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Hospital or Medial Blood Test in DUI Prosecutions

If your DUI case involve a blood test result found in your medical records, then your criminal defense attorney will fight to get that evidence excluded from the case at trial. In these cases, the prosecutor will often issue a subpoena to obtain a person’s medical records to find evidence about the alcohol concentration in the blood sample taken for medical purposes. In order to understand how this evidence might impact your case, it is important to understand the difference between a whole blood test and a blood plasma (serum) test.

The hospital will usually perform a blood plasma test instead of testing whole blood. The plasma blood test is performed on the liquid portion of a drawn blood sample after the solid cellular components have been removed. For a legal blood test, the test is performed on whole blood or blood that has not been broken down into solid and liquid components.

The distinction between the hospital blood and the legal blood becomes important when considering the reported BAC results because a plasma test will produce a result that is more than 10–15% higher than a whole blood test drawn at the same time. Expert testimony is usually required to explain the how the plasma BAC would equate to a determination of whole blood BAC.

Contact an experienced criminal defense attorney at Sammis Law Firm in Tampa, FL. Call us to find out more about defenses to blood testing in DUI cases. Call 813-250-0500.


Are Hospital Blood Tests Admissible in DUI Cases in Florida?

In 2000, the supreme court answered a certified question from the Fourth District which established that records of hospital blood tests can be admitted in DUI cases. See Baber v. State, 775 So. 2d 258, 382 (Fla. 2000), cert. denied, 532 U.S. 1022 (2001).

After the United States Supreme Court's decision in Crawford v. Washington, 541 U.S. 36 (2004), the predicate steps necessary to introduce such evidence are far more complicated in order to satisfy the requirements of confrontation, see Johnson v. State, 929 So. 2d 4, 7-8 (Fla. 2d DCA 2005), but it remains clear that such medical tests can be relevant to establish a DUI.

Given the differences between legal blood tests and medical or serum blood tests, at a minimum, a hospital blood test may need to be supported by additional expert evidence to be relevant and admissible in a case under a blood-alcohol theory. But in a case under an impairment theory, medical or serum blood tests are more likely to be admissible with a lesser degree of expert testimony.

But in a case under an impairment theory, medical or serum blood tests are more likely to be admissible with a lesser degree of expert testimony. See J.J. Paul, III, DWI: Blood, Tests & Fears: A Crash Course in Blood Alcohol Samples, 25 Champion 39 (June 2001); Carol A. Roehrenbeck & Raymond W. Russell, Blood is Thicker than Water: What You Need to Know to Challenge a Serum Blood Alcohol Result, 8 Crim. Just. 14 (Fall 1993).

DUI can be established under several alternative theories. In cases involving alcohol intoxication, a prima facie case can be established by proof that a person operating or in actual physical control of a vehicle is “under the influence of alcohol . . . to the extent that [his or her] normal faculties are impaired,” § 316.193(1)(a), Fla. Stat. (2009), the person has “a blood-alcohol level of 0.08 or more grams of alcohol per 100 milliliters of blood,” § 316.193(1)(b), or the person has “a breath-alcohol level of 0.08 or more grams of alcohol per 210 liters of breath.” § 316.193(1)(c).


Challenges to Fight the Medical Blood Test

The defense can file a motion to exclude the medical blood test results when the prosecutor seeks to admit this evidence. In many cases, the prosecutor will obtain the medical records that contain a notation about the blood test results. The criminal defense attorney will then object to the results of the hospital’s BAC test performed for the purposes of medical treatment. Those objections can be based on a showing that the notation in the medical records is hearsay, irrelevant, and that admitting the results would violate the Confrontation Clause.

Although the notation of a BAC level in the hospital records are hearsay, the state will often argue that the blood test results in the medical records are a business record exception. That exception only applies if the blood report is untrustworthy. The defense can challenge the trustworthiness of the hospital records by evidence from the quality control records of the hospital through its lab director including the maintenance log, package insert and method of the alcohol measuring instrument. 

Many hospitals use the VITROS 950 or similar types of preliminary tests. The hospital lab director will often admit that the hospital blood tests are not scientifically accurate but are merely used as screening tests to determine approximate levels of alcohol in order to evaluate the patient's condition and to prescribe medications. 

