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Explore the significance of pupil size measures in drug influence detection, utilizing scientific studies to redefine normative values for impaired vs. non-impaired individuals.
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Pupil Size Expected Values
“Changes” Change is needed in science and medicine DRE Protocols are “CLINICAL DECISIONS” It is by incorporating new information regarding the DRE clinical indicators and the application of adapted and newer DRE clinical decision making approaches that will lead to a more efficient and self confident drug recognition expert. Change is actually a good thing!
New Protocols These “changes” do not change WHAT we do, it simply improves HOW IT IS INTERPRETED.
Where did these Values Come from? Lots of previous research Cheng AC, Lam DS. Comparison of the Colvard pupillometer and the Zywave for measuring scotopic pupil diameter. J Refract Surg. 2004 May-Jun;20(3):248-52. Colvard M. Preoperative measurement of scotopic pupil dilation using an office pupillometer. J Cataract Refract Surg. 1998 Dec;24(12):1594-7. Etc. etc. etc. etc. The advent of LASIK and subsequent lawsuits
Where did these Values Come from specifically Related to the DRE program?
NTD Room Direct
Using This old and new information, it was Applied to the DRE Evaluation…. To determine What are the NORMAL SIZES FOR THE PUPIL ? The use of three distinct pupil size ranges for each of the different testing conditions may be considered more useful in the evaluation to determine impairment vs. non impairment.
FOR A “NORMAL” NON-IMPAIRED PERSON, THE AVERAGE PUPIL SIZE FOR Room light is approximately 4.0 mm. with an average range of normal pupil sizes ranging from 2.5 to 5.0 mm. Near Total Darkness is approximately 6.5 mm. with an average range of normal pupil sizes ranging from 5.0 to 8.5 mm. Direct light is approximately 3.0 mm with an average range of normal pupil sizes ranging from 2.0 to 4.5 mm
Let’s Apply These Concepts to Pupil Size Measures Expected Values
The “CUT-OFF “ CONCEPTis often used inappropriately and can lead to errors in decision making. The “Cut-Off “ implies that as long as a suspect is within the “ Average for Normals” then they are Normal. It gives the impression that if you are within the “Average Range ”, then you are not impaired and once you go just outside of the range, then you are impaired.
What Does “Average” and “Average Range” Indicate? • Since many of the DRE Test results involve “NORMATIVE VALUES”, • It is quite important for the DRE student to understand what these “NORMAL AVERAGE VALUES” and “ NORMAL AVERAGE RANGES ” mean as it applies to physiological functions in such areas as: • Pupils, • Eye Convergence • Blood pressure, • Pulse rate, • Body Temperature
Sometimes "average" just means "normal.“ Other times it refers to some number "in the middle"; there are several different ways to characterize an average or mean value
The best way to describe what Average means is that it is the Number that represents the value that the “MAJORITY OF NORMAL PEOPLE” would exhibit or have in a specific test. .
Room Light Normal Ranges Room light is approximately 4.0 mm. with an average range of normal pupil sizes ranging from 2.5 to 5.0 mm.
Near TotalDarkness Normal Ranges Near Total Darkness is approximately 6.5 mm. with an average range of normal pupil sizes ranging from 5.0 to 8.5 mm.
Direct Light Normal Ranges Direct light is approximately 3.0 mm with an average range of normal pupil sizes ranging from 2.0 to 4.5 mm
·For example, the “Average” or “Mean” value for pupil size in near total darkness is 6.5 mm. This means that when all the sizes were measured in a large number of pupils in healthy normal adults eyes, the average or mean pupil size was 6.5 mm and were in a normal distribution.
Mean +/- 1.STD Mean +/- 1.5 STD Mean +/- 2.STD
Mean or “Majority” Value For NTD Pupil Size Normal In People 80% 6.5 mm 60% Number of People with a Specific Value 40% 20% 0% Average or Normal “ Range
Let’s take an example and look at Three pupil sizes under near total darkness. Let’s look at where they Fall on the Curve And what does that mean in the evaluation.
Average or Mean Value The “Majority” Subject C Average Subject B Subject A Average Range for Majority Of Normal People 7 mm pupil 15% 5 mm pupil 8.9% 8 mm pupil 8.9% 4 mm pupil 1.8% 9 mm pupil 4.8%
GENERAL RULES: #1 The closer the test finding is to the average value for the majority of normal people, the more likely it is “normal” # 2 The farther away from the average and the closer to the edge of the “Average range for the Majority of People ”, the more likely the test finding is “abnormal” finding and indicates impairment #3 The farther outside the range for the majority of normal people, the higher is the chance that the test finding is truly abnormal and there is definite impairment.
Mean: The average of a given set of numbers Average range: The range of data in which 88% or greater are included Recent Research
Average Average Outside Normal Range Average Range Figure1 Mean vs. Average Range
Question If results are outside of the normal range, does that mean you have impairment? Three pulses taken during a DRE examination: 56, 58, 56. Is the pulse rate down? What if the subject was an athlete? Is he/she impaired by some drug?
Normal range for pulse • PULSE For resting heart rate: • Newborn infants; 100 to 160 beats per minute • Children 1 to 10 years; 70 to 120 beats per minute • Children over 10 and adults; 60 to 100 beats per minute • Well-trained athletes; 40 to 60 beats per minute
Pupil size ranges Normal range 2.5–5.0 mm
Pupil Size Ranges • Room Light: • Average – 4.0 mm • Range for majority of subjects – 2.5 mm to 5.0 mm • Near Total Darkness: • Average – 6.5 mm • Range for majority of subjects – 5.0 mm to 8.5 mm • Direct Light: • Average – 3.0 mm • Range for majority of subjects – 2.0 mm to 4.5 mm
Examples Dilated 5.5 4.0 8.0 4.0 5.5 8.0 3.0 Constricted 2.5 4.0 2.5 3.0 4.0 7.0 2.5 Normal 4.5 7.0 4.5 2.5
Photography by Dr. Jack Richman
Photography by Dr. Jack Richman
Photography by Dr. Jack Richman
Photography by Dr. Jack Richman
More Changes • 12 step Procedure: -Added wording to allow for times when the 12 step cannot be adhered to or done out of sequence…exception not the norm!
More Changes • Lack of Convergence: The DRE shall come into the bridge of the nose and stop approximately 2 inches from it.
More Changes • “Downside” Definition: An effect that may occur when the body reacts to the presence of a drug by producing hormones or neurotransmitters to counteract the effects of the drug consumed. • All references are removed that DREs do not classify subjects as being under the influence of the downside
More Changes • PCP Category Will be renamed as “Dissociative Anesthetics”. This was to encompass the several different categories of Dissociative drugs e.g., DXM etc.