Antiseptic and aseptic - historical data and methods

Antiseptics are antimicrobial substances applied to living tissue to reduce the possibility of infection, sepsis or putrefaction. Asepsis is the state of being free from disease-causing contaminants, and in surgery it is achieved by controlling the environment, the patient, the surgical team and the instruments. A truly sterile surgical field is very hard to achieve, so surgical practice depends on reducing contamination at every stage. This topic covers the history of antiseptic and aseptic surgery, the method of asepsis in the operating room and the antiseptics most often used in practice.

An antiseptic is an antimicrobial substance applied to living tissue or skin to reduce the possibility of infection, sepsis or putrefaction. Some antiseptics are true germicides, capable of destroying micro-organisms (bactericidal action), while others are bacteriostatic and only prevent or inhibit their growth. Antibacterials are substances that have proven the ability to act against bacteria.

Asepsis is the state of being free from disease-causing contaminants, such as pathogenic bacteria, viruses, pathogenic fungi and parasites, or the practice of preventing contact with micro-organisms.

Ideally a surgical field is sterile, meaning it is free of all biological contaminants. This is difficult to attain, especially because the patient is often a source of infectious agents. There is currently no method to safely eliminate all of the patient's contaminants without causing significant tissue damage.

The widespread introduction of antiseptic surgery followed the publication of the 1867 paper on the antiseptic principle in the practice of surgery by Joseph Lister. Lister was inspired by Louis Pasteur's germ theory of putrefaction. In that paper he advocated the use of carbolic acid (phenol) to ensure that any germs present were killed.

The modern concept of asepsis evolved in the 19th century. Ignaz Semmelweis showed that washing hands before delivery reduced puerperal fever. After Pasteur's suggestion, Lister introduced carbolic acid as an antiseptic and reduced surgical infection rates.

The procedure room is laid out according to specific guidelines covering filtering and airflow, and it is kept clean between surgical cases. The patient who is brought for the procedure is washed and wears a clean gown. The surgical site is washed, possibly shaved, and the skin is exposed to a germicide, for example an iodine solution such as Betadine (povidone-iodine).

Members of the surgical team wash their hands and arms with a germicidal solution. Operating surgeons and nurses wear sterile gowns and gloves. Hair is covered and a surgical mask is worn. Instruments are sterilised by autoclaving, and the suture material and dressing material are sterile.

Chlorhexidine is of particular interest in dentistry, because it is used both to reduce micro-organisms on the skin before surgery and to treat inflammation of the gums.