Difficulties associated with the interpretation of post-mortem toxicology.

While post-mortem (PM) toxicology results provide valuable information towards ascertaining both the cause and manner of death in coronial cases, there are also significant difficulties associated with the interpretation of PM drug levels. Such difficulties are influenced by several pharmacokinetic and pharmacodynamic factors including PM redistribution, diffusion, site-to-site variability in drug levels, different drug properties and metabolism, bacterial activity, genetic polymorphisms, tolerance, resuscitation efforts, underlying conditions and the toxicity profile of cases (i.e. single- or mixed-drug toxicity). A large body of research has been dedicated to better understanding and even quantifying the influence of these factors on PM drug levels. For example, several investigative matrices have been developed as potential indicators of PM redistribution, but they have limited practical value. Reference tables of clinically relevant therapeutic, toxic and potentially fatal drug concentrations have also been compiled, but these unfortunately do not provide reliable reference values for PM toxicology. More recent research has focussed on developing databases of peripheral PM drug levels for a variety of case-types to increase transferability to real-life cases and improve interpretations. Changes to drug levels after death are inevitable and unavoidable. As such, guidelines and practices will continue to evolve as we further our understanding of such phenomena.

Recent trends in an uncommon method of carbon monoxide suicide.

PURPOSE: The most prevalent method of carbon monoxide (CO) suicide is inhalation of vehicle exhaust (VE). However, a new method of CO suicide has recently emerged involving charcoal burning (CB) in a confined space to produce fatal CO levels. This method has been reported from countries in Asia, associated with economic instability and media reporting of high-profile celebrity cases. The current study was undertaken to analyze rates and characteristics of CB suicides in South Australia (SA) for comparison with respect to their characteristics and scene, autopsy and toxicology findings. METHODS: A search was undertaken for all intentional fatal carbon monoxide poisonings in SA between 2000 and 2019. Collected variables included age, sex, cause of death, location of death, decedent histories, scene, autopsy and toxicology findings and manner of death. Statistical analyses were performed using R (version 4.2.3). RESULTS: There was a significant decrease in VE suicides (p < 0.05) and a significant increase in CB suicides (p < 0.001) over the 20-year period. Those who used CB were found to be, on average, between 1.5 and 15.8 years younger than those who used VE (p = 0.017). The risk factors for CB suicide included psychological/psychiatric conditions and financial problems, while VE suicides were associated with a history of physical problems and contact with the legal system. External and internal autopsy findings were consistent with the literature. CONCLUSION: CB suicide is perceived to be widely accessible and painless and is therefore becoming a popular suicide method. Monitoring future trends will be important to determine whether intervention is required.

Increased incidence of mixed drug toxicity deaths involving tapentadol - A forensic study.

Tapentadol is a relatively new synthetic opioid analgesic prescribed for the management of moderate to severe pain. While tapentadol has been shown to be more effective than traditional opioid analgesics, it still carries the risk of addiction, abuse, and misuse. In Australia, tapentadol has become one of the top five most commonly prescribed opioid drugs, with prescriptions increasing by approximately 150,000 each year since it first became available. The rapid increase in tapentadol prescriptions has occurred in parallel to an increasing number of post-mortem tapentadol detections in South Australia (SA). While the number of deaths in SA related to tapentadol use was low in the current study, findings suggest that an increasing trend of deaths involving tapentadol will continue in parallel to a rapidly increasing number of prescriptions, mirroring trends associated with traditional opioids in SA. As a comparatively new opioid analgesic, monitoring future trends will be important to determine if additional prescribing education, intervention, or restrictions are required.

Prescribed and Diverted Methadone Toxicity in South Australia: An Update.

ABSTRACT: Methadone is one of the most common medications currently prescribed for the treatment of opioid use disorders (OUDs). While methadone maintenance programs (MMPs) have been highly successful in the management and treatment of OUDs resulting in a reduced number of fatalities, the risk of overdose/toxicity remains. The current study was undertaken to analyze trends in overdoses attributed to prescribed and diverted methadone in South Australia (SA) between 2000 and 2019. Over the 20-year period, 344 methadone-related deaths occurred in SA with a significant increase in deaths over the study period ( P = 0.03). The mean age of decedents was 42.5 years with a male to female ratio of 1.8:1, with approximately 20% of decedents enrolled in a MMP at the time of death. Overall, only 5.2% of cases demonstrated methadone diversion, which was associated with methadone prescribed for chronic pain and was most likely to be diverted from a friend/housemate or a partner. However, the source of methadone in more than half of cases was unknown, so this is likely a significant underestimate of actual MMP methadone diversion and total methadone diversion.

