#Asepsis means killing of all skin#

The aim of this review is to summarise the sensitivity profiles of skin microbes (relevant to surgical site infection) to CHX and PVI, and explore how these have changed over time. Overall, the current state of microbial sensitivity to CHX and PVI remains unclear. PVI resistance has been less commonly reported 23 although this might be secondary to the multimodal effect of iodine on microbes 23 or otherwise. Not only is the presence of reduced sensitivity concerning, but the presence of resistance conferring genes seems to be increasing annually 22. Methicillin resistant Staphylococcus aureus (MRSA) samples with qacA/B genes showed persistent MRSA carriage despite de-colonisation therapy 21. Multiple bacteria have shown reduced sensitivity (perhaps even resistance) to CHX, particularly through the multidrug resistance efflux protein qacA 19. This is particularly concerning given the accelerating global antibiotic resistance crisis 20. There are growing fears that as antiseptic use increases, sensitivity may reduce and resistance emerge 19. Both PVI and CHX are active against gram positive and negative bacteria, fungi and viruses 16, 18. When dissolved in water, iodine is released, penetrating microorganisms and oxidising proteins, nucleotides and fatty acids 17 causing cell death. PVI is an iodophor a chemical complex between a water soluble povidone polymer and iodine 16. At higher concentrations there is a complete loss of cellular structural integrity, having a bactericidal effect 15. By binding to the cell membrane and cell wall of bacteria, at lower concentrations it has a bacteriostatic effect by displacing the cations and destabilising the cell wall. CHX in an alcoholic solvent has been shown to halve the risk of SSI following clean 11, contaminated 12, 13 and dirty surgery when compared to other antiseptics such as povidone-iodine (PVI).ĬHX is a biguanide compound, utilised both as a broad spectrum antimicrobial and topical antiseptic 14. To reduce the risk of SSI, the World Health Organization (WHO) 7, United States of America Centres for Disease Control (CDC) 9 and United Kingdom National Institute for Health and Care Excellence (NICE) 10 recommend the application of topical chlorhexidine (CHX) in alcohol to the planned operative site, for skin antisepsis. are commonly implicated microbes in SSI, along with Enterococcus spp. Staphylococcus aureus and Streptococci spp. The use of skin antisepsis prior to surgery significantly reduces the risk of SSI and consequently, post-operative morbidity and mortality 5, 6, 7. They represent an important economic burden across all surgical specialties 4, increasing hospital inpatient stay time and adversely affecting patient’s mental and physical health 4. Surgical site infection (SSI) is the most common and costly complication of surgery 1, 2, occurring in approximately 5% of all surgical interventions 3.

This provides reassurance and confidence in the worldwide guidance that CHX should remain the first-choice agent for surgical skin antisepsis. Overall, we find no evidence of reduced susceptibility of common SSI-causing microbes to CHX over time. There was no change in the MBC of CHX to Staphylococci or Streptococci over time. Most studies investigated CHX (93%), with insufficient data for meta-analysis of PVI. Seventy-nine studies were included, analysing 6218 microbes over 45 years. MBC was pooled in random effects meta-analyses and the change in MBC over time was explored using meta-regression. We excluded studies using non-human samples and antimicrobial solvents or mixtures with other active substances. We included studies reporting the MBC of laboratory and clinical isolates of common microbes to CHX and PVI. The objective of this systematic review was to determine whether the minimum bactericidal concentration (MBC) of topical preparations of CHX or PVI have changed over time, in microbes relevant to SSI. There is concern that resistance to topical biocides may be emergeing, although the potential clinical implications remain unclear. Chlorhexidine (CHX) and povidone-iodine (PVI) are used for skin antisepsis, minimising SSIs. Surgical site infection (SSI) is the most common complication of surgery, increasing healthcare costs and hospital stay.

Asepsis means killing of all