FORENSIC TOXICOLOGY - Bio Medical Forensics

illicit drug use increase. Polydrug use further complicates the issue by
making interpretation more difficult, frequently as the result of
insufficient information to support an opinion. Unlike alcohol, drug
concentrations are not correlative to behavioral effects, particularly in
DUI cases. Furthermore, limited literature information is available
correlating drug concentrations with standardized field sobriety tests and
poor driving performance. The following cases are presented to support
the need for more case specific data correlating drug concentrations to
driving performance.
The first case involves a 43-year-old male charged with DWI (2nd
offense) after a witness reported observing the suspect driving erratically
on a major highway. The suspect failed the standardized field sobriety
tests (SFSTs) administered by the arresting officer. The suspect claimed
to suffer from chronic back pain, and several medications were seized
from him including Oxycontin® (40 mg), diazepam (10 mg), Skelaxin®
(metaxalone 800 mg), Lyrica® (pregabalin 75 mg), as well as other
drugs that were not readily identified. The breath alcohol test was
negative, so a DRE was summoned. Upon completion of the DRE
evaluation, the officer opineed that the suspect was under the influence
of a CNS depressant and narcotic analgesic. Blood and urine samples
were tested. The laboratory quantitatively determined diazepam (410
ng/mL), nordiazepam (481 ng/mL), oxazepam (48 ng/mL), and trace
amounts of temazepam, as well as oxycodone (114 ng/mL). The
laboratory did not test for metaxalone or pregabalin. The urine sample
was presumptively positive for benzodiazepines, opiates, cannabinoids,
and cocaine.
The second case involves a 38-year-old male nurse charged with
DUI after a witness complained of his erratic driving to state police. The
arresting trooper was also able to observe the driver’s dangerous
behavior while driving and pulled him over soon after. Upon initial
contact, the driver was observed to be wearing his coat inside out and
upside down. A recently filled prescription for lorazepam (0.5 mg) fell
out of the suspect’s pocket. The suspect failed initial SFSTs and the
breath alcohol was negative, so a DRE was called. The DRE opined that
the suspect was under the influence of a CNS depressant and cannabis.
The suspect admitted to taking lorazepam on an “as needed” basis, but
did not take it regularly. Physician affidavits were obtained verifying
that the suspect was under their medical care and prescribed Ativan®
and Seroquel®. The laboratory’s findings reflected a blood quantitation
of lorazepam (79 ng/mL). The laboratory did not test for the Seroquel®.
The presumptive positive cannabinoids drug screen was subsequently
confirmed negative for both THC and THC-COOH.
The last case involves a subject, who voluntarily participated in an
ongoing study evaluating the applicability of oral fluids to DRE
certifications/DUI investigations. Oral fluid testing is not new to
forensic toxicology; however, the use of oral fluids in DUI cases is being
developed. Oral fluids offer many potential advantages over
conventional blood and urine matrix testing, particularly the ease of
sample collection. Blood, urine, and oral fluid samples are collected
from the volunteer who is under the influence of CNS depressants and
narcotic analgesics. The results of each matrix are compared to one
another and against the DRE’s opinion.
All three cases reflect the laboratories’ limitations in terms of the
types of drugs tested and matrices used. Forensic Toxicology is an everexpanding
field that must consider ways to optimize and standardize
testing through collaborative research and sharing of data.
DRE, Impaired Driving, Forensic Toxicology
K30 Dissociative Driving: Ketamine DUID
Fatality Case Study
Kevin M. Lougee, BS*, Amy L. Lais, BS, Kim G. McCall-Tackett, BS,
Diane J. Mertens-Maxham, BS, R.E. Kohlmeier, MD, and Norman A.
Wade, MS, Maricopa Country Medical Examiner, 701 West Jefferson
Street, Phoenix, AZ 85007
After attending this presentation, attendees will understand the
pharmacological effects of ketamine and how it may adversely affect
driving tasks.
This presentation will impact the forensic community and/or
humanity by demonstrating the adverse effects of ketamine on driving
skills, motor performance, and behavior in an otherwise healthy individual.
Ketamine came into existence as a safer alternative to PCP. Even
before PCP was withdrawn from the market due to its problematic
adverse reactions in patients, pharmaceutical houses were looking for a
safer alternative that would have less toxic behavioral effects. It was
first synthesized in 1962 and patented in 1966 under the trade name
Ketalar® and received FDA approval in 1970 as a general anesthetic. It
is used as a short-acting induction anesthetic that provides a profound,
rapid, dissociative anesthesia and a short recovery time. Low doses
produce effects similar to PCP but doses in the anesthetic range
(1mg/kg) produce experiences where the individual feels separated from
his body, floating above his body and a near-death experience. This
state, which users call the “K-hole,” can either be spiritually uplifting or
terrifying (heaven or hell). Ketamine is a synthetic, sedative, nonbarbiturate
that acts as a central nervous system depressant and produces
a rapid-acting dissociative effect. It is used in the recreational drug
market by illegally diverting from legitimate suppliers, allowing the
liquid carrier to evaporate. The crystals are scraped into a fine powder
and packaged. The first reports of ketamine abuse occurred in the early
1970s in the San Francisco and Los Angeles areas.
In this case report, a 27-year-old Caucasian male was the driver and
sole occupant of a luxury sedan driving on a dry and clear Arizona
freeway at two thirty AM on an early February morning. He attempted
to exit this freeway for an unknown reason; however, in doing so, he hit
a traffic sign and then continued about 1100 feet until colliding head-on
with a large steel sign post. The force of the collision caused the vehicle
to rotate 180 degrees and caused very extensive front end damage with
major intrusion into the cab area of the automobile. It was reported that
the decedent was not wearing a seat belt and was not exceeding the
posted 65 miles per hour speed limit.
A full autopsy was performed approximately 48 hours after death
was pronounced and cause of death was determined to be massive blunt
force trauma due to head and neck (fractured and dislocated) injuries.
These included transection of the cervical spine, laceration of the
pericardial sac, transection of the thoracic aorta, bilateral rib fractures,
and contusions of all lobes of the lungs and multiple splenic lacerations.
The manner of death was accident. During autopsy the assistant medical
examiner collected pleural blood, bile, vitreous and gastric contents for
complete toxicological testing. Vitreous and blood were analyzed for
volatiles by GC-FID while the pleural blood was assayed by ELISA for
benzodiazepines, barbiturates, benzoylecgonine, opiates, and
methamphetamine with negative results. The blood and bile specimens
were subjected to a qualitative analysis for basic drugs, and ketamine
and its metabolites were confirmed by GC/MS using electron impact
ionization. Quantitation of the ketamine was performed on the pleural
blood with the result being 1.5 mg/L of parent compound. Further
quantitative testing of all tissues submitted will also be presented.
A presentation of this case study will contribute to establishing
guidelines on potential impairment concentrations of ketamine as it
relates to DUID cases. Although this case demonstrates only anecdotal
evidence for DUI impairment, it clearly demonstrates the adverse effects
of ketamine on driving skills.
Ketamine, DUID, Fatality
139 * Presenting Author