Inhaler Float Test?!
I was on a call with a group of nurses, and we were discussing the details of a new stock-inhaler law our state recently passed.
Some of you may be wondering what a stock inhaler law is. Well, some states in the U.S. have passed laws that allow schools to keep an emergency asthma inhaler in the front office. (If you are wondering if your state has passed that law, you can look at the map from the Allergy & Asthma Network.)1
Having a backup asthma inhaler for students
If a student forgets their inhaler or finds it is empty, they can use the emergency inhaler in the office. But first, they have to be diagnosed with asthma and have an asthma action plan on file. So, great idea, right? A student can use a rescue inhaler and have a puff or two, then go back to class.
As we discussed the details, some nurses wondered whether it would be better to have an emergency asthma inhaler or a nebulizer in the office. One of the nurses complained that it's hard to use an inhaler because you have to perform the "asthma inhaler float test" to see how many puffs are left.
Up to that point, I had just been listening to the conversation—but as a certified asthma educator (AE-C), I HAD to speak up during the phone call. Ethically, part of my job is to correct any misinformation. Nurses are amazing! But they can't be experts in every area, so I had to update them on asthma.
The Asthma inhaler float test is not recommended
The float test is no longer recommended for inhalers. In fact, information from as far back as 2002 said that:2
"Float characteristics are product-specific and a function of canister size, design, content, and method of testing. Clinicians and asthma educators should not advise patients to use a float test to assess the amount of medication remaining in an MDI."
Basically, they found that the "asthma inhaler float test" is not accurate. (And by the way, MDI stands for metered-dose inhaler.)
Another article shows that:3
Some people also believe that an empty inhaler will float, but this is not a reliable test. You can get different results depending on whether the stem of the inhaler is up or down in the water. Also, some inhalers will float when they are full."
Monitoring medicine without the asthma inhaler float test
So, how do you know if the inhaler has any medicine left in it? Well, most inhalers have counters now. Some are on the top of the canister, some are on the back. The trick is to remember to check the counter on your inhaler.
I am so caught up with work, college kids, car problems, etc., that sometimes I forget to check the counter. In fact, you can read more about my work trip with an empty inhaler here. It was definitely a "facepalm" moment...
You might ask, "Well, can't you tell when your inhaler is empty by how it feels?" The problem is that the inhaler may still have propellant, but no medicine. So you may take a puff and feel a "spray" come out of the inhaler. However, once it's empty, you will only get a puff of air, not a puff of medicine.
Make sure you use proper inhaler technique
For our schools, we are going to price-check options and see which would be better to have—inhalers or nebulizers. But I will train the nurses to make sure they know the proper inhaler technique. And I will make sure they just look at the counter on the inhaler (instead of using the "float test").
I wish I could give all our school nurses some chocolate and a massage gift certificate. But all I can give them is a little updated asthma education!
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