A comparative study of pleural effusion in water area, water temperature and postmortem interval in forensic autopsy cases of drowning

Akiko Ishigami,Hiroki Yamamoto,Masayuki Kashiwagi,Brian Waters,Aya Matsusue,Mizuho Nosaka,Toshikazu Kondo,Shin-Ichi Kubo,Kenji Hara,Yuko Ishida

doi:10.1038/s41598-021-01047-2

Akiko Ishigami, Hiroki Yamamoto + Show 8 more

Open Access

https://doi.org/10.1038/s41598-021-01047-2

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Abstract

Japan is surrounded by the sea and is also a mountainous country with many rivers. Japan has the second- highest rate of deaths caused by drowning in the world. Pleural effusion (PE) is one of the major findings at autopsy. It is found in approximately 80% of drowning mortalities and is observable for a relatively long postmortem interval (PMI). We focused on the amount of pleural fluid in drowning cases, discussed the relationship of PE with the drowning environment, water temperature, and postmortem interval, and established more simple and practical criteria for the diagnosis of drowning. We measured the weight of the lungs, PE, and their sum as the intrathoracic (IT) weight (total weight of lungs + pleural effusion), and calculated the PE ratio [(PE weight/IT weight) × 100]. A total of 130 drowning deaths diagnosed through forensic autopsies were investigated in this study. The cases were classified by drowning environment (freshwater, brackish water, and seawater), water temperature (under 20 °C, more than 20 °C), and postmortem interval (less than 1 day, 1–3 days, more than 3 days). The present study demonstrated that the PE ratio may be more effective for the diagnosis of drowning. Moreover, the accumulation of PE is affected by drowning environment, water temperature, and PMI. Collectively, it is important to assess the PE ratio and consider these factors in autopsy cases of victims found in water.

Highlights

Japan is surrounded by the sea and is a mountainous country with many rivers
External foam protruding from the nostrils and mouth, frothy fluid in the airways, lung overinflation and waterlogging, and pleural effusion (PE) are major findings in drowning[2,3]
External foam cannot be observed in victims with a long postmortem interval (PMI)

Summary

Result

The weight of the lungs was higher in the seawater group than in the brackish water group (p < 0.05). The PE ratio was lower in the freshwater group than in the brackish water group (p < 0.05) (Fig. 1). PE ratio The PE ratio increased in freshwater and seawater as the PMI increased In brackish water, it was significantly increased in the ≥ 3 days group than the 1–3 days group (Fig. 3c). 1. All cases classified by water temperature Each parameter showed no significant difference. 2. Drowning environment (Table 2) The PE ratio was higher in the < 20 °C group than in the ≤ 20 °C group in seawater (p < 0.01) (Fig. 4). In cases with PMI ≤ 1 day, the PE weight and ratio increased in the 20< °C group (p < 0.01). No significant differences were observed between the two groups in terms of trauma, drugs, or chemicals

Discussion

Methods

Findings

Trauma