Insights into the Origin of Postmortem Ethanol

Abstract

Accurate interpretation of the blood ethanol (EtOH) concentration at the time of death presents a difficult task since the origin of detected EtOH in postmortem cases (either in corpses or in specimens after sample collection) may vary. Headspace gas chromatography is the choice method for detecting EtOH in blood or other specimens, due to the accuracy and sensitivity it provides. Possible sources of postmortem EtOH have been the ante-mortem ingestion, the ante-mortem endogenous production and the postmortem microbial neo-formation, which has been considered the most critical factor that could complicate the results. It has been reported that EtOH could be formed postmortem in variable and non-predictable amounts, as a function of the type and number of microorganisms present either in corpses or specimens collected at autopsy. The presence of other volatiles-mostly n-propanol-has been correlated to microbial EtOH production, although the quantitative pattern between them and EtOH still remains obscure. The factors most frequently implicated in the mechanism of postmortem EtOH production in corpses have been considered the number and nature of microbes present, the availability of various types of substrates, the temperature and the time. Complication in the interpretation of blood alcohol concentration could arise due to the atypical distribution of EtOH in the body compartments after death. Specimens to blood EtOH ratios reported in the literature are presented. All the aforementioned aspects are discussed in a comprehensive way, providing a deep insight into this essential problem.

Biochemical pathways generating post-mortem volatile compounds co-detected during forensic ethanol analyses

“…It looks likely that these volatiles predominate between all the possible volatiles that could be formed postmortem and actually are formed. It is worth mentioning that the presence of volatiles in post-mortem specimen has been included among the criteria that could specify the origin of post-mortem ethanol [1,20]. More specifically, they have been considered as biochemical markers in order for a post-mortem specimen to be flagged as suspicious for microbial contamination, if present in abnormally high concentrations [19].…”

Ethanol production by Candida albicans in postmortem human blood samples: Effects of blood glucose level and dilution

“…Some forensic pathologists look on n-propanol as an index of putrefaction. Nanikawa et al [1] concluded that the amount of ethanol production post mortem is 20 times higher than that of npropanol, whereas other forensic pathologists consider that there is currently no reliable standard of interpretation of postmortem ethanol production [2,3]. We encountered two cases in which the ethanol concentration of blood samples taken post mortem increased with time, with no remarkable increase in n-propanol concentration.…”

Epidemiology of alcohol-related unintentional drowning: is post-mortem ethanol production a real challenge?

“…n-propanol) and of ethanol metabolites (e.g. glucuronide), as well as including bacterial culture, molecular analysis, and fermentation test to identify micro-organism capable of producing PM ethanol (Vuori et al 1983 ; Moriya and Hashimoto 2004 ; Ziavrou et al 2005 ).…”