BLOOD ALCOHOL CONTENT: corpses

It is widely accepted that the decomposing bodies of animals and humans produce a variety of alcohol byproducts as they undergo putrefaction, including ethanol, the manufactured alcohol typically found in intoxicants. This natural process of decay can often serve to confound coroners who, through reliance on standard BAC test applications, are hoping to achieve a foolproof shortcut to determining the exact amount of alcohol a person had consumed antemortem and how intoxicated they actually were at the moment of death. Bodies immersed in water for a period of time further add to the dilemma of establishing accurate BAC levels in corpses because immersion can cause major spikes in blood/alcohol concentrations. The following accredited medical resources will help to define the role putrefaction plays in postmortem alcohol, the origins of alcohol production in the dead, and preferred methods for toxicology testing of decomposing and waterlogged cadavers. 

 

 

CITATIONS & SOURCES: 

 

1. Post-mortem Production of Alcohol, by Dr Shelley Robertson MBBS, LLB, FRCPA, DMJ, FACLM, DAvMed, MHealSc (AvMed) [Extracts of report explaining the nature of alcohol production in decomposing corpses and the pitfalls of conducting accurate BAC tests on bodies of the dead]

“It is known that micro-organisms involved in the process of putrefaction after death can produce alcohol, usually a mixture of ethanol and other volatile substances. This process occurs when a body is not refrigerated soon after death and is hastened by environmental conditions such as high temperatures and when the body has been traumatized.

“Micro-organisms such as yeasts and bacteria are capable of producing alcohol from glucose (sugar) in the process of fermentation. This does not only occur when yeasts are deliberately introduced into the alcohol manufacturing process. They can produce alcohol whenever environmental conditions sustain their activity, and suitable substrates (e.g. glucose) are present. A deceased body may provide ideal conditions for microorganisms to flourish.

“Alcohol production by micro-organisms has been demonstrated in animals and humans. In one study, various groups of bacteria were isolated from deceased tissue, then inoculated into blood and the amount of alcohol produced was measured. In general, it has been shown that micro-organisms can produce alcohol in deceased bodies and that this process occurs within a few days of death, when an unpreserved body is stored at room temperature (~20-250C) and more rapidly at higher ambient temperatures.

“The alcohol produced by micro-organisms is usually not pure ethanol. A number of volatile products including alcohols may be produced. These include butanol, 2-propanol, acetone, methanol, 1-propanol.

“Post-mortem diffusion of ethanol across the gastric or bowel wall can occur in intact and disrupted bodies…It is usually not a problem in at least the first 24-48 hours following death. As the post-mortem interval increases, so does the likelihood of endogenous alcohol production by microorganisms, particularly when environmental temperatures are high and the body has been traumatized.

“It is difficult to state with any certainty, the time period after death at which post-mortem alcohol production commences. It is also difficult to state with certainty, the time interval after death when post-mortem alcohol production has occurred to a significant degree and is contributing to measured alcohol levels. The reason for this uncertainty is the large numbers of variable factors which affect the process. These include environmental conditions, particularly temperature, airflow and humidity, the state of the body (e.g. intact or traumatized, burnt or immersed), body size and presence of clothing. The state of health of the deceased during life is also a factor.

“When alcohol is produced postmortem by micro-organisms, the resultant compound is usually not pure ethanol. This is in contrast to ingested alcohol which usually consists solely of ethanol. It follows then, that if volatile substances other than ethanol are present in autopsy samples, the likelihood is that endogenous production of alcohol has taken place.…there will be cases where valid interpretation of toxicological analysis is not possible, either due to absolute unavailability of specimens (e.g. body not located, extent of trauma) or total unsuitability of specimens (charred remains or advanced decomposition). In these cases, it is important not to make speculative assessments of ethanol ingestion.”

Fair Usage Excerpts from Robertson's “INTERPRETATION OF MEASURED ALCOHOL LEVELS IN FATAL AVIATION ACCIDENT VICTIMS”

 

2. American Journal of Forensic Medicine and Pathology: Postmortem Production of Ethanol and Factors that Influence Interpretation, A Critical Review, by O'Neal, Carol L. M.F.S.; Poklis, Alphonse Ph.D. March 1996 - Volume 17 - Issue 1 - pp 8-20 Article:

Abstract: “Ethanol analysis is the most frequently performed assay in forensic toxicology laboratories. Interpretation of postmortem ethanol findings are often confounded by postmortem production of ethanol. Many species of bacteria, yeast, and molds are capable of producing ethanol from a variety of substrates. The probability of postmortem ethanol synthesis increases as storage temperature and the interval between death and autopsy increases. It is often difficult to distinguish between postmortem ethanol production and antemortem alcohol ingestion. This review presents a discussion of the criteria for the identification of postmortem ethanol synthesis and factors to consider in the interpretation of postmortem ethanol findings. The criteria include case history, condition of the specimens, types of microbes present, atypical fluid and tissue distribution of ethanol, the concentration of ethanol present, and the detection of other alcohols and volatiles. With careful consideration of all the information available, a valid interpretation of the source of ethanol, whether it be from antemortem ingestion or postmortem production, can be made.” © Lippincott-Raven Publishers

 

3. Forensic Pathology, Second Edition, by Vincent Joseph M. Di Maio, Dominick J. Di Maio (Extract of report explaining to medical examiners why the Vitreous Humor of the eye is the most stable organ in a decomposing body to test for BAC levels )

“If the individual stops drinking, their blood alcohol will continue to rise for a short time as absorption continues, plateaus, and then begins to go down. Vitreous alcohol, which lags behind blood alcohol, will continue to rise as the blood alcohol plateaus. The vitreous alcohol then plateaus and begins to decline. At the point of equilibration of blood and vitreous, the vitreous alcohol will be higher numerically because of the greater amount of water in the vitreous. This constant ratio of 1.2 to 1 will continue as the vitreous alcohol declines following the decline in the blood alcohol. Thus, only in the absorptive phase will vitreous alcohol be lower than blood alcohol. After vitreous, the next best tissue to analyze for alcohol is muscle.”

