Steam sterilisation proved to be the most effective and had the largest margin of safety when compared to low-temperature sterilisation technologies, increasingly required for plastic tools, a recent study published in Infection Control & Hospital Epidemiology shows.
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Researchers at the University of North Carolina at Chapel Hill set out to compare the microbicidal activity of steam sterilisation to three low-temperature sterilisation technologies, namely vaporised hydrogen peroxide (VHP), ethylene oxide (ETO) and hydrogen peroxide gas plasma (HPGP).
Stainless steel test carriers, which simulated surgical tools, were soiled
with salts and serum and inoculated with common bacteria found in healthcare
settings, such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus
aureus, vancomycin-resistant Enterococcus, Mycobacterium terrae, Bacillus
atrophaeus spores, Geobacillus stearothermophilus spores, or Clostridiodes
difficile spores. The carriers then were subjected to four sterilisation
technologies: steam, VHP, ETO and HPGP.
The results showed that VHP had the highest failure rate of 76.3% (206 of
270), and salt was the main interfering component. Sterilisation with steam,
ETO and HPGP inactivated the test organisms on the carriers much more
efficiently. Steam sterilisation, which is most common technique applied for
heat-resistant instruments, had no failures (0 of 220). For both ETO and HPGP,
the failure rate was 1.9% (6 of 310 and 5 of 270 cases respectively).
The authors underscore the importance of proper precleaning of surgical instruments
in cases when sterilisation relies on low temperature processes, such as VHP,
to ensure that tools are thoroughly and optimally sterilised.
References
Rutala W et al. (n.d.). Comparative evaluation of the microbicidal activity of low-temperature sterilization technologies to steam sterilization. Infection Control & Hospital Epidemiology, 1–5.
Source: EurekAlert
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