So read on to find out why vital signs are important, and why a second pulse is taken.
Second Pulse
The second pulse at this stage is a bit of a trick. Remember from last week that the officer has already had the driver engage in a series of physical tests, including two tests which require balancing on one leg. These tests can serve to elevate the heart rate of an individual, resulting in an increased pulse rate. Factor in the nerves and the nervousness that can also affect heart rate, and an unexpectedly high heart rate would likely be possible.
A high heart rate will cause the officer to conclude a person is impaired by a CNS stimulant, PCP, hallucinogens, inhalants, or cannabis. Given that it is consistent with so many probable outcomes, what is the point of measuring heart rate? It does not reliably indicate impairment by something, or even the presence of it. Rather, it indicates five out of seven possibilities. But, as I previously described, it also simply indicates a person is stressed.
What is really more important in this step of the evaluation is the blood pressure and the temperature.
Blood Pressure
Blood pressure is a funny thing. Look, for example, at this Blood Pressure Chart from the UK’s Blood Pressure Organization. You will see that there are pressures that are considered pre-high, which mean that they are high but not so high that it is of concern. The DRE does not distinguish blood pressures in this way. One over the normal systolic or diastolic, and your pressure is considered high. And a high blood pressure means stimulants, hallucinogens, PCP, or cannabis.
Oh, and it can also mean inhalants. But so can a low blood pressure. Fancy that. Either way, it could be inhalants.
According to the Mayo Clinic, hypertension (or high blood pressure) can be caused by a number of factors. Just look at the word: hyper tension. Does it surprise anyone that stress is a cause of high blood pressure? And what is more stressful than being poked, prodded, and examined by police, all the while being made to dance around like a trained monkey, while being accused of being impaired by a drug? Yeah. No wonder blood pressure would be elevated.
But even common factors, like age, salt intake in one’s diet, weight, and family history can have an impact on whether a person has high blood pressure. There is also a phenomenon known as primary hypertension, which is just a high blood pressure, all the time, with no identifiable cause. How can something that just happens to some people ever be considered a reliable indicator of impairment?
Now, low blood pressure is no different. It can be caused by factors as innocuous as dehydration, or as common as diabetes. Or – women pay attention – pregnancy. Now, considering the one leg stand and the balance tests I wrote about last week, a pregnancy can have a huge impact on the outcome of the DRE. And yet Drug Recognition Evaluators are not going to run a pregnancy test in the urine after collecting the sample. But also, heavy periods (blood loss) can explain low blood pressure.
Low blood pressure tells the DRE officer that a person is impaired by a CNS depressant or a narcotic. Or, as we discussed, an inhalant.
Temperature
Speaking of women and periods, hormonal changes in women can cause the body temperature to fall. I suspect this too is connected to the blood loss issue. But so can factors like dehydration and cold temperatures and fatigue. So it is again surprising (or is it, really?) that the DRE is relying on something that can so easily be influenced by outside sources.
High temperatures also are not necessarily indicative of a fever, though that is a common explanation for them. High temperatures are also detected when a person is suffering from heat stroke or an actual stroke. A stroke or a heat stroke could also explain the presence of psychomotor coordination problems and problems with the vision or responsiveness of pupils.
But it gets better! The Drug Recognition officer will conclude you are impaired by stimulants, hallucinogens, or PCP if your temperature is high. If your temperature is low, the conclusion will be impairment by narcotics. And I’m sure you’re wondering about what happens in the case of inhalants, which as we saw earlier in this post, can go either way. They’re the bisexauls of the Drug Recognition Evaluation. For inhalants, they can be present with high temperatures, low temperatures, or normal temperatures.
Yes, if you are normal you could be considered to be high on inhalants. That’s the last time I take whippits at the dessert table on Thanksgiving.
Now, if you’ve been paying attention to the seven categories of drug you probably recognize that two are missing from this temperature list: cannabis and CNS depressants. Both cannabis and CNS depressants are likely to be present if your body temperature is normal. Never mind the fact that they are also equally likely to not be present if your body temperature is normal.
Normal is suspicious. That’s the whole point of the DRE evaluation.
Next week, we will cover off the next stages of eye examinations. Please check back for more. And you can read the whole series to catch up at any time.
