Factors and circumstances influencing the development of hemorrhages in livor mortis.

Petechial hemorrhages or ecchymoses in the skin of the face and/or in eyelids and/or conjunctivae are one important feature in postmortem diagnosis of lethal strangulation. On the other hand, petechial bleedings can occur in various causes of death, especially in cases of neck or thoracic compression, they can occur in acute cardiac failure, as a result of blood or skin diseases or as a postmortem phenomenon. The focus of this investigation (retrospective study of 279 corpses, found initially in a prone position or some other face down position) was to analyse the frequency of postmortem (hypostatic) hemorrhages and factors which may influence their development. Petechial hemorrhages in livor mortis in the skin of the trunk and extremities were found in 110 cases (39%). The frequency ranged from 41% in the side position and 44% in the kneeling position to 50% in the prone position. Increasing intensity of livor mortis resulted in an increasing frequency of hemorrhages, up to 59%. In cases with a body-mass-index (BMI) of more than 26 the frequency of hemorrhages increased up to 64%. In cases without livor mortis when the corpses were found as well as in cases with complete movement of livor mortis after turning the corpses, no hemorrhages were found. If hypostasis was partly or completely fixed, the rate of hemorrhages increased up to 50%, without additional increase in longer postmortem intervals. Obviously postmortem petechiae develop neither very soon nor days after death, but within a period of several hours after death.