Chlorhexidine gluconate (CHG) is an antibacterial antiseptic with the ability to inhibit and kill bacteria associated with healthcare-associated infections (HAIs). In the last two decades, investigators have researched the use of CHG for hand hygiene, oral hygiene, pre-operative bathing, insertion and maintenance of central venous catheters (CVCs), and daily bathing of patients with CVCs. The rapid antimicrobial activity of CHG, in addition to the persistent and residual antibacterial effect for up to six hours on the skin, has led to recommendations for its use as a healthcare provider hand soap, showering/bathing agent prior to surgery, skin preparation agent for drawing blood cultures and for preparing the skin prior to the insertion of intravascular lines.
The strength of the literature related to CHG use for central line insertion skin preparation and the associated reduction in central line-associated bloodstream infections (CLABSIs) led to a Category 1A recommendation1 in the 2011 Centers for Disease Control Guidelines (CDC) for the Prevention of Intravascular Catheter-Related Infections. Chalyakunapruk and colleagues conducted a meta-analysis of studies which evaluated the efficacy of skin disinfection with chlorhexidine gluconate compared with povidone-iodine solution in preventing CLABSIs and concluded that the use of CHG reduced the CLABSI risk by 49% in hospitalized patients requiring short-term catheterization.2
- Recommendation: Prepare clean skin with a >0.5% chlorhexidine with alcohol preparation before central venous catheter and peripheral arterial catheter insertion and during dressing changes. If there is a contraindication to chlorhexidine, tincture of iodine, an iodophor, or 70% alcohol can be used as alternatives.
NEEDLELESS ACCESS PORTS:
Another Category 1A recommendation addresses the use of CHG for disinfection of needleless access ports prior to entry into the intravascular catheter system. Although CHG is not cited as the preferential agent, some studies have shown that disinfection with chlorhexidine/alcohol solutions appears to be most effective in reducing bacterial colonization of the connectors. In a randomized cross-over clinical trial comparing 3.15% chlorhexidine/70% alcohol (CHG) vs. 70% alcohol alone for routine disinfection of needleless connectors on CVCs, a 5 second scrub with CHG resulted in significantly less needleless connector contamination than the alcohol scrub (p<0.001).3 In addition, using an in vitro model, Hong, et al.4found that disinfection of needleless connectors with chlorhexidine-alcohol was superior to alcohol alone for brief scrub times and the disinfectant activity for the chlorhexidine-alcohol persisted for up to 24 hours after application. Adequate disinfection of these connectors represents a critical practice to prevent the intraluminal entry of bacterial pathogens into the bloodstream.
- Recommendation: Minimize contamination risk by scrubbing the access port with an appropriate antiseptic (chlorhexidine, povidone iodine, an iodophor, or 70% alcohol) and accessing the port only with sterile devices.
Although the guidelines rated the use of CHG for daily patient bathing to reduce CLABSI as a Category II recommendation5 based on the literature available at the time6, a meta-analysis of predominantly quasi-experimental designed studies conducted by O’Horo et al concluded that daily bathing with CHG resulted in a reduced incidence of bloodstream infections, including CLABSIs, among patients in the medical intensive care unit (MICU).7 Milstone and colleagues examined the impact of daily CHG bathing on the incidence of bacteremia among critically ill children.8 In this multicenter, randomized trial they found that children bathed with CHG had a 36% lower risk of bacteremia and the treatment was well-tolerated. The reduction of microbial bioburden on the skin of both adult and pediatric critically ill patients appears to be an effective practice for preventing extraluminal entry of bacterial pathogens into the bloodstream. The next version of the CDC guidelines will have a great deal more science available to categorize the recommendation for CHG daily bathing.
