Post Mortem Vitreous Electrolyte Analysis as an Adjunct in the Diagnosis of Salt Water Drowning

Abstract

Drowning is a potential cause of death in a deceased individual immersed in water. The diagnosis of drowning can be challenging because the post mortem findings are variable, transient, and non-specific and, thus, non-diagnostic. Traditionally, contextual investigation followed by a full post mortem examination has been required for all suspected drowning deaths. However, in cases of strong contextual evidence and the family's objection to a full post mortem examination, the availability of a non-invasive adjunct test to aid the diagnosis of drowning would be ideal. Although it was previously studied and subsequently abandoned in the 1970s and 1980s, post mortem vitreous electrolyte analysis (a non-invasive test) has recently been re-examined and showed promising results. This thesis examined and established post mortem vitreous electrolyte analysis as a useful adjunct in the diagnosis of salt water drowning. Three sections are presented that examine different aspects in the use of post mortem vitreous electrolytes as an adjunct in the diagnosis of salt water drowning. Each section contains published original studies and illustrative case(s). The first section established that the post mortem vitreous sodium and chloride (PMVSC) level increases, first from salt water drowning and subsequently from immersion. It demonstrated that PMVSC is a useful adjunct in the diagnosis of salt water drowning when the immersion time is less than 1 hour. The second section established that the post mortem vitreous magnesium (PMVM) level increases from salt water immersion, but not from drowning, which is different from the changes in the PMVSC. Because of this difference, PMVM can be used to assess the effect of immersion when the immersion time is greater than 1 hour or is unknown to aid in the interpretation of PMVSC levels. The third section demonstrated that combining PMVSC and lung weight (in the form of lung-body ratio, LB) provides greater diagnostic certainty for salt water drowning death compared to using either PMVSC or LB alone. The results have practical implications for the approach to salt water drowning deaths. The traditional approach of performing a full post mortem examination in all cases of suspected drowning deaths is challenged and may not be necessary. The use of post mortem vitreous electrolytes provides a less invasive approach that can be used in selected cases. Furthermore, the methodology and analytical techniques presented in this thesis can be extended to fresh water drowning deaths and non-drowning deaths.