Antiseptic Efficacy of Povidone Iodine and Chlorhexidine Gluconate Skin Preparation Solutions Used in Burns Surgery.

The authors devised a comparative prospective study to determine the in vitro microbicidal efficacy of skin preparation solutions in the concentrations and temperatures used in the burns theatre against common bacterial and fungal microorganisms. A panel of 10 microorganisms Staphylococcus aureus, streptococcus pyogenes, enterococcus faecalis, escherichia coli, pseudomonas aeruginosa, candida albicans, bacillus cereus were assembled comprising 8 common strains of S. aureus (including methicillin resistant staphylococcus aureus (MRSA)), S. pyogenes, E. faecalis, E. coli, P. aeruginosa, C. albicans, B. cereus, and multi-drug resistant Klebsiella and Acinetobacter. These were cultured in the following formulations: 1) povidone iodine (PVP-iodine) 10% stored at room temperature (250C), 2) PVP-iodine stored at 40 to 420C, 3) chlorhexidine digluconate stored at room temperature diluted with warmed saline to concentrations of 4%, 2%, 1%, 0.8%, and 0.5%. All 3 formulations met DIN EN (Deutsches Institut für Normung) (European Standards) requirements for antiseptics. Both antiseptics showed the same high bactericidal and fungicidal efficacy (P = < 0.05). For chlorhexidine, all minimum inhibitory concentrations at both 24 and 48 hours were very low (< 0.5mg/L), but for PVP-iodine the minimum inhibitory concentrations were much higher and ranged from 64 to 512 mg/L. All concentrations of chlorhexidine tested were superior to PVP-iodine with no bacterial growth. There was a small amount of growth in some of the PVP-iodine treated groups, but this was not clinically significant.