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Restraint and control techniques
Published in Jason Payne-James, Richard Jones, Simpson's Forensic Medicine, 2019
Jason Payne-James, Richard Jones
Positional asphyxia is a term that describes respiratory impairment as a consequence of the position in which a person finds themselves, including whilst being restrained. It can occur as a result of the individual being held down and being unable to maintain adequate respiratory movement either because of the chest and/or the diaphragm being splinted, for example, because law enforcement/security personnel are kneeling on the chest and thorax. The risk of death is further heightened by lying prone (face down), being handcuffed behind the back, being unable to change position, obesity, respiratory or cardiac disease, and struggling against restraint.
Mechanical and Physical Injury
Published in John M. Wayne, Cynthia A. Schandl, S. Erin Presnell, Forensic Pathology Review, 2017
John M. Wayne, Cynthia A. Schandl, S. Erin Presnell
Answer D is incorrect. Positional asphyxia occurs when the airway is obstructed due to the positioning of the body. This may result in someone who is impaired and unable to correct their position, such as a person under the influence of significant concentrations of alcohol. During positional asphyxia, there is no expectation of intermittent arterial impedance; thus, scleral hemorrhage is not a common finding. But, depending on the position, venous impedance may occur and the presence of petechial hemorrhages may be seen both with positional asphyxia as well as strangulation.
The Decomposed Body and the Unascertained Autopsy
Published in Julian L Burton, Guy Rutty, The Hospital Autopsy, 2010
Positional asphyxia occurs when an individual becomes trapped in a position so that he or she is unable to expand the chest and therefore cannot breathe. There may be few or no findings at autopsy, and indeed other possible causes of death must be excluded macroscopically, histopathologically and with the aid of microbiology and toxicology. A detailed knowledge of the position in which the body was found, ideally obtained by visiting the scene or reviewing the photographs of the scene of death, is essential if this diagnosis is to be made. ‘Found collapsed at bottom of stairs, ? positional asphyxia’ is not sufficient information on which to make this diagnosis. The body must have been in a position that would prevent gas exchange, and there should be a reason why the deceased was unable to move out of that position (Belviso et al., 2003).
The onset and severity of acute opioid toxicity in heroin overdose cases: a retrospective cohort study at a supervised injecting facility in Melbourne, Australia
Published in Clinical Toxicology, 2022
Nathan C. Stam, Shelley Cogger, Jennifer L. Schumann, Anthony Weeks, Amanda Roxburgh, Paul M. Dietze, Nicolas Clark
In this study, we also demonstrated that heroin overdose cases differ in the severity of acute opioid toxicity. Our results demonstrate exaggerated effects of central respiratory depression and depression of consciousness with higher levels of toxicity. Another key finding of our study was the risk and impact of airway occlusion in heroin overdose cases, including the inability to autocorrect positional asphyxia as an early and consistent feature across all levels of toxicity. This finding is consistent with a recent study indicating that positional asphyxia may contribute to greater than one-third of all opioid overdose-related deaths in the community [22]. In our study, the impact of airway occlusion as a clinical feature in heroin overdose cases was particularly highlighted in Grade 1 acute opioid toxicity severity cases. Findings showed rapid physiological deterioration and life-threatening hypoxia in many cases due to ventilatory impairment, despite underlying retained central respiratory drive, and where complete clinical resolution of these cases was achieved without the requirement for ventilation or naloxone. These results are important because a comprehensive understanding of the direct toxicological effects of acute opioid toxicity at the time of a heroin overdose is fundamental to implementing evidence-based clinical and public health interventions. Results from our study highlight that early intervention in heroin overdose cases is critical for reducing adverse outcomes in overdose cases, where timely intervention and the correction of airway occlusion, ventilation, and/or naloxone administration may be required.
Characteristics and circumstances of synthetic cannabinoid-related death
Published in Clinical Toxicology, 2020
Shane Darke, Johan Duflou, Michael Farrell, Amy Peacock, Julia Lappin
The most common circumstance of death was accidental drug toxicity (Table 1). In five cases, the cause of death was combined drug toxicity/cardiovascular disease. Possible positional asphyxia was noted in five cases, all of which were deaths due to toxicity.