Medicine
Surgical Site Infection Risk Factors and Preoperative Decolonization Strategies
Quick fact
Preoperative decolonization, such as applying mupirocin ointment to the nostrils and bathing with chlorhexidine, can reduce the risk of Staphylococcus aureus surgical site infections by up to 40% in carriers.
Why this is interesting
You wash your hands before surgery, but what about the bacteria already living on your skin and inside your nose? Did you know that most surgical site infections are caused by your own germs?
Read the full explanation
Understanding Surgical Site Infection Risk Factors and Preoperative Decolonization Strategies
When you have surgery, your skin is cut, creating an entry point for bacteria. Despite sterilizing the operating room and instruments, the patient's own skin and nasal passages harbor bacteria—especially Staphylococcus aureus. These bacteria can move to the surgical site or be transferred during the operation. Surgical site infections (SSIs) occur when bacteria multiply in the wound. Risk factors include diabetes, smoking, obesity, prolonged surgery, and being a carrier of S. aureus in the nose. Preoperative decolonization aims to reduce the number of these bacteria before surgery. For example, patients may apply mupirocin ointment inside their nostrils and bathe with chlorhexidine soap to decrease skin bacterial load. This strategy has been shown to reduce SSI rates in certain patient populations.
A deeper explanation
The key mechanism is that endogenous flora, particularly S. aureus, are the most common pathogens in SSIs. The anterior nares are a primary reservoir. During surgery, these bacteria can travel to the wound via the patient's skin or the hands of healthcare workers. Decolonization works by eradicating or reducing the bacterial load at these reservoirs. Mupirocin inhibits bacterial protein synthesis, while chlorhexidine disrupts bacterial cell membranes. Reducing the organism burden at the time of incision lowers the inoculum that can contaminate the surgical site, thereby decreasing infection risk. The effectiveness of decolonization is influenced by the proportion of patients who are carriers, the type of surgery, and adherence to the protocol. Moreover, decolonization must be coordinated with surgical antibiotic prophylaxis to maximize benefit. This approach is a cornerstone of modern surgical safety bundles and reflects a shift from treating infections to preventing them preoperatively.