Rainbowfish

Umm, sorry. I don't think Duoderm IS even gas permeable, though I know tegaderm is. Actually I have found evidence it is not semipermeable from australianprescriber and emedicine: Medscape: Medscape Access Current concepts in wound dressings - Australian Prescriber I can't see where it says semipermeable or gas permeable on the convatec site either.

Sorry this is so late gettingupthere, but I think you were right the first time. I think layering them would still reduce the gas permeability. Both Tegaderm and Duoderm are intended to be the only dressing, and you are effectively making it twice as hard for air to pass through by layering them, even if both are gas permeable. This would be very bad for infected wounds. I heard the practice of layering over gas permeable dressings slammed at a wound care course recently, I'm not sure if it was duoderm and tegaderm specifically. Though we were told 'if in doubt contact the manufacturer'. I suggest you do if you are using/thinking of using this practice.