What is the use of chlorhexidine (CHX)?

From the Guidelines

Chlorhexidine should be used as a 0.5% solution in alcohol for skin antisepsis before central neuraxial blockade (CNB) to minimize the risk of neurotoxicity while maintaining effective antimicrobial activity. This recommendation is based on the guidelines for skin antisepsis for CNB, which emphasize the importance of using chlorhexidine in alcohol while taking measures to prevent it from reaching the cerebrospinal fluid (CSF) 1. The use of a 0.5% solution is preferred over a 2% solution due to the lack of convincing evidence of antimicrobial superiority and the presence of clear evidence of neurotoxicity associated with higher concentrations 1.

When using chlorhexidine for skin antisepsis, it is essential to follow proper techniques to minimize the risk of contamination and ensure effective antimicrobial activity. This includes allowing the solution to dry before palpating or puncturing the skin, checking gloves for contamination, and using a large sterile drape to prevent contamination of equipment 1. In children under two months of age, the volume of chlorhexidine used should be minimized while still ensuring effective antisepsis 1.

In addition to its use in CNB, chlorhexidine is also used as an antiseptic and disinfectant in various healthcare settings, including preoperative skin preparation, insertion site cleansing for intravascular catheters, and oral care 1. Its broad-spectrum activity against gram-positive and gram-negative bacteria, as well as its substantivity, make it an effective agent for reducing bacterial colonization and preventing infection. However, patients should be aware of the potential for skin irritation and rare but serious allergic reactions associated with chlorhexidine use.

Key considerations for the use of chlorhexidine include:

• Using a 0.5% solution in alcohol for skin antisepsis before CNB
• Minimizing the volume used in children under two months of age
• Allowing the solution to dry before palpating or puncturing the skin
• Checking gloves for contamination and using a large sterile drape to prevent contamination of equipment
• Being aware of the potential for skin irritation and allergic reactions.

From the FDA Drug Label

Warnings For external use only Allergy alert This product may cause a severe allergic reaction. Symptoms may include: wheezing/difficulty breathing shock facial swelling hives rash If an allergic reaction occurs, stop use and seek medical help right away Do not use if you are allergic to chlorhexidine gluconate or any other ingredient in this preparation as a patient preoperative skin preparation (especially on the head or face) in contact with meninges in the genital area When using this product keep out of eyes, ears, and mouth May cause serious and permanent eye injury if placed or kept in the eye during surgical procedures or may cause deafness when instilled in the middle ear through perforated eardrums if contact occurs, rinse with cold water right away wounds which involve more than the superficial layers of the skin should not be routinely treated repeated general skin cleansing of large body areas should not be done except when underlying condition makes it necessary to reduce the bacterial population of the skin Stop use and ask a doctor if irritation, sensitization, or allergic reaction occurs and lasts for 72 hours. These may be signs of a serious condition. Keep out of reach of children. If swallowed, get medical help or contact a Poison Control Center right away.

Chlorhexidine is used as a patient preoperative skin preparation, for skin cleansing, and as an antiseptic.

• Key uses include:
  • Preoperative skin preparation
  • Skin cleansing
  • Antiseptic The FDA drug label warns against using chlorhexidine in certain areas, such as the eyes, ears, mouth, genital area, and meninges, and advises against using it on wounds that involve more than the superficial layers of the skin 2.

From the Research

Uses of Chlorhexidine

• Chlorhexidine is used as a skin antisepsis preparation and is an ingredient in toothpaste and mouthwash 3
• It is especially effective when combined with alcohol, and its antimicrobial effects persist due to its strong binding to proteins in the skin and mucosa 3
• Chlorhexidine is used for handwashing, skin preparation for surgery, and the placement of intravascular access 3
• It is also used to reduce the incidence of catheter-related bloodstream infections, as catheters impregnated with chlorhexidine and antimicrobial agents have been shown to be effective 3

Clinical Applications

• Chlorhexidine is widely used in clinical practice due to its broad-spectrum antiseptic properties and rapid action, with effects lasting for six hours 4
• It is not absorbed through the skin or mucous membranes, resulting in minimal systemic toxicity 4
• Chlorhexidine is used for preoperative skin antisepsis, and alcoholic formulations of 4%-5% chlorhexidine gluconate have been shown to be safe and effective in preventing infection after clean surgery in adults 5

Adverse Reactions

• Chlorhexidine can cause adverse reactions, ranging from mild irritant contact dermatitis to life-threatening anaphylaxis 6
• Allergic contact dermatitis can precede anaphylaxis, and it is essential for physicians to be aware of the potential sources of contact with chlorhexidine and recognize the potentially debilitating and catastrophic reactions that may occur due to chlorhexidine sensitization 6