Frequency of macroscopic intradural hemorrhage with and without subdural hemorrhage in early childhood autopsies.

Some authors have suggested that in the fetus, neonate and infant, intradural hemorrhage (IDH) is relatively common and often presents alongside subdural hemorrhage (SDH). These authors have theorized that pediatric SDH may result from an IDH due to blood leakage from a dural vascular plexus. In this study, we report the inter-observer variation for detection of IDH from a retrospectively collected series of pediatric autopsy photographs, with and without SDH. Autopsy photographs of the falx and tentorium from 27 neonatal, infant and early childhood autopsies were assessed by two independent consultant forensic pathologists blinded to all case histories for the presence and extent (focal or diffuse) of IDH. Inter-observer agreement between the pathologists was calculated using Cohen's kappa coefficient. The occurrence of subdural hemorrhage was also recorded at autopsy. A kappa coefficient value of 0.669 (p = 0.001), indicated a substantial level of agreement for the presence/absence of IDH between the pathologists. For the extent of IDH a kappa coefficient value of 0.6 (p = 0.038) indicated a moderate level of agreement. The pathologists agreed on the presence of IDH in 10 of the 27 cases. Subdural hemorrhage was recorded for 8 out of 27 cases. Of these 8 cases, it was agreed that 4 had IDH. Using standardized methods of image capture and assessment, inter-observer agreement for the presence/absence of IDH was substantial. In this paper, we report a much lower frequency of macroscopic IDH occurring alongside SDH than previous studies, which included both gross observation of IDH and histological examination.

Diagnostic accuracy of post-mortem CT with targeted coronary angiography versus autopsy for coroner-requested post-mortem investigations: a prospective, masked, comparison study.

BACKGROUND: England and Wales have one of the highest frequencies of autopsy in the world. Implementation of post-mortem CT (PMCT), enhanced with targeted coronary angiography (PMCTA), in adults to avoid invasive autopsy would have cultural, religious, and potential economic benefits. We aimed to assess the diagnostic accuracy of PMCTA as a first-line technique in post-mortem investigations. METHODS: In this single-centre (Leicester, UK), prospective, controlled study, we selected cases of natural and non-suspicious unnatural death referred to Her Majesty's (HM) Coroners. We excluded cases younger than 18 years, known to have had a transmittable disease, or who weighed more than 125 kg. Each case was assessed by PMCTA, followed by autopsy. Pathologists were masked to the PMCTA findings, unless a potential risk was shown. The primary endpoint was the accuracy of the cause of death diagnosis from PMCTA against a gold standard of autopsy findings, modified by PMCTA findings only if additional substantially incontrovertible findings were identified. FINDINGS: Between Jan 20, 2010, and Sept 13, 2012, we selected 241 cases, for which PMCTA was successful in 204 (85%). Seven cases were excluded from the analysis because of procedural unmasking or no autopsy data, as were 24 cases with a clear diagnosis of traumatic death before investigation; 210 cases were included. In 40 (19%) cases, predictable toxicology or histology testing accessible by PMCT informed the result. PMCTA provided a cause of death in 193 (92%) cases. A major discrepancy with the gold standard was noted in 12 (6%) cases identified by PMCTA, and in nine (5%) cases identified by autopsy (because of specific findings on PMCTA). The frequency of autopsy and PMCTA discrepancies were not significantly different (p=0·65 for major discrepancies and p=0·21 for minor discrepancies). Cause of death given by PMCTA did not overlook clinically significant trauma, occupational lung disease, or reportable disease, and did not significantly affect the overall population data for cause of death (p≥0·31). PMCTA was better at identifying trauma and haemorrhage (p=0·008), whereas autopsy was better at identifying pulmonary thromboembolism (p=0·004). INTERPRETATION: For most sudden natural adult deaths investigated by HM Coroners, PMCTA could be used to avoid invasive autopsy. The gold standard of post-mortem investigations should include both PMCT and invasive autopsy. FUNDING: National Institute for Health Research.

