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
