Saltwater Drowning Research Articles

Immunohistochemical and molecular study for differential diagnosis between freshwater and saltwater drowning

The postmortem identification of drowning in the field of forensic medicine is difficult due to unspecific autopsy findings, and usually, it is a “diagnosis of exclusion”. A model of drowning in salt and fresh water was established to discuss the postmortem changes after drowning and the differences between saltwater drowning (SWD) and freshwater drowning (FWD). The organs (brain and ‘lung) of 30 rats were extracted at three-time points (0 h, 24 h, and 48 h) after drowning. The histopathological, immunohistochemical,l, and molecular changes in the lung and brain of rats at different time points were investigated. Results show no significant difference in pathological findings between fresh and saltwater drowning. Casp3, JNK, and ERK all showed a rise in their postmortem expression in a time-dependent way; the expression of these three genes is much greater in cases of saltwater drowning compared to cases of freshwater drowning. So, it is concluded that after 24 h and 48 h from death, potent cellular oxidative stress occurred and caused the upregulation of the studied genes.

Application of Intracerebral Aquaporin-4 Expression in Differential Diagnosis of Drowning: an Immunohistochemical Study Related to Timing of Autopsy.

The role of forensic pathologists is pivotal in definitively diagnosing drowning cases. Further differentiation becomes essential for distinguishing between freshwater drowning (FWD) and saltwater drowning (SWD). Aquaporins are small integral membrane proteins that serve as major water transport pathways in various cell types. AQP4 appears to be involved in mechanisms related to cerebral volume regulation. Our study aims to examine the expression of AQP4 in the brain as a potential marker for differentiating between FWD and SWD relating to autopsy-performing timing. A total of 23 cases were classified into three groups: FWD, SWD, and controls. All samples were classified upon autopsy-performing timing into two subgroups: within and after 72 hours of death. The samples were then processed for histological and immunohistochemical investigations. For autopsies performed within 72 hours of death, we found a significantly higher value of AQP4-positive astrocytes in cases of FWD compared to SWD and control groups. We also found a significantly lower AQP4 expression in SWD cases compared to the control group. For autopsies conducted after 72 hours, the immunohistochemical staining does not reveal the peripheral terminations of astrocytes, which appear blurred and only recognizable as halos. In conclusion, the data aligns with existing literature about autopsies performed within 72 hours. However, in autopsies conducted after 72 hours, uncertain and even opposed results are observed. The difference can be ascribed to the post-mortem transformative processes that take place upon the cessation of vital functions.

Evaluation of eye and serum findings in different waters in rabbits by drowning and submersion modeling.

This study investigated serum, vitreous, and anterior chamber fluid electrolyte changes, corneal thickness (CT), corneal volume (CV), anterior chamber volume (ACV), and anterior chamber depth (ACD) as an auxiliary diagnostic method in the identification of drowning in fresh or salt water. The study used 35 healthy, adult, male, white New Zealand rabbits, seperated into five groups (control, saltwater drowning (SWD), saltwater immersion (SWI), freshwater drowning (FWD), freshwater immersion (FWI)). CT, CV, ACV, and ACD measurements were made with Pentacam topography at 0, 2, and 4 h in all groups. Magnesium (mg), sodium (Na), and chlorine (Cl) were measured in the blood at 0 and 2 h, and in blood, vitreous fluid, and humor aqueous at 4 h. It was determined that CT, CV, ACV, and ACD are not of great value in drowning diagnosis and are affected by the fresh or salt water rather than drowning. Vitreous Na, Cl, and Mg levels are ineffective in determining drowning after one h. Anterior chamber fluid may provide valuable information in the differentiation freshwater - saltwater drownings at the 4th h in corpses retrieved from water. Anterior chamber fluid Na and Cl levels, especially in corpses removed from salt water, can be an easily used test that can help diagnose drowning.

Study of possible biomarkers and electrolytes for diagnosis of death in fresh and saltwater drowning: A continual challenge in forensic practice

Study of possible biomarkers and electrolytes for diagnosis of death in fresh and saltwater drowning: A continual challenge in forensic practice

Forensic Diagnosis of Freshwater or Saltwater Drowning Using the Marker Aquaporin 5: An Immunohistochemical Study.

