Asepsis

thumb|Hand scrubbing procedure for surgery

Asepsis is the state of being free from disease-causing micro-organisms (such as pathogenic bacteria, viruses, pathogenic fungi, and parasites). There are two categories of asepsis: medical and surgical. The goal of asepsis is to eliminate infection, not to achieve sterility.

History

The modern concept of asepsis evolved in the 19th century through multiple individuals. Ignaz Semmelweis showed already in 1847–1848 that hand washing prior to delivery reduced puerperal fever. Despite this, many hospitals continued to practice surgery in unsanitary conditions, with some surgeons taking pride in their bloodstained operating gowns.

Only a decade later the situation started to change, when some French surgeons started to adopt carbolic acid as an antiseptic, reducing surgical infection rates, followed by their Italian colleagues in the 1860s. In 1867 Joseph Lister explained this reduction by Louis Pasteur's germ theory and popularized the disinfectant in the English-speaking world.

shifted the movement then from antisepsis to asepsis in the 1870s, publishing his findings in 1879. Gustav Adolf Neuber introduced sterile gowns and capes in 1883, and in 1891, Ernst von Bergmann introduced the autoclave, a device used for the practice of the sterilization of surgical instruments.

thumb|William Stewart Halsted

Rubber gloves were pioneered by William Halsted, who also implemented a no street clothes policy in his operating room, opting to wear a completely white, sterile uniform consisting of a duck suit, tennis shoes, and skullcap.

Antisepsis vs. asepsis

The line between antisepsis and asepsis is interpreted differently, depending on context and time. At the end of the 19th century, Joseph Lister and his followers expanded the term "antisepsis" and coined "asepsis", with the justification that Lister had initially "suggested excluding septic agents from the wound from the start." For example, sterile equipment and fluids are used during invasive medical and nursing procedures.

thumb|Packaged, sterilized surgical instruments

While all members of the surgical team should demonstrate good aseptic technique, it is the role of the scrub nurse or surgical technologist to set up and maintain the sterile field. To prevent cross-contamination of patients, instruments are sterilized through autoclaving or by using disposable equipment; suture material or xenografts also need to be sterilized beforehand. Basic aseptic procedures includes hand washing, donning protective gloves, masks and gowns, and sterilizing equipment and linens. As in infections caused by pathogens or microbes, the immune response is regulated by host receptors.

thumb|Medical illustration of Staphylococcus

Despite efforts to preserve asepsis during surgery, there still persists a 1-3% chance of a surgical site infection (SSI). Infections are categorized as superficial incisional, deep incisional, or organ; the first type are confined to the skin, the second to muscles and nearby tissues, and the third to organs not anatomically close to the operation site. The exact modes of infection depend on the types of surgery, but the most common bacteria that are responsible for SSIs are Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, and Enterococcus spp. The CDC emphasizes the importance of both antiseptic and aseptic approaches in avoiding SSIs, especially since Staphylococcus aureus, among other bacteria, are able to evolve drug-resistant strains that can be difficult to treat. In 2017, nearly 20,000 patients in the United States died from Staphylococcus aureus in comparison to the 16,350 from diagnosed HIV.

History

Antisepsis vs. asepsis

See also

References