gasplasma sterilization
DESCRIPTION
Gas plasma SterilizationTRANSCRIPT
Dr.T.V.Rao MD
GASPLASMA
STERILIZATION NEWER TECHNOLOGIES
DR.T.V.RAO MD 1
ADVANCES IN STERILIZATION
• Sterilization, as a specific discipline, has been with us for approximately 120 years, since the invention of the steam autoclave by Charles Chamberland in 1879.1 Since that time, we have seen progressive refinement in steam sterilizers: from the early, manually operated equipment to modern microprocessor-controlled, automatic machines. Although the efficiency, reliability, and performance monitoring of modern equipment is continually improving, the fundamental process remains essentially the same.
DR.T.V.RAO MD 2
• Gas Plasma (vaporized
hydrogen peroxide) is a
relatively new option that
can provide low heat
sterility cycles with none of
the off-gassing concerns
present with EtO. Gas
Plasma (VHP) sterilization
has, until now, been
exclusively used by large
manufacturers as the end
line process for in-house
sterilization.
GAS PLASMA
DR.T.V.RAO MD 3
• Who Found It? First
discovered by Sir
William Crookes, in
1879 But it wasn‟t
called „plasma‟ until
1928, when Irving
Langmuir coined the
term
WHO FOUND IT?
DR.T.V.RAO MD 4
PLASMA STERILIZATION
• A plasma is a quasi-neutral collection of electrons, positive ions, and neutrals capable of collective behavior
• Positive ions = free radicals
• Plasma sterilization operates synergistically via three mechanisms:
• Free radicals interactions
• UV/VUV radioactive effects
• Volatilization
• Dead microorganisms = sterilization
DR.T.V.RAO MD 5
• UV/VUV radiation
causes
• formation of thymine
dimers in DNA,
inhibiting bacterial
replication.
• Base damage
• Strand breaks
PLASMA STERILIZATION MECHANICS: IR
(NUCLEIC ACID VIEW), UV RADIATION
DR.T.V.RAO MD 6
• Gas plasma
sterilization
technology based
of Plasma was
patented in 1987,
and marketed in
U S 1993.
BEGINNING OF GAS PLASMA
DR.T.V.RAO MD 7
• Yes.
• Plasmas are currently
employed in many
industries to accomplish
both highly effective, and
delicate sterilization.
• Not future technology!
Plasmas are used today!
• But, how do they work?
CURRENT STERILIZATION
MEANS: PLASMAS?
• Plasma is a fourth state of matter which is distinguishable from liquid, solid, or gas. In nature, plasma is widespread in outer space.
• Gas plasma generated in an enclosed chamber under deep vacuum using Radio frequency or Microwave emery to excite gas molecules are produced charged particles
WHAT IS GAS PLASMA
DR.T.V.RAO MD 9
HOW GAS PLASMA WORKS.
• Many particles are in the form of free radicals
• A free radical is an Atom with an unpaired electron and
is a highly reactive species
• The mechanism of action of this device is the
production of free radicals within a plasma field that
are capable of interacting with essential cell
components, ie is enzymes and nucleic acids. And
thereby disrupt the metabolism of microorganisms.
DR.T.V.RAO MD 10
BASIC MECHANISMS OF PLASMA
STERILIZATION
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• A-Destruction by UV irradiation of the genetic material of the
microorganism; this is a statistical process requiring a sufficient
number of lesions of the DNA strands.
• B- Erosion of the microorganism, atom by atom, through intrinsic
photo desorption Photon-induced desorption results from UV
photons breaking chemical bonds in th microorganism material
and leading to the formation of volatile compounds from atoms
intrinsic to the microorganism. The volatile by-products of this
nonequilibrium chemistry are small molecules (e.g., CO and
CHx)
BASIC MECHANISMS OF PLASMA STERILIZATION
DR.T.V.RAO MD 12
• Erosion of the microorganism, atom by atom, through
etching. Etching stems from the adsorption of reactive
species from the plasma (glow or afterglow) on the
microorganism with which they subsequently undergo
chemical reactions to form volatile compounds
(spontaneous etching). The reactive species can be atomic
and molecular radicals, for example, O and O3,
respectively, and excited molecules in a metastable state,
for example, the O2 singlet state all spores are ultimately
inactivated by UV photon irradiation of their DNA material
• Materials and device
compatibility
• Rapid turnaround
times
• In-house control of
the sterilization
process
• Lower inventory
requirements.
