Site-, Technique-, and Time-Related Aspects of the Postmortem Redistribution of Diazepam, Methadone, Morphine, and their Metabolites: Interest of Popliteal Vein Blood Sampling.

Sampling site, technique, and time influence postmortem drug concentrations. In 57 cases, we studied drug concentration differences as follows: subclavian vein-dissection/clamping versus blind stick, femoral vein-dissection/clamping versus blind stick, right cardiac chamber, and popliteal vein-dissection and clamping only. Cases were distributed in group #1 (all cases with both techniques), group #2 (dissection/clamping), and group #3 (blind stick). Sampled drugs were diazepam, methadone, morphine, and their metabolites. To assess PMR, mean concentrations and ratios were calculated for each group. Time-dependent variations of blood concentrations and ratios were also assessed. Results indicate that site, method, and time may influence postmortem distribution interpretation in different ways. Popliteal blood seems less subject to PMR. In conclusion, our study is the first to evaluate concurrently three main aspects of PMR and confirms that the popliteal vein may represent a site that is more resistant to the changes seen as a result of PMR.

Popliteal Vein Blood Sampling and the Postmortem Redistribution of Diazepam, Methadone, and Morphine.

Postmortem redistribution (PMR) refers to the site- and time-related blood drug concentration variations after death. We compared central blood (cardiac and subclavian) with peripheral blood (femoral and popliteal) concentrations of diazepam, methadone, and morphine. To our knowledge, popliteal blood has never been compared with other sites. Intracardiac blood (ICB), subclavian blood (SB), femoral blood (FB), and popliteal blood (PB) were sampled in 30 cases. To assess PMR, mean concentrations and ratios were compared. Influence of postmortem interval on mean ratios was also assessed. Results show that popliteal mean concentrations were lower than those for other sites for all three drugs, even lower than femoral blood; mean ratios suggested that the popliteal site was less subject to PMR, and estimated postmortem interval did not influence ratios except for diazepam and methadone FB/PB. In conclusion, our study is the first to explore the popliteal site and suggests that popliteal blood is less prone to postmortem redistribution.

Postmortem Concentration and Redistribution of Diazepam, Methadone, and Morphine with Subclavian and Femoral Vein Dissection/Clamping.

Postmortem redistribution (PMR) concerns blood drug concentration variations after death, depending on many factors such as sampling site and technique. In our study, we focused on sampling method. 30 cases were sampled, each at cardiac, subclavian, femoral, and popliteal sites. Targeted substances were diazepam, methadone, and morphine. Blind stick and dissection/clamping techniques were concomitantly performed at subclavian and femoral sites. Subclavian and femoral concentrations were compared according to technique used. To assess the influence of sampling technique on PMR, central/peripheral ratios were calculated depending on sampling method. Results show that drug concentrations tend to be lower when drawn from a clamped subclavian or femoral vein whereas ratios including subclavian and/or femoral blood concentration are influenced according to the technique used. In conclusion, clamping a subclavian or femoral vessel before sampling tends to result in lower drug concentrations and may influence ratios, suggesting the importance of isolating vessels from thoraco-abdominal viscera.