Michael J. Shkrum

Fire and Suicide: A Three-Year Study of Self-Immolation Deaths

Thirty-two self-immolation deaths by fire, representing about 1% of suicides, occurred in the province of Ontario (population 9 million), Canada, from 1986 through 1988. The victims, mostly male (male/female ratio, 26:6), were between 21 and 71 years old (mean age, 38 years). Although the scene of self-immolation was usually familiar to the deceased, some chose remote locations. Eleven were found dead in motor vehicles. An accelerant, usually gasoline, was used in most cases. Many of these individuals had, at some time, indicated their intent to commit suicide, a few by self-immolation, but only about half had a diagnosed psychiatric illness. Most of the victims had a reason to kill themselves, but the factors that motivated them to chose self-immolation by fire were uncertain. Fourteen individuals died in hospitals from severe burn complications. The remainder were found dead at the scene. The postmortem findings of soot in the airway and elevated carbon monoxide in the blood of most of these victims [the carboxyhemoglobin (COHb) concentration was in one case less than 10%, in ten cases greater than or equal to 10 to 50%, and in seven cases greater than 50%] were helpful in determining that the individuals were not only alive at the time of the fire but also that a significant number died from smoke inhalation and carbon monoxide poisoning. The highest levels of carbon monoxide were observed in victims discovered in motor vehicles.

Mechanisms of Aortic Injury in Fatalities Occurring in Motor Vehicle Collisions

Case reviews based on autopsy studies have shown that motor vehicle collisions cause between 50 and 90% of traumatic aortic ruptures. Very few studies have analyzed the nature and severity of the collision forces associated with this injury. Our passenger car study (1984-1991) examined 36 collisions in which 39 fatally injured victims sustained aortic trauma. In this injury group, a disproportionate number of heavy truck and roadside fixed-object impacts occurred. Vehicle crash forces were generally severe and were either perpendicular or oblique to the vehicle surface. Intrusion into the occupant compartment was a significant factor in most of these fatal injuries. Occupant contact with vehicle interior surfaces was identified in most cases, and occupant restraints were often ineffective, especially in side collisions. The more elderly victims were seen in the least severe collisions. The most frequent site of aortic rupture was at the isthmus. A majority of victims had rib/sternal fractures indicating significant chest compression. Of the various traumatic aortic injury mechanisms proposed in motor vehicle impacts, the favored theories in the literature combine features of rapid deceleration and chest compression. This study supports that predominant impression, concluding that rapid chest deceleration/compression induces torsional and shearing forces that result in transverse laceration and rupture of the aorta, most commonly in the inherently vulnerable isthmus region.

Contributing Factors to Methadone-Related Deaths in Ontario

To identify factors contributing to methadone-related deaths in Ontario in 2004, demographic factors, methadone blood levels, evidence of concurrent drug use, the source of methadone (prescribed or illicit), and its contribution in exacerbating preexistent disease were studied to identify users at risk for methadone toxicity and death. This retrospective study reviewed postmortem data, autopsy reports, police reports, hospital data, and postmortem toxicological analyses available in the Ontario Chief Coroners Information System. There were 54 cases with methadone detected in postmortem blood samples. Of total, 9 cases were not included in the study because of incomplete documentation. About 11 deaths were due to methadone toxicity alone; 25 deaths were due to combined methadone and other drug toxicity (notably cocaine and alcohol); 7 deaths were due to the exacerbation of a preexisting disease by methadone; 1 death was due to disease alone, and 1 death was due to trauma sustained in a motor vehicle collision. A significant number of methadone-related deaths were due to illicit methadone ingestion, which exceeded the opioid tolerance level. The source of methadone in these cases was unknown. Drug addicts, unaware of the hazard of consuming other illicit or prescription drugs concurrently, are at risk. This study demonstrated that methadone toxicity is enhanced by underlying disease, especially in individuals with underlying cardiac and pulmonary pathology.