Another practice addressed in the guidelines to reduce microbial bioburden on the skin at the insertion site of central venous catheters is the use of CHG-impregnated dressings. A Category 1B recommendation9 cites the use of a chlorhexidine-impregnated sponge dressing for temporary short-term catheters in patients older than 2 months of age if the CLABSI rate is not decreasing despite adherence to basic prevention measures. No recommendation is made regarding the use of other types of CHG dressings. However, a draft guideline update regarding CDC recommendations on use of CHG-impregnated dressings for prevention of intravascular catheter-related infections was recently posted in the Federal Register for public comment in early 2017 and provides an appendix of primary evidence and data evaluation tables supporting the use of these dressings.10
SKIN PREP FOR BLOOD CULTURE:
Additional clinical support for CHG not specifically addressed in the guidelines pertains to its efficacy for reducing blood culture contamination when used as a skin preparation. Mimoz et al compared CHG to povidone-iodine for skin preparation prior to blood culture among adult intensive care unit patients.11 The investigators found that CHG significantly reduced the rate of blood culture contamination compared with povidone-iodine (1.4% vs. 3.3%; odds ratio, 0.44; p = 0.004).
NEONATAL INTENSIVE CARE UNITS:
Although the guidelines state that no recommendation can be made for the safety or efficacy of chlorhexidine in infants aged <2 months, a recent paper by Johnson and colleagues12 revealed an increasing trend toward the use of CHG in neonatal intensive care units (NICUs) in the United States. A survey of NICUs with fellowship training programs conducted in 2009 found that 57% of responding institutions used CHG with many restricting use by age and weight based on the FDA labeled indication of “do not use in premature or low birthweight infants or children less than 2 months of age”. However, in 2012, the FDA modified the labeled indication to “use with care in premature infants or infants under 2 months of age”. A repeat of the survey in 2014 revealed an increase in CHG use from 57% to 86% by these NICUs although there remains concern regarding potential side effects in this population. More prospective studies are needed to provide specific CHG guidelines for neonatal practice and to demonstrate safety in this venerable patient population.
Based on the plethora of studies investigating the clinical use of CHG to reduce CLABSIs in recent years and its demonstrated efficacy, we can anticipate that the update to the 2011 CDC Guidelines for the Prevention of Intravascular Catheter-Related Infections will elevate recommendations for its use.
1 Strongly recommended for implementation and strongly supported by well-designed experimental, clinical, or epidemiologic studies.
2 Chalyakunapruk N et al. Chlorhexidine Compared with Povidone-Iodine Solution for Vascular Catheter-Site Care – A Meta-Analysis. Ann Intern Med 2002;136:792-801.
3 Hayden M et al. A Randomized Cross-Over Clinical Trial To Compare 3.15% Chlorhexidine/70% Isopropyl Alcohol (CHG) VS 70% Isopropyl Alcohol Alone (ALCOHOL) And 5 Second VS 15 Second Scrub For Routine Disinfection Of Needleless Connectors On Central Venous Catheters In An Adult Medical Intensive Care Unit. Presented at IDWeek, Philadelphia, PA October, 2014.
4 Hong BA et al. Disinfection of Needleless Connectors With Chlorhexidine-Alcohol Provides Long Lasting Residual Disinfectant Activity. Am J Infect Control 2013: 41(8); 77-79.
5 Suggested for implementation and supported by suggestive clinical or epidemiologic studies or a theoretical rationale.
6 Bleasdale SC et al. Effectiveness of chlorhexidine bathing to reduce catheter-associated bloodstream infections in medical intensive care unit patients. Arch Intern Med 2007; 167:2073-9.
7 O’Horo JC et al. The Efficacy of Daily Bathing with Chlorhexidine for Reducing Healthcare-Associated Bloodstream Infections: A Meta-Analysis. Infect Control Hosp Epidemiol 2012;33(3):257-67.
8 Milstone AM et al. Daily Chlorhexidine Bathing to Reduce Bacteraemia in Critically Ill Children: A MultiCentre, Cluster-Randomised, Crossover Trial. Lancet2013;381:1099-1106.
9 Strongly recommended for implementation and supported by some experimental, clinical, or epidemiologic studies and a strong theoretical rationale; or an accepted practice (e.g., aseptic technique) supported by limited evidence
11 Mimoz O et al. Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. Ann Intern Med 1999;131:834-837.
12 Johnson J et al. Trends in Chlorhexidine Use in US Neonatal Intensive Care Units: Results from a Follow-Up National Survey. Infect Control Hosp Epidemiol2016;37(9):1116-17.