Fatal positional asphyxia

Body-kun/body-chan style model figures for artists in forensic visualization applications

Posture and body position are often in the focus of forensic medicine. Visualization for the purposes of documentation, teaching, scientific presentation or expert opinion in court is often desired. Plenty of possible tools to support visualization are available. However, there is a significant gap between quick drawings and more complex techniques. Body-chan (female) and body-kun (male) artist's model figurines (genericized trademark) may provide a useful means to fill this gap. These models, about 12-15 cm in height, are multi-articulated humanoids of realistic proportions, intended to serve as models for manga (japanese comic) drawing. Plenty of different models are available in different quality which usually are equipped with interchangeable hand and feet attachments, a frame for 'levitating' positions as well as assorted objects to scale. These inexpensive models may be positioned quickly and intuitively. Photodocumentation from various angles can be performed using a mobile phone camera. Images may be further improved applying digital image manipulation software. Taken together, the process is quick and intuitive and the level of achievable complexity is sufficient for many forensic applications.

Postmortem Otorrhagia in Positional Asphyxia

Otorrhagia is generally associated with basilar skull fractures or diving accidents. In routine forensic medical practice, an accurate knowledge of the etiology of otorrhagia may have a key role to distinguish between traumatic and atraumatic causes and accidental, homicidal, or suicidal manners. The authors present the case of an unusual cause of atraumatic otorrhagia occurred in an elderly farmer found dead in a barn. He remained entrapped in a narrow tunnel created by some hay bales. The autopsy findings revealed only an intense polyvisceral congestion and subpleural petechiae, with no signs of traumatic injuries and no fractures of skull base or temporal pyramid. The cause of death was determined to be positional asphyxia, and the manner of death was deemed accidental. In fact, the head-down position resulted in diaphragm compression causing respiratory failure in combination with the stasis of the upper venous circle districts. Mechanical and gravitational forces related to upside-down position and increased vascular pressure also caused postmortem otorrhagia. In this case, the death scene investigation and circumstantial information allowed for reconstruction of the unique dynamics of the death. At the death scene, the position of the corpse must be accurately investigated because it can explain some cadaveric findings such as the ear bleeding or other markers of increased cephalic venous pressure like pink teeth, facial and conjunctival petechiae, or Tardieu spots. Therefore, forensic pathologists should consider that ear bleeding in dead bodies is not always the evidence of severe head blunt trauma or diving accidents, but it might be a postmortem phenomenon mostly related to body position.

Sudden deaths from positional asphyxia: A case report

RATIONALE

Positional asphyxia is a rare cause of sudden death and a difficult diagnosis, based mostly on the circumstances of the incident, along with particular external and internal findings, frequent in asphyxia (signs of sudden death).

PATIENT CONCERNS

In this report, we are describing one case of adult who was found positioned in a way that led to eventual asphyxiation.

DIAGNOSES

The final diagnosis of positional asphyxia was determined after the autopsy.

INTERVENTIONS

In a head-down position, gravitation and mechanical forces lead to an increased pressure on the diaphragm from the weight of the abdominal organs. Abdominal breathing, and later, chest breathing were hindered by the raised diaphragm and the difference between abdominal and breathing pressures.

OUTCOMES

It is known that death from positional asphyxia can emerge in several ways, such as the external breathing suppression when the victim's torso is compressed or deformed.

LESSONS

Therefore, the current criteria for positional asphyxia are based on the obstruction of normal gas exchange caused by the body position, the impossibility to move to another position, and the exclusion of other causes of death. The forensic medical examination must also be started at the scene of the incident.

Acute forces required for fatal compression asphyxia: A biomechanical model and historical comparisons

Background Fatalities from acute compression have been reported with soft-drink vending machine tipping, motor vehicle accidents, and trench cave-ins. A major mechanism of such deaths is flail chest but the amount of force required is unclear. Between the range of a safe static chest compression force of 1000 N (102 kg with earth gravity) and a lethal dynamic force of 10-20 kN (falling 450 kg vending machines), there are limited quantitative human data on the force required to cause flail chest, which is a major correlate of acute fatal compression asphyxia. Methods We modeled flail chest as bilateral fractures of six adjacent ribs. The static and dynamic forces required to cause such a ribcage failure were estimated using a biomechanical model of the thorax. The results were then compared with published historical records of judicial "pressing," vending machine fatalities, and automobile safety cadaver testing. Results and conclusion The modeling results suggest that an adult male requires 2550 ± 250 N of chest-applied distributed static force (260 ± 26 kg with earth gravity) or 4050 ± 320 N of dynamic force to cause flail chest from short-term chest compression.