Aseptic and Sterile Techniques

Infection remains one of the most potentially devastating and challenging complications of surgery. Infection in a veterinary surgical practice may occur during surgery or at any time during hospitalization. It is incumbent upon the veterinary practitioner and staff to ensure that all possible measures are taken to reduce the risk of iatrogenic infection. The terms aseptic technique and sterile technique are used interchangeably by some authors (Box 1-1), but in strict terms, asepsis is defined as the absence of microorganisms that cause disease, whereas sterile is defined as being free of all living microorganisms. Therefore, techniques to maintain sterility are more appropriate for the operating room (OR) setting, but aseptic principles should be applied to the entire hospital. Outside the OR, these techniques have been referred to as medical asepsis and are designed to protect both the patient and hospital staff.

The complete absence of microorganisms cannot be achieved in a hospital environment, but use of aseptic techniques substantially aids in control of pathogens and decreases the risk of infection for patients and staff. When specific procedures are discussed, aseptic technique has been referred to as clean technique. Sterile technique (see Box 1-1) applies to work performed in a sterile field. The higher level of protection in a sterile field is critical because the natural defenses of the patient are breached by surgical incision, puncture, or introduction of instruments into the vascular system. Studies in human surgical practice have attempted to determine when sterile technique versus clean technique is necessary for certain minor procedures. For example, arthrocentesis (see pp. 1217-1218) performed under sterile technique might require the use of sterile gloves, a sterile patient preparation kit, and a small drape, whereas the same procedure performed using clean or aseptic technique would require only nonsterile gloves and an alcohol wipe. The differences in time and cost involved for sterile technique versus clean technique can be substantial.

Principles of Hospital Asepsis

Minimization of infection in a surgery practice involves applying principles of aseptic technique throughout the hospital. Goals are to minimize sources of contamination and to block transmission of microorganisms. Some techniques that aid in reduction of the quantity of pathogenic microorganisms are listed in Box 1-2.