What is the risk for surgical site infection (SSI) in a patient with complex medical history undergoing coronary artery bypass graft surgery with chlorhexidine gluconate in alcohol for preoperative skin antisepsis?

Risk of Surgical Site Infection with Chlorhexidine Gluconate in Alcohol for Preoperative Skin Antisepsis

Based on the Widmer study, there is no increase in the risk for deep incisional SSI, organ space SSI, or superficial SSI when using chlorhexidine gluconate in alcohol for preoperative skin antisepsis in this patient undergoing CABG surgery.

Understanding Surgical Site Infections (SSIs)

SSIs are classified into three distinct categories according to the Centers for Disease Control and Prevention 1:

1. Superficial incisional SSI: Involves only the subcutaneous tissue, occurs within 30 days of surgery
2. Deep incisional SSI: Involves deep soft tissues (fascia and muscle), typically occurs within 30 days
3. Organ/space SSI: Involves any anatomical part opened during surgery other than the incision

Evidence Supporting Chlorhexidine Gluconate Use

Chlorhexidine gluconate (CHG) in alcohol has been shown to be effective for preoperative skin antisepsis and is associated with a lower risk of SSIs compared to other preparations:

• The FDA approves chlorhexidine gluconate for "patient preoperative skin preparation" to prepare the patient's skin prior to surgery 2
• A high-quality multicenter international trial demonstrated that chlorhexidine-alcoholic solution is associated with a lower rate of surgical site infections compared to povidone-iodine solution 3
• A study comparing 2% CHG/70% IPA with 0.5% CHG/70% IPA found that the higher concentration reduced the number of microorganisms detectable on a surgical patient's skin perioperatively, with fewer superficial SSIs in the 2% CHG group (though not statistically significant) 4

Patient-Specific Risk Factors for SSI

While the choice of skin antisepsis is appropriate, this patient has multiple risk factors for SSI that should be addressed:

• End-stage renal disease requiring dialysis: Significantly increases infection risk
• Diabetes mellitus: Associated with almost six times higher risk of deep SSI 5
• Coronary artery disease: May affect tissue perfusion and healing
• Recent myocardial infarction: May affect overall health status
• Multiple vessel CABG: Complexity and duration of procedure increases risk 6

Preventive Strategies for High-Risk Patients

For this high-risk patient, additional measures should be implemented:

1. Appropriate perioperative antibiotics: Administer within 60 minutes before surgical incision 3
2. Maintain normothermia: Critical during the intraoperative period 3
3. Glycemic control: Particularly important for this diabetic patient
4. Proper surgical technique: Gentle tissue handling, maintaining vascularity, avoiding hematomas 3
5. Postoperative surveillance: Especially important given multiple risk factors

Avoiding Common Pitfalls

• Overreliance on skin antisepsis alone: While chlorhexidine is effective, it must be part of a comprehensive infection prevention strategy
• Inadequate antibiotic timing or selection: Ensure appropriate coverage for likely pathogens
• Failure to recognize deep extension: Be vigilant for signs of deeper infection given patient's risk factors
• Delayed intervention: Any signs of infection should prompt immediate evaluation

Conclusion

The surgical team's choice of chlorhexidine gluconate in alcohol for preoperative skin antisepsis is appropriate and does not increase the risk of any type of SSI. However, this patient's multiple comorbidities (ESRD, diabetes, CAD) place him at elevated risk for infection, requiring vigilant perioperative care and monitoring.