Abstract
Post-mortem redistribution may contribute to changes in blood alcohol concentration, rendering questionable results in a court of law. Two experimental approaches using Wistar rats and human plasma were developed to improve the reliability of femoral blood in post-mortem alcohol analyses. First, rats were administrated with ethanol (0.6 g/kg, p.o) and 30 min later were euthanized by exposure to CO2. After perimortem cardiac blood sampling, samples of blood, liver and lung were collected 6, 12 and 24 h post-mortem in order to measure alcohol concentration, water content and haematocrit. Plasma from human corpses obtained from central and peripheral blood was supplemented with ethanol and afterwards incubated at 37 °C. The animal model revealed a significant decrease of both blood alcohol concentration and water content. Moreover, significant differences between central and peripheral sites were observed in human blood autolysis markers, revealing an exacerbation of haemolysis, which in turn affected alcohol stability by the oxidation of alcohol to acetaldehyde. Our study confirmed that both dehydration and autolysis of blood exacerbate alcohol diminution in the central blood in the first six hours after death. This study reinforces the suitability of femoral blood over central blood for ethanol analyses.
Acknowledgements
We are extremely grateful to Dr Jerome Niquet who kindly edited this manuscript and Mr Felipe Loyo-Ramos for their excellent technical assistance. J. Martínez-Quiroz acknowledges Conacyt Doctoral Scholarship register number 174769. The sponsor did not participate in the study design, data collection, data analysis, interpretation of the data, writing of the manuscript, or decision to submit the paper for publication.