Interpretation of postmortem forensic toxicology results for injury prevention research

Preanalytical factors influencing the results of ethanol analysis in postmortem specimens

Excessive drinking and drunkenness are underlying factors in many fatal accidents, which make the quantitative determination of ethanol in postmortem (PM) specimens an essential part of all unnatural death investigations. The same analytical methods are used to determine ethanol in blood taken from living and deceased persons although the interpretation of the results is more complicated in medical examiner cases owing to various preanalytical factors. The biggest problem is that under anaerobic conditions ethanol can be produced naturally in decomposed bodies by microbial activity and fermentation of blood glucose. Ways are needed to differentiate antemortem ingestion of ethanol from PM synthesis. One approach involves the determination of ethanol in alternative specimens, such as bile, cerebrospinal fluid, vitreous humor and/or urine, and comparison of results with blood alcohol concentration (BAC). Another approach involves the analysis of various alcohol biomarkers, such as ethyl glucuronide, ethyl sulfate and/or phosphatidylethanol or the urinary metabolites of serotonin 5-hydroxytryptophol/5-hydroxyindoleacetic acid (5-HTOL/5-HIAA). If ethanol had been produced in the body by microbial activity, the blood samples should also contain other low-molecular volatiles, such as acetaldehyde, n-propanol and/or n-butanol. The inclusion of 1-2% w/v sodium or potassium fluoride, as an enzyme inhibitor, in all PM specimens is essential to diminish the risk of ethanol being generated after sampling, such as during shipment and storage prior to analysis. Furthermore, much might be gained if the analytical cut-off for reporting positive BAC was raised from 0.01 to 0.02 g% when PM blood is analyzed. During putrefaction low BACs are more often produced after death than high BACs. Therefore, when the cadaver is obviously decomposed, a pragmatic approach would be to subtract 0.05 g% from the mean analytical result. Any remaining BAC is expected to give a more reliable indication of whether alcohol had been consumed before death.

High-'n'-dry? A comparison of cannabis and alcohol use in drivers presenting to hospital after a vehicular collision

DESIGN

This was a prospective observational study.

BACKGROUND AND AIMS

The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations.

SETTING

The study was conducted in 15 Canadian trauma centres between January 2018 and December 2021.

CASES

The cases (n = 6956) comprised injured drivers who required blood testing as part of routine trauma care.

MEASUREMENTS

We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: high THC (THC ≥ 5 ng/ml and BAC = 0), high alcohol (BAC ≥ 0.08% and THC = 0) and THC/BAC-negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership.

FINDINGS

Most injured drivers (70.2%) were THC/BAC-negative; 1274 (18.3%) had THC > 0, including 186 (2.7%) in the high THC group; 1161 (16.7%) had BAC > 0, including 606 (8.7%) in the high BAC group. Males and drivers aged less than 45 years had higher adjusted odds of being in the high THC group (versus the THC/BAC-negative group). Importantly, 4.6% of drivers aged less than 19 years had THC ≥ 5 ng/ml, and drivers aged less than 19 years had higher unadjusted odds of being in the high THC group than drivers aged 45-54 years. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers and drivers injured in single-vehicle, night-time or weekend collisions had higher adjusted odds ratios (aORs) for being in the high alcohol group (versus THC/BAC-negative). Drivers aged less than 35 or more than 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the high THC group (versus the high BAC group).

CONCLUSIONS

In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single-vehicle, night-time, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions, but are more strongly associated with cannabis-related collisions.

Psychotropic and other medicine use at time of death by suicide: a population-level analysis of linked dispensing and forensic toxicology data

OBJECTIVES

To determine the numbers and types of medicines dispensed around the time of death to people who die by suicide; to compare the medicines recently dispensed and those recorded in post mortem toxicology reports.

DESIGN, SETTING, PARTICIPANTS

Analysis of linked National Coronial Information System (NCIS) and Pharmaceutical Benefits Scheme (PBS) data from the Australian Suicide Prevention using Health Linked Data (ASHLi) study, a population-based case series study of closed coronial cases for deaths of people in Australia aged ten years or more during 1 July 2013 - 10 October 2019 deemed by coroners to be the result of intentional self-harm.

MAIN OUTCOME MEASURES

Proportions of people to whom medicines were dispensed around the time of death, by medicine group, class, and specific medicine; comparison of medicines recently dispensed and those detected by post mortem toxicology.

