What is the recommended use and concentration of chlorhexidine (CHG) for skin disinfection and wound care?

Recommended Use and Concentration of Chlorhexidine (CHG) for Skin Disinfection and Wound Care

For skin disinfection, 0.5% chlorhexidine in alcohol is recommended as the optimal concentration for central neuraxial blockade procedures, while 2% chlorhexidine in alcohol is preferred for general skin antisepsis and surgical site preparation. 1

Skin Disinfection Applications

Central Neuraxial Blockade (CNB) Procedures

• Concentration: 0.5% chlorhexidine in alcohol is the safest effective option 1
  • Provides optimal balance between antimicrobial efficacy and reduced neurotoxicity risk
  • Higher concentrations (2%) have not demonstrated superior efficacy against infection for CNB
  • Neurotoxicity of chlorhexidine is well-established in vitro at concentrations as low as 0.01% when in direct contact with neural tissue

General Skin Antisepsis (Non-CNB)

• Concentration: 2-2.5% chlorhexidine in alcohol is preferred 1, 2
  • More effective than povidone-iodine for preventing surgical site infections
  • Recommended for central venous access device insertion 1
  • Demonstrates superior efficacy across various surgical procedures 2

Application Method Considerations

• Use pre-soaked antiseptic sponge applicators ("swab-sticks") rather than pouring into gallipots 1
  • Prevents cross-contamination with other solutions
  • Minimizes risk of accidental contamination of equipment
• Allow complete drying before any procedure to minimize neurotoxicity risk 1
• For surgical hand scrub: use full-strength 4% chlorhexidine gluconate 3
  • Apply 5mL and scrub for 3 minutes, rinse, then repeat for optimal effect 3, 4

Wound Care Applications

• Concentration: Use minimal effective amounts of diluted chlorhexidine 3, 5
  • For general skin cleansing: apply minimum amount necessary to cover wound area 3
  • For wound irrigation: 0.05% CHG has been studied for wound irrigation prior to closure 6
  • Thoroughly rinse with water after application 3

Safety Considerations and Precautions

• Avoid direct contact with:

  • Eyes (can cause conjunctivitis and severe corneal damage) 1
  • Inner or middle ear (ototoxicity) 1
  • Brain tissue and meninges 1
  • Use with caution in premature infants or infants under 2 months 3

• Potential adverse effects:

  • Skin irritation (concentration-dependent, higher with 4% formulations) 1
  • Staining of teeth, restorations, and tongue (reported by 77% of dentists) 7
  • Allergic reactions (uncommon) 1
  • Potential for chemical burns in certain populations 3

Application Protocol

1. For skin disinfection:

   • Wet the area to be cleansed with water
   • Apply appropriate concentration based on procedure type
   • Allow complete drying before proceeding with any invasive procedure
   • Do not dilute commercial preparations unless specifically indicated

2. For wound cleansing:

   • Thoroughly rinse the area with water first
   • Apply minimum amount necessary to cover wound area
   • Wash gently
   • Rinse thoroughly with water (twice) 3

The evidence strongly supports chlorhexidine's superior efficacy compared to povidone-iodine, particularly when formulated with alcohol, but concentration should be carefully selected based on the specific application and anatomical location to minimize risks while maximizing antimicrobial benefits.