Asthma – Peak Flow Meters

Andrew:
Dr Shapiro, please explain for us, what a peak-flow meter is and its value.

Dr. Shapiro:
There are a number of different models, but they are a plastic tube with a little scale and stylus, and you blow into it hard and deflect the stylus and get numbers. You have certain numbers that are right for you–personal best is what we usually talk about–what’s the best that you can be when you’re in the best situation. And a person should deviate only about 10 percent or so from that personal best. If they’re getting lower than 20 percent of that number, it means that something is going on, their asthma is kicking up even though they might not yet feel it. And when they get down to 50 percent that’s really a red flag that there’s trouble and they need to be talking to the doctor.

Andrew:
It sounds like you advocate the use of peak-flow meters.

Dr. Shapiro:
I don’t think everybody needs a peak-flow meter, because there are a lot of people who just don’t have too much trouble, and they can feel what’s going on pretty easily. But for many people it’s a major help.