Background and Objectives: Aquaporins are a family of water channel proteins. In this study, the renal and intrapulmonary expression of aquaporin-5 (AQP5) was examined in forensic autopsy cases to evaluate it as a drowning marker and to differentiate between freshwater drowning and saltwater drowning. Materials and Methods: Cases were classified into three groups: freshwater drowning (FWD), saltwater drowning (SWD), and controls (CTR). Samples were obtained from forensic autopsies at less than 72 h postmortem (15 FWD cases, 15 SWD cases, and 17 other cases) and were subjected to histological and immunohistochemical investigations. Results: In FWD group, intrapulmonary AQP5 expression was significantly suppressed compared with SWD and CTR; there was no significant difference in AQP5 expression among the other two groups. The same differences in expression were also observed in the kidney. Conclusions: These observations suggest that AQP5 expression in alveolar cells was suppressed by hypotonic water to prevent hemodilution. Moreover, it is possible to hypothesize that in the kidney, with the appearance of hypo-osmotic plasma, AQP5 is hypo-expressed, as a vital reaction, to regulate the renal reabsorption of water. In conclusion, the analysis of renal and intrapulmonary AQP5 expression would be forensically useful for differentiation between FWD and SWD, or between FWD and death due to other causes.

Histopathological Differentiation of Drowning in Freshwater and Saltwater in Rats: Forensic Point of View

The postmortem diagnosis of death by drowning is one of the most difficult issues in forensic pathology. We investigated possible evidence differentiating saltwater drowning from freshwater drowning by histopathological changes in brain, heart, lungs, liver, and kidneys tissues. A cross section descriptive study was carried out on eighteen 12-week-old male Wistar rats; they were divided equally into 3 groups. Group 1: control group; Group 2: death by drowning in freshwater; Group 3: death by drowning in saltwater. Immediately after death, all tested organs were removed and fixed for histopathological examination. The brain of freshwater group depicted degenerated neurocytes with dystrophic changes in the form of shrunken cell, pyknotic nuclei and deeply eosinophilic cytoplasm. The heart showed clear evidence of myocyte injuries in saltwater drowning compared to the control and freshwater groups. The kidneys of rats drown in saltwater revealed more glomerular destruction with no differences in tubulo-interstitial changes in comparison with those drown in freshwater. In the lungs, the changes in freshwater were restricted to the alveoli, and the bronchial changes were more distinctive in saltwater. No disturbed liver architecture was seen in both test groups, however hydropic degeneration, congested vessels, and sinusoids were more distinct in saltwater group. In conclusion, diagnostic differentiation between fresh and saltwater drowning was reliable in rats’ lungs and heart with minimal differentiation in liver, kidneys, and brain. Further studies of drowning with different staining techniques will help to clarify the potential role of histopathological changes in body organs as indicator of drowning.

Epidemiology and autopsy findings of 500 drowning deaths

IntroductionDrowning is a significant public health problem worldwide and the WHO reported that drowning is the world’s third leading unintentional injury death. Nevertheless, there is still uncertainty regarding the estimate of local and global drowning deaths. In addition, the postmortem diagnosis of drowning is challenging and the physiological mechanisms of death by drowning are complex and not very well understood. PurposeTo analyze a large series of bodies retrieved from the water in Connecticut (U.S.) in order to compare epidemiologic and toxicological data with those of the literature, as well as to examine the weights of the lungs and brains in drowning deaths. Material and methodWe conducted a descriptive, retrospective, population-based analysis of all bodies retrieved from the water and subjected to a forensic autopsy at the Office of the Chief Medical Examiner in Connecticut (2008–2020, n = 500). Variables collected were sex, age, date of death, location of drowning, season, type of water, cause of death, manner of death, circumstances of death, signs of decomposition, BMI, brain weight, lung weight, presence of pulmonary edema, stomach contents, and toxicological analysis. ResultsThe death rates of drownings in Connecticut ranges from 0.75 to 1.28/100,000/year. They occurred predominantly in males (73.4%) and most were accidents (75.6%), though this gender difference diminishes in suicides (55.4% of males). Sex distribution is also different in bathtub drownings, where women drown more frequently (67.3%). Weights of the brains (p = 0.013) and lungs (p < 0.001) were higher in saltwater drownings. ConclusionsDrowning is more frequently an accident involving men, except for suicides where there is only a slight difference among sex. Heavy lungs and cerebral edema continue to be identified in numerous drowning deaths. These anatomic findings, however, must still be interpreted in the context of the entire case investigation. Weights of the brains and lungs are higher in salt water, although these organs’ weights are mostly dependent on other variables such as BMI and decomposition.

