Medicolegal Implications of Deaths due to Agricultural Accidents.

ABSTRACT: Agriculture encompasses a variety of activities that carry with them a variety of different risks. The unsafe use of vehicles, machinery, and tools as well as animal husbandry, working at heights, and exposure to chemical, biological, and weather events may result in the deaths of agricultural workers. Inexperienced operators and/or their inappropriate conduct may lead to avoidable fatalities. Forensic pathologists operating with the support of agricultural engineers or other professionals must evaluate the death scene, the case background and circumstances, the autopsy findings, and the toxicological data to establish the factors and dynamics responsible for such accidents and deaths.The aim of this review is to focus on the diagnostic approach required, by means of an interdisciplinary approach, to identify the cause of some typical agricultural fatalities, to confirm that death was accidental, and to help exclude the possibility of homicide or suicide.

Heart weight must not be measured before dissection during autopsies.

During autopsies, weighing the heart is a standard procedure. In addition to myocardial pathologies, heart size, and ventricular wall thickness, heart weight is a common parameter to describe cardiac pathology and should be recorded as accurately as possible. To date, there exists no standard for recording heart weight at autopsy, although some authors recommend weighing the heart after dissection and removal of blood and blood clots. In the study presented, the hearts of 58 decedents were weighed after being dissected out of the pericardial sac (a), after dissection using the short-axis or inflow-outflow method with manual removal of blood and blood clots (b), and after rinsing and drying (c). Depending on the dissection method, the heart weight was 7.8% lower for the inflow-outflow method and 11.6% lower for the short-axis method after dissection compared to before and correspondingly 2.9% to 5% lower again after rinsing and drying respectively. Accordingly, the heart should be dissected, blood and blood clots removed, rinsed with water, and dried with a surgical towel after dissection, before weighing.

Binucleated Myocytes and Heart Weight: A Preliminary Study Linking Cardiac Hypertrophy and Myocyte Hypertrophy.

ABSTRACT: Hypertrophy of the heart is assessed by heart weight (and dimensions) and myocyte hypertrophy. Establishing an association between the two may be useful in assessing hypertrophy in cases where there are limitations in assessing the heart weight. This preliminary study explored the association between the number of binucleated myocytes (a feature of myocyte hypertrophy) in a randomly chosen single high-power field of the left ventricular free wall and heart weight in an adult White population. It also compared the number of binucleated myocytes between cases with increased heart weight (>400 g in female and >500 g in male) and cases with normal heart weight. Heart weight and number of binucleated myocytes correlated significantly in male only. Increased heart weight had a significantly higher number of binucleated myocytes, with 8.5 binucleated myocytes being able to segregate cases with increased heart weight (74% sensitivity and 79% specificity). The results of this study showed the number of binucleated myocytes may have a complementary role in assessing hypertrophy of the heart.

Gross Heart Dimensions From Postmortem Computed Tomography and Postmortem Examination Measurements: Heart Weight and Cardiac Hypertrophy.

ABSTRACT: An increased heart weight (cardiac hypertrophy) is associated with underlying heart disease and sudden cardiac death. Gross heart dimensions can be used to estimate heart weight as a surrogate for cardiac hypertrophy. These dimensions can be obtained from either postmortem computed tomography or postmortem examination. This study compared the gross heart dimensions, heart weight estimations, and ability to determine cardiac hypertrophy (>400 and >500 g) between these 2 methods. The results showed that gross dimensions from postmortem computed tomography were significantly smaller and overall had less accuracy in estimating heart weight than dissection. In terms of cardiac hypertrophy, both methods were comparable and had reasonably high sensitivity and specificity, albeit having slightly varied characteristics, to determine whether the heart showed hypertrophy.

Significant difference in cardiac ventricular dimensions when measured using two different standard methods.

Cardiac ventricular dimensions measured at postmortem examination are used to assess whether there is hypertrophy of the heart chambers. However, there is no clear consensus on where these measurements should be taken. Some have proposed this should be measured at the mid-ventricular level, but others advocate it should be measured at a set distance (e.g. 20 mm) from the base of the heart. Twenty consecutive adult hearts were examined and showed the ventricular dimensions were significantly higher (mean: 5-15 mm, p < 0.01) when measured at a level 20 mm from the base of the heart compared to the mid-ventricular level. Of clinical significance is that in slightly less than half the cases, normal ventricular dimensions at mid ventricle level fell within the criteria considered pathological (> 40 mm) when measured at 20 mm from the base of the heart. In terms of actual ventricular dimensions, only the left ventricle diameter measured at 20 mm from the base of the heart correlated significantly (albeit moderately) with heart weight, suggesting it can be a predictor for cardiac hypertrophy.