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.

Socioeconomic and psychosocial determinants of substance misuse - a national perspective.

Accurate estimates of population drug use and an understanding of the factors that influence substance choice are essential for the development of appropriate and targeted prevention strategies and campaigns. This review aims to provide an overview of the socioeconomic and psychosocial factors that influence substance use patterns within the Australian population through exploration of current and historical examples of substance misuse. Australia's comparatively large online drug market is reflective of the country's relative geographic isolation and high local drug prices. Legislation, particularly relating to cannabis cultivation and personal use, has evolved significantly in response to increased scientific and commercial applications and changing attitudes towards medical and personal use. Methylamphetamine use is disproportionately high, attributed to Australia's geographic location, high rates of local manufacture, steady cost, and increased purity. Despite the increased cost of cocaine over time, the profile of users appears to dictate rates of use. The prevalence of injecting drug use is driven by a lack of education, perceived risk, stigma, and other social factors. Additionally, psychosocial factors also contribute to substance misuse among specific population subgroups such as petrol sniffing among Indigenous Australians. Understanding the reasons for geographical variability in illicit drug use assists in the interpretation of substance-associated behavior in specific groups/populations and in guiding future intervention efforts and predictions of emerging trends. In addition, an understanding of factors influencing local drug usage may assist forensic practitioners in evaluating the occurrence and effects of particular substances that may emerge as significant factors in drug-related deaths.

Features of fatal pesticide ingestion in South Australia.

Pesticides are used to kill, repel or control any animal or plant species which are considered pests, but have also been associated with intentional and unintentional human fatalities. A rapid increase in pesticide suicides was observed during 'The Green Revolution' after pesticides were introduced into low- and middle-income rural households without appropriate guidelines for safe use and storage. While national pesticide bans have contributed to a significant decrease in pesticide-related suicides, such cases still comprise a large proportion of all suicides around the world. The aim of the current study was to provide a profile of pesticide suicides in a high-income country as a point of comparison against studies from low- and middle-income countries. Statistical analyses were performed using R (version 4.2.3). Over the 20-year study period, there were a low, yet consistent number of pesticide suicides which were most common among males over the age of 40. Paraquat and methomyl pesticides collectively contributed to almost half (48.8%) of all fatalities. Consistent with the literature, such cases often occurred with little premeditation in response to an acute emotional crisis. While interpretation of autopsy findings was mostly limited, there were some pesticides that demonstrated findings consisted with previously reported characteristics (e.g., gastroesophageal erosions with paraquat). Given the high proportion of cases where paraquat and methomyl pesticides were implicated, it may be appropriate to review the availability and accessibility of such compounds to reduce the occurrence of pesticide suicides in South Australia and potentially the wider Australian population.

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.

The effect of age on injury patterns in pedestrian deaths.

Although it is known that elderly pedestrians are at increased risk of injury and death from vehicle crashes the specific pattern of lethal injuries related to age has not been extensively studied. Data on the numbers of pedestrian fatalities and ages were obtained from 1990 to 2020 from the Traffic Accident Reporting System, The University of Adelaide, Adelaide, South Australia and detailed autopsy data on fatal pedestrian crashes from the pathology database at Forensic Science SA, Adelaide, South Australia from 2000 to 2020. Fatal injuries were separated into the following regions: head/face, spine, chest, abdomen and limbs/skeleton. Analysis of 634 cases of pedestrian fatalities (1990-2020) showed a significant decline in numbers over the years (p < 0.001). Analysis of fatal injuries in 219 cases (2000-2020) showed a significant reduction in the proportion of fatal head injuries with increasing age (p < 0.05), a significant increase in the proportion of fatal chest injuries with increasing age (p < 0.01) and a significant increase in the proportion of fatal limb/skeletal injuries with increasing age (p < 0.05). Older pedestrians are, therefore, more likely to sustain lethal chest and limb/skeletal injuries than head injuries compared to those who are younger, presumably due to greater physical fragility that occurs with age, with loss of protective muscle bulk and bone density.

