500 patients exposed to CJD

[Dr Mordrid]

http://www.cnn.com/2004/HEALTH/conditions/10/01/brain.disease.emory.ap/index.html

Why in Gods name they weren't using disposable instruments I have NO f***king idea. We were using those in the 80's for Christssake

Dr. Mordrid

[KRSESQ]

Which is a hospital bean counter likely to consider more expensive: one-use disposables or conventional autoclavable instruments?

And just what is the life expentancy of a reusable instrument? Who sharpens the scalples?

Kevin

[High_Jumbllama]

Of course causing someones death should weigh heavilly for costs not to mention the lawsuit that could ensue.

[James_D]

If you can't afford disposable equipment, then you sterilize them with
Sodium hypochlorite for 60min
followed with a standard gravity steam sterilization cycle at 132 C (270 F for all you americans) for 60 minutes. Or use Ozone autoclave.

There are some complex equipment that you cant sterilize, well, inform the patient. and let him/her decide.

JD

[Brian Ellis]

Scalpel/bistouri blades and suchlike are disposable but clamps, retractors, trepans, saws and suchlike are sterilisable. I see the problem here that prions are notoriously heat-resistant and are not necessarily killed by routine autoclaving. Chemical sterilants are more effective by oxidation or, better, gas. However, gas sterilisation, used extensively for disposable syringes, needles, catheters, sponges, dressings etc. requires a hefty capital investment. It has the advantage that the washed, used instruments can be wrapped in a towel, placed in a paper envelope, and the instruments, towel and envelope can all be sterilised together, before placing in a sterilised polypropylene packaging.

I was involved in a gas sterilisation unit in a syringe/needle factory in India, which replaced a CFC-carrier steriliser. In this case, the unsterilised syringes were packed individually in cellophane-faced paper envelopes, backed in cardboard boxes, which were then placed in transport cartons for sterilisation. The gas penetrated, by vacuum techniques, right through to the syringes, as the paper/cellophane/cardboard are porous and a small amount of gas stays in each part for the syringe lifetime (I think two years).

[ZokesPro]

I would imagine that an ozone autoclave would be THE most efficient way of sterilisation?

[Paddy]

I see the problem here that prions are notoriously heat-resistant and are not necessarily killed by routine autoclaving. Chemical sterilants are more effective by oxidation or, better, gas.

I never understood why this was such a big deal! After all if they are having to use disposable equipment because they can't disinfect tools, then how the hell do the prions get off them and onto you?

[Jon P. Inghram]

Emory officials said they routinely sterilize all surgical equipment

Something about that statement is disturbing... it's like saying "We routinely use trained medical professionals to perform surgury" or "We routinely use new sutures when closing wounds" or something.

[Dr Mordrid]

Conventional sterilzation doesn't destroy infectious prions, which are the presumed causative agent in CJD, mad cow etc. Bleaches, strong acids, strong bases, formaldahyde, alcohol, autoclaving, UV & Gamma radiation and freezing; all of 'em have no effect on them.

Some of the damned things can survive being put in a freakin' KILN until the tissue they're found in is incinerated to ashes, for Gods sake!!

Basically infectious prions are a malformed protein and as such they have no RNA or DNA, but in the case of mutated prions it appears that proteins can behave as a form of "gene". Some argue they are the first known life form without RNA or DNA, but others look at them as a chemical anomaly.

Yes: you can get disposable clamps etc. in disposable surgical packs. We used 'em all the time. Problem is mainly cost, but with neuro cases and the persistance of prions I'd have expected a bit more caution.

IMO there has been a major case of laziness as regards screening of people with high risk factors (some people are genetically prone to prion infection) and for procedures known to be of risk (neuro, opthalmic etc.)

Dr. Mordrid