Drowning: A Study of Temporal Bone Haemorrhage and an Analysis of Vitreous Humour

Deaths by drowning are a regular occurrence in the practice of forensic medicine. Since the external and internal signs are not always classical, the diagnosis is often determined by the exclusion of other causes of death. Some of the signs are regarded only as supportive evidence of drowning and cannot be used to establish accurately if the victim was breathing at the time of his immersion. Additional techniques have therefore been developed in attempt to establish more definitely, a diagnosis of drowning. Examination of internal organs for minute unicellular algae called diatoms is one such method and it has been successfully achieved by using an enzyme digestion method. One of the most significant aspects of the diatom test is the examination of the lungs and the distribution and number of diatoms in them. However, the value of the diatom test as a diagnostic method is still not entirely decided; it merely confirms that absorption of diatom-containing media has taken place. Therefore, while the diatom test cannot be considered as conclusive evidence of drowning, it has resolved some difficulties in the diagnosis. It is not considered a final solution to the problem. Drowning is a more complicated mechanism than mere inhalation of water and the results obtained in this work by the diatom test support this. Temporal bones from cases of drowning, possible drowning, other forms of asphyxia, and miscellaneous causes of death were examined to determine the reliability of intrapyramidal haemorrhage as a distinctive sign of drowning. Intracavitary haemorrhage of the middle ear and mastoid air cells is a highly characteristic feature of drowning; submucosal haemorrhage of the lining mucosa of the air cells is, also, an important sign and is considered a noteworthy feature. Although intracavitary and submucosal haemorrhages were detected in cases other than drowning, they were of a milder degree and grade than those found in true drowning. By using this finding, i.e. intrapyramidal haemorrhage, it has proved possible to establish or exclude a diagnosis of drowning. Moreover the lesion is a vital phenomenon, and by excluding other conditions, it can establish whether the victim was alive or dead before immersion. To estimate the immersion time in cases of drowning, the vitreous humour was analysed for Magnesium, Calcium, Potassium, Sodium, and Chloride to find a suitable correlation with the time spent in the water. It appears that dilution of these elements in fresh water submersion is caused both by water entering the hyperosmolar vitreous humour and ions diffusing out of it. However, individual variation in the degree of dilution restricts the application of the method in estimating the immersion time. Though there was an obvious depletion of vitreous humour ions, it was not consistently related to the time of immersion. It appears, however, that sodium and chloride in fresh water cases are related, albeit erratically, to the length of the immersion period