The defense can often call its own expert including a Forensic Toxicologist to show that the BAL in the medical records are not consistent with the patient’s clinical presentation. The defense expert can also explain the testing method as specified in the manufacturer's instructions which disclose the reportable dynamic range of the VITROS alcohol device was up to 300 MG/DL.

If the patient’s reading is “out of range” and was subject to “sample dilution” then it must be retested according to the manufacturer. When no sample dilution was performed and the hospital ignored the manufacturer's instructions to confirm the results by gas chromatograph, then the hospital blood specimen might contain a possible false-positive result caused by a crush injury.

In many of these cases, the hospital testing lacked quality control when there is no proper chain of custody to prevent a source of contamination of the specimen and the hospital used serum not whole blood.

The blood tests in these cases do not always comply with the common law for scientific tests because no three-prong proper predicate can established. That predicate requires a showing of the following:

  • the test was reliable;
  • the test was performed by a qualified operator with the proper equipment; and
  • expert testimony was presented concerning the meaning of the test.

See State v. Bender, 382 So.2d 697, 699 (Fla.1980). 

The results might not be reliable because it involved the extraction of arterial rather than venous blood, an alcohol swab was used at the extraction site, and the testing method resulted in mistaking other chemicals in the blood for alcohol. Many of these tests are performed without any of the safeguards that would be present in a forensic laboratory.

Actual deficiencies in this particular test can be shown. In many of these cases, the prosecution has very little information about who extracted the blood or their qualifications. In some cases, the prosecutor has not listed an expert who can testify about the meaning of the test by converting the serum blood alcohol result into a whole blood alcohol reading that would indicate significant alcohol intoxication.

Other problems can result when there is an insufficient showing of the chain of custody. In many cases, the blood alcohol test report is for medical purposes only and the testing parameters do not meet requirements for legal interpretation.


How to Convert Serum and Plasma Results to Whole Blood

Since it represents the water portion of whole blood, serum or plasma will have a higher AC than the whole blood from which it is derived.This means that serum and plasma alcohol results must be reduced to obtain a whole blood equivalent.The average ratio of serum and plasma AC to whole blood AC is approximately 1.14:1 (range 1.04:1 – 1.26:1).

To convert a serum alcohol concentration to a whole blood equivalent:

Step 1.

If necessary, convert the units to g/100 mL.

mg/dL = mg/100 mL

mg/100 mL = g/100 mL

_________

1000

120 mg/dL = 0.120 g/100 mL

Step 2.

Convert serum alcohol concentration (SAC) to an equivalent whole blood concentration (your witness may use a different average ratio than 1.14:1): Whole Blood AC = SAC /1.14.

0.120 = 0.105 g/100 mL = average whole blood equivalent

_____

1.14


Conversion Between Alcohol Concentrations in Whole Blood, Plasma Blood and Serum Blood

Enzymatic assay testing is used in hospitals for determining the alcohol concentration in plasma or serum. The plasma is gathered when whole blood is centrifuged or spun and the red blood cells, white blood cells, and platelets are removed. The serum is gathered in the same way except that coagulation proteins are also removed.

The result of the plasma or serum for alcohol concentration will return a result that is 16-25% higher than the alcohol concentration in whole blood. Different conversion numbers are used by different experts. The most common range used is .13 to .20. In some cases, a technical supervisor will use .16.

For example, if a .10 serum/plasma alcohol concentration is converted to a whole blood alcohol concentration, the following calculations will result:

  • .10 / 1.25 = .080
  • .10 / 1.20 = .083
  • .10 / 1.18 = .084
  • .10 / 1.16 = .086

DUI Defense Attorneys for the Blood Test in Tampa, Florida

If your driving under the influence (DUI) cases involves blood testing, then contact an experienced DUI defense lawyer in Tampa, Florida. The attorneys at Sammis Law Firm in Tampa, FL, are experienced in represent clients throughout the Tampa Bay area.

Find out more about the charges pending against you, the method used to for the DUI blood test and defenses that might apply to your case.

Call 813-250-0500 to discuss your case.


This article was last updated on Thursday, May 11, 2017.