Forensic consideration of death in the bathtub.

About 100-120 cases of 'sudden death in bathroom' are reported every year in our prefecture, which is 8-10% of the total number of what is considered unnatural deaths. For reasons that are still unclear, the victims die while bathing in the bathtub. This baffling form of death occurs mostly in the winter season and 80-% of these are elderly persons. However, despite a full autopsy, it is sometimes still very difficult to determine the cause of death or the direct cause of drowning in the bathtub. To prevent others from this mysterious form of death and to determine the risk factors for the elderly while bathing, we examined several parameters such as physiological changes and biochemical blood analysis in a total of 54 volunteers during both the winter and summer seasons in Japan. We found that some of the elderly developed cardiac arrhythmia such as ventricular tachycardia, ventricular extrasystole, supraventricular extrasystole, and bradycardia. Also, decreases of systolic blood pressure during bathing were observed during this experiment. We conclude that the development of extrasysytole or ventricular tachycardia can be a stress involved in bathing. These changes might contribute to cardiac arrest or to drowning in the bathtub. Moreover, a sudden decrease of blood pressure is considered to be a risk factor of cerebrovascular accident.