jiafm-35-1 - forensic medicine

J Indian Acad Forensic Med. Jan-March 2013, Vol. 35, No. 1 ISSN 0971-0973
small intestine with their contents, pieces of liver,
spleen and kidneys and sample of blood) were
preserved in saturated solution of common salt
for chemical analysis. To increase the specificity
of results of chemical analysis, additional
samples of gastric lavage were collected from
the casualty and were also sent other than
routine viscera of autopsy.
In present study gastric lavage was
available for chemical analysis only in 186 cases
(64.36%), while in rest 103 cases (35.64%) it
was not available due to inclusion of received
dead cases, cases of inhalational poisoning and
corrosive poisoning and the cases which were
brought to us from private hospitals from where
lavage sample was not sent with dead body.
The results were analyzed after
receiving the chemical analyzer reports and the
details of the parameters used in the study were
filled up in Performa and finally conclusions were
drawn after comparing and discussing with
similar type of the work carried out by the foreign
and Indian authors.
Results:
During the period of present study total
1712 autopsies were conducted and out of them
289 cases (16.88%) of death due to poisoning
were studied in detail. In all these cases routine
viscera were preserved for chemical analysis,
and the analysis was done at Forensic Science
Laboratory Surat (Gujarat). In present study
gastric lavage was available for chemical
analysis only in 186 cases (64.36%), while in
rest 103 cases (35.64%) it was not available to
send with viscera. In 92.04% cases we received
FSL reports while only in 7.96% cases FSL
reports were not received till the date of this
study. (Table 1)
The analysis of results of FSL reports
shows that when additional sample of gastric
lavage was also sent other than routine viscera
of autopsy the poison was detected by FSL
report in 83.33% cases while it was not detected
only in 9.68% cases and in rest 6.99% cases
FSL reports are not received till the date of this
study. (Table 2) On the other hand when
additional sample of gastric lavage was not sent
with routine viscera, poisoning was confirmed
only in 53.36% cases and not confirmed in
36.9% cases. Analysis of the cases according to
duration of hospital stay shows that as the
duration of hospital stay increases the positivity
of FSL reports were also increasing in cases
where we have sent the additional sample of
gastric lavage with viscera as compared to other
cases where we did not sent it. (Table 3) After
adding lavage sample, the incidences of positive
FSL reports become almost double in cases
where the hospital stay was about 4-7 days and
increased up to almost six times in cases where
the hospital stay was up to more than 7 days.
Discussion:
Diagnosis of death due to poisoning and
detection of specific poison by chemical analysis of
viscera is a routine procedure during the practice
of Forensic Medicine. Vadodara is a city of mid
Gujarat in India and as the chemical factories are
more, it is also known as a ‘chemical city’. Our
institute is a tertiary health center of Gujarat and
we are doing every year around 1800-1900
autopsies in Department of Forensic Medicine.
Failure to detect any poison in the viscera
or other specimen of the individual whose death
was allegedly due to poisoning is not expected
here due to incorrect sampling of fluids and tissues
or their improper preservation, but rather
commonly observed in hospitalized cases where
the patients were treated for few days before the
death. In such cases of false negative viscera
reports, analysis of gastric lavage, blood and
urine samples collected during the treatment
may help us to detect the exact nature of poison
and cause of death.
But similar to other health centers in
India here also the investigations done before
death of the victims are not analyzed with postmortem
investigations, which unable to detect
the exact nature of poison and to confirm the
poisoning as a cause of death in such cases.
On the other hand it also creates an
unwanted legal contradiction in the
circumstances of death as the investigating
agencies believe that results of FSL are reliable
and accurate and performed by a competent
scientific officer, which is an incorrect
presumption, because chemical analysis of
viscera of autopsy has a good specificity and
poor sensitivity as the laboratories use several
methods to screen for toxins and there is no
single, accurate, inexpensive method that
detects all toxins.
There can be other limitations also
because each method differs in cost, accuracy,
complexity, speed and specificity. Problems may
also arise from the changes that occur in the
storage of biological fluids, the transfer of drugs
from tube to tube, and the standards used to test
the particular drugs and poisons. [10] So it is not
wise always to blame the autopsy surgeon for
not able to confirm poisoning as a cause of
death in cases of alleged poisoning.
In present study, to improve the results
of chemical analysis in favor of circumstances of
death we collected ante-mortem samples of
8