19th century, the biggest killer after surgery was sepsis ('hosptial gangrene'). This was infection caught during or after an operation. Surgeons themselves dismissed the idea that they were spreading infection through dirty clothes and unsterile equipment.

Ignaz Semmelweis pioneered antiseptics in 1847. He was the head of the maternity ward in Vienna General Hospital, Austria. The death rate in his maternity ward reduced from 35% to less than 1% through him insisting doctors wash their hands in calcium chloride before operating. However, very few hospitals introduced this procedure.

Joseph Lister:

Lister (1827-1912) was an English surgeon who advanced the chances of survival in surgery. Lister utilised an operating room sterilised with carbolic acid. This was based off his experiments on frogs. He also sterilised all surgical equipment and dressings with carbolic acid. The mortality rate in his operations reduced from 46% to 15% in three years. In 1871, he invented a device which sprayed carbolic acid over the entire operation room.