Researching and writing a book is always a sure-fire means of generating a list of interesting things that one might want to look into one day, and my recent Group B Strep project didn’t let me down in this regard! A couple of things that I discovered during this project about chlorhexidine – an antiseptic antibacterial agent in common use in many areas of health care and Western medicine – have gone onto that list and, although I’ve not yet researched this systematically, I am going to share some initial thoughts today. As ever, I am really interested to find out what others think…
What is Chlorhexidine?
Chlorhexidine is a medicine which is manufactured by companies in a range of preparations, dosages and forms (including liquid, washes, gels, creams and in pads and dressings) and under a number of different brand names, including hibiclens, hibistat, betasept, chlorostat, dyna-hex and stanhexidine. It is on the World Health Organisations’ Model List of Essential Medicines, which lists the “minimum medicine needs for a basic health care system, listing the most efficacious, safe and cost-effective medicines for priority conditions”. (Although is has been on that list as an antiseptic for some time, it was also added to the section covering neonatal umbilical cord care in 2013, on the basis of the results of research carried out in Bangladesh, Nepal and Pakistan. I’ll come back to that in a bit.)
Chlorhexidine and GBS
Chlorhexidine is also sometimes used by pregnant women in a very specific context. It is sometimes used to flush out the vagina, in the hope of clearing it of group B strep (GBS) bacteria. In my experience and understanding, there are two reasons why a woman might want to attempt to clear GBS bacteria from her vagina:
1) To reduce the chance that GBS bacteria is passed on to her baby.
2) To reduce the chance of having a positive result to a GBS test which she feels unable to avoid. This might be, for instance, because a negative GBS result is the ‘pass’ that gets her into a particular birth centre, or that enables her to remain in the care of a midwife.
Both of these reasons sit within incredibly complex and uncertain contexts. Current evidence doesn’t show that the practice of douching with chlorhexidine makes any difference to the chances of a baby becoming ill as a result of GBS infection, and the fact that some women feel the need to use a home-based intervention as a means of circumventing medical intervention obviously raises myriad issues which are worthy of further and deeper discussion.
But neither of these are the area that I want to write about today. Instead, I want to point out some snippets from the medical literature that I don’t think have yet been shared widely within the birth world and which may be worthy of our attention.
Risks to babies
The first is the concern that chlorhexidine is not safe for newborn skin, especially for babies who were born preterm. This issue has been discussed by several groups of researchers, including Tamma et al (2010), whose survey showed that most of the US neonatal units they surveyed were using chlorhexidine despite safety concerns, and Lashkari et al (2012), who described and photographed a case of a very preterm baby with chlorhexidine-induced burns. In June 2014, the UK Medicines and Healthcare Products Regulatory Agency released a statement about the risk of chemical burns when chlorhexidine was used on the skin of preterm babies in neonatal intensive care units:
“We have received 14 reports of serious side effects in premature infants who were treated with chlorhexidine solution before central venous catheterisation (umbilical catheterisation or long line insertion). Another 14 cases were identified in the medical literature. The side effects included erythema and chemical burns with and without skin loss. Four of these cases had a fatal outcome, although severe complications of prematurity might have contributed to two of the fatal cases. The chemical injuries occurred in infants of less than 32 weeks gestation and within the first few days of life when alcohol based chlorhexidine solutions (0.5% or 2% in 70% alcohol) or 2% aqueous chlorhexidine solutions were used.” (Full statement here).
Are there better alternatives?
More recently, a discussion about chlorhexidine and possible alternatives has been taking place in the pages of The Lancet. Maiwald et al (2014) wrote a letter questioning the results of a trial that was originally published more than two decades ago (Maki et al 1991). This trial had evaluated the efficacy of different substances in preventing infection in intravascular devices (central venous and arterial catheters, or tubes which are used to pump fluids into patients’ blood vessels, usually in an intensive care situation). Maki et al (1991) found that, compared to 10% povidone-iodine or 70% alcohol, 2% chlorhexidine substantially reduced the incidence of device-related infection.
Maiwald et al (2014) are clearly concerned about some of the claims of Maki et al’s (2014) research, which they came across ‘while investigating the relevant literature’. Their concern seems to relate to the fact that Maki et al’s (1991) research is one of those studies which has gained prominence in an area and is often cited, despite being potentially flawed. (Those who know me well may now understand why this caught my eye!)
Maiwald et al (2014) go on to point out several methodological issues with Maki et al’s (1991) paper alongside the fact that that earlier reseach by the lead author “was supported by a chlorhexidine-producing company”. Maki et al (2014) understandably responded and defended their paper and position while challenging Maiwald to put his own beliefs on (randomised controlled) trial, and this is the point at which the entire situation becomes like a game of research tennis, where one can only look from each paper to the next, knowing that the only way to truly understand what is going on is to spend several hours tracking back and digging out all of the relevant research, correspondance and related literature.
What to think?
I don’t have those hours right now, but my discovery of these things – the concerns about the effects of chlorhexidine on delicate newborn skin, the questions raised by Maiwald et al’s (2014) letter, the addition of chlorhexidine to the Essential Medicines List for neonatal cord care and my knowledge that some women are using this in relation to GBS – made me want to share some of these links, so that anyone who is interested has a starting point from which to begin their own exploration of the issues. There is no doubt that antibacterial drugs and substances such as chlorhexidine can be life-saving when used appropriately. But I want to argue that we must not become so used to the existence of such substances in medical settings that we become complacent about their possible side effects or forget to consider the bigger picture surrounding their use and value.
Lashkari HP, Chow P, Godambe S (2012). Aqueous 2% chlorhexidine-induced chemical burns in an extremely premature infant. Arch Dis Child Fetal Neonatal Ed 2012; 97: F64.
Maiwald M, Assam PN, Chan ES-Y et al (2014). Chlorhexidine’s role in skin antisepsis: questioning the evidence. The Lancet, 384(9951): 1344-1345
Maki DG, Alvarado CJ, Ringer M (1991). Prospective randomised trial of povidone-iodine, alcohol, and chlorhexidine for prevention of infection associated with central venous and arterial catheters. The Lancet, 338(8763): Pages 339-343
Maki DG (2014). Chlorhexidine’s role in skin antisepsis: questioning the evidence–Author’s reply. The Lancet. 384(9951): 1345-46.
Chlorhexidine solutions: risk of chemical burn injury to skin in premature infants. MHRA Drug Safety Update 7(11):S2.
Tamma PD, Aucott SW, Milstone AM (2010). Chlorhexidine use in the Neonatal Intensive Care Unit: Results from a National Survey. Infect Control Hosp Epidemiol. 31(8): 846–849.