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.

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.

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.

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.

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.

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.

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.

Phlegmonous Psoas Muscle Infection Causing Sepsis and Death With Missing Postmortem Computed Tomography Scan Correlation.

ABSTRACT: Infection of the psoas muscle is a rare pathology, which carries a high risk of sepsis and is a potential cause of death. Classic symptoms include back pain and fever and it may be diagnosed premortem on computed tomography or magnetic resonance imaging, where abscess formation may be identified as a discrete rim enhancing and low-attenuation lesion. Infections without abscess formation, such as phlegmonous infection, may be more difficult to identify however, particularly if there is absence of other nonspecific findings, such as gas bubbles. We report a case of Staphylococcus aureus phlegmonous psoas muscle causing sepsis and death with no postmortem computed tomography scan correlation, where clinical history of back pain and an unknown source of sepsis was the only prompt for psoas dissection. This case highlights a potential postmortem computed tomography blind spot in abdominal pathology and we recommend dissecting the psoas muscle if sepsis is suspected but a definitive septic focus is unable to be identified.

Medicolegal Implications of Biphasic Anaphylaxis.

ABSTRACT: Biphasic anaphylaxis is an uncommon IgE-mediated condition whose pathophysiological mechanisms, risk factors, and predictive signs are not properly understood. Fortunately, the lethality of biphasic anaphylaxis, although probably underestimated, is low. Preventive clinical measures for biphasic anaphylaxis are neither standardized nor commonly applied. Furthermore, there are no laboratory protocols or anaphylactic markers to help identify the onset of biphasic anaphylaxis in clinical settings. The aim of this review is to highlight the medicolegal difficulties facing coroners and forensic pathologists in terms of the diagnosis and assessment of harm for victims and survivors of biphasic anaphylaxis.

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.

Differences Between Central and Peripheral Postmortem Tryptase Levels.

ABSTRACT: Postmortem tryptase is a commonly used biochemical test to aid in the diagnosis of fatal anaphylaxis, which is currently recommended to be sampled from peripheral (femoral) veins because of a research showing comparatively elevated levels from central blood sources. Previous studies have used nonstandardized or nondocumented sampling methods; however, more recent research demonstrates that tryptase levels may vary depending on the sampling method. This study used the recommended sampling method of aspirating the femoral vein after clamping and compared in a pairwise comparison with aspiration of central venous and arterial blood sources (inferior vena cava and aorta) in 2 groups of 25 nonanaphylactic deaths. We found no statistically significant differences in postmortem tryptase between central and femoral vein blood; however, sporadic outliers in central blood (particularly aortic blood reaching levels above documented cutoffs for fatal anaphylaxis) were observed. Our findings provide evidence for the existing recommendations that femoral vein blood remains the preferred sample for postmortem tryptase over central blood.

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.

Ventricular Weight Increases Proportionally With Total Heart Weight in Postmortem Population.

Heart weight is routinely measured at postmortem examination and is critical to determine whether the heart is enlarged (ie, cardiomegaly). Cardiomegaly has the potential to cause sudden death by being electrically unstable, resulting in fatal arrhythmias. The majority of fatal cardiac arrhythmias is ventricular in origin and is assumed that ventricular size is disproportionately larger in cardiomegaly. This prospective study compared ventricular weight (VW) and total heart weight (THW) in 40 consecutive cases. The results, unexpectedly, showed that VW increases proportionally and linearly with THW in normal and enlarged hearts (THW, >500 g) and did not increase disproportionally with increased THW. The ratio of VW/THW did not have any significant correlation or difference with sex, height, weight, and cardiac causes of death but did have a negative correlation with age. Further studies are indicated to document the morphological changes when the heart enlarges, which may aid in understanding the pathophysiology of sudden death from cardiomegaly.

Combining Postmortem Cerebrospinal Fluid Biochemistry With Lung-to-Body Ratio to Aid the Diagnosis of Salt Water Drowning.

Diagnosing drowning as a cause of death can pose many challenges for the forensic pathologist and a number of ancillary tests have been proposed to assist in the diagnosis, whether the body was in salt water or fresh water. Although elevated vitreous humor sodium and chloride is a reliable marker, its limitation to prolonged immersion has resulted in the recent investigation of cerebrospinal fluid (CSF) sodium and chloride as alternative matrix in cases of longer or unknown immersion times. This study investigated postmortem CSF from lumbar puncture (CSF_L_Na_Cl) and ventricular aspiration (CSF_Vent_Na_Cl), as well as lung/body (LB) ratio in the diagnosis of salt water drowning and performed comparison and combination testing of methods to improve diagnostic accuracy of the drowning diagnosis. This study found that CSF_L_Na_Cl was the most accurate method (89%) in the given cohort, but that CSF_Vent_Na_Cl and LB combined was the second most accurate method (83%), exceeding CSF_Vent_Na_Cl (77%) and LB (81%) used alone. These findings are useful for stratifying and prioritizing postmortem samples in the investigation of salt water drowning and also have significance for future studies using this methodology to combine and compare the accuracy of different investigations.

Perinephric Fat Stranding on Postmortem Computed Tomography Scan in Acute Pyelonephritis: A Case Report.

Infection/inflammation of solid organ can be difficult to appreciate at postmortem computed tomography (CT) scan (PMCT). Perinephric fat stranding is a clinical CT finding to suggest pyelonephritis; however, PMCT scan showing perinephric fat stranding in acute pyelonephritis has not been documented in the forensic literature. We present a death from acute pyelonephritis in a setting of hypertensive heart disease, in which the unenhanced PMCT performed before postmortem examination was able to show florid bilateral perinephric fat stranding. This PMCT finding subsequently guided the pathologist to pay special attention to the kidney and take appropriate microbiology specimens to confirm the diagnosis. Perinephric fat stranding on PMCT may be a useful sign to alert the pathologist to consider acute pyelonephritis during the postmortem examination.