GLOBAL MULTI-SITE (SUBCLAVIAN, FEMORAL AND POPLITEAL) AND TIME-DEPENDENT EVALUATION OF POST-MORTEM REDISTRIBUTION OF PSYCHOACTIVE DRUGS: PRELIMINARY RESULTS

Abstract

Post-mortem redistribution (PMR) refers to the site and
time-dependent blood drug concentration variations
occurring after death.
Our study aimed to compare central blood concentration
(subclavian site) with peripheral blood concentration
(femoral and popliteal sites) of selected psychoactive substances. Time-dependent variation of blood concentration
is also assessed by means of two methods.
To our knowledge, popliteal blood concentration has
never been compared with other sites before.
In this preliminary study, there were 23 cases divided in
2 groups: a general group in which central (subclavian)
and femoral blood was drawn, and a group labelled
popliteal in which an additional blood sample was
obtained from the popliteal vein. Each group was also
divided in 2 subgroups, one with only one sample and
the other with a second sample taken from the same case
at a later time.
The targeted substances were diazepam and metabolites,
methadone and metabolite and morphine and metabolites.
For each substance, mean concentration ratios were
calculated as follows: [subclavian]/[femoral] in the
general group and [subclavian]/[femoral], [subclavian]/[popliteal] and [femoral]/[popliteal] in the
popliteal group.
In the cases sampled only once, correlations between
concentration ratios and estimated post-mortem interval
were obtained for each substance.
In those cases sampled a second time after a time interval, correlations between concentration difference ratios
(and concentration differences) and precise time interval
elapsed between samples No. 1 and No. 2 were obtained
for each substance.
The results indicate that the popliteal sample site appears
to be less subject to PMR as seen in the concentration
ratios in the group with popliteal sampling.
Cases sampled only once, as well as those sampled a
second time, when correlated with the post-mortem
interval, show that the latter did not have significant
influence on concentration ratios, concentration difference ratios or concentration differences.