Seat belt injuries and external markings at autopsy in cases of lethal vehicle crashes.

A study was undertaken to determine what injuries are associated with the wearing of seat belts and if the presence of cutaneous seat belt markings observed on victims of lethal vehicle crashes increased the likelihood of underlying injury. Autopsy reports from the files at Forensic Science South Australia were reviewed for all fatal motor vehicle crashes from January 2014 to December 2018. A total of 173 cases were included for analysis with 127 occupants wearing seat belts at the time of impact (73.4%) (age range = 18-93; mean = 45 M:F = 81:46). Of these, only 38 had external seat belt markings (29.9%) (age range = 19-83; mean = 49 M:F = 20:18). Logistic regression modelling showed that occupants who were wearing seat belts were more likely to experience closed head injury without skull fractures in addition to mesenteric and gastrointestinal injury. Increasing body mass index increased the incidence of seat belt markings (p < 0.01) and markings were more likely to be found in the presence of bilateral pelvic fractures. Thus, external seat belt markings were observed in only a minority of seatbelt wearers, and more often in individuals with higher BMIs and with bilateral pelvic fractures (possibly associated with greater momentum and impact force).

Success of Low Aromatic Fuel in Preventing Gasoline Sniffing Deaths.

ABSTRACT: Gasoline (petrol) sniffing is a form of volatile substance misuse that is particularly prevalent within Australian indigenous communities. Although epidemiological studies have shown that gasoline sniffing has decreased over recent years, rates of gasoline sniffing deaths have not been widely reported. Therefore, a study was undertaken to assess the association between the implementation of low aromatic fuel (LAF) and gasoline sniffing deaths. All cases of fatal gasoline sniffing in South Australia between 2000 and 2019 were identified from the Toxicology Database and autopsy reports at Forensic Science South Australia. Furthermore, previous studies of gasoline sniffing deaths were assessed to provide historical context and approximate rates of gasoline sniffing deaths before the current study. The rate of gasoline sniffing deaths decreased significantly ( P = 0.039) over the study period concomitant to an increase in the number of LAF sites nationally. Although not supported by findings of statistical significance because of the small number of cases, this study provides further supportive evidence for the effectiveness of LAF by showing a significant associated decrease in local rates of gasoline sniffing deaths.

Characteristics of fatal insulin overdoses.

This study was undertaken to review fatal cases of insulin overdose in South Australia (SA) over a 20-year period to assess rates and characteristics of insulin-related deaths among insulin-dependent diabetics and non-diabetics for all manners of death. Records from the National Coronial Information System (NCIS) and Forensic Science SA (FSSA) were searched for all cases of fatal insulin overdose in South Australia (SA) between 2000 and 2019. Collected variables included age, sex, cause of death, scene findings, manner of death, decedent medical and personal histories, biochemistry, toxicology, histopathology, and autopsy findings. Statistical analyses were performed using R (version 4.1.2). Forty cases of insulin overdose were identified in SA between 2000 and 2019. Twenty-nine cases (72.5%) were suicides, with the remaining cases classified as accidental or undetermined intent. Thirteen of the 22 insulin-dependent diabetics (59%) had a history of depression, 10 of whom had previously demonstrated suicidal ideation. The current study has shown that suicides using insulin among insulin-dependent diabetics are equally as prevalent, if not more so than fatal accidental insulin overdoses. This can largely be attributed to insulin-dependent diabetic access to a potentially lethal substance. Suicide prevention strategies should focus on insulin-dependent diabetics with a history of depression, particularly for those with access to rapid-acting insulin.

Fatal blunt chest trauma: an evaluation of rib fracture patterns and age.

