Suicide by Inhalation of Carbon Monoxide of Car Exhausts Fumes

Carbon monoxide related deaths: A Verona case series. When cooperation becomes compulsory

INTRODUCTION

Carbon monoxide (CO) poisoning is a significant concern in forensic medicine, as it often presents unique challenges in terms of diagnosis, investigation, and determination of the cause of death. CO is a colourless, odourless, and tasteless gas that can be lethal when inhaled in high concentrations. It binds strongly to haemoglobin, forming carboxyhaemoglobin (COHb), which reduces the oxygen-carrying capacity of the blood, leading to tissue hypoxia and ultimately death.

MATERIALS AND METHODS

Circumstantial data, medical history information, autopsy findings, and toxicological analysis results related to 24 CO poisoning cases at the Institute of Legal Medicine in Verona were collected and analysed. The data were examined in an integrated manner to identify correlations and common patterns. A comparison was also made with the data available in the literature.

RESULTS

The male gender was confirmed to be the most frequently involved. COHb levels were found to be less than 50% in 6 cases. Three individuals had concurrent cardiovascular pathologies, while 11 subjects tested positive for various substances, including alcohol, benzodiazepines, and morphine. In most cases, the manner of fatal intoxication was accidental, although 6 suicides and 1 homicide are reported.

CONCLUSIONS

The Verona case series demonstrates that deaths due to CO poisoning require a multidisciplinary approach. The integration of diverse expertise is essential for assessing the manner of death. This approach enables a comprehensive evaluation of the available data, aids in distinguishing between accidental, suicidal, and homicidal deaths, and ensures accurate and reliable forensic conclusions.

The spectrum of presentations of unintentional carbon monoxide poisoning

Carbon monoxide (CO) is an odourless and tasteless gas which can be produced by the incomplete combustion of carbon-containing fuels. Compared to vehicular CO suicides, unintentional cases (excluding those related to fires) are much less common. Increased education surrounding the risks associated with the accumulation of CO in enclosed spaces has contributed to a reduced incidence of unintentional CO poisonings. However, such cases may remain undetected, particularly in domestic and recreational settings where scene findings are often non-specific. The current study of unintentional CO poisonings in South Australia and the Northern Territory, each with a unique climate (Mediterranean and tropical respectively), demonstrated differences in the circumstances of death. Several cases where individuals used carbon-producing fuel sources for heat, both in domestic and vehicular settings and without adequate ventilation, resulted in fatal outcomes. Less common scenarios involved faults in equipment (e.g. a hot water heater), vehicle faults resulting in the accumulation of fatal levels of CO in enclosed spaces, and inadvertent introduction of CO into a diving oxygen supply in a recreational aquatic setting. In ascertaining the cause of death, other considerations include the potential role of underlying chronic cardiovascular and respiratory disease and age which may increase an individual's susceptibility to CO toxicity. Understanding the wide variety of presentations and contributing factors in cases of fatal CO poisoning including consideration of climate-specific differences in domestic and extra-domestic settings may enable improved detection at autopsy.

Characteristics of deaths by suicide in postmortem studies in Brazil: A systematic review and meta-analysis

INTRODUCTION

Suicide is one of the leading causes of death, with a trend for its increase in Brazil in past decades. This study aimed to review the characteristics of suicides in Brazilian postmortem studies.

METHODS

Studies investigating suicide deaths in Brazil, and based on autopsy or psychological autopsy were included. Proportions were pooled across studies with the use of random and fixed effects models.

RESULTS

6777 references were retrieved from six databases (searches up to January, 2023), and 45 studies included. In autopsy studies (k = 37, n = 16,231), substance use at toxicological analysis was found in 36.42% of cases (95% CI: 30.05-43.32), previous suicide attempts in 23.92% (95% CI: 6.73-57.78). In psychological autopsy studies (k = 8, n = 139), previous suicide attempts were reported in 28.09% (95% CI: 19.74-38.28), psychiatric conditions/symptoms in 90.67% (95% CI: 67.79-97.82), family history of suicidality in 21.33% (95% CI: 13.5-32.03). Most suicide deaths were reported in males and took place at the victim's home, hanging was the most frequent suicide method. Included studies presented significant limitations in quality assessment.

CONCLUSION

Future studies should present more robust methodology, including bigger samples, the use of controls, and validated methodology.

An overview of suicides related to motor vehicles

Although vehicles may be used in a wide variety of suicides, this has not been a focus in the forensic literature. Thus, an analysis of coronial autopsy reports at Forensic Science SA, Adelaide, South Australia over a 16-year period from January 2005 to December 2020 was undertaken to provide an overview of cases in which it was considered that a vehicle had been integral to the successful completion of a suicide. De-identified details were collected from all cases in which a vehicle had facilitated or been used as a method of suicide. A number of different types of vehicle-related suicide methods were identified, including cases where vehicles had been used as secure places for suicide or where the vehicle had been used to cause significant blunt force trauma or to enter a lethal environment such as water. Specific examples were taken from the following categories: (1) inhalation of gas, (2) drug toxicity, (3) hanging or ligature strangulation, (4) self-immolation, (5) drowning, (6) vehicle collision, (7) driving off a cliff, (8) jumping or lying in front of a vehicle and (9) the use of more than one method (i.e. complex). This report is not intended to provide an epidemiological analysis of car-related suicides. Instead, the details of selected cases have been used to illustrate the spectrum of methods that may be used in vehicle-assisted suicides.

One image is worth more than a thousand words: producing an atlas of medical signs for teaching clinical and forensic toxicology

Clinical and forensic toxicology are critically involved in the acquisition of basic skills to correctly suspect intoxication, collect biological and non-biological materials for toxicological analysis, comprehend the complexities inherent to laboratory activity, and understand the fundamentals of toxicokinetics and toxicodynamics that underlie the interpretation of results. This works presents a pedagogical innovation proposal for the teaching of clinical and forensic toxicology based on a compilation of more than 3 000 cases where the image was fulcra for suspicion. The experience in this article follows the model practiced in bachelors, masters, and PhD degrees, as well as in other continuing training courses, where we are teaching toxicology for more than 15 years. All these levels of education are considered fundamental to the sound development of this science. This approach aims also to offer strength to the intervention of the true toxicologist in all the toxicological phases, besides the classic analytical chemistry. Indeed, it is impossible to provide effective clinical and forensic toxicological interpretations without a proper and broad education, and not thinking exclusively in terms of laboratory techniques. In the future, it will be interesting to evaluate knowledge retention and to propose a database of videos of signs related to intoxications.

Greenish-blue discoloration of the brain and heart after treatment with methylene blue

Greenish-blue discoloration of the brain and heart was observed during the autopsy of a 63-year-old woman who had been treated with methylene blue for septic shock following a traffic accident. This "pistachio" or "avatar" discoloration occurs when the colorless metabolite leucomethylene blue is oxidized to methylene blue upon exposure to atmospheric oxygen. Other clinically documented adverse effects of methylene blue include greenish-blue urine and bluish discoloration of the skin and mucosa. In medicine, methylene blue is an inhibitor of nitric oxide synthase and guanylate cyclase with different clinical applications, namely, rapid reversal of circulatory shock that is refractory to fluid administration, inotropic agents, and vasoconstrictors. Postmortem differential diagnosis with putrefaction and hydrogen sulfide poisoning should be made, and forensic pathologists should be aware of methylene blue-related greenish-blue discoloration to avoid unnecessary workup and investigations.