26/10/2021
Today, we share a review report based on the clinical abstracts of Michael S. Block, DMD and Brian G. Rowan, DMD, MD.
Hypochlorous Acid: The Review
The surgeon needs to have an inexpensive, available, nontoxic, and practical disinfectant that is effective in sanitizing against the COVID-19 (Coronavirus Disease 2019) virus. The purpose of this article was to review the evidence for using hypochlorous acid in the office setting on a daily basis. The method used to assemble recommendations was a review of the literature including evidence for this solution when used in different locations and industries other than the oral-maxillofacial clinic facility. The results indicate that this material can be used with a high predictability for disinfecting against the COVID-19 (Coronavirus Disease 2019) virus.
Hypochlorous Acid:
An ideal disinfectant and sanitizer must be nontoxic to surface contact, noncorrosive, effective in various forms, and relatively inexpensive. HOCl may be the disinfectant of choice for coronaviruses in an oral-maxillofacial surgery (OMS) office.
HOCl is an endogenous substance in all mammals and is effective against a broad range of microorganisms. Neutrophils, eosinophils, mononuclear phagocytes, and B lymphocytes produce HOCl in response to injury and infection through the mitochondrial membrane–bound enzyme known as “respiratory burst nicotinamide adenine dinucleotide phosphate oxidase. HOCl selectively binds with the unsaturated lipid layer and subsequently disrupts cellular integrity. Between pH levels of 3 and 6, the predominant species is HOCl that has maximal antimicrobial properties.
HOCl is a powerful oxidizing agent. In aqueous solution, it dissociates into H+ and OCl–, denaturing and aggregating proteins. HOCl also destroys viruses by chlorination by forming chloramines and nitrogen-centered radicals, resulting in single- as well as double-stranded DNA breaks, rendering the nucleic acid useless and the virus harmless. HOCl has been shown to inactivate a variety of viruses including coronaviruses in less than 1 minute. At a concentration of 200 ppm, HOCl is effective in decontaminating inert surfaces carrying noroviruses and other enteric viruses in a 1-minute contact time.
Other Clinical Applications:
Ophthalmology:
HOCl is used in the treatment of blepharitis by reducing the bacterial load on the surface of the periocular skin. Twenty minutes after application of a saline hygiene solution containing HOCl at 100 ppm, a greater than 99% reduction in the staphylococcal load was achieved.
Biofilm:
HOCl may be effective for cleaning biofilm-contaminated implant surfaces. HOCl significantly lowered the lipopolysaccharide concentration of Porphyromonas gingivalis when compared with sodium hypochlorite and chlorhexidine and was well tolerated by the oral tissues. HOCl significantly reduced bacteria on toothbrushes; it was effective as a mouthwash and for toothbrush disinfection.
Wound Care:
In a clinical study on intraperitoneal wound care, patients underwent lavage of the peritoneal cavity with 100-ppm HOCl and washing of the wound with 200 ppm. No adverse effects were observed.
HOCl has been shown to be an effective agent in reducing wound bacterial counts in open wounds. In irrigation solution in an ultrasonic system, HOCl lowered the bacterial counts by 4 to 6 logs. By the time of definitive closure, the bacterial counts were back up to 105 for the saline solution–irrigated control wounds but remained at 102 or lower for the HOCl-irrigated wounds. Postoperative closure failure occurred in more than 80% of patients in the saline solution group versus 25% of those in the HOCl group.
Hand Sanitizing:
Hand antiseptics are alcohol based or non–alcohol based containing antibiotic compounds. Chlorine-based sanitizers, at a concentration of 50 to 100 ppm, are effective against bacteria and viruses. HOCl specifically used for hand sanitizers is effective at 100- to 200-ppm strengths.
Surface Application:
A study looked at disinfecting outpatient surgical centers using HOCl. After cleaning, the rooms in the HOCl cleaning and disinfection study arm had significantly lower bacterial counts than the rooms that underwent standard cleaning and disinfection.
HOCl Applied by Spray or Fogger:
A fogger takes a solution and creates a small aerosol mist, ideally less than 20 μm in size, to disinfect an area. HOCl fogs are highly effective in the microbial disinfection of surfaces. The fogging process can alter the physical and chemical properties of the disinfectant. It was found that fogging reduced the AFC concentration by approximately 70% and increased the pH by approximately 1.3, making the solution slightly more basic; it is speculated that the loss of chlorine resulted from evaporation of chlorine gas. Because the changes in the properties of hypochlorous fogs are predictable, pre-fogging adjustment of the concentration and pH of the solution makes it possible to control the concentration levels to the desirable range to inactivate pathogens after fogging. When the appropriate concentrations are used, a study found 3 to 5 log10 reductions in both the infectivity and RNA titers of all tested viruses on both vertical and horizontal surfaces, suggesting that fogging is an effective approach to reduce viruses on surfaces.
HOCl solutions appear to be virucidal based on concentrations above 50 ppm. HOCl was evaluated against a low-pathogenic avian influenza virus (AIV), H7N1. The HOCl solutions contained 50-, 100-, and 200-ppm chlorine at pH 6. Spraying with HOCl decreased the AIV titer to an undetectable level (