IDENTIFIED ADVANTAGES
DR.T.V.RAO MD 13
• The advantages of gas
plasma sterilization include
its ability to provide safe,
non toxic, dry, low-
temperature sterilization in
about one hour. By-
products of plasma
sterilization are primarily
water and oxygen. Because
these by-products are
harmless, there is no need
for aeration or
environmental hazard
concerns.
BENEFICIAL FOR STERILIZING TEMPERATURE-
SENSITIVE POLYMERIC MATERIALS
DR.T.V.RAO MD 14
STEPS IN PLASMA STERILIZATION • The Vacuum Phase
• The chamber is evacuated, reducing internal pressure in preparation
for the subsequent reaction.
• The Injection Phase
• A measured amount of liquid peroxide is injected into the chamber, evaporating the aqueous hydrogen peroxide solution and dispersing it into the chamber, where it kills bacteria on any surface it can reach.
DR.T.V.RAO MD 15
• The hydrogen peroxide
vapour permeates the
chamber, exposing all load
surfaces to the sterilant and
rapidly sterilizes devices
and materials without
leaving any toxic residues.
At the completion of this
phase, the chamber
pressure is reduced and
the plasma discharge is
initiated.
THE DIFFUSION PHASE
DR.T.V.RAO MD 16
THE PLASMA PHASE
An electromagnetic field is created in which the hydrogen peroxide vapour breaks apart, producing a low-temperature plasma cloud that contains ultraviolet light and free radicals. Following the reaction, the activated components lose their high energy and recombine to form oxygen and water. Phases 1, 2, and 3 are then run a second time for added efficacy. This built-in reprocessing assures optimal sterilization for even the most difficult-to-sterilize devices.
DR.T.V.RAO MD 17
The chamber is vented to equalize the pressure enabling the chamber door to be opened. There is no need for aeration or cool-down. Devices are ready for immediate use.
THE VENT PHASE
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GRAPHIC REPRESENTATION OF GAS
PLASMA TECHNOLOGY
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PLASMA STERILIZATION
MECHANICS: IR (CELLULAR VIEW)
• IR impacts the cell, three outcomes can result.
• Low-Temperature Hydrogen
Peroxide Gas Plasma
(LTHPGP) has a number of
advantages compared to
established sterilization
technologies. These include a
short (one to four hours)
sterilization cycle, low
temperature and humidity, no
aeration requirement, no toxic
chemical residues or
environmental impact, and broad
compatibility with materials.
ADVANTAGES OF PLASMA
STERILIZATION
DR.T.V.RAO MD 21
• The Sterrad system offers a
short cycle (averaging 75
minutes), low temperature and
humidity, no aeration
requirement, no chemical
residues, negligible
environmental impact, and wide
compatibility with materials. Its
drawback is an inability to
process liquids, powders, or
strong absorbers (e.g.,
cellulosics).
HYDROGEN PEROXIDE GAS PLASMA.
DR.T.V.RAO MD 22
THE BIOLOGICAL INDICATOR FOR
QUALITY CONTROL
• The Biological indicator used with system is Bacillus atrophaeus
spores. And Bacillus sterothermophilis
DR.T.V.RAO MD 23
• The newer version of
unit, which employs
a new vaporization
system that removes
most of the water
from hydrogen
peroxide, has a
cycle time from 28-
38 minutes.
IMPROVEMENT TO NEW
TECHNOLOGY
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The process inactivates
microorganisms primarily
by the combined use of
hydrogen peroxide gas and
the generation of free
radicals ( hydroxyl and
hydroproxyl free radicals )
during the plasma phase of
the cycle.
