Carboxyhemoglobin blood concentrations in suicides by fire

Problems associated with the diagnosis of vitality in burned bodies

The most important signs of vitality in burned bodies are soot deposits in the respiratory tract, the esophagus and the stomach as well as elevated CO-Hb values in the blood. But these findings show only that a person was exposed to fire fumes while alive; they are no indicator for vital heat exposure. As the external findings in burned bodies are often not very conclusive due to postmortem consumption by the fire, the internal findings are all the more important. Macroscopic signs that hot fumes were inhaled may be edematous swelling and vesicular detachment of the mucosa in the pharynx, the larynx and/or the upper section of the esophagus. As histological changes in the respiratory tract soot deposits, vesicular detachment of the epithelium, hyperemia and edema of the tracheal and bronchial mucosa as well as increased secretion of mucus have been described. These findings may partly be absent although the victim was alive during the fire, which can make diagnosis more difficult. Especially in peracute deaths vitality findings are usually sparse. The significance of the macroscopic and histological parameters of vitality was systematically investigated on the basis of our own autopsy material from the years 1996-2002 (88 cases) and compared with the statements found in the literature. In our study material, the vitality parameters were incomplete in 23% of the burned corpses. In 3% of the cases the question whether there was an antemortem heat exposure could not be answered.

Suicide by self-immolation in Durban, South Africa: a five-year retrospective review

Self-immolation is an uncommon method of suicide, and its occurrence in South Africa is thus far unknown. This study aimed to determine the prevalence of self-immolation deaths and to establish a profile of these cases and the circumstances under which this condition occurs. A 5-year (1996-2000) retrospective review at a mortuary in Durban, South Africa, was conducted. Data were obtained from the Department of Forensic Medicine, the Medical Research Council's National Injury Mortality Surveillance System, and police and hospital records. During the study period, there were 12339 nonnatural deaths, of which 696 (5.6%) were suicides. Self-immolation accounted for 69 (0.6%) of all nonnatural deaths and 69 (9.9%) of all suicides. The subjects had a mean age of 31.2 years and were predominantly female (76.8%) and black (81.2%). The mean burn surface area was 63.3%, and the mean injury severity score was 36.9. Accelerant use was documented in 53 (76.8%) of cases, and paraffin was preferred. All cases occurred indoors. The proportion of suicides due to self-immolation in our study is excessive when compared with international studies that report figures between 0.9% and 2.2% of suicides. Additional studies are necessary to further elucidate the reasons for this discrepancy.

Death from thermal effects and burns

One hundred and fifteen unselected autopsy cases of death from thermal effects and/or fire between 1990 and 1999 were analyzed with regard to time of death, signs of vitality at the scene of the fire, the manner and cause of death, and the extent of soft tissue loss. The cases represented approximately 6% of all autopsy cases at the Institute of Legal Medicine responsible for a catchment area with approximately 700,000 inhabitants. In 23 victims suffering burn injuries, death occurred during initial medical care or clinical treatment. The causes of death were primary respiratory arrest due to smoke poisoning or delayed shock caused by thermal injuries to the skin. Death occurred at the scene of the fatal event in 85 cases: eight cases exhibited no thermal effects; the cause of death in one of these cases was polytrauma incurred in a leap from a height; in seven cases there was poisoning due to smoke inhalation. The remaining 77 cases were characterized by signs of intensive thermal and/or fire effects. Clear signs of vitality (carboxyhemoglobin (COHb) in blood, inhalation and/or swallowing of soot) were found in 84.7% of the victims dying at the site of the fatal event. Of the 13 victims showing no signs of vitality at the scene, a cause of death could be determined in only seven cases; death in the other six cases remains unexplained. Quantification of the soft tissue loss revealed a possible correlation with the temperature and time course of heat exposure.