A Guide to the Postmortem Investigation of Starvation in Adults.

ABSTRACT: Starvation is a rare cause of death in developed countries and is a complex multifaceted pathological process. To complicate the forensic investigation of starvation further, many medical conditions independent of starvation may cause wasting. This article provides one of the first comprehensive guides to the postmortem investigation of starvation in adults, with reference tables on organ-specific macroscopic and microscopic features, as well as features for excluding alternative causes of wasting. The eclectic literature on this complex topic is summarized in an accessible and easily referenced format, including mechanisms of death and ancillary postmortem investigations.

Sudden cardiac deaths have higher proportion of left stellate ganglionitis.

One of the hypothesized mechanisms of sudden cardiac death in humans is an arrhythmia precipitated by increased sympathetic outflow to a compromised heart. The stellate ganglia provide the main sympathetic innervation to the heart, where the left stellate ganglion appears to play a role in arrhythmogenesis. Case reports of sudden cardiac death have described left stellate ganglion inflammation but no larger studies have been performed. Thus, we have specifically assessed whether the left stellate ganglion was inflamed in those dying from sudden cardiac death versus other causes of death. Thirty-one left stellate ganglia were resected from cadavers diagnosed with sudden cardiac deaths and compared with 18 ganglia from cadavers diagnosed with non-sudden cardiac deaths. Ganglia were stained with hematoxylin and eosin and lymphocytic aggregates compared. The proportion of left stellate ganglion inflammation (77%) was significantly higher in deaths from sudden cardiac deaths than non-sudden cardiac deaths (33%). This study provides information on a previously recognized, but understudied, structure that may help understand sudden cardiac death. We found high prevalence of stellate ganglion inflammation and propose that this may trigger sympathetic storms.

Isolated Atrial Neutrophilic Myocarditis: A Rare Cause of Death and Potential "Blind Spot" for Postmortem Computed Tomography and Postmortem Examination.

ABSTRACT: Myocarditis can focally or diffusely involve the myocardium and is associated with arrhythmia, cardiac failure, and sudden death. The majority of cases of myocarditis are lymphocytic in etiology, and neutrophilic myocarditis is relatively uncommon. Although reported in lymphocytic myocarditis, isolated/focal neutrophilic myocarditis of the atrium causing death is not reported in the postmortem literature, and its postmortem computed tomography correlation is not documented. We report a fatal case of isolated neutrophilic atrial myocarditis affecting only the left atrium in a 33-year-old woman presenting as a sudden unexpected death. Microscopy of the left atrium, a not commonly sampled area of the heart, showed florid neutrophilic myocarditis with the remaining right atrium, conduction system, and both ventricles uninvolved. Similar to previously reported fatal isolated atrial lymphocytic myocarditis, postmortem computed tomography was unable to detect any atrial abnormalities. This case highlights a potential "blind spot" for both routine postmortem imaging and examination.

First Identified Case of Fatal Fulminant Necrotizing Eosinophilic Myocarditis Following the Initial Dose of the Pfizer-BioNTech mRNA COVID-19 Vaccine (BNT162b2, Comirnaty): an Extremely Rare Idiosyncratic Hypersensitivity Reaction.

RATIONALE: Transient myopericarditis has been recognised as an uncommon and usually mild adverse event predominantly linked to mRNA-based COVID-19 vaccines. These have mostly occurred in young males after the second dose of mRNA COVID-19 vaccines. OBJECTIVES: Fulminant necrotising eosinophilic myocarditis triggered by a variety of drugs or vaccines is an extremely rare hypersensitivity reaction carrying a substantial mortality risk. Early recognition of this medical emergency may facilitate urgent hospital admission for investigation and treatment. Timely intervention can lead to complete cardiac recovery, but the non-specific clinical features and rarity make early diagnosis challenging. FINDINGS: The clinical and pathological observations from a case of fatal fulminant necrotising myocarditis in a 57-year-old woman, following the first dose of the Pfizer-BioNTech vaccine, are described. Other causes have been discounted with reasonable certainty. CONCLUSION: These extremely rare vaccine-related adverse events are much less common than the risk of myocarditis and other lethal complications from COVID-19 infection. The benefits of vaccination far exceed the risks of COVID-19 infection.