Immunohistochemical renal expression of aquaporin 2, arginine-vasopressin, vasopressin receptor 2, and renin in saltwater drowning and freshwater drowning.

The diagnosis of drowning is considered one of the most difficult in forensic medicine. Due to the paucity of signs, it is a classical diagnosis by exclusion. For this reason, specific immunohistochemical markers would be useful. Far too little has been done to analyze in-depth the differences between SWD and FWD. We focused on the renal immunohistochemical expression of aquaporin 2, AVP, V2R, and renin in cases of drowning. This study has two purposes: (1) to better understand the differences between saltwater drowning (SWD) and freshwater drowning (FWD), which may indicate different pathophysiology and (2) to eventually identify markers useful for the diagnosis of drowning. We retrospectively investigated 10 cases of SWD gathered from the Institute of Legal Medicine in Genoa (Italy), and 10 cases of FWD from the University Center of Legal Medicine in Geneva (Switzerland). As a control group, we investigated 10 cases of death by gunshot to the head. A strong expression of AQP2 and AVP was significantly (p < 0.05) more evident in cases of SWD than in FWD and control cases. Regarding the V2R, no statistically significant differences were found between the studied groups. The renin tubular expression was particularly intense (p < 0.05) both in SWD and in FWD compared controls. According to our results, AQP2 and AVP represent potential useful markers for the differential diagnosis between SWD and other causes of death, including FWD. Renin may be a useful marker in the diagnosis of drowning but it does not allow for differentiation between FWD and SWD.

Biochemical Markers and Pathological Features of Postmortem Time Interval Distinguishing Freshwater and Saltwater Drowning Induced Death in Albino Rats

Mahmoud M Elalfy1*, Hadeer H Ragheb1, Mohamed F Hamed2 and Fathy R Sleem1 Author Affiliations 1 Forensic medicine and toxicology faculty of veterinary medicine, Egypt 2 Pathology department faculty of veterinary medicine, Egypt Received: July 17, 2019 | Published: July 23, 2019 Corresponding author: Mahmoud Elalfy, Forensic medicine and toxicology faculty of veterinary medicine, Mansoura university, 35516 Egypt 60-Elgomhouria Street, Mansoura City, Egypt DOI: 10.26717/BJSTR.2019.20.003382

Elevation of Postmortem Cerebrospinal Fluid Sodium and Chloride Levels Is a Potential Adjunct Test in the Diagnosis of Salt Water Drowning.

Postmortem vitreous humor biochemistry is a useful test in the diagnosis of salt water drowning (SWD). A significant limitation of vitreous humor is the potential effect of prolonged immersion. A recent animal study and case report suggested that cerebrospinal fluid biochemistry may be an alternative to vitreous because it is more resistant to the effects of immersion, given its protected anatomical location. This study compared postmortem cerebrospinal fluid sodium and chloride (PMCSC) levels collected via ventricular aspiration (PMCSC_V) and via lumbar puncture (PMCSC_L) in 13 SWD and 31 nonimmersion deaths. It showed a significant elevation in PMCSC levels in SWD deaths for both PMCSC_V and PMCSC_L (P < 0.05). The areas under the curve on the receiver operating characteristic curves for PMCSC_V and PMCSC_L were 0.73 and 0.83, respectively. The optimal cutoff for PMCSC_V was 216 mmol/L (sensitivity, 0.60; specificity, 0.72; likelihood ratio, 1.80; positive predictive value, 0.45) and for PMCSC_L was 241 mmol/L (sensitivity, 0.78; specificity, 0.73; likelihood ratio, 2.89; positive predictive value, 0.46). This study supports PMCSC levels as another biochemical test that can potentially aid in the diagnosis of SWD, particularly in cases where vitreous humor samples are unavailable or uninterpretable.

A comparative digital morphometric study of lung tissue in saltwater and freshwater drowning

Acute pulmonary emphysema (APE) is describedin cases of drowning and can be considered as a sign of vitality. In our experience, however, APE is not very evident in cases of saltwater drowning. The present study aims at investigating whether APE is present in both fresh and saltwater drowning by means of digital morphometric analysis of lung tissue.We investigated and compared a group of saltwater drowning and a group of freshwater drowning, while cases of acute external bleeding were investigated as negative control group. Tissue samples from each pulmonary lobe were collected during autopsy and examined by optical microscope. The area of alveolar spaces was calculated by means of image analysis software, recording the mean alveolar area (MAA) for each group.MAA was 24,852 μm2 in the saltwater drowning group, 34,133 μm2 in the freshwater drowning group and 21,871 μm2 in the negative control group.The MAA in freshwater drowning was significantly higher than in saltwater drowning and controls. No statistical differences were observed between saltwater drowning and controls.The results of this study suggest that APE is not a typical sign of death by saltwater drowning.

