BLOOD DRAWS IN TEXAS

Transcription

1 BLOOD DRAWS IN TEXAS A Pre-Trial Primer for a DWI Case with a Blood Draw By Deandra Grant Knowledge Can Take You Far Garriott smedicolegal Aspects of Alcohol, 5 th edition Understanding DUI Scientific Evidence (Aspatore Publ.) DPS Physical Evidence Handbook you can download it off DPS website under the Crime Lab section Phlebotomy Essentials, 4 th ed. 1

2 Forced Blood Draw Chair Houston PD 2

3 DPS Blood Kits 3

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5 Where was the draw site? Typical site cubital vein located inside the elbow Hospital draw may use an artery due to convenience Why does this matter? Absorption phase Arterial blood has higher alcohol concentration Elimination phase Venous blood has higher alcohol concentration 5

6 Contamination of the sample Improper insertion of the needle into the vacutainer-can allow for outside air to be sucked into the tube Contaminated draw site What was used to clean site? Alcohol free? The swab packages have expiration dates. Poor swabbing technique supposed to swab in concentric circles away from puncture site Piercing of sebaceous gland during draw -Can introduce bacteria into the blood which can consume glucose in the sample and produce ethanol as a waste product 6

7 Compromised tube top seal -Look for the expiration date on the tube refers to seal, not chemicals in the tube If Candida Albicansis present in the blood, it can produce ethanol even in the presence of sodium flouride (Yeast + Sugar = EtOH). Contamination can occur before, during or after blood collection. TIP:Check the amount of blood drawn (10 ml tube) -Short blood draw (9 ml or less) could indicate the vacuum was compromised allowing outsidecontaminants (bacteria) into the sample 7

8 3 different types of gray top tubes -Only one has the preservative sodium flouride(should have 100 mg) and the anticoagulant potassium oxalate(should have 20 mg) Red top tubes are empty. Blood Tubes CHECK YOUR TUBE LABEL! 8

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10 Inversion NOT SHAKING! BD recommends 8-10 inversions with a gray top tube to ensure proper mixture of blood and chemicals What is an inversion? Why does it matter? Why is shaking bad? 10

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12 BLOOD CLOTS Blood starts to clot immediately after draw unless exposed to an anticoagulant Clots within the specimen can yield inaccurate results, even if not evident to the naked eye One cause of clotting is the inadequate mixing of blood and anticoagulant 12

13 The Blood Doggie Bag : Issues with Transport and Storage What happened to the blood between the draw and analysis? Refrigeration only slows biological activity, it does not stop it chicken salad in the refrigerator for a couple of weeks still goes bad should be stored between 2 and 8 degrees centigrade Was blood frozen? Freezing breaks blood cells and can effect analytic results in whole blood. 13

14 Contamination in the lab Cross contamination of sample Contamination of laboratory solutions Mislabeling of sample tubes Storage of samples in non-secure areas Using same source solution to calibrate that is used for quality control Important to obtain extensive discovery from the lab and let a toxicologist review it. Whole Blood vs. Serum or Plasma Whole blood - often referred to as legal blood. Serum the clear liquid left when blood is clotted. Plasma -The liquid part of the blood and lymphatic fluid, which makes up about half of its volume. Plasma is devoid of cells and, unlike serum, has not clotted. Blood plasma contains antibodies and other proteins. Higher water content = higher alcohol percentage Conversion of serum result to whole blood: Conversion factor range of 1.16 or 1.18 often used. Dr. AW Jones recommends 1.20 or

15 What is Blood? The Texas Penal Code does not define blood Normal definition? Serum/plasma is a part of blood like your toe is a part of your foot. 15

16 Example:.10 serum blood test result.10 / 1.16 = / 1.18 = / 1.20 = / 1.25 =.080 Testing methods Hospital test - for medical purposes fast, only need a ballpark figure usually enzyme analysis which is less specific for ethanol (ie. a screening test) than GC analysis and needs to be confirmed indirect method for alcohol analysis you need to find out what type of immunoassay kit was used Forensic test -for purposes of prosecution usually gas chromatography (GC) Headspace Direct injection 16

