• Energy Research

The blood alcohol concentration (BAC) is the most frequent determination in a Forensic Toxicology Laboratory. Despite its apparent simplicity, the results interpretation can be complex and always have relevant social and legal implications, particularly in postmortem analysis. In the present report we describe the case of a 55-year-old male with an apparent natural death by myocardial infarction, whose initial BAC was 0.18g/L but, in repeated determinations prompted by discrepancies observed in the first two, it rapidly increased to 0.85g/L three days later, leading to the suspicion of in vitro ethanol production. A microbiological examination of the sample revealed the presence of the bacteria Escherichia coli and Enterococcus faecalis, and yeast Candida parapsilosis, known for their involvement in ethanol production. Although this is a case report and it is not meant to be generalizable, we discuss an existing large body of scientific literature showing the difficulties, limitations and some relevant medico-legal questions regarding BAC determinations in postmortem samples and their interpretation, particularly in the context of plausible in vitro ethanol production. The key conclusion is that evaluating a postmortem BAC is a complex and multifactorial process that always deserves a thorough analysis and a careful interpretation.

This study presents the prevalence of ethanol and illicit drugs in fatal road traffic accident victims in the Centre of Portugal between January 1990 and December 2007. Among the violent deaths, road traffic accidents presented the highest percentage (around 35%; n=3095), but decreasing throughout the years. Accidents were preponderant in males (about 80%; n=2402), between 21 and 30 years-old. Accidents involving drivers (55%; n=1310) were of the most common, being the car the main vehicle (45%), followed by the motorcycle (40%). An alcohol analysis request was present in 50% of the cases (n=1687), but increasing each year. Ethanol concentrations >1.2g/L, the legal limit in Portugal, were found in 55% (n=283) of the cases. Concerning drugs of abuse requests, only 4.4% (n=137) and 17.3% (58 cases) of the cases included the analysis at the Forensic Pathology Department (FPD) and at the Medico-Legal Office (MLO), respectively. Among the road accident cases analysed, 18 were positive, mainly in men (84%), between 21 and 30 years-old; opiates (47.1%; n=8) and cannabinoids (50%; n=4) were the most found, at the FPD and at the MLO, respectively. In conclusion, ethanol was identified as a key factor to traffic accidents, which explains the definition of specific legislation and methods of enforcement to prohibit this form of impairing. Nevertheless, ethanol still remains the psychoactive substance most frequently identified in the blood of divers killed in road-traffic crashes, recommending additional actions of supervision and control.

Pentobarbital is a barbiturate, acting as a central nervous system depressant (CNS), being used for its anticonvulsant, sedative, hypnotic and anaesthetic properties. Barbiturates were replaced by benzodiazepines, leading to a decrease in poisoning cases with these compounds. However, pentobarbital is still used in many countries as an anaesthetic in veterinary medicine. Due to its properties, this compound is sought after by people who wish to commit suicide, acquiring it on the black market. The authors present an unusual fatal pentobarbital intoxication case, in a 37 years-old male salesperson, with no known connection with the veterinary field, being more difficult to obtain this compound. Toxicological results in cardiac blood revealed the presence of pentobarbital (111mg/L), ethanol (0.94g/L), diazepam (33ng/mL), nordiazepam (50ng/mL), oxazepam (3.3ng/mL), temazepam (5.3ng/mL), and metoclopramide. No illicit drugs were detected. Pentobarbital analysis in urine and gastric content was also positive, as well as its presence in the glass powder and in the bottle residue sent to the laboratory. In the present case, it was possible to conclude that the death was a suicide due to pentobarbital intoxication in association with other depressants of the CNS (benzodiazepines and ethanol). It is important to search pentobarbital in routine toxicological analyses, since it is one of the drugs most frequently mentioned by entities defending "painless death", advising the simultaneous use of metoclopramide for emesis avoidance.