The following study was undertaken to determine if any specific occupant characteristics, crash factors, or associated injuries identified at autopsy could predict the occurrence or number of fractured ribs in adults. Data were accrued from the Traffic Accident Reporting System (TARS) and coronial autopsy reports from Forensic Science SA, Adelaide, South Australia, from January 2000 to December 2020. A total of 1475 motor vehicle fatalities were recorded in TARS between January 2000 and December 2020, and 1082 coronial autopsy reports were identified that corresponded to TARS fatal crash data. After applying exclusion criteria involving missing data, 874 cases were included in the analysis. Of the 874 cases, 685 cases had one or more rib fractures. The leading cause of death for those with rib fractures was multiple trauma (54%), followed by head injury (17%) and chest injuries (10%). The strongest predictor of one or more rib fractures was increasing age (p < 0.001). Other factors found in the regression to be predictive of the number of rib fractures were the presence of a variety of other injuries including thoracic spinal fracture, lower right extremity fracture, splenic injury, liver injury, pelvic fracture, aortic injury, lung laceration, and hemothorax. Age is most likely associated with increasing rib fractures due to reduced tolerance to chest deflection with greater injuries occurring at lower magnitudes of impact. The association of other injuries with rib fractures may be a marker of higher impact severity crashes.

Causes of fatalities in motor vehicle occupants: an overview.

Injuries from motor vehicle collisions are frequently encountered in routine forensic practice. While the most common lethal events involve blunt force trauma with injuries to the head and neck, chest, abdomen, pelvis and limbs, review of the literature and case files shows that a wide variety of other fatal situations can occur that may involve sharp force and penetrating trauma, incineration, drowning, asphyxia, organic diseases and combinations of these. The following overview details potential factors that may contribute to death following vehicle crashes.

Cardiac disease and driver fatality.

To determine the role of cardiac disease in driver fatalities, a retrospective review of autopsy files at Forensic Science SA in Adelaide, Australia, was undertaken over a 13-year-period January 2005-December 2017 for individuals aged ≥ 40 years who had died while driving a motor vehicle. The incidence of significant coronary artery atherosclerosis (CAA) and cardiomegaly was evaluated with comparisons between drivers and a control group of passengers. Autopsy examinations were performed on 303 drivers and 72 passengers who died of trauma and on 63 drivers who died of a cardiac event while driving. The average age for drivers dying of trauma was 58.5 years (range 40-93 years) with 48 (15.8%) having CAA and 31 (10.2%) having cardiomegaly. This was not statistically different to passengers (aged 63.3 years; range 40-93 years; 20.8% having CAA; 11 (15.2%) cardiomegaly; (p > 0.2). Drivers with significant cardiac disease did not, therefore, have increased rates of death in crashes, although a distinct subgroup of drivers consisted of those who had died from cardiac events and not trauma, while driving. The latter may be increasing in number given the aging population.

Increasing use of sodium nitrite in suicides-an emerging trend.

Sodium nitrite (NaNO2) is a compound with broad practical applications in food preservation, automotive maintenance, and animal control. Sodium nitrite is also potentially fatal when ingested, as it interferes with the ability of red blood cells to transport oxygen. While incidents of accidental consumption have been reported in the literature, case reports of sodium nitrite being used as a pharmacological suicide agent are becoming more frequent. Therefore, a study was undertaken to evaluate trends in sodium nitrite deaths in South Australia between 2000 and 2019. All cases of fatal sodium nitrite ingestion were identified in the Toxicology database and autopsy reports at Forensic Science SA (FSSA). Ten cases of fatal sodium nitrite ingestion were identified, with the rate of cases increasing significantly over the study period (p > .001). Of the ten deaths attributed to sodium nitrite toxicity, eight were male, and two were female. The age range of decedents was 22-74 years (mean 51.9, SD 21.1), 22-74 years for males (mean 58.4, SD 18.2) and 23-29 years for females (mean 26.0, SD 4.2). Males (80%) and those with a history of depression and/or suicidal ideation (70%) were over-represented within the study population. While autopsy findings were generally consistent with the literature, scene findings emphasized the accessibility of sodium nitrite to the general public. This study highlights both a significant increasing trend in the use of sodium nitrite in suicides and important analytical limitations in the evaluation of suspected cases.

Investigating the Source of Fatal Pulmonary Thromboembolism in a Coronial Postmortem Population.

