Atherosclerotic and Hypertensive Cardiovascular Disease are Associated with Death at Sublethal Carboxyhemoglobin Levels: A Postmortem Study

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.

Analyses of physical factors that contribute to the blood carboxyhemoglobin saturation in autopsy cases of house fire fatalities

The authors analyzed data from forensic autopsies of 75 patients who died as a result of house fires to clarify the physical factors that affect blood carboxyhemoglobin (COHb) saturation. Blood COHb saturation levels were significantly lower in patients who survived in the hospital. No significant differences were found in the blood COHb saturation levels between patients who died immediately at the scene and those who were pronounced dead at the receiving hospital without heartbeat being restored. The COHb saturation levels were significantly different among the groups of patients classified by the amount of soot. Although age, coronary artery stenosis, and blood alcohol concentration did not significantly affect blood COHb saturation, on comparing patients who died in the same fire, lower COHb saturation was observed in two patients, one with severe coronary artery stenosis and other with severe alcohol intoxication. To accurately interpret blood COHb saturation during forensic autopsy, the heartbeat status (present or absent) at the time of the rescue and the amount of soot in the trachea must be determined. Low levels of COHb saturation may be observed in fatalities with severe coronary atherosclerosis or severe alcohol intoxication.

Medical Examiner Review of the Characteristics of Fire-Related Homicides

While fire-related deaths are regularly encountered by medical examiners, fire-related homicides are relatively uncommon. Although some large retrospective studies of fire-related deaths have been performed, few large studies have specifically reviewed fire-related homicides. Autopsy, scene investigation, and ancillary studies were reviewed for 38 fire-related homicides evaluated at the Wayne County Medical Examiner's Office in Detroit, Michigan. The largest proportion of cases were inhalation-related deaths in dwelling fires (n = 21, 55%), followed by deaths from thermal injury after immolation (n = 8, 21%) and traumatic death with contemporaneous or subsequent immolation (n = 8, 21%). There was one case of postmortem immolation. Although carboxyhemoglobin (COHb) levels played a significant role in evaluation of these cases, no single factor was diagnostic of a particular cause or manner of death. Fire-related homicides present unique diagnostic challenges because multiple insults frequently contribute to the cause death. Death at the scene and COHb level above 10% are the most useful factors in establishing smoke and soot inhalation as the cause of death. Some autopsy findings are helpful in establishing or ruling out smoke and soot inhalation as contributing to or sole cause of death, but an evaluation of the entire circumstances and autopsy findings is necessary.