Vitreous Humor Sodium Levels in Immersion Deaths

Objective evaluation of changes in serum transmittance over time using a portable color digitizer

Forensic pathologists empirically understand that postmortem changes can decrease serum transparency and change its color. Such changes are potential indicators for estimating postmortem intervals; however, reports on color changes focusing on postmortem changes in serum are scarce. To elucidate the effect of postmortem intervals on serum levels, we quantitatively evaluated and investigated the relationship between serum color and time using venous blood samples obtained from three healthy male volunteers. The serum samples were separated at 0 (1 h), 1, 2, 3, 4, 7, 10, 16, 21, and 28 days of storage. Serum transmittance and color were measured using a portable color digitizer and a custom-made measurement tool, respectively. Additionally, serum sodium (Na) and potassium (K) concentrations were measured. Serum transmittance showed a logistic curve-like decrease from 0.652 ± 0.016 (0 days) to 0.101 ± 0.014 (28 days) over time. The color changed from greenish yellow (dominant wavelength: 574.4 ± 0.63 nm) to reddish orange (603.97 ± 1.31 nm). Serum Na concentration decreased, whereas serum K concentration increased along the logistic curve. Strong (0.89, p < 0.001) and inverse correlations (-0.93, p < 0.001) were observed between the serum transmittance decrease and the Na concentration decrease and the K concentration increase, respectively. Serum transmittance decreased over time, indicating a transition from bright to dark. Moreover, a strong correlation was observed between serum transmittance and electrolytes, indicating a relationship between time course, serum transmittance, and electrolytes. These findings may contribute to the estimation of postmortem intervals in the future.

Use of cadaveric vitreous humor as an innovative substrate for diatoms research and forensic diagnosis of drowning

The search for diatoms is the test that most of all may contribute to the forensic diagnosis of drowning. Diatoms can be extracted through different methods, which are all complex and long. In this preliminary study, we assessed human vitreous humor as an innovative substrate on which to research diatoms. Sampling and analyses were performed on 3 groups of 10 corpses each. The first one was composed of drowned victims. The second one of victims of traffic accidents with subsequent projection in water; based on the severe traumatic injuries reported at autopsy, we considered such victims as ideally assimilable to bodies immersed in water postmortem. The third group was composed of subjects who died for natural causes and without any relationship with water. The vitreous humor was centrifugated and cytocentrifuged and spotted on two different histological slides: one was left blank and the other one was assessed with hematoxylin and eosin staining. Microscopic observation successfully revealed diatoms in all cases of the first group; in the second group diatoms were not detected in 6 cases; in the third group, no diatoms at all were observed. Diatoms were always qualitatively and quantitatively consistent with those found in the corresponding viscera and waters, which had been investigated through classical acid digestion. Our analyses have demonstrated that the vitreous humor behaves in a completely similar way to the other viscera in cases of drowning. Although further investigations are necessary, vitreous humor has proved to be an innovative, suitable, and reliable substrate for the forensic research of diatoms.

The use of vitreous renal chemistries in the discrimination of postmortem fresh water drowning

Background:

The World Health Organization (WHO) has estimated drowning as the leading cause of unintentional death in the world, with 372,000 deaths reported annually. Not all drowning are unintentional; some could be disguised to cover up an act of heinous criminality. This study was aimed at using some vitreous renal function biochemical parameters as a discriminant of postmortem fresh water drowning. Twelve albino rabbits constituted the sample size as validated by Mead’s formula. The study was divided into three groups; the control, postmortem-drowned and truly drowned as mimicked using an artificial fresh water pond. Vitreous humours were extracted using Coe method. The vitreous renal chemistries were analysed using diacetyl monoxime, Jaffe’s test, uricase and ion-selective electrode (ISE) methods respectively.

Result:

The mean of vitreous creatinine, urea, uric acid, Na+, K+, Cl−, Ca2+, glucose and CO2 of the control, postmortem-drowned and truly drowned groups were compared using One-way Anova (post-hoc-LSD) with the aid of SPSS Inc., Chicago, IL, USA; Version 18–21 package. The findings revealed a significant increase in concentrations of vitreous creatinine, glucose, Ca2+ and K+ of the drowned death group, whereas vitreous concentrations of CO2 and urea significantly decreased when compared to the controls and/or postmortem-drowned death.

Conclusion:

The study has shown that some of the studied vitreous biochemical parameters could be used as an ancillary tool in discriminating death due to fresh water drowning from that of disguised or postmortem-drowned death.

Vitreous humor endogenous compounds analysis for post-mortem forensic investigation

The chemical and biochemical analysis of bodily fluids after death is an important thanatochemical approach to assess the cause and time since death. Vitreous humor (VH) has been used as a biofluid for forensic purposes since the 1960s. Due to its established relevance in toxicology, a literature review highlighting the use of VH with an emphasis on endogenous compounds has not yet been undertaken. VH is a chemically complex aqueous solution of carbohydrates, proteins, electrolytes and other small molecules present in living organisms; this biofluid is useful tool for its isolated environment, preserved from bacterial contamination, decomposition, autolysis, and metabolic reactions. The post-mortem analysis of VH provides an important tool for the estimation of the post-mortem interval (PMI), which can be helpful in determining the cause of death. Consequently, the present review evaluates the recent chemical and biochemical advances with particular importance on the endogenous compounds present at the time of death and their modification over time, which are valuable for the PMI prediction and to identify the cause of death.

