The use of topical, un-buffered sodium hypochlorite in the management of burn wound infection.

Abstract

Burn wound infections are a major cause of morbidity and mortality. The bactericidal action of sodium hypochlorite has been known for centuries and it has been in clinical practice for over 70 years. Whereas a buffered sodium hypochlorite solution is not universally available, an un-buffered solution is cheap and easy to prepare. The aim of this study was to determine the optimum concentration with regard to safety and efficacy, as well as shelf life of an un-buffered sodium hypochlorite solution for the topical management of burn wound infections. Human fibroblasts were exposed to serial dilutions of un-buffered sodium hypochlorite solutions for 30 min and assessed for viability. Isolates of Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes were exposed to the same dilutions of un-buffered sodium hypochlorite to establish the minimum bactericidal concentration. The pH, osmolality and electrolyte concentrations were measured. These experiments were repeated with solution stored at room temperature for 6 consecutive days. 24% of fibroblasts were viable after exposure to a 0.025% solution and 98.9% with a 0.003% solution. The MBC for the P. aeruginosa isolates was 0.003%, for S. aureus was 0.006% and for S. pyogenes was 0.0015%. This remained constant for 6 consecutive days. The un-buffered 0.0025% solution has a pH of 10, an osmolality of 168 sodium concentration of 89 mmol/dl and chloride of 84 mmol/dl. This remained stable for 14 days. An un-buffered solution of sodium hypochlorite with a concentration of 0.006% would be suitable for the topical management of burn wound infections caused by common pathogens. It has a shelf life of at least 6 days.