ABSTRACT: The incidence of how often a deep vein thrombosis is found in the calves of the legs at coronial postmortem examination is unclear. This study retrospectively examined postmortem examination reports from Australian Coronial investigations of sudden death resulting from pulmonary thromboembolism to determine the likelihood of dissection of the deep veins of calves of the legs revealing the source of a pulmonary thromboembolism. From 450 cases taken from the National Coronial Information System (NCIS) for 2016, the postmortem reports of 327 cases were reviewed to provide demographic details of victims of sudden death from pulmonary thromboembolism. In 235 cases, it was possible to determine in 76.6% a thrombus had been found in the deep veins of the calves of the legs after dissection. In 141 cases, it was documented that both sides had been examined. From these, it was determined there was no statistically significant difference in the prevalence of thrombus in either side. However, it was shown that the presence of an abnormality of a lower limb (such as leg or hip infection, burns, surgery and nonoperated fractures, or a larger circumference) increased the likelihood that a deep vein thrombus would be found on that side.

Methamphetamine use and the risk of diabetic ketoacidosis.

Diabetic ketoacidosis (DKA) is a life-threatening condition arising in individuals with insulin-dependent diabetes mellitus, associated with hyperglycaemia and hyperketonaemia. While drugs such as methadone, cocaine and certain prescription medications may precipitate DKA, the potential effect of methamphetamine is unclear. Analysis of autopsy and toxicology case files at Forensic Science SA, Adelaide, South Australia, was therefore undertaken from 1 January to 31 December 2019 of all cases where methamphetamine was detected in post-mortem blood samples. There were 94 cases with 11 diabetics (n = 6 type 1 and n = 5 type 2). Four of the six decedents with type 1 diabetes had lethal DKA (66.7%; age range 30-54 years; average age 44.6 ± 10.5 years; M:F ratio 1:1). This incidence of DKA was higher than that of the general insulin-dependent diabetic population (6%) and also significantly higher than in medico-legal cases (13%; p < 0.05). The clinical and autopsy assessment of insulin-dependent diabetics presenting with DKA should therefore include specific screening for methamphetamine. The increase in both insulin-dependent diabetes and methamphetamine abuse in the community may lead to increases in such cases in medico-legal and health contexts.

Methamphetamine and alcohol detection in vehicle-driver fatalities in South Australia: A 10-year survey (2008-2018).

Motor vehicle driver fatalities (≥18 years) from the files at Forensic Science South Australia were reviewed from January 2008 to December 2018 for cases in which either positive blood sample for methamphetamine (MA) or an illegal blood alcohol concentration (BAC) >0.05g/100 ml were found. Three hundred driver deaths were found with MA detected in 28 cases (age range 21-62 years; ave. 37.8 years; M:F 23:5). Hundred and fifteen cases with a BAC > 0.05 g/100 ml were identified (age range 18-67 years; ave 35.7 years; M:F 95:20). No change was found in numbers of MA cases, although alcohol cases showed a significant decline (p < 0.001). Drunk driving-related fatal crashes tended to occur in the evening (5 p.m. to 11 p.m.), while MA-related fatal crashes had a longer peak extending from late evening until late morning (11 p.m. to 8 a.m.). This study has demonstrated that while roadside breath testing, legislative changes, and increased monitoring have resulted in reduced levels of drunk driving, similar safety countermeasures have had negligible effects on MA use in drivers. Continued monitoring of MA use by drivers will, therefore, be necessary to assess the possible effects, or not, of new countermeasures.

Upper and lower limb amputations in vehicle-related fatalities.

Traumatic limb amputation is rare in occupants following a motor vehicle collision (MVC). A retrospective analysis of autopsy reports at Forensic Science South Australia (FSSA) over a 19 year period from January 2000 to December 2018 was performed to determine the incidence of limb amputation in lethal collisions and to identify predisposing factors. Only 18 cases (1.54%) of occupant fatalities had a traumatic limb amputation with an age range of 18-78 years (mean 44.2 years), male to female ratio 13:5, and an average body mass index (BMI) of 28.5 (overweight). There were nine cases of upper limb amputation and nine cases of lower limb amputation (one case had both upper and lower limb amputations). Head on impacts without subsequent rollover were the most common collision type in both upper and lower amputation. The likely cause of limb amputation in vehicle crashes is, therefore, speed on impact rather than rollovers as has been previously suggested.