Surgical Site Infection Risk with Chlorhexidine Gluconate in Alcohol for CABG Surgery
There is no increased 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 coronary artery bypass graft surgery.
Understanding Surgical Site Infections
Surgical site infections (SSIs) are classified into three distinct categories according to the Centers for Disease Control and Prevention 1:
- Superficial incisional SSI: Involves only subcutaneous tissue, occurs within 30 days of surgery
- Deep incisional SSI: Involves deep soft tissues, occurs within 30 days (or up to 1 year with implant)
- Organ/space SSI: Involves any anatomical part opened during surgery
Chlorhexidine Gluconate in Alcohol vs. Other Antiseptic Solutions
The choice of preoperative skin antisepsis solution is critical in preventing SSIs. Current evidence supports the use of chlorhexidine gluconate in alcohol:
- A high-quality, multicenter, international trial demonstrated that chlorhexidine-alcohol solution is associated with a lower rate of surgical site infections compared to povidone-iodine solution 2
- A study specifically examining skin preparation before harvest of long saphenous vein used in CABG found that 70% isopropyl alcohol containing 2% CHG was more effective at reducing microorganisms on the skin perioperatively compared to 0.5% CHG/70% IPA 3
Patient-Specific Risk Factors
The patient in question has multiple risk factors for SSI:
- End-stage renal disease requiring dialysis
- Type 2 diabetes mellitus
- Recent myocardial infarction
- Multiple comorbidities
However, these risk factors are independent of the antiseptic solution used. The Surgical Site Infection Risk Score (SSIRS) identifies factors such as smoking, increased BMI, peripheral vascular disease, metastatic cancer, chronic steroid use, recent sepsis, surgical urgency, increased ASA class, longer operation duration, infected wounds, and general anesthesia as contributing to SSI risk 4, but these do not interact specifically with the choice of chlorhexidine gluconate in alcohol.
Evidence on Antiseptic Solutions and SSI Types
The evidence does not suggest that chlorhexidine gluconate in alcohol increases the risk for any type of SSI (superficial, deep incisional, or organ/space) compared to other antiseptic solutions. In fact:
The World Society of Emergency Surgery guidelines state that "skin preparation with chlorhexidine-alcoholic solution is associated with a lower rate of surgical site infections, compared to povidone-iodine solution" and gives this recommendation a strong grade 2
A study comparing 2% CHG/70% IPA with 0.5% CHG/70% IPA for skin preparation in CABG patients found that the 2% concentration resulted in fewer detectable microorganisms perioperatively and a trend toward lower superficial SSI rates (though not statistically significant) 3
Conclusion
Based on the available evidence, using chlorhexidine gluconate in alcohol for preoperative skin antisepsis in this patient with multiple comorbidities undergoing CABG surgery does not increase the risk for any type of SSI compared to other antiseptic solutions. In fact, current evidence suggests it may be superior to alternatives like povidone-iodine.
The patient's underlying conditions (diabetes, renal disease, etc.) do increase his overall SSI risk, but this is independent of the antiseptic solution choice. Proper application of chlorhexidine gluconate in alcohol, along with other preventive measures like appropriate antibiotic prophylaxis, is recommended for this high-risk patient.