RESULTS

Toxicology reports were available for 13 541 of 14 206 people who died by suicide (95.3%; 10 246 men, 75.7%); poisoning with medicines contributed to 1163 deaths (8.6%). At least one PBS-subsidised medicine had been dispensed around the time of death to 7998 people (59.1%). For three medicine classes, the proportions of people in whom the medicines were detected post mortem and their death was deemed medicine-related were larger for those without records of recent dispensing than for people for whom they had been dispensed around the time of death: antidepressants (17.7% v 12.0%), anxiolytics (16.3% v 14.8%), and sedatives/hypnotics (24.3% v 16.5%). At least one recently dispensed medicine not detected post mortem was identified for 6208 people (45.8%).

CONCLUSIONS

A considerable proportion of people who died by suicide were not taking psychotropic medicines recently dispensed to them, suggesting non-adherence to pharmacotherapy, and a smaller than expected proportion were using antidepressants. Conversely, medicines that had not recently been dispensed were detected post mortem in many people for whom poisoning with medicines was a contributing factor, suggesting medicine stockpiling.

Deliberate Self-Poisoning: Real-Time Characterization of Suicidal Habits and Toxidromes in the Food and Drug Administration Adverse Event Reporting System

INTRODUCTION

Deliberate self-poisoning (DSP) using drugs is the preferred method of suicide at a global level. Its investigation is hampered by limited sample sizes and data reliability. We investigate the role of the US FDA Adverse Event Reporting System (FAERS), a consolidated pharmacovigilance database, in outlining DSP habits and toxidromes.

METHODS

We retrieved cases of 'intentional overdose' and 'poisoning deliberate' from the FAERS (January 2004-December 2021). Using descriptive and disproportionality analyses, we estimated temporal trends, potential risk factors, toxidromes, case-fatality rates and lethal doses (LDs) for the most frequently reported drugs.

RESULTS

We retrieved 42,103 DSP cases (17% fatal). Most cases were submitted in winter. Reports of DSP involved younger people, psychiatric conditions, and alcohol use, compared with non-DSP, and fatality was higher in men and older patients. Suspected drugs were mainly antidepressants, analgesics, and antipsychotics. Multiple drug intake was recorded in more than 50% of the reports, especially analgesics, psychotropics, and cardiovascular agents. The most frequently reported drugs were paracetamol, promethazine, amlodipine, quetiapine, and metformin. We estimated LD25 for paracetamol (150 g).

CONCLUSION

Worldwide coverage of the FAERS complements existing knowledge about DSP and may drive tailored prevention measures to timely address the DSP phenomenon and prevent intentional suicides.

Cannabis Legalization and Detection of Tetrahydrocannabinol in Injured Drivers

BACKGROUND

The effect of cannabis legalization in Canada (in October 2018) on the prevalence of injured drivers testing positive for tetrahydrocannabinol (THC) is unclear.

METHODS

We studied drivers treated after a motor vehicle collision in four British Columbia trauma centers, with data from January 2013 through March 2020. We included moderately injured drivers (those whose condition warranted blood tests as part of clinical assessment) for whom excess blood remained after clinical testing was complete. Blood was analyzed at the provincial toxicology center. The primary outcomes were a THC level greater than 0, a THC level of at least 2 ng per milliliter (Canadian legal limit), and a THC level of at least 5 ng per milliliter. The secondary outcomes were a THC level of at least 2.5 ng per milliliter plus a blood alcohol level of at least 0.05%; a blood alcohol level greater than 0; and a blood alcohol level of at least 0.08%. We calculated the prevalence of all outcomes before and after legalization. We obtained adjusted prevalence ratios using log-binomial regression to model the association between substance prevalence and legalization after adjustment for relevant covariates.

RESULTS

During the study period, 4339 drivers (3550 before legalization and 789 after legalization) met the inclusion criteria. Before legalization, a THC level greater than 0 was detected in 9.2% of drivers, a THC level of at least 2 ng per milliliter in 3.8%, and a THC level of at least 5 ng per milliliter in 1.1%. After legalization, the values were 17.9%, 8.6%, and 3.5%, respectively. After legalization, there was an increased prevalence of drivers with a THC level greater than 0 (adjusted prevalence ratio, 1.33; 95% confidence interval [CI], 1.05 to 1.68), a THC level of at least 2 ng per milliliter (adjusted prevalence ratio, 2.29; 95% CI, 1.52 to 3.45), and a THC level of at least 5 ng per milliliter (adjusted prevalence ratio, 2.05; 95% CI, 1.00 to 4.18). The largest increases in a THC level of at least 2 ng per milliliter were among drivers 50 years of age or older (adjusted prevalence ratio, 5.18; 95% CI, 2.49 to 10.78) and among male drivers (adjusted prevalence ratio, 2.44; 95% CI, 1.60 to 3.74). There were no significant changes in the prevalence of drivers testing positive for alcohol.

