Bacterial transmission fro HH tank

Does anyone have the link to one of the mfg site that has a diagram explaining why microbes CANNOT be transmitted from the heated water tank?

I am involved in a very heated discussion over at yahoo.
One of the posters gave this link:
http://www.aasmnet.org/jcsm/AcceptedPap ... 001707.pdf

it seems to contradict all that I have been led to belileve.
If true, they contend that pathogens can indeed be aerosolized and transmitted to the patient.
Do I need to do a paradigm shift in my thinking on this matter?

my positon is that pathogens cannot be transmitted from the tank as esplained by the site I am looking for.
Any help is appreciated along with any thoughts on this paper.

tom

I knew I'd seen this image SOMEWHERE:

http://www.talkaboutsleep.com/sleep-dis ... humid9.htm

I finally tracked it down in a post from ozij in May of last year.

viewtopic.php?p=77135&highlight=pathogens#77135

Don't know if that helps or not, but maybe.....

Den

All you have to do is point out what is on page 1 ... "Funding This work was funded by Pall Corporation" ... then Google "Pall Corporation" ... and it is easy to understand the reason for the contradiction.

It's like Exxon funding a climate study

I believe the original link is at Fisher and Paykel at their website here:
http://www.fphealthcare.com/osa/faqfamilies.asp

This is one of their FAQ, "Can germs pass from the heated humidifier to me?"
to which their reply is:
"No, using a heated humidifier in line with you CPAP therapy will not cause you to get sick or give you germs. Fisher & Paykel Healthcare heated humidifiers are passover humidifiers that do not produce aerosols. Moisture is added in the form of water vapor. Water vapor is very small so it is impossible for bacteria or viruses to be transported up to the mask (and then to you). Even if pathogens were able to exist in the chamber, they would not be able to be transported to you. Refer to the diagram below which demonstrates the size of water vapor, bacteria and viruses.


The important thing to remember is that all equipment (especially your mask) needs to be cleaned thoroughly on a regular basis, so that it does not become a desirable environment for bacterium to live and grow. Follow the cleaning instructions for all equipment to ensure proper hygiene and cleaning." (with the picture from Wulfman's link as the diagram).

Assuming this is accurate, I read this as saying that bacteria, viruses (or presumably mold) cannot be transferred from the water chamber to the air in the hose. This leaves the mask and the hose itself, and the air filter system as potential venues for infection/transmission of harmful stuff (which is the point of the second paragraph).

Of course, it could be argued that F&P have a commercial interest in this subject too. But any can argue and the beauty of it is is that you don't have to be right to do it.

Best wishes,
Bill

And all along, I thought is was because their wings were too small. Jim

That, too....

Good one, GoofProof

tomjax wrote:Any help is appreciated along with any thoughts on this paper.

"Flow rates were set to 20 cm water pressure providing flow rates of 60-70 LPM and confirmed by air flow meter measurements at the beginning and end of each experiment." Page 7

In other words the experiment was done at the extreme top end of what is considered the normal range for CPAP treatments. If aerosoling effects were going to be demonstrable anywhere it would have to be at the highest possible pressures, on the fullest possible tanks where the water being passed-over had the greatest chance of becoming agitated!

"Our study also employed slightly [?] higher flow rates of 60-70 LPM, in contrast to the 46 LPM reported in the referenced study. This could also account for observable differences." Page 15

And they even tacitly admit that the study was skewed and could account for the results!

"Data provided here support the view that a properly positioned hydrophobic breathing filter may reduce transmission of bacteria from inadvertently contaminated water that may be present in heated humidifier water used with nCPAP for OSA." Page 16

So at the end of the paper, nothing has been proved (or arguably, even well demonstrated) at all, just a manufacturers view supported! Say no more!

Cheers,

Bill

1. I have no worry about pathogens being transmitted from my humidifier tank to my body.

2. On the other hand, if I knew there was anthrax in my tank, I would not go into the bedroom.

It is always prudent to look at the funding source for research projects as a source of bias in the results.

Meticulous methodology and appropriate statistical analyses go a long way in reducing or eliminating bias. Not being either a microbiologist or a skilled statistician I cannot speak to these issues in this research. I am willing to remain open and take some precautions just in case what I think to be true today is disproven in the future. And I'd hate being the case of HH pneumonia that gets written up in NEJM.