Principles of asepsis

Asepsis means freedom from pathogenic (that is, disease-causing) microorganisms, whilst sepsis indicates the presence of micro-organisms causing toxicity in the body. Infection can occur endogenously or exogenously.

• Endogenous – from sites on or in the host, for example from the client’s skin, nose, or intestines
• Exogenous – from routes outside the host or environmental, such as:
– airborne, for example droplets, dust, dressings, bedding
– direct or indirect contact, for example hands, clothing, equipment, and food
– percutaneously, for example intravenous infusions, needles.

In order to reduce the potential for exogenous infection, nurses and other health care professionals employ what is termed a sterile (or aseptic), nontouch technique when undertaking invasive procedures such as urethral catheterization and injections, or procedures where the risk of crossinfection is high, for example when dressing wounds or removing sutures and drains. The basic principles of this technique are outlined below.