Regula Wick

Conditions and circumstances predisposing to death from positional asphyxia in adults

Positional asphyxia refers to a situation where there is compromise of respiration because of splinting of the chest and/or diaphragm preventing normal respiratory excursion, or occlusion of the upper airway due to abnormal positioning of the body. Examination of autopsy files at Forensic Science SA revealed instances where positional asphyxia resulted from inadvertent positioning that compromised respiration due to intoxication, multiple sclerosis, epilepsy, Parkinson disease, Steele-Richardson-Olszewski syndrome, Lafora disease and quadriplegia. While the manner of death was accidental in most cases, in one instance suicide could not be ruled out. We would not exclude the possibility of individuals with significant cardiac disease succumbing to positional asphyxia, as cardiac disease may be either unrelated to the terminal episode or, alternatively, may result in collapse predisposing to positional asphyxia. Victims of positional asphyxia do not extricate themselves from dangerous situations due to impairment of cognitive responses and coordination resulting from intoxication, sedation, neurological diseases, loss of consciousness, physical impairment or physical restraints.

Fatal electrocution in adults--a 30-year study

A retrospective study was undertaken of all cases of death in adults (>16 years) due to electrocution which were autopsied at Forensic Science SA, Adelaide, Australia, over a 30-year period from 1973 to 2002. A total of 96 cases were identified with 87 males (91%) (mean age = 41.6 years; range 17 to 86 years) and nine females (9%) (mean age = 49.2 years; range 20 to 76 years). Deaths were due to accidents in 66 cases (69%; M:F = 63:3), suicides in 28 cases (29%; M:F = 24:4) and homicides in two cases (2%). Both homicide victims were females, with females accounting for only 5% of the accidents and 14% of suicides. The number of accidental deaths increased until the early 1990s and then declined, whereas suicidal electrocutions were only found in the last 20 years of the study. Most deaths (N = 80; 83%) were due to low voltage circuits (<1000 volts), with deaths due to high voltages occurring in 15 cases (16%). One death was due to lightning (1%). While suicides were evenly distributed throughout the year, most accidental deaths occurred in late spring and summer (N = 42; 64%) with the lowest number of accidental deaths occurring in winter and early spring. This report demonstrates a significantly higher rate of electrocution deaths among males, with a summer predominance of accidental deaths, most likely due to increased outdoor activities in better weather. The reduction in cases over the last decade of the study may be a reflection of the success of workplace and domestic safety campaigns. Female electrocution suicides and electrocution homicides were rare events.

Inhalant Deaths in South Australia: A 20-Year Retrospective Autopsy Study

A 20-year retrospective study of inhalant deaths in South Australia, autopsied at Forensic Science SA, was undertaken from January 1983 to December 2002. Thirty-nine cases were identified from an autopsy pool of 18,880 cases, with a male to female ratio of 12:1. Sixty-four percent of the victims (N = 25) died during voluntary inhalation of volatile substances and 28% (N = 11) committed suicide utilizing a volatile substance or gas. The remaining 3 cases involved a workplace accident (N = 1) and 2 cases of autoerotic death where inhalants were being used to augment solitary sexual activity. The mean age of the 28 victims of accidental inhalant death of 21 years (range, 13–45 years) was considerably less than that of the 11 suicide victims of 31.5 years (range, 17–48 years). No homicides were found. Approximately one quarter of the victims were Aboriginal (N = 11), 10 of whom had died as a result of gasoline inhalation (“petrol sniffing”). Other common substances of abuse were aliphatic hydrocarbons such as butane. The study has shown that those most at risk for accidental or suicidal inhalant deaths were young males, with 92% of victims overall being male, and with 77% of victims being under 31 years of age. Gasoline inhalation remains a significant problem in Aboriginal communities in South Australia.

Congenital mesenteric defects and unexpected death-a rare finding at autopsy.

Gastrointestinal causes of sudden and/or unexpected death in the young are uncommon and only rarely involve congenital anomalies of the mesentery. Two cases are reported of unexpected deaths following herniation of intestine through congenital mesenteric defects to illustrate the forensic issues that may arise. Case 1 involves a 2.5-year-old girl who collapsed on arrival to hospital following 18 hours of fever and apparently mildly nonspecific symptoms. Resuscitation was unsuccessful, and at autopsy a segment of gangrenous small intestine was found that had herniated through a congenital mesenteric defect. Case 2 involves a 23-year-old woman with a past history of severe mental and physical disabilities who was found dead in her bed. She had a recent history of mild diarrhea and vomiting, but had not appeared particularly ill. At autopsy the peritoneal cavity was filled with a very dilated and obstructed colon as a result of herniation of a segment of sigmoid colon through a distal small intestinal mesenteric defect. These cases demonstrate that symptoms and signs of intestinal ischemia may not be clearly manifested in early childhood and that developmental delay may also result in older individuals presenting in a nonspecific manner. Although rare, congenital mesenteric abnormalities with compromise of the intestinal vasculature remain a possibility to be considered at autopsy in all cases of unexpected death, despite the lack of a clear history of significant gastrointestinal disturbance. Death may relate to ischemic compromise of either the herniated portion of intestine (as in case 1) or to the stretched intestine bordering the hernial orifice (as in case 2).

Electrocution and the Autopsy

Deaths due to the passage of electric current through the body are most often accidental, although suicides and homicides may occasionally occur. Electrical energy represents electron flow, or current, between two points with different potentials, measured in voltage. The amount of current is determined by the resistance of the conducting material. Electrocutions involving humans may be due to low voltages ( 1000 V), or to lightning. Deaths are caused by a direct effect of current on the heart, resulting in ventricular fibrillation, on respiratory muscles resulting in respiratory paralysis or on the brainstem respiratory centers. Deaths may also be caused by thermal effects of current, or by trauma or drowning associated with exposure to an electrical current, or to multiorgan failure complicating initial injuries. The autopsy assessment of possible electrocution is complicated by the non-specificity and subtlety of lesions. Victims may have classical targetoid electrical burns of the skin with central charring, surrounding pallor and hyperemic rims. There may also be adjacent nodules of burnt keratin due to arcing of current. Victims of lightning strikes may demonstrate the typical ferning pattern of Lichtenberg figures. Conversely, other cases, e.g., electrocutions occurring in water, may have no pathological indicators of electrical injury. For this reason, the investigation of possible electrocution requires careful evaluation of the death scene and assessment of the electrical safety of the building and any electrical equipment that had been used. Meticulous examination of all body surfaces for subtle electrical burns with histological sampling is also required.