Fatal light aircraft accidents in Ontario: a five year study

Fatal civil aviation crashes in Ontario from 1985 to 1989 were studied. Data regarding accident circumstances, injury patterns and medical factors (disease, alcohol/drugs) which could have contributed to accident causation was obtained from a review of the files of the Chief Coroner for Ontario in Toronto and the aviation occurrence reports of the Transportation Safety Board of Canada. Forty-seven crashes involving mainly general aviation type aircraft but also 2 gyroplanes, 2 ultralights and a glider were reviewed. About half occurred during the cruise phase of the flight. Seventy (40 pilots; 30 passengers) of the 98 occupants died. The bodies of 68 victims were recovered; 63 were dead at the scene and 5 survived up to ten hours after impact. Multiple trauma killed about half of all the victims (n = 34); 29% (n = 20) drowned; 16% (n = 11) and 3% (n = 2) died of head/neck injuries and coronary disease respectively. Neck trauma was observed mostly in pilots and was the most frequent major blunt trauma injury in drowning victims. Passengers sustained relatively more craniofacial fractures and abdominal/retroperitoneal trauma. Pilot error was the most frequent cause of crashes (55%; 26/47 impacts) followed by mechanical failure (15%; 7/47) and adverse weather/environmental conditions (11%; 5/47). Coronary artery disease incapacitated two pilots (4% of crashes) and ethanol intoxication was implicated in two other accidents. Other drugs did not appear to be a definite factor in accident causation.

A Comparison of Injuries, Crashes, and Outcomes for Pediatric Rear Occupants in Traffic Motor Vehicle Collisions

BACKGROUND This study was initiated was initiated to describe pediatric rear-occupant motor vehicle collision (MVC) injuries, including injury patterns and outcomes as well as characteristics associated with severe injury to the head and abdomen. METHODS A retrospective cohort of severely injured (Injury Severity Score [ISS] > 12) pediatric (age <18 years) patients involved in a traffic MVC as a rear occupant and treated at one of two Ontario trauma centers (2001–2010) was studied was studied. Demographic, injury, crash and outcome data were obtained from the trauma registries. Data were statistically compared by two pediatric age groups: children (0–8 years; requiring a child or booster seat) versus adolescents (9–17 years; requiring a lap-shoulder belt). RESULTS There were 36 children (34%) and 70 adolescents (66%) severely injured as rear occupants in MVCs. Despite similar ISS (p = 0.716) and mortality rates (p = 0.680) between age groups, there were significant differences in injury patterns and risk factors. Children were more likely to have severe head injuries (78% vs. 39%, p < 0.001) associated with a lack of an age-appropriate child restraints (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.1–10.8; p = 0.029), middle seating (OR, 6.2; 95% CI, 1.5–26.1; p = 0.013), and side-impact crashes (p = 0.007). Adolescents were more likely to have severe abdominal injuries (23% vs. 6%, p < 0.001) associated with the use of lap-shoulder belts (OR, 3.8; 95% CI, 1.1–13.3; p = 0.034), single-vehicle MVCs (p = 0.007), and vehicle extrications (p = 0.035). CONCLUSION While safer than the front seat for children, additional study is needed on the restraint systems and the potential for injury to pediatric rear occupants in an MVC. Our data suggest that pediatric age groups differ in injuries, risk factors, and MVC impacts. Recommendations for improved protection of child occupants and preferred seating positions are required. LEVEL OF EVIDENCE Epidemiologic study, level III.

Commercial Logging Fatalities in Ontario, 1986-1991

Despite the economic importance and hazardous nature of commercial logging in various regions, few medical studies have examined fatalities in this industry. Data derived from the files of the Ontario Chief Coroners Office revealed 52 deaths, all men, from 1986 to 1991 in the province of Ontario. Forty-four cases were accidents (age range 20-73 years; average, 44 years), the majority involving experienced loggers. Personal error resulting in preventable unsafe work practices was a factor in most accidents (n = 35; 79.5%). Almost one half of injured workers were struck by either dead or cut trees. Although the majority of cases occurred in remote areas, delayed medical attention as a factor contributing to death was uncommon. Many of the injuries were nonsurvivable and most victims (n = 33; 75%) were dead at the scene. Most deaths were caused by either head and neck injuries (n = 20; 45.5%), multiple trauma (n = 10; 23%), chest trauma only (n = 6; 13.5%), or mechanical asphyxia (n = 5; 11%). Blood alcohol was negative in 24 accident victims tested. Eight deaths (age range 42-52 years; average, 49 years) were due to cardiac causes, mainly ischemic heart disease. Disease may have contributed to two accidents.