Diagnosis of Drowning and the Value of the Diatom Test in Veterinary Forensic Pathology

The detection of diatoms into the organs is considered an important “biological marker” for the diagnosis of drowning in human pathology, but it still has a high possibility for false positive results. The aims of this study were: (1) to evaluate the contribution of pathological examination in drowning cases and (2) to investigate the differences in the number and location of diatoms between animals who died in drowning and non-drowning conditions. For these purposes, 30 dead adult dogs were selected for the study and subdivided into five groups. The group A comprised six cadavers dead for drowning; the group B comprised six control animals; the groups C, D, and E comprised six animals dead for causes other than drowning and subsequently immersed in water for 24, 48, and 72 h, respectively. On each animal, a complete macroscopic and histological examination and diatom test were performed. Diatoms test and quantification were also performed on drowning mediums. Pathological findings of the animals in the group A showed pulmonary congestion, oedema, and hemorrages in the lung. However, similar injuries were also observed in control and experimentally submerged cadavers. In contrast, we observed a statistically differences between drowning animals and all experimentally submerged groups and control animals regarding diatom numbers recovered from organ tissue samples (p < 0.05). Therefore, these findings suggest that the number of diatoms may be used as a valid tool to differentiate animals who died in drowning and non-drowning conditions, even if the latter were found in an aquatic environment.

[Exercise-Associated Hyponatremia in Endurance Performance]

Exercise-Associated Hyponatremia in Endurance Performance Abstract. Exercise-associated hyponatremia is defined as a plasma sodium concentration of <135 mmol/l and was first described by Timothy Noakes at the Comrades Marathon in South Africa in the mid-1980s. A decrease in plasma sodium <135 mmol/l occurs with excessive fluid intake. Risk factors include long to very long endurance performance, extreme climatic conditions, female gender and competitions in the USA. Regarding its prevalence by sport, exercise-associated hyponatraemia tends to occur while swimming and running, but rarely when cycling. While mild exercise-associated hyponatremia does not lead to clinical symptoms, severe hyponatremia due to cerebral edema can lead to neurological deficits and even death. The best prevention of exercise-associated hyponatremia is the reduction of fluid intake during exercise.

The persistent problem of drowning - A difficult diagnosis with inconclusive tests

Although the diagnosis of drowning may appear straightforward the reality is that it is sometimes one of the most difficult in forensic pathology. To begin with, there is no universal agreement on what constitutes drowning with some definitions using the term in the absence of a lethal outcome. Next are the significant problems that arise in finding immersed bodies and in assessing the death scene. Prolonged post mortem intervals are associated with artefactual modifications of the body from putrefaction and post mortem animal predation. Both of these may create and disguise injuries. The absence of pathognomonic pathological features at autopsy and the presence of potentially life threatening underlying organic illnesses complicate determination of both the cause and manner of death. There may even be no autopsy findings to indicate that immersion had occurred. Finally, the unreliability of laboratory tests with significant overlap with control cases where death had no association with immersion presents further problems. Thus lethal drowning remains a complex event that requires the use of a wide variety of information sources, not just data gleaned from the dissection table.

Veterinary Forensic Pathology

Determining the cause of death in animals recovered from bodies of water, swimming pools, or other water-containing vessels is challenging. Animals recovered from water may or may not have drowned. The diagnosis of drowning is usually one of exclusion, requiring information from the crime scene, recovery scene, the medical history or reliable witness accounts. While there are characteristic macroscopic and microscopic lesions of drowning, none are specific and are dependent on the volume and tonicity of the drowning medium. Beyond interpreting the postmortem findings, the court may ask pathologists to comment on the behavioral and welfare implications of drowning. This requires an understanding of the drowning process, which is a complex series of sequential, concurrent, and overlapping cardiorespiratory reflexes, electrolyte and blood gas abnormalities, aspiration, physical exhaustion, and breathlessness eventually culminating in death. This review addresses the mechanisms, lesions, and diagnostic issues associated with drowning in nonaquatic companion animals.

Svechnikov's sign as an indicator of drowning in immersed bodies changed by decomposition: an autopsy study

PURPOSE

Bodies recovered from water often present as a difficult problem in forensic pathology. The aim of this study was to examine the presence and amount of free liquid in the sphenoid sinus in cases of freshwater drowning, and to compare this to the amount found in putrefied bodies recovered from freshwater, as well as in putrefied bodies found in an indoor environment.

METHODS

Free liquid from the sphenoid sinuses was aspirated using a syringe and a needle, after piercing the hypophyseal fossa. Non-putrefied drowning cases were also examined for hemolytic staining of the intima of the aortic root.

RESULTS

In 29 non-putrefied cases of freshwater drowning there was 1.36 ± 1.48 ml in the sphenoid sinuses, with 21 of them having hemolytic staining of aortic intima. In putrefied bodies recovered from freshwater (22 cases) there was 1.26 ± 1.40 ml within the sphenoid sinuses, and in putrefied bodies found in an indoor environment (52 cases), there was significantly less-0.57 ± 0.92 ml.

CONCLUSIONS

Free liquid in the sphenoid sinuses (Svechnikov's sign) may be considered a vital reaction in drowning non-putrefied cases. Hemolytic staining of the aortic intima could be a significant sign of freshwater drowning. In putrefied bodies recovered from water, an amount of 0.55 ml of free liquid in the sphenoid sinuses may imply that the victim was alive upon their contact with the water, but the presence of free liquid in the sphenoid sinuses does not necessarily indicate that drowning had been the cause of death.