Macromorphological findings in cases of death in water: a critical view on "drowning signs"

Abstract

Death in water is a challenging issue in forensic pathology since from natural death to homicide all circumstances of death in water are conceivable. Therefore, the correct interpretation of all abnormal autopsy findings is important. In order to determine a death by drowning, numerous internal and external signs of drowning are already described. However, these are supposed to be influenced by various factors reducing their significance and evidence. Moreover, the autopsy of water corpses often reveals further pathological findings that should not be underestimated for determining the cause of death. The aim of this study was to set frequencies of the observed drowning signs in context to the forensic literature and to identify possible influencing factors. In this study, we observed that pathological organ changes of the cardiovascular system were significantly more common in corpses after shortened (atypical) drowning processes than in classical drowned victims. Furthermore only a complete formation of external foam, immediately after the corpse's recovery, was exclusively found in drowning victims. All other drowning signs were either also observed in non-drowning deaths in water or no information could be provided with reasonable assurance. In addition, many of the examined drowning signs were negatively affected by prolonged postmortem intervals, putrefaction, or resuscitation attempts. It can be concluded from our analysis that morbidity is an important factor in deaths in water. Morbidity can support a death by drowning in case of incidents in water. For the examined drowning signs, no high diagnostic certainty could be observed. Nevertheless, these findings can increase their diagnostic value-if forensic physicians take influencing factors into consideration.

Keywords: Autopsy diagnoses; Drowning; Emphysema aquosum; Foam; Putrefaction; Svechnikov sign.

Fig. 1

In all other parts of the airways, except the bronchi, the frequency of foam on site, which was spread out less, decreased. The difference is significant at p = 0.006

Fig. 2

Manifestation of foam depending on laytime in water. The degree of foam expression is illustrated depending on the corpse laytime in water. A complete external foam formation at time of autopsy could only be observed at laytimes of less than 24 h (6.5% of cases). With increasing laytime in water, the frequency of foam detection in autopsy at all decreased. This influence by prolonged laytimes in water is highly significant (p < 0.001)

Fig. 3

Frequencies of drowning signs within drowning or other causes of death. Of all examined drowning signs, only external foam directly after corpse recovery could be observed significantly and exclusively in cases of drowning. Foam in the airways at time of autopsy was also seen in non-drownings. Other signs, seen exclusively in cases of drowning, occurred in a small number of cases. Emphysema aquosum and hemorrhagic breathing muscles were also common in non-drownings. *Significant distribution