Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, 545-8585, Osaka, Japan; Forensic Autopsy Section, Medico-legal Consultation and Postmortem Investigation Support Center, c/o Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, 545-8585, Osaka, Japan. Electronic address: [Email]
The water contents of individual organs are maintained in a narrow range, but altered in morbidity owing to a disturbance of water equilibrium. The present study investigated the tissue water contents of major organs with regard to the cause of death in serial autopsy cases within 3 days postmortem (n = 329; 223 males, 106 females; age range, 1-100 years). Individual tissue water contents differed markedly across organs, but no significant postmortem or survival-period dependence, gender-related difference, or age dependence was observed. However, the lung water contents were higher in drowning cases, especially in saltwater cases (p < 0.05), and in strangulation among the acute mechanical asphyxiation cases. The brain water contents were higher in hypothermia cases (cold exposure) and tended to be higher in hyperthermia cases (heatstroke). The kidney water contents were higher in drowning and acute cardiac cases than in fatal intoxication and fire fatality cases, but tended to be higher in fresh- and bathwater drowning cases than in saltwater cases (p > 0.05). The spleen water contents were higher in bathwater drowning than in saltwater and freshwater cases, but did not differ among other the causes of death. These findings suggest that the postmortem tissue water content of individual organs, especially the lungs and/or kidney, depends on the cause of death and particularly contributes to differentiation between saltwater and freshwater drowning, respectively. This work therefore provides insight into the investigation of varied tissue water imbalances during the death process. In conclusion, we recommend the measurement of tissue water content because it is easy to perform and appears to be useful for evaluating the pathophysiology of systemic circulatory failure.