An autopsy case of suction injury.

The right upper extremity of a 38-year-old man was entrapped in an underwater intake of a water duct of a dam reservoir, and he died despite being promptly rescued. His right upper extremity was swollen and exhibited purplish-red discolourations. The skin had numerous blisters and increased tension. Severe subcutaneous and muscle bleeding were observed in the right upper extremity. The circumference and volume of the right upper extremity were approximately 1.2 and 1.4 times, respectively, that the circumference and volume of the left upper extremity. The increase in weight of the right extremity was calculated to be approximately 2.1 kg; this finding indicates a severe decrease in the victim's central blood volume. Furthermore, it is possible that much more than 2.1 kg of blood accumulated in the upper extremity upon exposure to vacuum pressure. We conclude that the victim died of circulatory collapse that was attributable to haemorrhage and re-distribution of blood as a result of vacuum pressure on the right upper extremity. Thus, we have examined the cause of death and the effects of vacuum pressure on the human body.

Complete decapitation of a motorcycle driver due to a roadblock chain.

An 18-year-old male driving an off-road motorcycle died from complete decapitation when his motorcycle tore a roadblock chain from its attachment. The decapitation injuries of the head and the torso corresponded perfectly, without apparent loss of tissue. The severance plane passed horizontally through the upper cervical region and C4, which sustained a comminuted fracture. The sharply delineated severance edge had a band-like abrasion. The decapitation resulted from the rotational movement of the unstrung chain, which struck and strangled the driver's neck. We were able to explain the movement of the chain and the decapitation mechanism. This case emphasizes the importance of discussing dynamics with experts to clarify a causal mechanism.