Diagnosis of drowning by combined computer-assisted histomorphometry of lungs with blood strontium determination

The aim of our study was to examine the combined contribution of computer-assisted histomorphometry of lungs with blood strontium (BS) measurement to the diagnosis of drowning in cadavers recovered from fresh water. The study population comprised 116 drowned subjects. The results for this group were compared with those obtained for three non-drowned groups: 22 subjects who died from causes other than asphyxia, 13 subjects who died of asphyxia (strangulation or hanging); and 23 healthy living subjects in whom normal BS level was measured. Samples of water where the bodies had been found were analyzed in order to establish a relation with the BS concentration of the drowned subjects. Histologically, each type of pulmonary lesion (congestion, edema, alveolar macrophages, alveolar hemorrhage, and emphysema aquosum) was evaluated semiquantitatively using a score according to the severity of the pathology. Then, a quantitative histomorphometric study was performed using a computer-assisted image analyzer to measure the length and thickness of the alveolar walls, and the area and density of the alveolar cavities. The mean values of the BS levels in the 116 drowned subjects and of the water strontium concentrations were found to be much higher than in the living individuals. Although the ranges were wide, we found no overlap between values found in drowned subjects and those in non-drowned subjects. Emphysema aquosum and to a lesser extent alveolar hemorrhage were found to be the most significant histologic changes in the drowned and asphyxia groups compared with the nonasphyxia control groups.