In surgery, infections are very common and may even lead to death in spite of a high quality of operative technique. The prevention of such a complication in surgical practice is therefore a major challenge which should be based on the principles of asepsis and antisepsis.
The measures to prevent an infection from entering a wound are referred to as asepsis, while those to cause the exclusion or destruction of harmful microbes are generally called antisepsis.
The two principles represent the united whole in the prophylaxis of surgical infections. They have to be considered in terms of the interrelationship between the source of infection, its mode of transmission and the susceptibility of the body.
The source is taken to mean the place of dwelling, growth and proliferation of microorganisms. Relative to the patient the source of infection can be either exogenous (from outside) or endogenous (from within the body).
The main sources of exogenous infections include patients with purulent inflammation or «healthy» carriers of the microbes, and occasionally animals.
The modes of transmission from exogenous sources are usually as follows: airborne, direct contact and implantation (fig. A).
The major sources of endogenous infections incorporate chronic infections outside the area of the operation (e.g. skin diseases, dental or tonsillar conditions) or of the organs operated on as is (e.g. appendicitis, cholecystitis, osteomyelitis), as well as the oral, intestinal and respiratory saprophytes (fig. B).
Among the modes of transmission of endogenous infections are direct contact, lymphoand haematogenous spread.
To successfully prevent an infection, it is necessary to affect each stage of the infectious process, i.e. the source of infection, the mode of transmission, and the host.