CONCLUSIONS

After cannabis legalization, the prevalence of moderately injured drivers with a THC level of at least 2 ng per milliliter in participating British Columbia trauma centers more than doubled. The increase was largest among older drivers and male drivers. (Funded by the Canadian Institutes of Health Research.).

Summary statistics for drugs and alcohol concentration recovered in post-mortem femoral blood in Western Switzerland

In post-mortem investigations of fatal intoxication, it is challenging to determine which drug(s) were responsible for the death, and which drugs did not. This study aims to provide post-mortem femoral blood drug levels in lethal intoxication and in post-mortem control cases, where the cause of death was other than intoxication. The reference values could assist in the interpretation of toxicological results in the routine casework. To this end, all post-mortem toxicological results in femoral blood from 2011 to 2017 in Western Switzerland were considered. A full autopsy with systematic toxicological analysis (STA) was conducted in all cases. Results take into account the cause of death classified into one of four categories (as published by Druid and colleagues): I) certified intoxication by one substance alone, IIa) certified intoxication by more than one substance, IIb) certified other causes of death with incapacitation due to drugs, and III) certified other causes of death without incapacitation due to drugs. This study includes 1 990 post-mortem cases where femoral blood was analysed. The material comprised 619 women (31%) and 1 371 men (69%) with a median age of 50 years. The concentrations of the 32 most frequently recorded substances as well as alcohol are discussed. These include 6 opioids and opiates, 3 antidepressants, 6 neuroleptics and hypnotics, 1 barbiturate, 11 benzodiazepines (and related drugs), 2 amphetamine-type stimulants, cocaine, paracetamol, and tetrahydrocannabinol (THC). The most common substances that caused intoxication alone were morphine, methadone, ethanol, tramadol, and cocaine. The post-mortem concentration ranges for all substance are categorized as I, IIa, IIb, or III. Statistical post-mortem reference concentrations for drugs are discussed and compared with previously published concentrations. This study shows that recording and classifying cases is time-consuming, but it is rewarding in a long-term perspective to achieve a more reliable information about fatal and non-fatal blood concentrations.

Interpretation of melperone intoxication: post-mortem concentration distribution and interpretation of intoxication data

OBJECTIVES

Since melperone abuse with lethal intoxication is common, expert opinions based on therapeutical and lethal concentration ranges can be considered as important. Because there is a lack of information about fatalities caused by melperone mono-intoxications and data on tissue samples with concentration distribution, the aim of this work is the examination of lethal concentration ranges of melperone and drug quantification in different matrices.

METHODS

An LC-MS/MS method was applied for analyses performed in blood and tissue samples. Quantification based on standard addition and sample preparation on liquid-liquid extraction with 1-chlorobutane. An appropriate tissue homogenization was performed ahead of extraction with an IKA Ultra-Turrax-Tube-Drive^®. A Luna 5 µm C18 (2) 100 Å, 150  × 2 mm analytical column was used for chromatographic separation and the elution was performed with two mobile phases consisted of A (H₂O/methanol = 95/5, v/v) and B (H₂O/methanol = 3/97, v/v) both with 10 mM ammonium acetate and 0.1% acetic acid.

RESULTS

A multi-drug LC-MS/MS analytical method developed was applied successfully for melperone quantification in different post-mortem matrices. No analytical problems could be identified during method development and analyses of real samples. The melperone lethal concentration calculated in femoral blood of the drug mono-intoxication investigated was 10 mg/L. Melperone concentration distribution was presented for the first time.

CONCLUSIONS

The lethal reference concentration of melperone in femoral blood of 17.1 mg/L pointed out in different reference lists should be used with caution. Instead, a lower lethal melperone concentration should be considered. The post-mortem concentration distribution of the drug presented could be helpful in the interpretation of cases where no blood samples are available.

Interpretation of melperone intoxication: post-mortem concentration distribution and interpretation of intoxication data

OBJECTIVES

Since melperone abuse with lethal intoxication is common, expert opinions based on therapeutical and lethal concentration ranges can be considered as important. Because there is a lack of information about fatalities caused by melperone mono-intoxications and data on tissue samples with concentration distribution, the aim of this work is the examination of lethal concentration ranges of melperone and drug quantification in different matrices.

