Breathing Patterns And DUI Breath Testing Results

Today we’re talking about breath testing in a DUI case, and specifically how a person’s breathing patterns can influence, either positively or negatively, the result that the breath machine produces.

So, what I have here is a chart, and what we’re going to be looking at is the relationship between a person’s BrAC, which is the Breath Alcohol Content, over a certain period of time.

So, when a person is giving a sample, when they’re blowing into a breath machine, this is what a normal pattern looks like when a person is breathing normally.

When they blow into the machine, over a certain period of time, you’re going to see a person’s BrAC rise. And it’s going to look something like that. It’s probably actually going to level out here a little bit. Because once it finds that number, it’s going to stay around that same level.

And that’s what’s normal. So we’ll say this is a normal… Breathing pattern.

So that would be, like I am sitting here, speaking normally, breathing normally, nothing really abnormal going on. But that’s not what always happens in a DUI case. Instead, there are external variables; people have a lot of emotions running through their minds. And so patterns may not be very normal.

And so there a couple of different ways that that can impact what we see here as a result. So… Many people, when they’re in stressful situations, they will do what’s called hyperventilating. And you may have experienced this in your own life. And what that means is that you’re breathing very, very rapidly. So you are taking deep breaths, short, choppy breaths. You’re circulating a lot of air through your body very quickly. It’s very, kind of, short. Breathing very, very quickly because you’re nervous, you have a lot of anxiety.

And what that does, practically speaking, is it’s cycling a lot of air through your lungs. Meaning a lot of air is coming in and it’s coming out. So it doesn’t have a lot of time to pick up any alcohol from your lungs that’s being transferred into your lungs, or into that air by the blood. And so, if somebody’s hyperventilating, that can reduce the resulted BrAC level. And so that pattern would look something like this.

And I have it ingrained because a lower BrAC is better in a DUI case.

So that pattern may look like something like this, where it’s actually decreased. My marker’s running out. But you can see it’s lower than what it would be in a normal breathing pattern. On the other hand, you have what’s called hypoventilation. Or hypoventilating.

This is where somebody’s actually not breathing. So it’s the opposite of hyperventilating.

They’re not breathing in a very rapid pace. In fact, they’re hardly breathing at all. They’re taking big deep breaths, and it’s going into their lungs, and they’re not circulating it out very, very frequently. And what happens then, it’s the opposite.

So instead of circulating a lot of air, you have a lot of air hanging out in your lungs. It’s just sitting there, and that’s giving it time to absorb more, and more, and more alcohol content that’s being transferred in your lungs from your blood.

And so what that result looks like is it actually increases. So it’s above the normal line. And so that will look like this.

And so the BrAC level would actually be higher. And so what we’re seeing now, is that if somebody’s breathing differently, there could be as much as a 15% difference between a person breathing normally and abnormally.

So 15% higher, or 15% lower, based on just the simple breathing patterns.

So, it’s very important; if you have been charged for DUI, if you’re investigating a DUI, and you want to determine “How accurate is that number,” you want to take a look at a person’s breathing patterns.

And we do this by getting jail footage, we do this by listening to audio recordings, we do this by doing interviews with people to determine how somebody was breathing, and whether or not the actual reported numbers… So this number here.

Whether it’s considerably higher than what it would have been if they were breathing normally.

And so you can shave about 15% off of whatever that number is. So if this number is above the legal limit, or just barely above the limit or some threshold, but you can show there was some hypoventilation- So somebody was hypoventilating; they were holding a lot of air in their lungs ’cause they were scared, they were crying, they could not be breathing normally, that number may be artificially inflated by at least 15%.

So, it’s a very important thing to look into. If you believe that this may apply to you, or this is your particular situation, and you want to talk with our firm about it, give us a call. We offer free case evaluations. We’re happy to sit down with you, review the facts of your case, and make sure that you have a good plan for moving forward.

Thanks for watching.

How do your breathing patterns affect your breath test? Breathing a certain way changes your result by as much as fifteen percent!

The result of a breath test machine is a function of BRAC (breath-alcohol content) and time. As a person gives a sample into a breath machine, the BRAC reading rises the longer they exhale. Their breathing pattern will affect the BRAC reading if they exhale more slowly or quickly.

In a DUI case, there are a lot of external variables; people can get very emotional and a lot of different things start running through their minds. Therefore, breathing patterns tend to vary, which will affect the breath test results.

When people are in stressful situations, sometimes they will hyper-ventilate. Essentially, this means that they will start breathing rapidly in a short, choppy way. What that does, practically speaking, is cycle a lot of air through your lungs; a lot of air is coming in and going out. When this happens, the air has little time to pick up the alcohol that has been transferred into your lungs by the blood. That can reduce the
resulting BRAC level.

Conversely, people can hypo-ventilate. This is when someone is not breathing; it is the opposite of hyperventilating. When someone is hypo-ventilating, they are taking deep breaths into their lungs, but not circulating it out very frequently. When that happens, the air resides in the lungs for a longer period and has time to absorb more alcohol content. This will result in a higher BRAC reading.

Breathing slowly or quickly can affect the results of a BRAC reading by as much as fifteen percent. In DUI cases, it is very important to determine the accuracy of the breath test results. This is done by examining the breathing patterns. This can be done by examining jail footage, listening to audio recordings, interviews. If a BRAC reading is considerably higher than it would have been if someone was breathing normally, it could have a substantial impact on a DUI case, especially if the number is close to the legal limit.

These types of cases are unfortunately very common. If someone happened to be scared or crying when they were taking a breath test, their result could be artificially inflated simply because they were not breathing normally.

Because breathing patterns affect the BRAC results so much, it is a very important factor to look into in a DUI case.