Surgical site infections (SSIs) are the second to third most common site of health care associated infections (HAIs). These complications of surgical procedures cause considerable morbidity and, when these occur deep at the site of the procedure, can carry mortality as high as 77%. As illustrated below there are several key steps or “chains” that have to be connected to result in infection. However, for SSIs, the initial introduction of microbial pathogens occurs most often during the surgical procedure performed in the Operating Theatre (OT). Fig. 8: Transmission cycle in OT
Clients Service providers Ancillary Staff Community members
People Water and solutions Instruments and other items Equipment Soil and air
Places of exit Places of entry
Broken skin Parasite Puncture wound Surgical site Mucous membranes
Infectious Agents Microorganisms such as Bacteria, Viruses, Fungi
Respiratory, genitourinary, and vascular systems Gastrointestinal tract Skin Mucous membranes Placenta
Modes of transmission
Contact Droplet Vehicle Airborne
Thus, to reduce the risk of SSI, a systematic but realistic approach must be applied with the awareness that this risk is influenced by characteristics of the patient, operation, personnel, and health care facility. For most SSIs, the source of pathogens is the endogenous flora of the patient’s skin, mucous membranes, or hollow viscera. When mucous membranes or skin is incised, the exposed tissues are at risk for contamination with endogenous flora. These organisms are usually aerobic gram-positive cocci (e.g., staphylococci), but may include fecal flora (e.g., anaerobic bacteria and gram-negative aerobes) when incisions are made near the perineum or groin. When a gastrointestinal organ is opened during an operation gram-negative bacilli (e.g., E. coli), gram-positive organisms (e.g., enterococci), and sometimes anaerobes (e.g., Bacillus fragilis) may become typical SSI isolates. Exogenous sources of SSI pathogens include surgical personnel (especially members of the surgical team), the operating room environment (including air), and all tools, instruments, and materials brought to the sterile field during an operation. Exogenous flora are primarily aerobes, especially gram-positive organisms (e.g., staphylococci and streptococci). Interventions to prevent SSIs therefore are aimed at reducing or preventing microbial contamination of the patient’s tissues or of sterile surgical instruments. Other interventions include preoperative antibiotic prophylaxis, careful surgical technique, adequate ventilation of the OT, etc. Of the variables involved in the “equation” of SSI, operative characteristics such as preparation of the patient’s and health care worker’s skin, appropriate timing of antibiotic prophylaxis, and preparation of the OT are easier to control than patient risk factors such as presence of underlying diabetes, age, smoking history, and obesity. Therefore the balance of this chapter will focus on the operative characteristics associated with infection prevention.
Infection Prevention in the Operating Theatre
Infection prevention in the operating room is achieved through prudent use of aseptic techniques in order to: 15
• Prevent contamination of the open wound. • Isolate the operative site from the surrounding unsterile physical environment.
• Create and maintain a sterile field in which surgery can be performed safely. Although all infection prevention practices contribute to this effort, aseptic technique refers to those practices performed just before or during clinical procedure including:
• Properly preparing a client for clinical procedures • Handwashing 95
• Surgical hand scrub • Using barriers such as gloves and surgical attire • Maintaining a sterile field • Using good surgical technique • Maintaining a safe...