17 Hospital Serum Ethanol Test Errors by Dr. Stefan Rose No chain of custody sample results may belong to another patient No sample available for independent re-test Serum results always higher than whole blood Hospital may draw arterial blood instead of venous Arterial blood may have 40% higher ethanol concentration than venous blood Hospital chemistry analyzers can cause false positive results Hospital protocols do not follow forensic quality control guidelines Hospital serum ethanol error is plus or minus 25% Serum ethanol enzyme assay method is prone to false positives Hospital serum ethanol testing is performed for medical, not legal purpose 17

18 Variables Affecting Accuracy: Pre-Analysis by Dr. Stefan Rose Serum has more water than whole blood = potential 20% or higher ethanol result Arterial blood has more ethanol than venous blood during absorption phase = potential 40% higher ethanol result Fermentation can be caused by contamination or improper storage (ie. heat) = potential 100% error Chain of custody error could result in blood sample not being from subject = potential 100% error Subject could be in absorption phase = up to 0.15 g/dl lower for each hour between driving and blood draw Variables Affecting Accuracy: During Analysis by Dr. Stefan Rose False positives are common in Enzyme Assay analysis = potential 100% error False positives may occur in single column gas chromatography = potential 100% error External contamination of negative control = potential error Sample could be mixed up during preparation = potential 100% error Sample could be mixed up due to auto-sampler failure = potential 100% error 18

19 What is Gas Chromatography Imagine a pile of different types of balls resting at the bottom of an inclined, paved driveway. This pile includes ball bearings, marbles, ping pong balls, golf balls, wiffleballs, handballs, tennis balls, hockey pucks, baseballs, soccer balls, volley balls, basketballs, footballs, and bowling balls. Attempt to move this motley collection of balls up the driveway with a normal leafblower. Some of the pile will quickly move to the top of the driveway immediately, some balls will migrate at varying speeds, and some balls may take an eternity to reach the end of the driveway. The difference in the time that each type of ball takes to travel to the top depends upon the characteristics of each ball. Obviously, the lighter balls travel more quickly. Also, some balls may take longer due to their shape, like the hockey puck or the football. The different balls interact with each other as the air from the leaf blower acts on the pile. This interaction may hinder or accelerate the ball's travel as the balls strike each other. The surface characteristics of the ball may be important, as in the examples of the tennis ball and golf ball. GC analysis depends on similar phenomena to separate chemical substances. A mixture of chemicals present in a specimen can be separated in the GC column. Some chemical and physical characteristics of the molecules cause them to travel through the column at different speeds. If the molecule has low mass it may travel more swiftly. Also, the molecule's shape may affect the time needed to exit the column. How the different substances relate to each other may cause the time needed to travel the column to increase or decrease. Interactions between the sample's molecule and the column surface may cause the molecule to be retained inside the column for a different amount of time than similar molecules that interact with the column differently. By Frederic Douglas, Attorney 19

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22 Immunoassay testing From Wikipedia An immunoassayis a biochemicaltest that measures the concentrationof a substance in a biological liquid, typically serumor urine, using the reaction of an antibodyor antibodies to its antigen. The assaytakes advantage of the specific binding of an antibody to its antigen. Common types of immunoassay kits: Radioimmunoassay (RIA) Enzyme immunoassay (EIA) Kinetic interaction of microparticlesin a solution (KIMS) Fluorescence polarization immunoassay (FPIA) Each has its own pros and cons which is why you need to do DISCOVERYto find out what was used to test your client s blood! 22

23 Discovery: Taking the Fight to Them See attached Discovery Motion and Order courtesy of attorney Troy McKinney for forensic lab tested blood **Check with lab often you can just fax the Order and they will pull all of the information together for you See attached sample Subpoena DucesTecumrequest for hospital-tested blood **Prepare for battle with the hospital Chain of Custody Affidavits Must be filed by State no later than 20 days prior to trial Defense must object in writing no later than 10 days prior to trial See CCP & Melendez-Diaz case (5-4 decision) Issue: Is a state forensic analyst's laboratory report prepared for use in a criminal prosecution "testimonial" evidence subject to the demands of the Sixth Amendment's Confrontation Clause as set forth in Crawford v. Washington? YES! 23

