The efficacy of sodium hypochlorite antiseptic: a double-blind, randomised controlled pilot study

Abstract

Objective: According to a recent clinical trial, 82% of hard-to-heal wounds harbour levels of bacteria that impede healing. A follow-up analysis of trial data revealed that the use of antiseptic cleansers did not correlate with bacterial burden. At a minimum, these findings suggest the need for clinical research into the efficacy of antiseptics in reducing bacterial burden. Evidence supporting the bacterial killing ability of antiseptics is largely derived from preclinical and laboratory studies. Few clinical trials have examined bacterial levels and healing rates in hard-to-heal wounds. Fortunately, the advent of fluorescence imaging to detect bacterial burden has simplified the conduct of clinical research examining the effectiveness of antiseptics in the clinic setting. The aim of this study was to evaluate the efficacy of a modified sodium hypochlorite (NaOCl) solution in reducing wound size and bacterial load in hard-to-heal wounds. Method: In this randomised, double-blind pilot study, patients were randomised to one of two groups: daily wound cleansing with either normal saline solution (NSS) or NaOCl. Patients and investigators were blinded to the allocation. All wound types were included. Results: A total of 16 patients consented to participate. At the initial visit, the target ulcer was measured and a fluorescence image to evaluate bacterial load obtained. The wound was then cleansed with either NSS or NaOCl and fluorescence imaging repeated. Patients cleansed the wound daily in accordance with the randomisation schedule. They returned to the clinic weekly for four weeks, and on each visit the wound was measured and a fluorescence image captured. Patients receiving NaOCl had a greater percent reduction in wound area versus NSS; although the first phase of the study was not powered for statistical significance, there was a strong trend favouring NaOCl. In addition, there was greater bacterial reduction in the NaOCl group. Conclusion: Based on the results of this pilot study, enrolment has continued in order to increase the study's power. This pilot study suggests that sodium hypochlorite is efficacious in reducing bacterial burden and promoting healing.

WHAM evidence summary: traditional hypochlorite solutions

“…Traditional hypochlorites are preparations that occur as a reaction between chlorine and an alkaline salt, most commonly sodium or calcium 28,29 . They typically have a pH from 7.5 up to 11.8.…”

“…32,34 Traditional hypochlorites are unstable and have a short shelf life. 29,34 They have a high pH [2][3][4][5] , which is associated with impaired wound healing. Both full strength (0.5%) Dakin's® solution 8 and half strength (0.25%) Dakin's® solution 6 have been reported to be cytotoxic to fibroblasts in laboratory studies, raising concerns that traditional hypochlorites at their full concentration may delay wound healing 11,16,[29][30][31][34][35][36] .…”

“…29,34 They have a high pH [2][3][4][5] , which is associated with impaired wound healing. Both full strength (0.5%) Dakin's® solution 8 and half strength (0.25%) Dakin's® solution 6 have been reported to be cytotoxic to fibroblasts in laboratory studies, raising concerns that traditional hypochlorites at their full concentration may delay wound healing 11,16,[29][30][31][34][35][36] . To address these limitations, hypochlorites are now prepared electro-chemically to produce contemporary hypochlorites referred to as super-oxidised solutions 29,37 .…”

“…Both full strength (0.5%) Dakin's® solution 8 and half strength (0.25%) Dakin's® solution 6 have been reported to be cytotoxic to fibroblasts in laboratory studies, raising concerns that traditional hypochlorites at their full concentration may delay wound healing 11,16,[29][30][31][34][35][36] . To address these limitations, hypochlorites are now prepared electro-chemically to produce contemporary hypochlorites referred to as super-oxidised solutions 29,37 . Although superoxidised solutions have a longer shelf-life and a neutral pH, and they appear to have a good safety profile, 29,38 they are not universally available.…”

“…To address these limitations, hypochlorites are now prepared electro-chemically to produce contemporary hypochlorites referred to as super-oxidised solutions 29,37 . Although superoxidised solutions have a longer shelf-life and a neutral pH, and they appear to have a good safety profile, 29,38 they are not universally available. In low resource settings, traditional hypochlorites are still used for managing wound infection 39,40 .…”