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Close adherence to this protocol ensures op-
erator exposures remain well within OSHA
guidelines.


Continuous processing

Depending on the size of the chamber and the
size ofthe bags being loaded, sterilization can
take place as a continuous process. In other
words, unlike a batch process, you do not
have to wait for one load to be finished before
startinganother. Bags can be loaded andun-
loaded as a continuous process, each one iden-
tified with a preprinted label. You don’t have
to think about starting or stopping at any par-
ticular time. While there is no cut-off time
typical of batch processing, you do have to be
careful to only remove bags that have un-
dergone the full cycle.

To help you do this is a multi-load track-
ing system. A microprocessor tracks the
progress of each load. The status of any load
can be checked or printed out as many times,
either automatically or manually, as you re-
quire. The microprocessor prints when each
load went in and the time remaining. These
printouts are the necessary documentation
that each load was in the chamher for the re-
quired time and temperature. In addition, of
course, you have the chemical and biological
indicators for each load.

Just as is true of any sterilization system,
operator training is necessary. Can you fool
the system and remove aload before its time?
Yes, but it isn’t easy. By following a few
rules, operator error can be eliminated. In an
emergency, there is a supervisor-only dis-
crete code that will allow the supervisor to in-
terrupt a cycle and remove a bag before its
full time. This is strictly for emergencies,
when the product in the load is needed and
there is no alternative. Even then, the su-
pervisor must wait for the five-minute purge
cycle before the door will open.

Is this Andersen EOGas Sterilization Sys-
tem a viable alternative to low temperature
sterilization problems? Yes. On the plus side,
it uses EtO, which has a proven record of re-
liability. The unibdose cartridges can be han-
dled and stored safely. Cartridges contain on-
ly enough EtO to sterilize the contents of the
bag for which they are designed. Typically,
they will use less gas than a chamber system
because there is no chamher dead air space
to fill. Figure 2 shows gas concentration over
the entire cycle in a #6 bag containing items
that do not absorb the EtO gas. A load con-
taining PVC or rubber products would peak
later and degas over a longer period of time.

The load tracking system is effective and
the modular design is flexible. It appears
easy to install and maintain. There are no
compressed air or water lines. It only re-
quires tying in to an existing dedicated ex-
haust system. There is a back-up battery
system in the event of power intemptions.
Maintenance requirements are low, mainly
regular temperature calibration, lubrication
of fans, and changing air filters.

Besides being a primary sterilization sys-
tem, it could also find a market as an EtO sys-
tem for anyone with a low-temperature ster-
ilization system that cannot sterilize every-
thing the hospital uses. Total annual
processing costs for 300 cycles in the large #6
hag size would be about $5,000.

In states that have emission controls, a gas
disposal system can be acquired and operat-
ed very economically. Because the sterilizer
uses less gas and releases it very slowly, a
low-cost passive catalyst-bed system can be

employed. With the small 6 ft.3 unit running
every day, emissions can be below the four-
pound thresholds at which state EPAs, like
California, require gas disposal equipment.

On the minus side, you have the cost of ac-
quiring the sterilizer, approximately $20,000
for the 6 ft3 chamber, $30,000 for the 10 ft3,
and $40,000 for 33 ft3. These costs should be compared to upgrading or acquiring another
system.

Training is required, as it would he with any new system. You are limited to one supplier for
your gas and other components, and cur-
rently you are required to use the entire 16-
hour cycle.

User experience

We checked with some users to find out how
satisfied they were. Fitzroy Jennings, CS
Supervisor at Lincoln Hospital (Bronx, NY)
does low-temperature sterilization primari-
ly for cystology and surgery. His depart-
ment is open from 5 a.m. to 10 p.m. He has
three Andersen EOGasTM System sterilizers
and does 15 to 20 bags a day, seven days per
week, enough to meet all the hospital’s needs.
He has had the system for a few years and
feels that it is safer than the old 12/88 system
they had with leaking tanks. His sterilizer op-
erators were certified after five days of in-
tensive training by the company.

Others have found the modular concept of
this system useful. The ability to choose the
bag size to match their needs is cost effec-
tive compared with running a full load re-
gardless of the number of items requiring
sterilization. Users advise to be careful not
to overload the bag. With support from An-
dersen, they have been able to validate their
procedures for determining how much of a
load each bag can sterilize.

Conclusion

We found no serious negatives with the
process and end users seem to be content
with what they are doing. As with any low-
temperature sterilization process, meticu-
lous cleaning and drying of items prior to
sterilization is essential. Validate carefully
the ability to sterilize complex, difficult-to-
clean products with lots of places for air to be
trapped and long, closed-ended tubes. Frac-
tional cycles run on their Model 310 in a #6
bag showed a six logreduction (half-cycle) in
45 minutes with the BI in a glassine envelope,
just under two hours when placed in the bar-
rel of a disassembled syringe and a little over
three hours in an AAMI routine test pack
(Figure 3).

Remove batteries or any other potential
source of electrical discharge from items that
are to be sterilized. They can be safely ster-
ilized once all connections are removed and
accidental discharge prevented.

Economically, and systemically this is an-
other viable alternative to low temperature
sterilization.

Oh yes, the sterilizer and its storage cab-
inet base are “blue.”

-Dan Mayworm is publisher of Infection Control and Sterilization Technology and the journal of Healthcare Resource Management.

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