Yajima et al evaluated the concentration of electrolytes in the pleural fluid of drowning victims. The sum of sodium, chloride and potassium concentrations in the pleural fluid can help to distinguish drowning in freshwater versus seawater. The authors are from Chiba University in Japan.


Subject selection: drowning victim



(1) sodium concentration in pleural fluid in mmol/L

(2) chloride concentration in pleural fluid in mmol/L

(3) potassium concentration in pleural fluid in mmol/L


Measurement of electrolyte concentrations was average if pleural fluid from both sides were analyzed.


sum of electrolyte concentrations =

= SUM(concentrations of the 3 electrolytes)


Sum of Electrolytes


< 195.9 mmol/L

freshwater drowning

195.9 to 282.7

indeterminate or non-drowning control

> 282.7 mmol/L

seawater drowning



• Some patients who drown in seawater or freshwater will have values in the indeterminate range.

• One of the control patients had a value just over the threshold for seawater drowning.


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