Assessment of postmortem blood alcohol concentrations by ethanol levels measured in fluids from putrefactive blisters

It was the aim of the present study to investigate whether the postmortem blood alcohol concentration (BAC) can be assessed by means of ethanol values measured in fluids from putrefactive blisters. Fluids from one or two putrefactive blisters were collected in 45 putrefied corpses (postmortem interval: 3-23 days, graduation of the degree of decomposition into four stages) and compared with femoral vein blood or femoral muscle. Ethanol and so-called putrefactive alcohols were determined in all samples by double GC-measurements. The results were converted to the medium water content of blood of 80%. The investigations revealed a significant correlation between the ethanol values of femoral blood/muscle and putrefactive blister fluid (PBF) (r = 0.725, P < 0.001). With the exception of one case, PBF values of 0.11% or more (n = 11) corresponded to minimum blood/muscle concentrations of 0.085%; PBF values of more than 0.15% (n = 8) corresponded to blood/muscle levels of at least 0.159%. Regression analysis revealed the formula BAC (in %) = 0.785 X ethanol (PBF) +0.011. Relevant concentrations of putrefactive alcohols such as 1- and 2-propanol and l-butanol only occurred in cases with far advanced decomposition. Ethanol levels determined in fluids from different putrefactive blisters of the same body also demonstrated a significant correlation (r = 0.791, P < 0.001). Ethanol concentrations determined in PBF must be judged with caution, but PBF values > 0.15% point to corresponding blood levels with a high degree of probability, at least where advanced putrefaction is excluded.