Chlorhexidine baths in preterm infants — are we there yet?

Abstract

We enjoyed reading the article by Johnson et al. [1] presenting the efficacy of chlorhexidine (CHG) baths in preterm neonates. A key finding was the temporary reduction in skin bacterial burden in 18 preterm neonates, which returned to baseline by ~72 h with no reported healthcareacquired infections (HAI) or adverse skin events. Although the study demonstrated efficacy, it does not highlight the safety concerns perceived by many neonatologists regarding CHG use for central line insertions and dressing changes, let alone for routine baths. The results of this study may potentially increase CHG use in this at-risk population without convincing evidence of long-term safety. The epidermis in preterm infants is immature with thin stratum corneum that does not fully mature until about 34 weeks, leading to higher risk of local complications of CHG such as contact dermatitis, and chemical burns. Furthermore, detectable serum levels from systemic absorption have been shown after topical CHG exposure in preterm infants ≥1500 grams (≥7 days old), and at low concentrations [2, 3]. The risk is higher in smaller infants with poor skin integrity. The blood–brain barrier permeability to CHG and its neurological impact on the immature preterm brain are unknown. Fears of CHG-related neurodevelopmental complications stem from previous experience using Hexachlorophene (a phenol derivative similar to CHG) to decrease HAIs in the 1970 s, which later was found to be associated with vacuolar encephalopathy [4]. CHG also had a clear toxic effect on the vestibular and cochlear function in sand rats. Milstone et al. showed that in vitro CHG use decreased neuronal growth at concentrations similar to blood levels found in preterm infants exposed to CHG [5]. Despite limited evidence showing CHG safety in preterm neonates, and lack of randomized control trials showing statistically significant reduction in neonatal HAIs, recent surveys of NICUs across the USA have shown increased utilization of CHG in neonates [2]. HAIs can lead to increased morbidity, mortality, and financial penalties for hospitals. Hence, simple practices that reduce HAI are often adopted quickly before fully exploring longer term complications. It is also unclear if decreasing bacterial colonization may be associated with altered microbiome, increased risk of future infections, allergies, or atopic disease. While several practical issues await standardization, including the age of neonates receiving CHG, concentration, and type of CHG preparation (water-based or alcoholbased), the use of CHG might be justified in resourcelimited settings with a high risk of HAI. However, for units with well-established infection prevention protocols, it may be worth waiting for safety data. Potential for cumulative toxicity from repeated skin exposure is especially important to consider in the context of using routine CHG baths [3]. To conclude, this article provides valuable information regarding the efficacy of CHG use in preterm neonates; however, potential risks need to be highlighted before enthusiastically accepting the authors’ conclusion. It is imperative to avoid the deja vu of the 1970s with the widespread use of hexachlorophene before the establishment of long-term safety data, resulting in HAI reduction with unfortunately higher neurological morbidities.