Regional measurements of radio-density in the right atrium do not show differences between salt-water or fresh-water drowned or control decedents

Abstract Purpose To determine whether the use of post-mortem computed tomography (PMCT) measurements of blood radio-density within the right atrium could differentiate decedents grouped according to cause of death as controls, fresh-water or salt-water drowning. Methods PMCT images from drowning cases comprising fresh-water (n = 34) and salt-water (n = 30) incidents and also controls (n = 48) were selected from a forensic database. Four regions of interest (ROIs) were placed within the right atrium of the heart using a standardised procedure that accounted for sedimentation effects. Statistical analysis was undertaken using a two-way random effect inter-class correlation (ICC) test set for absolute agreement and then a repeated measures ANOVA test. Results ICC tests demonstrated very good agreement for the readings for all ROIs (ICC ≥ 0.90). A statistically significant sedimentation effect was observed across the anterior middle and posterior regions of the right atrium (F(2,218) = 212, p Conclusions Aspiration of fluid while drowning may cause changes in blood concentration. Blood concentration is measured using radio-density on PMCT images. PMCT radio-density data extracted from regional ROIs demonstrates the presence of the sedimentation effect but is not supportive of classification of drowning. There was good agreement between readers in the performance of this task.

Electrolytes and Biochemical Changes in Cerebrospinal Fluid in Drowning: Experimental Rabbit Model.

The diagnosis of drowning is still a difficult task in forensic science. Biochemical changes in different body fluids have been examined for the identification of drowning. However, none of them alone gives accurate results in the diagnosis of drowning and differentiation of saltwater and freshwater drowning. This study aimed to examine cerebrospinal fluid changes in drowned rabbits. Six groups of rabbits were used including immersed dead rabbits in freshwater or saltwater (as control groups), alive fully conscious rabbits drowned in freshwater and saltwater, and anesthetized rabbits drowned in freshwater and saltwater. Cerebrospinal fluid electrolytes except for potassium levels were significantly higher in rabbits drowned consciously in saltwater than their level in the control group. In rabbit drowned in freshwater, the examined electrolytes decreased significantly. In addition, urea, creatinine, uric acid, glucose, and tumor necrosis factor were different in cases of freshwater and saltwater drowning from those of control rabbits. Electrolytes and biochemical changes of unconscious rabbits drowned in water showed no significant difference from those of control rabbits. Cerebrospinal fluid examination in drowning gives promising results in the diagnosis of drowning. In addition, the differentiation between freshwater and saltwater drowning was possible.

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

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. The aim of this study was to compare the changes of vitreous Na, Cl, and Mg when immersed in salt water. 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. 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. 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.

Combining Postmortem Vitreous Sodium and Chloride and Lung-Body Ratio in Aiding the Diagnosing Saltwater Drowning

Diagnosing death due to drowning can be difficult, and several postmortem findings have been postulated to aid the diagnosis. Increased lung weights are often seen in drowning deaths. Lung-body (LB) ratio was described to be the best anatomical lung measurement in diagnosing drowning. Postmortem vitreous humor sodium and chloride (PMVSC) was reported to be a useful biochemical test in diagnosing saltwater drowning when the immersion time is less than 1 hour (SWD1). The presented study compared the diagnostic accuracies between LB ratio, PMVSC, and their combination in diagnosing SWD1 in 20 SWD1 and 50 nonimmersion deaths. Classification tree models were used for analysis and revealed that combination of PMVSC and LB ratio was most accurate in diagnosing SWD1 (misclassification rate, 4%), followed by PMVSC (misclassification rate, 10%) and LB ratio (misclassification rate, 24%). A quantifiable diagnostic improvement was established when both LB ratio and PMVSC were used. After adjusting for interlaboratory variations, the developed tree models can be a reliable way in aiding the diagnosis of SWD1.

Fluid Responsiveness: Goal-Directed Care or Resuscitative Guide to Salt Water Drowning?