Azygos Vein Laceration Due to Blunt Trauma

The azygos vein ascends along the thoracic spine through the mediastinum and drains into the superior vena cava at the level of the fourth thoracic vertebra. Fracture-dislocation of the mid-thoracic spine, as a result of blunt thoracic trauma, can tear the azygos vein. Four such fatal cases (three motor vehicle accidents and one fall) were studied, only one of which was recognized prior to death. The vein can also be torn, in the absence of skeletal injuries, by horizontal acceleration/deceleration forces. The pathologist must consider azygos vein laceration as a possible cause of either hemothorax or hemomediastinum or both in a victim of a blunt chest trauma, if that individual had persistent hypotension during the few hours before death and no identifiable source of hemorrhage can be found postmortem in sites such as the heart, great vessels, lung, and chest wall. A fracture-dislocation of the thoracic spine may not necessarily be present. Azygos vein laceration seems to be an uncommon cause of hemothorax and hemomediastinum; however, this injury is probably more frequent than is implied by the few cases described in the medical literature.

Skull fractures in fatalities due to motor vehicle collisions.

A retrospective analysis of 89 fatalities with skull fracture resulting from motor vehicle-pedestrian and various single passenger car frontal, side, rear and rollover collisions was done. Passenger compartment intrusion and occupant ejection were responsible for most, but not all, cranial fractures occurring in impacted motor vehicles. Victims of frontal collisions usually were unrestrained; however, a majority of individuals in cars hit by heavy trucks were wearing seatbelts. Vehicles involved in frontal crashes had crush profiles reflecting a barrier equivalent velocity (BEV) of at least 50 km/h (about 30/mph). In side impacts, most ejected occupants were unrestrained, whereas many of those intruded upon were belted. The minimum BEV calculated in these collisions approached 20 km/h (12 mph). The observation of a skull fracture integrated with accident investigation (that is, determination of head contacts) was useful in the reconstruction of various collisions. Skull fracture patterns, as documented by autopsy, reflected certain kinematic trajectories described in motor vehicle-pedestrian frontal collisions.

An Experimental Model of Tool Mark Striations by a Serrated Blade in Human Soft Tissues

AbstractTool mark analysis is a method of matching a weapon with the injury it caused. In a homicidal stabbing using a serrated knife, a stab wound that involves a cartilage may leave striations from the serration points on the blade edge. Assessing tissue striations is a means of identifying the weapon as having a serrated blade. This prospective study examines the possibility that similar striations may be produced in human soft tissues. Using tissues taken at the time of hospital-consented autopsies, stab wound tracks were assessed in a variety of human tissues (aorta, skin, liver, kidney, and cardiac and skeletal muscle). Stab wounds were produced postmortem with similar serrated and smooth-edged blades. The walls of the stab wounds were exposed, documented by photography and cast with dental impression material. Striations were identified by naked-eye examination in the skin and aorta. Photodocumentation of fresh tissue was best achieved in the aorta. Striations were not identified in wound tracks produced by the smooth-edged blade. Three blinded forensic pathologists were assessed for their ability to detect striations in photographs of wound tracks and had substantial interobserver agreement (&kgr; = 0.76) identifying striations. This study demonstrates that tool mark striations can be present in some noncartilaginous human tissues.

Injury Patterns Sustained in Fatal Motor Vehicle Collisions with Driver's Third-Generation Airbag Deployment†

The Office of the Chief Coroner for Ontario database for 2011–2012 was used to compare fatal injury patterns in drivers whose third‐generation airbags deployed compared to first‐ and second‐generation airbag deployments and airbag nondeployments with and without seatbelt use. There were 110 frontal and offset frontal crashes analyzed. The small sample size meant that the odds of craniocerebral, cervical spinal, thoracic, and abdominal injuries were not statistically different for airbag generation, deployment status, and seatbelt use; however, the risk of fatal thoracic injuries in third‐ and second‐generation cases was increased. Seatbelt usage in third‐ and second‐generation deployment cases reduced the risk of all injuries except abdominal trauma. High severity impacts and occupant compartment intrusion were frequently observed. The analyses in this retrospective study were challenged by data that were not collated in a standardized way and were limited in details about scene, vehicle, and driver variables.