 

4. National Study Centre for Trauma and EMS, School of Medicine, University of Maryland, 701 West Pratt Street, 5th Floor, Baltimore, MD 21201, USA. (Study conducted by NSC UofM which cautions medical examiners about acceleration of alcohol production in submerged corpses and how this causes spikes in BAC levels) 

Abstract: "Endogenous alcohol production can increase the blood alcohol concentration (BAC) of drowning victims following submersion and confound epidemiological studies of the role of alcohol. This study seeks to determine how soon after a drowning death a victim's BAC is influenced by post-mortem alcohol production. The drop in mean lung weight that occurs over time in the water was hypothesized to serve as a proxy for the time course of decomposition, and thus provide an empirical measure to determine how soon after death to first suspect endogenous alcohol. The autopsy lung weights of 562 previously healthy males who drowned were compared across six submersion time groups (0-11.9, 12-23.9, 24-47.9, 48-95.9, 96-167.9 and >or=168 h) and two times of year (winter and non-winter). The hypothesis that a drop in lung weight is sensitive to the time course of decomposition was supported by (1). a statistically significant drop in mean lung weight that occurred 12-23.9 h post-submersion in the non-winter months, but not until 96-167.9 h in the colder winter months; and (2). a significant drop in lung weight was not observed in the group of cases with zero BAC. With a parallel finding that an increase in the proportion of cases with a positive BAC first occurred at the 12-23.9 h submersion group during the warmer non-winter months, we concluded that production of alcohol can occur in bodies recovered from the water as early as 12 h after death. Because excluding drownings with submersion durations greater than 12 h would exclude almost half of our cases from epidemiological studies of alcohol and drowning, additional evidence from the forensic literature was used to develop an adjustment procedure to account for endogenous alcohol production for submersion times of up to 1 week." PMID:12850077 [PubMed - indexed for MEDLINE]

5. Department of Forensic Medicine, Karolinska Institutet, SE-171 77 Stockholm, Sweden (Report cautioning medical examiners of the spike in production of alcohol in decomposing bodies and cross contamination into organ systems other than the eyeball with emphasis that "Bodies recovered from water are particluarly problematic" because of the "enhanced  risk of microbial synthesis of ethanol.")

Abstract: "We searched the scientific literature for articles dealing with postmortem aspects of ethanol and problems associated with making a correct interpretation of the results. A person's blood-alcohol concentration (BAC) and state of inebriation at the time of death is not always easy to establish owing to various postmortem artifacts. The possibility of alcohol being produced in the body after death, e.g. via microbial contamination and fermentation is a recurring issue in routine casework. If ethanol remains unabsorbed in the stomach at the time of death, this raises the possibility of continued local diffusion into surrounding tissues and central blood after death. Skull trauma often renders a person unconscious for several hours before death, during which time the BAC continues to decrease owing to metabolism in the liver. Under these circumstances blood from an intracerebral or subdural clot is a useful specimen for determination of ethanol.

"Bodies recovered from water are particular problematic to deal with owing to possible dilution of body fluids, decomposition, and enhanced risk of microbial synthesis of ethanol. The relationship between blood and urine-ethanol concentrations has been extensively investigated in autopsy specimens and the urine/blood concentration ratio might give a clue about the stage of alcohol absorption and distribution at the time of death. Owing to extensive abdominal trauma in aviation disasters (e.g. rupture of the viscera), interpretation of BAC in autopsy specimens from the pilot and crew is highly contentious and great care is needed to reach valid conclusions.

"Vitreous humor is strongly recommended as a body fluid for determination of ethanol in postmortem toxicology to help establish whether the deceased had consumed ethanol before death. Less common autopsy specimens submitted for analysis include bile, bone marrow, brain, testicle, muscle tissue, liver, synovial and cerebrospinal fluids. Some investigators recommend measuring the water content of autopsy blood and if necessary correcting the concentration of ethanol to a mean value of 80% w/w, which corresponds to fresh whole blood. Alcoholics often die at home with zero or low BAC and nothing more remarkable at autopsy than a fatty liver. Increasing evidence suggests that such deaths might be caused by a pronounced ketoacidosis. Recent research has focused on developing various biochemical tests or markers of postmortem synthesis of ethanol. These include the urinary metabolites of serotonin and non-oxidative metabolites of ethanol, such as ethyl glucuronide, phosphatidylethanol and fatty acid ethyl esters. This literature review will hopefully be a good starting point for those who are contemplating a fresh investigation into some aspect of postmortem alcohol analysis and toxicology." PMID: 16782292 [PubMed - indexed for MEDLINE]

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