Generally, decontamination of hospital rooms has been done manually, using traditional applied disinfectant technologies as we have discussed in previous Disinfectant Chemistry Report Cards. Concerns associated with conventional cleaning and disinfection methods include: lack of proper cleaning and disinfection protocols, incompatibility between the disinfectant chemistry and cleaning substrate (e.g. the cloth...), operator error (e.g. was the product diluted correctly), concerns with unrealistic contact time and if surfaces were actually contacted. In looking for an adjunct to improve the level of cleanliness in a patient room, a new technology has been developed which uses hydrogen peroxide in an automated system to disinfect rooms.
There are two main room decontamination technologies that make use of hydrogen peroxide or hydrogen peroxide-based mixtures; hydrogen peroxide vapour (HPV) or dry-mist (aerosol) hydrogen peroxide.
Though dry-mist and hydrogen peroxide vapour systems use H2O2 to decontaminate rooms, the main difference between them is the droplets of peroxide they generate. HPV uses 30–35% H2O2 to form a gas for distribution resulting in micro-condensation on surfaces, generating a comparatively higher concentration of H2O2 in enclosed areas. Dry-mist systems form particles smaller than 10 μm, which are comprised of ~5% H2O2, occasionally supplemented with peroxyacetic acid, phosphoric acid or silver nitrate.
From an efficacy perspective, published studies have shown H2O2 Room Decontamination devices to be more effective than conventional quaternary ammonium cleaners in decontaminating hospital rooms containing MRSA, C. diff spores and Aspergillus spp. HPV has been shown to be effective in decontaminating hospital rooms containing MRSA, C. diff, VRE, Acinetobacter, Norovirus, Cl. botulinum, non-toxigenic Clostridium spp. and Geobacillus stearothermophilus. Dry-mist has been shown to be effective in decontaminating rooms containing TB, MRSA and Acinetobacter baumannii on open surfaces, and C. diff. A number of studies have shown that use of HPV in epidemic situations can rapidly reduce rates of infection and two studies have shown that endemic rates of HAI can be reduced 30 to 60 percent.
These systems are automated and they ensure all surfaces are decontaminated; coverage of surfaces is not user-dependent. While both systems are more effective than conventional cleaning in elimination of bacteria on surfaces they are not a substitute for cleaning. One study gave a mean time of 2 hours and 20 minutes for disinfection using the device after 32 minutes for conventional cleaning techniques. The long cleaning time is likely due to the time required for the vapours to reach all surfaces at a high enough concentration to inactivate pathogens. However, during cleaning, the room must be kept uninhabited due to the high concentration of hydrogen peroxide released in the air, as it would be toxic to patients and hospital staff, and, in the case of HPC systems, the rooms must be sealed to prevent leakage. From an environmental perspective peroxide-based cleaning systems are more environmentally preferred than other misting or fogging techniques (e.g. bleach, quats, formaldehyde), as they contain no volatile organic compounds and hydrogen peroxide simply degrades into water and oxygen.
Routine use of these decontamination systems would be confined to hospital bed rooms, operating rooms, etc due to the need for complete containment during decontamination. Entire units can be decontaminated, but this requires closure of the unit. These systems present a high initial entry cost for hospitals, as the equipment would need to be purchased (or rented, if possible) in addition to the ongoing cost of liquid canisters. In addition, special staff training is required for safe operation.
Here’s how we would score Hydrogen Peroxide Room Decontamination on the key decision making criteria for room disinfection:
· Speed of Disinfection – C
o Cycle time can range from 90 minutes to 3 hrs depending on room size and system used
· Spectrum of Kill – A
o Proven efficacy against all organisms: bacteria, viruses, fungi, mycobacteria and bacterial endospores
o All surfaces in a room, no matter the room configuration, are disinfected by the process
· Cleaning Effectiveness – D
o H2O2 Room Decontamination systems do not eliminate the need for the physical removal of soils to ensure effectiveness and provide an aesthetically pleasing environment
· Safety Profile – C
o Used correctly, the safety concerns can be minimized, however the rooms must be properly aerated to ensure hydrogen peroxide concentrations do not exceed OSHA criteria of 1ppm before re-entry
· Environmental Profile – A
o Hydrogen Peroxide degrades into water and oxygen
- Cost Effectiveness – C
- Costs of capital expenditure, labour, and consumables need to be considered
**For more in-depth scientific information about Hydrogen Peroxide Room Decontamination Devices, stay tuned to www.infectionpreventionresource.com.