CPAP requires basic cleaning

Dear Dr. Roach: I have just recently begun seeing advertisements for a product that cleans the inside of your CPAP machine. This new CPAP cleaning machine costs approximately $250-$300, and I have already read a few reviews posted by people who have had lots of problems with it functioning properly. Is it really necessary to clean the inside of your CPAP machine? — C.P.

A CPAP machine is a pressurized device used mostly for people with obstructive sleep apnea. I also have seen these advertisements, but a review of the literature suggests that there’s a very low risk of infection or allergic reaction due to a dirty machine, mask or hose. Although the cleaning devices do work, I could find no evidence that they are necessary or offer any benefit beyond regular cleaning with soap and water. This should be done regularly. Filters should be changed every two to four weeks.

Dear Dr. Roach: If you have had hepatitis B, are you able to donate anything (e.g., blood or organs)? I was never diagnosed with the disease, but I tested positive for the antibodies during a blood donation over 30 years ago. Someone recently told me that I can still donate plasma. Is this true? I don’t want to endanger anybody unknowingly. — J.S.

Antibodies to hepatitis B may be developed during natural infection or through vaccination.

A doctor can tell which kind from a blood test, by determining whether the hepatitis B core antibody is positive.

People who have had natural infection (a positive core antibody) may not donate blood or plasma. People who have been vaccinated (the surface antibody is positive, but the core antibody is negative) may safely donate blood and plasma.