Quantifying exposure to chlorhexidine from decontamination of peripheral intravenous injection ports

BACKGROUND

Annually, almost 2 billion peripheral intravenous cannulas (PIVCs) are placed worldwide. In response to concerns of infectious complications, chlorhexidine is increasingly utilised for maintenance decontamination of PIVC injection ports. Concomitantly, the allergenic potential of chlorhexidine exposures has been highlighted by several case reports, implicating it as a trigger when used for this seemingly innocuous process. Given how widespread this application is, elucidating potential chlorhexidine exposure is needed to gauge its risks and benefits.

OBJECTIVE

To examine and quantify if chlorhexidine is entrained when used for PIVC injection port cleaning.

METHODS

Twenty benchtop PIVC set-ups were cleaned with 2% chlorhexidine and 70% alcohol wipes, following three different pragmatic protocols. Each set-up was injected with 10 ml ultrapure water, and samples tested by liquid chromatography-electrospray tandem mass spectrometry for entrained chlorhexidine.

RESULTS

Chlorhexidine was detected in every sample. Mean concentrations and standard deviations from each protocol were 41.47 ppb (4.08), 54.76 ppb (17.46), and 65.84 ppb (7.01). One-way ANOVA indicated a statistical difference between at least two groups (df = 2, F = 24.11, p < .00001), with Tukey's testing verifying significantly different mean concentrations between all groups (p < .01).

CONCLUSIONS

Using 2% chlorhexidine and 70% alcohol swabs to decontaminate PIVC injection ports resulted in consistent entrainment of chlorhexidine, with varying amounts correlated to how it was applied. These results validate case reports attributing anaphylactic/allergic reactions to suspected intravenous chlorhexidine entrainment and should factor into future risk-benefit assessments for its use in PIVC maintenance antisepsis policies and protocols.

Photocrosslinkable methacrylated gelatin hydrogel as a cell-friendly injectable delivery system for chlorhexidine in regenerative endodontics

OBJECTIVES

This work sought to formulate photocrosslinkable chlorhexidine (CHX)-laden methacrylated gelatin (CHX/GelMA) hydrogels with broad spectrum of action against endodontic pathogens as a clinically viable cell-friendly disinfection therapy prior to regenerative endodontics procedures.

METHODS

CHX/GelMA hydrogel formulations were successfully synthesized using CHX concentrations between 0.12 % and 5 % w/v. Hydrogel microstructure was evaluated by scanning electron microscopy (SEM). Swelling and enzymatic degradation were assessed to determine microenvironmental effects. Compression test was performed to investigate the influence of CHX incorporation on the hydrogels' biomechanics. The antimicrobial and anti-biofilm potential of the formulated hydrogels were assessed using agar diffusion assays and a microcosms biofilm model, respectively. The cytocompatibility was evaluated by exposing stem cells from human exfoliated deciduous teeth (SHEDs) to hydrogel extracts (i.e., leachable byproducts obtained from overtime hydrogel incubation in phosphate buffer saline). The data were analyzed using One- and Two-way ANOVA and Tukey's test (α = 0.05).

RESULTS

CHX/GelMA hydrogels were effectively prepared. NMR spectroscopy confirmed the incorporation of CHX into GelMA. The addition of CHX did not change the micromorphology (pore size) nor the swelling profile (p > 0.05). CHX incorporation reduced the degradation rate of the hydrogels (p < 0.001); whereas, it contributed to increased compressive modulus (p < 0.05). Regarding the antimicrobial properties, the incorporation of CHX showed a statistically significant decrease in the number of bacteria colonies at 0.12 % and 0.5 % concentration (p < 0.001) and completely inhibited the growth of biofilm at concentration levels 1 %, 2 %, and 5 %. Meanwhile, the addition of CHX, regardless of the concentration, did not lead to cell toxicity, as cell viability values were above 70 %.

SIGNIFICANCE

The addition of CHX into GelMA showed significant antimicrobial action against the pathogens tested, even at low concentrations, with the potential to be used as a cell-friendly injectable drug delivery system for root canal disinfection prior to regenerative endodontics.

Review of allergic reactions from use of chlorhexidine on medical products in clinical settings over 40 years: Risks and mitigations

Chlorhexidine is an antimicrobial agent widely used for infection prevention in medical settings. Nevertheless, allergic reactions ranging from mild to severe have been reported following its use. In this review, we analyzed all case reports published between the introduction of chlorhexidine and the end of 2019 for allergic responses associated with the use of medical devices and or other medical products containing chlorhexidine (CHX) to ascertain the prevalence of severe CHX allergic reactions and what practices might best mitigate those risks.In total, 77 publications containing 124 reported cases of allergic reactions were grouped into 3 product categories, catheters, semisolids, and fluid products. The country, type of reaction, route of sensitization, allergy confirmation, and intervention or mitigation was extracted for each case. Overall, 30 cases were associated with catheters, 46 cases were associated with semisolid products, and 48 cases were associated with the use of other medical products. Severe cases were managed with intravenous fluids, steroids, and epinephrine (adrenaline). None of the reported cases were fatal. The allergy risks can be mitigated by better warning and training clinicians and by recording and screening patient histories for CHX presensitization from prior exposure. For patients undergoing pre-use blood tests, IgE antibody screens can also be performed. Finally, as a precaution in the event a rare severe allergic reaction occurs, procedure carts and rooms can be prestocked with injectable epinephrine and other rapidly acting anti-inflammatory medications.