Estimation of postmortem interval using vitreous potassium levels in cases of fatal road traffic collision

AIM OF THE STUDY: To produce a formula that can accurately predict postmortem interval (PMI) based on vitreous potassium levels using road traffic collision fatalities. MATERIAL AND METHODS: Vitreous humour samples were taken from 78 individuals who had died following road traffic collisions between 2010 and 2015. Samples were obtained from both eyes and were sent for on-site analysis. Measurement of potassium was by an indirect ion-specific electrode Siemens diagnostics ADVIA 2400 chemistry system. Exact time of death was known from police reports, the time of postmortem was recorded and the postmortem interval was calculated. Linear regression was then used to analyse the relationship between the two. The impact of age was also assessed. RESULTS: PMI was between 6 and 162 hours. As vitreous potassium increases, the PMI also increases; exhibiting a linear relationship. This is illustrated by a regression equation of PMI = 6.42[K+] - 40.94, R = 0.67 (p < 0.001). This produced a formula closely comparable with three other studies proposed in previous literature and produces estimates that may exceed one calendar day. When both age and medical intervention are accounted for there is an insignificant improvement in prediction. CONCLUSIONS: Validated methods have been used to produce a formula for prediction of PMI using vitreous potassium. Although this is specific to road traffic collisions, the methods are transferable and can be seen to be comparable with other recently published methods. Nonetheless, if greater levels of accuracy are required it is suggested that biomarkers delivering a higher level of precision should still be sought.

Detection of bacterioplankton using PCR probes as a diagnostic indicator for drowning; the Leicester experience.

Bodies found immersed in water can pose difficulties to the investigating authorities. Pathologists may be assisted with the diagnosis by the use of tests such as the analysis for diatoms or the levels of strontium in the blood, although there is a recognised level of uncertainty associated with these tests. Recent work from Japan has shown that using molecular approaches, most recently real-time polymerase chain reaction (PCR) assays with TaqMan probes for bacterioplankton, it is possible to undertake rapid, less laborious, high throughput tests to differentiate freshwater from marine bacterioplankton and in doing so provide a molecular diagnostic test to assist in the diagnosis of drowning. We report the experiences of a United Kingdom forensic pathology unit in the use of this PCR based system for the diagnosis of drowning. We applied this technique to 20 adult and child cadavers from 4 bath, 12 freshwater, 2 brackish and 2 salt water scenes both from within the United Kingdom and abroad. Drowning was concluded to be the cause of death in 16 of these 20 cases and the PCR method supported this conclusion in 12 of these 16 cases. The PCR did not provide evidence of drowning in the four cases where death was from other causes. We illustrate that this PCR method provides a rapid diagnostic supportive test for the diagnosis of drowning that can be applied to United Kingdom autopsy practice.

The role of histology in forensic autopsies: is histological examination always necessary to determine a cause of death?

In England and Wales there is a conflict between the law and advice from regulatory bodies in relation to the sampling of human tissue for histological examination following medico-legal post-mortem examinations. Considering the results of previous publications, we performed a specific study to investigate the role of histology in determining the cause of death in cases at a forensic unit. A retrospective study of 500 adult forensic cases was performed. Cases were categorized by the role the histological examination played in determining a cause of death and its contributory factors. Furthermore, cause of death, manner of death, organ systems involved, and discrepancies were assessed. Of the 500 cases, histology was undertaken in 287 cases (58 %). Microscopic examination provided the cause of death in 2 % of cases where histology had been undertaken, and it added to the cause of death in 8 %. In 61 % of cases microscopy confirmed the macroscopic findings, and in 30 % it did not influence the medical cause of death. Histological examination of all organs in all forensic cases for the purpose of providing a medical cause of death is not supported. Practice guidance should be adjusted to reflect that, while histological examination is essential in certain circumstances, the decision to retain material for histology should be made on a case by case basis at the pathologist's discretion.