METHODS

An LC-MS/MS method was applied for analyses performed in blood and tissue samples. Quantification based on standard addition and sample preparation on liquid-liquid extraction with 1-chlorobutane. An appropriate tissue homogenization was performed ahead of extraction with an IKA Ultra-Turrax-Tube-Drive®. A Luna 5 µm C18 (2) 100 Å, 150  × 2 mm analytical column was used for chromatographic separation and the elution was performed with two mobile phases consisted of A (H2O/methanol = 95/5, v/v) and B (H2O/methanol = 3/97, v/v) both with 10 mM ammonium acetate and 0.1% acetic acid.

RESULTS

A multi-drug LC-MS/MS analytical method developed was applied successfully for melperone quantification in different post-mortem matrices. No analytical problems could be identified during method development and analyses of real samples. The melperone lethal concentration calculated in femoral blood of the drug mono-intoxication investigated was 10 mg/L. Melperone concentration distribution was presented for the first time.

CONCLUSIONS

The lethal reference concentration of melperone in femoral blood of 17.1 mg/L pointed out in different reference lists should be used with caution. Instead, a lower lethal melperone concentration should be considered. The post-mortem concentration distribution of the drug presented could be helpful in the interpretation of cases where no blood samples are available.

Evaluation and review of ways to differentiate sources of ethanol in postmortem blood

Accurate determination of a person's blood alcohol concentration (BAC) is an important task in forensic toxicology laboratories because of the existence of statutory limits for driving a motor vehicle and workplace alcohol testing regulations. However, making a correct interpretation of the BAC determined in postmortem (PM) specimens is complicated, owing to the possibility that ethanol was produced in the body after death by the action of various micro-organisms (e.g., Candida species) and fermentation processes. This article reviews various ways to establish the source of ethanol in PM blood, including collection and analysis of alternative specimens (e.g., bile, vitreous humor (VH), and bladder urine), the identification of non-oxidative metabolites of ethanol, ethyl glucuronide (EtG) and ethyl sulfate (EtS), the urinary metabolites of serotonin (5-HTOL/5-HIAA), and identification of n-propanol and n-butanol in blood, which are known putrefaction products. Practical utility of the various biomarkers including specificity and stability is discussed.

Intentional Carbofuran poisoning in 7 dogs

Background

Carbofuran is a widely used broad-spectrum pesticide that, despite strict regulation and being banned for more than a decade, is still encountered in cases of intentional poisoning in dogs and wildlife. The objective of the study was to provide a complete and detailed description of the pathological, histological and toxicological findings of 7 cases of intentional carbofuran poisoning in dogs.

Results

In this retrospective study, 7 cases of carbofuran intoxication recorded from July 2015 to June 2017 were analyzed. Following complete history recording, all cases were examined by complete necropsy and histopathology. Carbofuran intoxication was confirmed in all cases by gas chromatography. The postmortem examination revealed extensive hemorrhaging and congestion located mainly within the respiratory, nervous and cardiovascular systems, accompanied by degeneration and necrosis within the lungs, heart, and kidneys.

Conclusions

Although carbamates have been banned in the European Union, carbamate poisoning is still frequently encountered, especially in wild animals. This paper will contribute to a better understanding of the occurrence and pathogenesis of acute carbofuran exposure in dogs and contribute some peculiar pathological features of this type of poisoning to the current literature.

Population study of orofacial injuries in adult family violence homicides in Victoria, Australia

BACKGROUND

This study describes the prevalence and orofacial injury patterns associated with adult family violence (FV) homicides in Victoria, Australia. It follows a methods study for case selection of all FV homicides and injury measurement. Comprehensive analysis of orofacial injuries in FV homicides and their clinico-demographic context will inform future research on clinical FV indicators and sentinel injuries, and potentially lead to premorbid intervention in health services.

METHODS

All closed cases of FV homicides aged ≥18 years, January 2006 to December 2018, were identified by screening Victorian fatal assaults, based on victim-offender relationship. Primary data such as post-mortem computed tomography scans and photographs were assessed. Socio-demographic, clinical, interpersonal and incident parameters were descriptively analysed and statistically compared across FV homicides with and without facial injuries using cluster analysis and nonparametric tests.

