Antibioprophylaxie en Chirurgie

Study Notes

But: Reduce surgical site infections (SSIs) by limiting bacterial growth during surgery. Surgical wounds are ideal environments for bacteria due to factors like hematomas, ischemia, and oxidants.
Additional Risk Factors for SSIs:
- General hygiene measures
- Operating room environment
- Surgical duration
- Surgical technique
- Skin preparation (including shaving and disinfection)
- Surgical asepsis (sterile technique)
- Perioperative management (blood sugar, temperature, patient's health conditions like immunocompromised/diabetic patients, malnutrition, and obesity).
Presence of Materials Increases Risk:
- Antibiotic prophylaxis (ABP) can reduce infection risk by about 50%.
- The targeted bacteria depend on the type of surgery, the patient's endogenous flora, and the hospital unit's environment.
Consequences:
- Risk of Clostridium difficile colitis (infections due to the antibiotic medicine)
- The risk is proportional to the duration and number of broad spectrum antibiotics used.
- Aiming for a single, appropriate antibiotic is important/recommended.
- Resistance development is a significant concern.
Duration of Prescription:
- ABP should ideally be limited to the operative period.
- In some cases, it may be limited to 24 hours, or exceptionally to 48 hours, but never exceeding this time.

Criteria to Determine Necessary ABP: Different surgical procedures have varying risks of infection. Surgical classification systems are used to determine whether ABP is needed.
Different surgical classifications with their infection rates and whether ABP is applied are reviewed.
Specific examples of surgeries and infection risks are described.

Principle: The antibiotic must be effective against the most common bacteria causing surgical site infections.
Common Pathogens:
- Clean procedures: Gram-positive cocci (such as Staphylococcus) require cephalosporins like cefazolin.
- Clean-contaminated procedures: Gram-negative bacteria (such as Escherichia coli) may require a combination of drugs like cefuroxime and metronidazole/augmentin.
- Antibiotic resistance: Methicillin-resistant Staphylococcus aureus (MRSA) requires vancomycin.
Optimum Timing:
- Administering 30 to 60 minutes before the surgery.
- If possible, administering ABP before the tourniquet is inflated and as soon as possible, ideally within 30 minutes of the actual start of the surgery.
- 5-10 minutes should be considered a buffer between the induction of general anesthesia.

Initial dose: Usually double the usual dose.
Higher doses for obese patients: Obese patients require potentially higher doses due to altered pharmacokinetics and potentially increased tissue concentrations needed.
Repeated doses: Repeated doses of antibiotics may be given every two half-lives.
Responsibility: The anesthesiologist is responsible for the prescription in most cases.
Time to incision: ABP should precede the incision by at least 30 minutes in normal cases, and sometimes even before the anesthesia.