Postmortem Vitreous Sodium and Chloride Elevate After 1 Hour and Magnesium After 2 Hours in Bovine Eyeballs Immersed in Salt Water.

BACKGROUND: Postmortem vitreous sodium (Na) and chloride (Cl) are good ancillary tests in diagnosing salt-water drowning. Vitreous Na and Cl appear to elevate from salt-water drowning and immersion, whereas vitreous magnesium (Mg) appears to be unaffected by drowning, but elevates from immersion. The relative changes of these electrolytes during salt-water immersion are unknown, particularly with shorter immersion times. Understanding the relative changes may aid in the interpretation of vitreous electrolytes in bodies recovered from salt water. AIM: The aim of this study was to compare the changes of vitreous Na, Cl, and Mg when immersed in salt water. METHODS: Bovine eyeballs were randomized into 2 groups (submerged in salt water and control). The vitreous Na, Cl, and Mg from 6 eyeballs were measured from each group (without replacement) at 1, 2, 4, and 6 hours. RESULTS: There were no statistically significant elevations in bovine vitreous Na and Cl for up to 1 hour and vitreous Mg for up to 2 hours. CONCLUSIONS: Bovine vitreous Na and Cl elevate earlier than Mg when immersed in salt water. Assuming similar physical properties, an elevation in vitreous Mg in bodies immersed in salt water indicates the immersion effects of causing raised vitreous Na and Cl have started.

Postmortem Vitreous Humor Magnesium Does Not Elevate in Salt Water Drowning When the Immersion Time Is Less Than an Hour.

BACKGROUND: Elevation in postmortem vitreous humor sodium and chloride (PMVSC) in salt water drowning (SWD) when the immersion time is less than 1 hour (SWD1) is hypothesized to result from electrolyte changes in blood from salt water inhalation/ingestion during drowning. After approximately 1 hour after death, electrolytes may diffuse into the vitreous humor via the eye coverings. Another abundant element in salt water is magnesium, which is approximately 50 times higher in concentration than the blood and vitreous humor magnesium levels. Magnesium is able to diffuse across the eye coverings but not as easily through the blood-ocular barrier. With these properties, we hypothesize that postmortem vitreous magnesium (PMVM) would not be elevated in SWD1 but become elevated in SWD with immersion times greater than 1 hour (SWD>1). AIM: The aim of this article was to investigate the differences in PMVM and PMVSC between nonimmersion deaths, SWD1, and SWD>1. METHODS: This is a 1-year retrospective study comparing PMVM and PMVSC in nonimmersion deaths, SWD1, and SWD>1. RESULTS: Postmortem vitreous magnesium is significantly higher in SWD>1 than SWD1 and nonimmersion deaths, with no significant difference between SWD1 and nonimmersion deaths. Postmortem vitreous humor sodium chloride is statistically higher in SWD1 and SWD>1 than nonimmersion deaths. CONCLUSIONS: As a conclusion, PMVSC elevates and PMVM does not elevate in SWD1.