FORENSIC TOXICOLOGY - Bio Medical Forensics

0.18 mg/L in aortic blood and 2.1 mg/kg in liver from the same case. In
contrast, benzoylecgonine, like other drugs, was undetectable by TOF-DART
when it was detected by traditional methods as low as at 6.9 mg/L. This
unpredictability was found to occur in both blood and tissue samples.
Conclusions: Although the AccuTOF-DARTsystem has the ability
to detect the presence of analytes by direct analysis, current indications show
that drugs are not detected in postmortem samples without extraction or
protein precipitation. Even with extraction and some concentration, many
drug were not detected at high or low levels in both blood and tissue samples.
It has been previously reported detection of many of the drugs, such as
cocaine, at lower levels when drugs spiked into blank blood or urine, but
these same drugs in the more complex matrix of postmortem blood and t issue
were not as readily detectable. The samples analyzed in this study are
archived postmortem samples and the stability of the drugs in these particular
samples was not confirmed by traditional postmortem methods after TOF-
DART. The AccuTOF-DARTsystem is a novel approach in the analysis
of compounds; however, due to the nature of many postmortem specimens
it does not have the sensitivity to detect the presence of many drugs.
AccuTOF DART, Postmortem, Toxicology Screening
K59 Statistical Interpretation of Meprobamate
Concentrations in Bone Marrow, Vitreous,
and Bile
Fabien Bévalot, MD*, Laboratoire Lumtox, Institut Universitaire, De
Médecine Légale De Lyon, 12 Avenue Rockefeller, Lyon, 69008, FRANCE;
Laurence Dujourdy, PhD, Laboratoire De Police Scientifique De Lyon,
31 Avenue Franklin Roosevelt, 69134, Ecully Cedex, FRANCE; Laurent
Fanton, MD, Nathalie Cartiser; and Lise Magné, Laboratoire Lumtox,
Institut De Médecine Légale, 12 Avenue Rockefeller, Lyon, 69008,
FRANCE; and Fabrice Besacier, Laboratoire De Police Scientifique
De Lyon, 31 Avenue Franklin Roosvelt, 69134, Ecully Cedex, FRANCE;
Catherine Le Meur, MD, Laboratoire Lumtox, Institut De Médecine
Légale, 12 Avenue Rockefeller, Lyon, 69008, FRANCE; Yvan
Gaillard, PhD, Laboratoire Lat, Quai Jean Jaures, La Voulte Sur Rhône,
FRANCE; and Daniel Malicier, MD, Instutu Medico Legal, 12 Avenue
Rockfeller, Lyon, 0 69007, FRANCE
Upon completion of this presentation, participants will have some tools
to interpret postmortem meprobamate concentration in bone marrow,
vitreous and bile. The proposed methodology could be applied to interpret
the concentrations measured in other biologic matrices.
In numerous cases of toxic death investigations, the interpretation of
blood concentrations is difficult (postmortem redistribution, putrefied bodies)
or impossible (lack of blood sample). This presentation will impact the
forensic community by enabling an interpretation of meprobamate
concentrations measured in sample types other than blood sample.
The interpretation of concentrations in samples other than blood is
complex due to the lack of reference ranges. The presented statistical
methodology enables the decision of an intoxication or a therapeutic case
with a quantified risk of error, which is very important when discussing the
results in court.
The presented study is based on 116 forensic cases. On the basis of
blood concentration, 70 cases were classified as therapeutic blood concentrations
and 46 as toxic blood concentrations. For each case, at least one of
the following sample types was collected during the autopsy: bile (n=107),
right vitreous (n=40), left vitreous (n=43), and bone marrow (n=51).
Meprobamate was quantified by GC/MS. For each sample type, the average
concentration and the standard deviation showed that the meprobamate concentrations
between the toxic and therapeutic populations were statistically
significantly different.
Modeling of the toxic and therapeutic populations allowed the definition
of a toxic threshold with less than 5% false positives. Multivariate analysis,
such as Principal Components Analysis (PCA) and Partial Last Square Data
* Presenting Author
Analysis (PLSDA) showed that it was possible to distinguish therapeutic
cases and the toxic cases by simultaneous use of the concentrations measured
in the 4 alternative matrices.
Practical applications of these results on some cases will be presented,
as well as cases previously published in the international literature.
Meprobamate, Bone Marrow, Forensic Toxicology
K60 Rapid Determination of N 2 O in
Postmortem Biological Samples:
A Case of Serial Fatal Poisoning
Diana Poli*, University of Parma, Via Gramsci 14, Parma, 43100,
ITALY; Roberto Gagliano-Candela, PhD; Giuseppe Strisciullo; Luigi
Strada, PhD; Domenica Laviola, MD, University of Bari, Policlinico,
Piazza G. Cesare 11, Bari, 70124, ITALY; and Antonio Mutti, PhD,
University of Parma, Sezione di Medicina del Lavoro, Via Gramsci, 14,
Parma, 43100, ITALY
After attending this presentation, attendees will be briefed on eight cases
of fatal poisoning which occurred during general anesthesia.
This presentation will impact the forensic community and/or humanity
by demonstrating the presence of N2O in forensic biological samples by
headspace- gas chromatography analysis using ECD detector (HS-GC/ECD).
Case History: In a public hospital during anesthesia, eight accidental
deaths occurred due to an erroneous replacement of O2 with N2O. Four were
females and four were males with a mean age of 77.75 years (range 67-85).
Five of the decedents showed cardiovascular diseases, two had lung disease
and one had gastrointestinal disease. During anesthesia, all were exposed to
N2O for a mean period of 58,25 min (range 25-125 min) until they expired.
Goal: It is known that Nitrous oxide (N2O) is an asphyxiant at high
concentrations [ACGIH 1991]. Determination of the cause of death in
gaseous asphyxiation cases is very difficult due to the variation in
circumstances during the event. To clarify the cause of death and identify the
factors involved in asphyxia, gases from different lines were characterized
and N2O concentrations in postmortem biological samples (air and tissue
samples), collected after 19 days postmortem (range 6 – 31) were analyzed.
Methods: Analyses, carried out on the gas samples both from the O2 and the N2O lines in the surgery room, confirmed the incorrect connection
of the lines. In fact, gas samples from O2 lines showed the presence of pure
N2O, while in those collected from the air lines there was pure O2 with a low
percentage of N2O (less then 0.1%). Analysis of gas samples from the lines
supplying each bed, produced the same results.
The analyses performed on the postmortem biological samples, showed
an abnormal concentration of N2O. Particularly, air samples collected from
the stomach of all patients during autopsy revealed concentrations from 0.12
mM to 1.9 mM N2O corresponding to 0.30 % and 4.55%, respectively. All
samples were collected in duplicate and stored in 100 ml syringes until
analysis. Calibration was carried out using air samples with a known amount
of N2O. The presence of high levels of N2O was found in urine, blood, kidney
and liver. Results showed a variation in the distribution of the gas consistent
with its solubility in the different tissues.
Results confirmed that the air supply lines were indeed switched. The
data also indicate that N2O could be detected in biological samples 31 days
postmortem due to the high exposure concentrations.
Therefore, this report presents valuable findings for the correct
diagnosis of the cause of death and helps to clarify the true nature of the
cause of death.
Nitrous Oxide, Anesthesia, Accidental Death
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