Fluid Responsiveness: Goal-Directed Care or Resuscitative Guide to Salt Water Drowning?

Body Mass Index and Saltwater Drowning.

Comparison of body mass index (BMI) was undertaken between 30 cases of salt water drowning and 30 age- and sex-matched controls randomly selected from the autopsy files of Forensic Science SA, Adelaide, Australia, during the period 2000 to 2017. The age range of drowning cases and controls was 18 to 80 (average, 49) years, with a male to female ratio of 19:11. The BMIs of the drowning cases ranged from 15.5 to 37.5 (average, 25.4; median, 23). The control cases had higher BMIs ranging from 22.9 to 44.3 (average, 29.2; median, 25). The number of obese (BMI, ≥30) decedents in the drowning group was 5 (17%) and in the controls was 9 (30%). Individuals who drown in the sea may regularly swim, and thus be fitter and therefore slimmer than more sedentary controls. However, it is also possible that greater amounts of adipose tissue may be protective against drowning, as increased fat stores could improve buoyancy. Thinner individuals with denser body mass may have to struggle more to avoid submersion. It could be that a low BMI is an underappreciated finding that may increase the risk of lethal immersion along with alcohol intoxication and poor swimming skills.

Drowning investigated by post mortem computed tomography and autopsy

Abstract Case control study of drowning fatalities investigated with autopsy and post mortem computed tomography (PMCT). 40 drowning fatalities (25 men, 15 women; 24 salt water, 16 fresh water) and 80 controls were included. The aim was to investigate the difference in lung tissue density (g/liter) and radio opacity between drowning cases compared to control cases and to determine if it was possible to differentiate saltwater and freshwater drowning by measuring a difference in radio density of blood in the hearth chambers or great vessels before and after passage through the lungs of a drowned individual or when comparing drowned individuals with controls. The lung density was measured by a combination of PMCT measured total lung volume and autopsy measured total lung weight. We found that the lung density and the lung radio density were decreased, the lung volume increased and the lung weights equal in drowning cases compared to controls, illustrating the phenomenon knows as “emphysema aquosum”. The physiological explanation could be washing out of surfactant by the drowning media, resulting in atelectasis and trapping of air in the peripheral lung regions. It was not possible to separate fresh and saltwater drowning by comparing radio opacity of blood in the hearth chambers or great vessels or by comparing the radio opacity of blood in cases and controls. We suspect that sedimentation of red blood cells after death makes such measurements meaningless.

Is There a Clinical Difference between Salt Water and Fresh Water Drowning?

Introduction: Salt water near-drowning events are not uncommon in coastal regions. The difference in tonicity between salt and fresh water in near-drowning events leads many to believe there should be differences in the approach to managing the patient. We present a case of near-drowning in salt water and a thorough review of the literature in managing these patients.

Comprehensive investigation of postmortem glucose levels in blood and body fluids with regard to the cause of death in forensic autopsy cases

The serum glucose level is regulated within a narrow range by multiple factors under physiological conditions, but is greatly modified in the death process and after death. The present study comprehensively investigated glucose levels in blood and body fluids, including pericardial fluid (PCF), cerebrospinal fluid (CSF) and vitreous humor, reviewing forensic autopsy cases (n=672). Right heart blood glucose level was often higher than at other sites, and the CSF glucose level was the lowest, showing greater dissociation in acute/subacute death cases. The glucose level was higher in the diabetic (high HbA1c) than in the non-diabetic (low HbA1c) group at each site (p<0.01-0.0001). Fatal diabetic ketoacidosis cases had evidently high glucose levels at each site; whereas in the non-diabetic group, blood glucose level was higher in fatal alcohol abuse, saltwater drowning, electrocution, cerebrovascular disease and sudden cardiac death due to ischemic heart disease. Fatal methamphetamine (MA) abuse, sepsis, malnutrition (starvation) and hypoglycemia due to antidiabetics showed markedly lower blood glucose levels. Ketones in bilateral cardiac blood and PCF were increased in diabetic ketoacidosis and fatal alcohol abuse as well as in most cases of hyperthermia (heatstroke), hypothermia (cold exposure) and malnutrition. These findings suggest that combined analysis of glucose, HbA1c and ketones in blood and body fluids is useful to investigate not only fatal diabetic metabolic disorders but also death processes due to other causes, including alcohol and MA abuse, as well as thermal disorders, sepsis and malnutrition.