RESULTS

Of 170 adult homicides screened for eligibility, 151 were included for final analysis. Over the 12-year period, 78.1% of all Victorian adult FV homicides had orofacial injuries. Significant cluster patterns of injury mechanism, victim-offender relationship and drug/alcohol impairment were identified in all homicides. Non-facial injuries were significantly higher in facial vs. non-facial injury homicides. Facial abrasion and incised wounds were the most common injury types.

CONCLUSIONS

This is the first forensic-epidemiologic study evaluating the empirical evidence concerning orofacial injuries associated with population-wide adult Victorian FV homicides. The high level of orofacial injuries in this population during the study period may inform clinical practice and policy in FV intervention in Victoria and globally.

Self-inflicted neck wounds under influence of lysergic acid diethylamide: A case report and literature review

RATIONALE

Lysergic acid diethylamide (LSD) is a highly potent psychedelic drug derived from ergot alkaloids. The available literature data derived from controlled studies or usage in a medical setting seem reassuring; however the literature contains very rare cases of fatal self-inflicted injuries associated with LSD exposure. The behavioral disorder that created the conditions conducive to death is a maladaptive or irrational response to the psychiatric manifestations induced by the substance.

PATIENT CONCERN

Here, we report the case of a 26-year-old man found dead with large neck wounds in a locked house. No medical history other than recreational use of alcohol and narcotics was reported as well as any history of psychotic disease. The entirety of the other investigations carried out did not demonstrate the presence of a third party at the place of death and a dropper bottle containing LSD was found near the body.

DIAGNOSIS

We report the first case of fatal self-inflicted neck wounds with a cutting instrument in the context of acute exposure to LSD in a patient with no psychiatric history and without suicidal symptoms at the time of the self-aggressive act.

INTERVENTION AND OUTCOMES

In the present work, we used a validated method using liquid chromatography coupled with mass spectrometry for simultaneous quantification of LSD and its metabolites (O-H-LSD and Nor-LSD) in whole blood and urine samples. LSD and O-H-LSD were respectively found at 1460 and 182 pg/mL in blood. In the urine, the concentrations of LSD, nor-LSD, O-H-LSD were, respectively, 3670, 201, and 4890 ng/L.

LESSONS

This observation is particularly relevant in view of the resurgence of interest in the therapeutic use of LSD, notwithstanding the fact that the literature has not demonstrated a link between suicidal risk and acute or chronic exposure to LSD.

Opioid Deaths in Milwaukee County, Wisconsin 2013-2017: The Primacy of Heroin and Fentanyl

Heroin and fentanyl are the overwhelming and increasing cause of opioid deaths in Milwaukee County, Wisconsin. We reviewed all drug and opioid deaths from 2013 to 2017 to delineate the specific opioid drugs involved and changes in their incidence. From 2013 to 2017, 980 deaths were due to opioids, rising from 184 in 2013 to 337 in 2017. In 2017, opioid deaths exceeded combined non-natural deaths from homicide and suicide. Illicit heroin and fentanyl/analogs caused 84% of opioid deaths and 80% of drug deaths, with no increase in deaths due to oral prescription drugs such as oxycodone and hydrocodone. Any approach to decreasing this dramatic increase in opioid deaths should first focus on interdicting the supply and cheap availability of these illicit opioids. Fentanyl and its analogs represent the most deadly opioids and the greatest threat to human life in our population.

Frequency of forensic toxicological analysis in external cause deaths among nursing home residents: an analysis of trends

There is a paucity of research examining the utility of forensic toxicology in the investigation of premature external cause deaths of residents in nursing homes. The aim of this study is to describe the frequency and characteristics of toxicological analysis conducted in external cause (injury-related) deaths amongst nursing home residents in Victoria, Australia. This study was a retrospective cohort study examining external cause deaths among nursing home residents during the period July 1, 2000 to December 31, 2012 in Victoria, Australia, using the National Coronial Information System (NCIS). The variables examined comprised: sex, age group, year-of-death, cause and manner of death. One-third of deaths among nursing home residents in Victoria resulted from external causes (n = 1296, 33.3%) of which just over one-quarter (361, 27.9%) underwent toxicological analysis as part of the medical death investigation. The use of toxicological analysis varied by cause of death with a relatively low proportion conducted in deaths from unintentional falls (n = 286, 24.9%) and choking (n = 36, 40.4%). The use of toxicological analysis decreased as the decedents age increased. Forensic toxicology has the potential to contribute to improving our understanding of premature deaths in nursing home residents however it remains under used and is possibly undervalued.