How Does Asthma Impact Breath Test Results When Arrested for OUI?

As a Massachusetts OUI lawyer, there are many defenses that I have successfully used for my past clients that failed the Breathalyzer.

It is important to remember that the Breathalyzer is not an accurate tool of alcohol level measurement. It has been used for over 50 years and little changes have been made during this period.

Although various medical conditions can affect your performance on your Breathalyzer results, breathing conditions such as asthma have a particularly negative affect on your ability to complete the test, thus distorting the final measurement.

The Breathalyzer only takes a sample of air from the end of your exhalation into the device. In other words, the final result is dependent on that final amount of air you release just before stopping the Breathalyzer. This means that the Breathalyzer only measures the last part of your breath, not the average alcohol concentration of your entire breath. As the air deeper into our lungs is more concentrated, the last part of your breath is naturally more concentrated than the first parts of when you breath out.

This information is contrary to popular thought, as the Breathalyzer was originally administered with the assumption that breath alcohol concentration was constant after it reached its peak, when in fact it continues to increase in concentration the closer to the end of our breath we reach.

So what does this mean for people with asthma? Although asthma does not explicitly affect the lung size, it does affect the individual's ability to breathe out (versus breathing in). Asthma can impact a breath test result making it artificially high because a person with Asthma will have to force themselves to exhale a larger amount of lung air volume than they normally would - giving higher alcohol concentrated gas.

If you have Asthma or any medical condition, you should understand how that may impact the reliability of any breath test results in your case.