The effects of drying the rinsed dissected heart on postmortem heart weight.

Blood and blood clots should be removed from the heart chambers before being weighed. The actual method in removing blood and blood clots may vary and can include manual removal with subsequent rinsing the heart in water. It is unclear whether drying the rinsed heart affects the heart weight. The objective of this article was to investigate the effects drying the rinsed dissected heart (residual rinsing water) on postmortem heart weight. The prospective study compared 44 dissected heart weights after being rinsed and after being pat dried. An average 18-20 g of residual rinsing water (4% of heart weight) was present in the dissected heart. The amount of residual rinsing water correlates positively with heart weight. The effects of drying the rinsed dissected heart were considered clinically insignificant. Although being clinically insignificant, this study highlights the lack of standardized approach in weighing the heart and the potential implications in interpreting heart weights.

Heart Weight Is an Independent Factor Associated With, But Is a Poor Predictor for, Sudden Cardiac Death.

ABSTRACT: An enlarged heart can cause electrical instability and impaired contractility, leading to fatal arrhythmia and acute heart failure, and is associated with sudden cardiac death. However, there is limited postmortem evidence on whether heart weight is an independent factor associated with sudden cardiac death. This 18-month retrospective study examined 108 adult heart weights in which all the hearts were weighed after dissection, blood and blood clots removed, rinsed in water, and pat dried. The multivariate logistic regression analysis showed heart weight was an independent factor associated with sudden cardiac death. However, after normalization, the heart weight was a poor predictor of sudden cardiac death with an area under the curve less than 0.7 in the plotted receiver operating characteristic curve.

Medicolegal Implications of Fatalities Because of Entanglement in the Augers of Feed Mixer Wagons.

ABSTRACT: Feed mixer or total mixed ration mixer wagons are powerful agricultural machines used to shred and mix silage with other ingredients and deliver it direct to the feeding troughs on livestock farms. Fatalities involving these feed mixers may occur when operators become trapped in the augers or, less frequently, are crushed by moving wagons. Death can occur very rapidly because of dismemberment, multiple lesions, or crushing. The aim of this review is to focus on the diagnostic evaluations that need to be performed to confirm that the death was accidental and to exclude a hypothesis of murder or suicide. Forensic investigations in such cases must involve the detailed analysis of the death scene and the mechanical characteristics of the machinery with an accurate postmortem and toxicological examination.

Cervical Epidural Abscess: A Blind Spot for Postmortem Computed Tomography.

ABSTRACT: Spinal epidural abscess is an uncommon condition, which may have serious complications, including neurological sequelae and death. Classical symptoms include spinal pain, fever, and neurological deficit; however, diagnosis is difficult and requires a high degree of clinical suspicion. Antemortem magnetic resonance imaging (MRI) scanning is the gold-standard diagnostic tool. Computed tomography (CT) is less sensitive and as such, postmortem CT may miss the diagnosis. We report a case of Staphylococcus aureus cervical epidural abscess presenting as neck pain and causing flaccid paralysis and subsequently death. Antemortem MRI showed a small epidural collection, spinal cord edema, and fluid in the adjacent cervical disc and facet joints; however, these findings could not be appreciated on postmortem CT. Postmortem examination, guided by the antemortem imaging, was able to confirm a cervical spinal epidural abscess; however, similar deaths may occur before medical presentation. This case demonstrates a limitation of postmortem imaging in diagnosing spinal epidural abscess and highlights that such cases may be missed.

Assessing Protein Biomarkers to Detect Lethal Acute Traumatic Brain Injuries in Cerebrospinal Fluid.

