The article takes aim at past studies supporting the use of CHG, saying the researchers in most of those studies misread their own data. “Effects cannot be attributed to one factor when in fact several factors were tested in combination,” said co-author Dr. Matthias Maiwald of the National University of Singapore.
The report comes as two U.S. safety organizations are considering whether to recommend that all hospitals use CHG formulas to prevent surgical infections. In January, CareFusion reached a settlement with the Justice Department over accusations of attempting to influence the National Quality Forum to add its CHG product to a list of patient-safety recommendations.
CHG is the abbreviation for chlorhexidine gluconate, which is typically sold in a solution mixed with isopropyl alcohol and used to sterilize surgical sites and central-line venous catheters. Medical products company CareFusion, which sells its 2% chlorhexidine solution under the commercial name ChloraPrep, claims the superiority of CHG over traditional surgical antiseptics is well-supported in the clinical literature.
“There's really good evidence that shows the chlorhexidine molecule is an important antimicrobial agent,” said Dr. Carlos Nunez, chief medical officer at CareFusion.
The Centers for Disease Control and Prevention is expected to address the issue in its upcoming guidelines for preventing surgical-site infections. Meanwhile, the NQF is investigating whether it should delete a reference to a specific CHG formula from its 2010 Safe Practices report. A draft of the NQF revisions (PDF) says the group plans to continue recommending the use of CHG to prevent central line infections, but it will no longer recommend the precise formulation in ChloraPrep products.
A CDC expert panel concluded in 2011 that while CHG should be used as a skin antiseptic before inserting venous catheters, researchers haven't resolved the question of whether chlorhexidine in alcohol is better than the traditional antiseptic, povidone-iodine in alcohol, for general cleaning of skin.
CHG products typically cost more than traditional surgical antiseptics.
“The jury is still out whether CHG is better for skin preparation immediately before surgery,” said Dr. Dale Bratzler, associate dean at the University of Oklahoma's College of Public Health who has served on the CDC's Healthcare Infection Control Practices Advisory Committee.
Last December, the Journal of the American College of Surgeons published an observational study of 16,000 surgical patients in Washington state that found no difference in surgical infection rates between patients who had CHG-based skin preps and those who had traditional iodine-based preparations. “After adjusting for relevant factors, we found that no single antiseptic agent was associated with a comparatively lower risk” of surgical-site infection, the study concluded.
That seemed to contradict the conclusion of a 2010 New England Journal of Medicine study openly funded by CareFusion concluding that the CHG formula of 2% chlorhexidine and 70% alcohol in ChloraPrep worked better than traditional iodine for preventing surgical-site infections.
The CDC currently is updating its guidelines for surgical-site infection prevention, which haven't been updated since 1999. The 2011 CDC recommendations on CHG were contained in a report on central-line infections, not on surgical-site infections.
Meanwhile, the NQF is reviewing its 2010 report that recommended all hospitals use CareFusion's 2% chlorhexidine formulation to prevent central-line bloodstream infections. That review was prompted by allegations contained in a $40 million settlement last January that CareFusion tried to influence the Forum's recommendations by paying $11.6 million in overpriced contracts to the co-chairman of an NQF committee, Dr. Charles Denham.
Denham has denied wrongdoing through a spokesman, noting that the Justice Department allegations dealt solely with CareFusion's conduct, not his. He left his role as co-chairman of the NQF Safe Practices Committee in 2010.
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