24 On the Horizon The Supreme Court will hear oral arguments in January Briscoe v. Virginia Issue: Does a notice and demand statute violate the Confrontation Clause? Example: State gives Defense notice that it intends to offer an affidavit from the lab. If the Defense objects, the affidavit or evidence is not admissible. If the Defense does not object, then there is a waiver and the affidavit is admissible. See Deenerv. State, 214 S.W.3d 522, PDR refused Red flags Blood drawn after an injury Blood drawn from somewhere other than the cubital vein Blood drawn after IV fluids have been given A long time delay from collection to the lab A short blood draw less than 9 ml 24

25 Blood case checklist How was warrant obtained? If phone call/fax, file MTS. Did the cop use a DPS blood kit? What was used to clean the draw site? What was the expiration date on the swab package? Where was the draw site? RED FLAG if not drawn from cubitalvein. How was the draw site cleaned? Back and forth or concentric circles away from puncture site? What color was the stopper on the vacutainertube? Who manufactured the tube? Was powder observed in the tube prior to the blood draw? What color was the powder? How much blood was drawn? RED FLAG if less than 9 ml. Was the tube detached from the collection needle and holder prior to needle being withdrawn from the vein? How was the blood mixed with the chemicals in the tube? Blood should have been inverted 8-10 times make nurse demo her inversion technique important that blood sample not shaken. Who labeled the tube? How much time elapsed between blood draw and refrigeration? What was the temp of the refrigerator? Need 4 degrees centigrade which is 39.2 degrees Farenheit. Where is it located? Who transported it? How was it transported? When was it transferred to the lab? Who transferred it? How long was it un-refrigerated during the transfer? When was it logged into the lab? Where was it placed? When was it removed for testing? Who tested it? Need to go into qualifications. What was the condition of the blood kit when it was tested? Was there any leakage of blood? Did the stopper make a popping sound when removed? (to indicate vacuum still intact) 25

26 Were any blood clots observed? Did the sample show signs of hemolysis? (pink-tinged plasma) How was the sample tested? If GC, was it tested using headspace or direct injection? Note any problems with GC equipment if indicated in the discovery obtained from the lab. If hospital test, what type of testing was done? If enzymatic immunoassay, was sample sent to a forensic lab for a confirmatory test? (ie. GC) Trial issues Serum/whole blood conversion Who will testify about it? Retrograde extrapolation Lab personnel often are not qualified to do it. Do you want it in? Who will testify about it? Medical records Is the blood sample identified throughout the records by a particular number? Learn to love 702/704 hearings. 26

27 TRE 705(b) Prior to the expert giving the expert s opinion or disclosing the underlying facts or data, a party against whom the opinion is offered upon request in a criminal case SHALL be permitted to conduct a voirdire examination directed to the underlying facts or data upon which the opinion is based. This examination shall be conducted out of the hearing of the jury. Deandra M. Grant Deandra Grant primarily handles DWI offenses in Collin and Dallas County. She has extensive experience in all aspects of DWI trial practice and is the co-author of The Texas DWI Manual, scheduled for re-release in the Fall of Deandra is a national speaker at legal seminars, lecturing on all aspects of DWI law, strategy and science. After a peernomination process, D Magazine recently named her to its list of the Best Women Lawyers in Dallas for Deandra is a member of the National College for DUI Defense, has completed NHTSA SFST Instructor training, was certified through Florida International University and CES Consulting on the use and maintenance of the Intoxilyzer 5000 breath testing device and has completed over 24 hours of coursework in DWI forensic blood and urine testing. In addition, she is the founder and moderator of the Texas DWI Defender list serve on Yahoo. She maintains offices in both Plano and Dallas. Law Offices of Deandra M. Grant PC 1700 Alma Drive, Ste. 227 Plano, Texas (972) Office [email protected] 27