Diagnostic of Drowning in Forensic Medicine (original) (raw)

It was stated that fresh water is hypotonic and hyponatremic relative to blood inducing, after inhalation, a movementt of water from the alveoli into the blood and movement of sodium from the blood into the alveoli. These changes induce haemodilution, hypervolemia, hypnonatremia, hyperkalemia and haemolysis (Jeanmonod et al., 1992). As the sea water is very hypertonic relative to the blood, the water movement goes from blood into the alveoli and the electrolytes (sodium, chloride, magnesium) from the alveoli into the blood. The consequences of the sea water drowning should be haemoconcentration, hypovolemia and hypernatremia. The biochemical tests that proposed to assess the diagnostic of drowning are based on these fluids and electrolytes shifts. It is during the phases where water is penetrating from the alveoli into the blood circulation that particles like diatom passing through the alveolar-capillary interface before reaching internal organs. A vagal reflex may be also induced by inhalation of water, it will increase peripheral airway resistance with pulmonary vasoconstriction, decreased lung compliance and reduction of ventilation-perfusion ratios (Ornato, 1986). An intense stimulation of nerve endings at the skin, the mucosa of the ear drum, the pharynx or the larynx by cold water can lead to a cardiac reflex arrest. It was assumed that 10% of the drowned humans die after laryngospasm or breath-holding without actually aspirating fluid (Ludes & Fornes, 2003). A discussion was also hold about the volumes of inhalated water and the effect on the circulation. In drowning, the inhalated volume of water can range, from relatively small to very large. It has been showed that small amount of water, particularly cold water, may induce vaso vagal reflex or cardiac arrest reflex. When great amounts of water are inhalated and pass through the alveolar-capillary interface and enter the circulation, the phenomenon of destruction of surfactant and of the alveoli architecture leads to asphyxia. During the entering of water into the blood stream, the diatoms present in the drowning fluid may reach the internal organs. T o e s t a b l i s h t h e d i a g n o s i s o f d r o w n i n g i t i s o f p a r t i c u l a r i m p o r t a n c e t o c o r r e l a t e informations about the circumstances preceding the death, the past medical history of the victim if known, the circumstances of the body recovery from the water, the external examination, the autopsy findings and the results of the complementary analyses (histologic, biochemical, toxicological analyses and diatom test).