Diagnosing traumatic brain injury (TBI) from body fluids in cases where there are no obvious external signs of impact would be useful for emergency physicians and forensic pathologists alike. None of the previous attempts has so far succeeded in establishing a single biomarker to reliably detect TBI with regards to the sensitivity: specificity ratio in a post mortem setting. This study investigated a combination of body fluid biomarkers (obtained post mortem), which may be a step towards increasing the accuracy of biochemical TBI detection. In this study, serum and cerebrospinal fluid (CSF) samples from 30 acute lethal TBI cases and 70 controls without a TBI-related cause of death were evaluated for the following eight TBI-related biomarkers: brain-derived neurotrophic factor (BDNF), ferritin, glial fibrillary acidic protein (GFAP), interleukin 6 (IL-6), lactate dehydrogenase, neutrophil gelatinase-associated lipocalin (NGAL), neuron-specific enolase and S100 calcium-binding protein B. Correlations among the individual TBI biomarkers were assessed, and a specificity-accentuated threshold value analysis was conducted for all biomarkers. Based on these values, a decision tree modelling approach was performed to assess the most accurate biomarker combination to detect acute lethal TBIs. The results showed that 92.45% of acute lethal TBIs were able to be diagnosed using a combination of IL-6 and GFAP in CSF. The probability of detecting an acute lethal TBI was moderately increased by GFAP alone and considerably increased by the remaining biomarkers. BDNF and NGAL were almost perfectly correlated (p = 0.002; R2 = 0.944). This study provides evidence that acute lethal TBIs can be detected to a high degree of statistical accuracy using forensic biochemistry. The high inter-individual correlations of biomarkers may help to estimate the CSF concentration of an unknown biomarker, using extrapolation techniques.

Stellate ganglionitis in sudden cardiac death: A case report.

Sudden cardiac death (SCD) is the most common natural cause of death. The hypothesized mechanism of death is an arrhythmia precipitated by increased sympathetic outflow. The left stellate ganglion provides sympathetic innervation to the heart and plays a role in arrhythmogensis. We present a SCD with stellate ganglionitis in which the inflammatory cells were characterized. The case was 37-year-old man who died from ischemic and hypertensive heart disease. The left stellate ganglion showed lymphocytic inflammation with features of humoral immune response. This case report provides evidence that stellate ganglionitis can be seen in SCD and raises the possible association between the two.

Classifying Microscopic Acute and Old Myocardial Infarction Using Convolutional Neural Networks.

ABSTRACT: Convolutional neural network (CNN) has advanced in recent years and translated from research into medical practice, most notably in clinical radiology and histopathology. Research on CNNs in forensic/postmortem pathology is almost exclusive to postmortem computed tomography despite the wealth of research into CNNs in surgical/anatomical histopathology. This study was carried out to investigate whether CNNs are able to identify and age myocardial infarction (a common example of forensic/postmortem histopathology) from histology slides. As a proof of concept, this study compared 4 CNNs commonly used in surgical/anatomical histopathology to identify normal myocardium from myocardial infarction. A total of 150 images of the myocardium (50 images each for normal myocardium, acute myocardial infarction, and old myocardial infarction) were used to train and test each CNN. One of the CNNs used (InceptionResNet v2) was able to show a greater than 95% accuracy in classifying normal myocardium from acute and old myocardial infarction. The result of this study is promising and demonstrates that CNN technology has potential applications as a screening and computer-assisted diagnostics tool in forensic/postmortem histopathology.

Coronary artery thromboembolism from left appendage mural thrombus- a rare complication from atrial fibrillation.

A 54-year-old man with recurrent, persistent atrial fibrillation was found dead unexpectedly. He was reportedly non-compliant with his medications and was not on anti-coagulant therapy. He was found dead in his residence after complaining of abdominal discomfort a day prior to death. Postmortem examination revealed a thromboembolus occluding the left anterior descending coronary artery that originated from a mural thrombus in the left appendage, in addition to kidney infarcts. Although atrial fibrillation-related thromboembolism is often speculated to be a cause of myocardial infarction with non-obstructive coronary arteries, supporting pathological evidence is rare. This case documents radiological, macroscopic and microscopic images of this important complication from atrial fibrillation.

Levels of haemolysis have no effect on femoral vein post-mortem tryptase levels.

Haemolysis is reported to be an artefact that may alter post-mortem tryptase levels. However, previous studies did not sample peripheral blood using newly standardised methods. Recent studies have shown that some previously recognised peri- and post-mortem confounders can be muted by careful sample collection with first clamping and then sampling the femoral vein. This prospective study investigated the relationship between the degree of haemolysis of the blood samples and femoral vein post-mortem tryptase levels when sampled using this recommended method. Seventy consecutive post-mortem tryptase levels in non-anaphylactic deaths were compared to the degree of haemolysis of these samples, and results showed no significant correlation between them. The mean post-mortem tryptase level was 9.5 µg/L. This study demonstrated that the effects of haemolysis on femoral vein post-mortem tryptase was negligible when the blood was sampled using the recommended sampling method. Future studies on post-mortem tryptase as well as other typically used blood markers in forensics are recommended to adopt this method of blood sampling in routine practice.