June 09, 2009

Sleep 2009 (day 1) - Most important sleep apnea abstract

There are is a lot of good research going on in the world sleep apnea medicine as evidenced by the "posters" or abstracts of research presented at the 2009 Associated Professional Sleep Societies meeting in Seattle Washington.

The one that really struck my eye is the following:
Sleep and Breathing: Care of CPAP Equipment a Factor of Compliance and Hygiene.

Quoting from the abstract...
This study was designed to test wheter patients have difficulty adequately cleaning CPAP interfaces and if contaminated equipment increases problems and eventual abandonment. Regular washingt of equipment should be an effectivemeans of controlling bacterial and fungal growth with older interfaces morelikely to be contaminated.

30 patients on CPAP for more than one month were studied. Baterical and fungal cultures were taken from the interfaces and humidifiers. Cultures were classified, photographed, and colonies counted. Culture growth was so significant on the first 20 patients, that a secondary trial of mask washing and repeat culture was added.

Although the cultures grew mostly normal flora, the colony counts were high: 21% of the patients had 100-500 colonies and 48% grew >2000 colonies per plate. There was no correlation of severity or cleaning frequency with colony counts. Mask age was important: with fungal growth from 100% > 1 year old, and only 25% aged 1-3 months. Gram negative bacteria increased almost linearly with mask age. In the secondary trial, interfaces were rewashed, resulting in 90% lower colony counts, unless they were > 1 year old when washing was ineffective,

Conclusion: This pilot study suggests there are high counts of bacterial and fungal flora on CPAP interfaces, despite routine washing, with the older interfaces, more contaminated and resistant to cleaning. Furhter research willbe required to determine wheter increasing frequnecy of mask replacement is effective at reducing bacterial contamination, and ultimely improve patient outcome by influencing CPAP adherence or infection risk.
I spoke with the presenters and they indicated that they were using warm soapy water to clean the masks once a week to remove the contamination.

The message here is to clean your mask regularly and to replace the mask at least every six months.

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