2. EtO vs. VHP. Your main choices in low-temp sterilization process-
es are ethylene oxide (EtO) or vaporized hydrogen peroxide (VHP).
Besides being toxic, carcinogenic and explosive, EtO gas has an
excessively long sterilization cycle that's incompatible with the pace
of outpatient surgery. Including the required aeration to remove EtO
residue, the EtO cycle ranges from 14 to 30 hours. Very impractical.
Who's got that kind of time to reprocess instruments when the most
efficient and safest form of low-temp sterilization that eliminates con-
taminating microbes in a fraction of the time is available?
With VHP, the most common cycle is 28 minutes — with no aeration
necessary. Some items such as lumened flexible scopes may stay in for
an hour-long extended cycle. It's simple to operate, install (all you need
is a 208 V outlet) and monitor. It's also safe for the environment and
compatible with most medical devices. Here's how it works: The sterili-
zation chamber is evacuated and hydrogen peroxide solution is injected
from a cassette and vaporized in the sterilization chamber.
3. EtO hasn't gone away. I'm the manager of the sterile processing
department at Henry Ford Wyandotte (Mich.) Hospital. We service 11
ORs, 3 procedure rooms and 18 off-site clinics. We reprocess 2,500 to
3,000 instrument trays per month. In addition to 3 steam sterilizers,
we have 2 VHP sterilizers and 2 EtO sterilizers. Surprised? Let me
explain.
Some instruments are only EtO-compatible. If you have an outdated
endoscope inventory, for example, certain flexible scopes might not
be validated with VHP. If given the choice to upgrade their instrument
inventory or keep their EtO sterilizer in good working order, many OR
managers would choose to keep the old instruments in play. With flex-
ible scopes costing the same as a car ($30,000) and low-temp steriliz-
ers ranging in price from $80,000 for certified pre-owned to $180,000
4 4 • O U T PA T I E N T S U R G E R Y M A G A Z I N E • M A y 2 0 1 8