MODE OF ACTION IN GAS PLASMA
USAGE
DR.T.V.RAO MD 25
• Materials and devices that cannot tolerate high temperatures and humidity such as some plastics, electrical devices, and corrosion- susceptible metal alloys, can be sterilized by hydrogen peroxide
• This method proved compatible with most (>95%) medical devices and materials tested.
USES OF GAS PLASMA IN HOSPITALS
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GAS PLASMA APPARATUS
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GAS PLASMA WORK STATION
• Medical instrumentation can be sterilized through a hydrogen peroxide gas plasma process with the Sterrad 100 system (Advanced Sterilization Products). Photo: Advanced Sterilization Products
DR.T.V.RAO MD 28
DISADVANTAGES OF PLASMA
STERILIZATION
• Weak penetrating power of the plasma species. Complications arise in:
• Presence of organic residue
• Packaging material
• Complex geometries
• Bulk sterilization of many devices
• Solutions: Introduce preferentially targeting UV/VUV radiation of proper wavelength
DR.T.V.RAO MD 29
• The disadvantages of gas
plasma sterilization are that it
may not penetrate well,
especially in channels or devices
designed with long lumens. In
addition, the gas plasma
sterilization method may corrode
some materials and cannot be
used on paper, cellulose
or linen. An additional
drawback to plasma sterilizers is
their small chamber.
DISADVANTAGES
DR.T.V.RAO MD 30
ACCEPTABLE TECHNOLOGY
• According to experts, only a few disadvantages
associated with gas plasma sterilization exist.
These include the inability to process liquids,
powders, or strong absorbers (cellulosics), and
some lumen restrictions. Also, gas plasma
sterilization is not recommended for liquids and
other devices that can be damaged physically or
changed by exposure to low pressure.
DR.T.V.RAO MD 31
• In 1993, the STERRAD
Technology received
clearance and was
introduced into the United
States. It is now available
in more than 60 countries
throughout the world with
over 6,000 units sold,
making it the world's fastest
growing sterilization
technology.
STERRAD TECHNOLOGY
DR.T.V.RAO MD 32
• The STERRAD 100
sterilization system
(Johnson & Johnson
Medical Ltd) uses
low temperature
hydrogen peroxide
gas plasma for
sterilization of heat
labile equipment.
STERRAD 100
DR.T.V.RAO MD 33
• An important shortcoming
of plasma sterilization is its
dependence on the actual
“thickness” of the
microorganisms to be
inactivated since the UV
photons need to reach the
DNA. Any material covering
the microorganisms,
including packaging, will
slow down the process.
SHORT COMING OF GAS PLASMA
STERILIZATION
DR.T.V.RAO MD 34
GROWING PROBLEM WITH PRIONS
• Prion diseases, or proteinaceous infectious particle only agents, are able to
induce abnormal folding of normal cellular prion proteins in the brain and can
develop into neurodegenerative disorders including Gerstmann-Straussler-
Scheinker Syndrome, fatal familial insomnia and Creutzfeldt-Jakob Disease
(CJD) in humans. Such prion diseases can have long asymptomatic
incubation periods but will result in fatality in all cases. Unlike infectious
agents in other difficult-to-treat infectious diseases, prions exhibit an
unusually high level of resistance to common
sterilization methods and disinfection methods,
including steam, and pose a threat to infection prevention in healthcare
facilities.
DR.T.V.RAO MD 35
• The effectiveness of low-
temperature STERRAD®
technology against the
prion threat confirmed that
is possible to eliminate
these deadly pathogens
while helping to preserve
the integrity of medical
devices, including heat
sensitive surgical
instruments
STERRAD TECHNOLOGY IS SAFE IN DEALING
IN CONTAMINATION WITH PRIONS
DR.T.V.RAO MD 36
THE TOPIC CREATED AS PER GUIDELINES
FOR DISINFECTION AND STERILIZATION IN
HEALTHCARE FACILITIES,2008
CDC
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