Pleural effusion in bodies recovered from water

Emerging issues in the approach to submerged bodies: Water-related deaths in Friuli, northeastern Italy (1993-2020). Analysis of post-mortem reports and some unusual cases

When analysing bodies recovered from a watery environment, all manners of death, a variety of causes of death and the possibility of body disposal have to be considered. Unclear circumstances of death, unidentified victims and body decomposition may hamper a forensic investigation. The lack of specific and sensitive drowning-related autopsy findings and post-mortem blood alcohol levels (blood alcohol concentrations (BACs)) may also lead to erroneous conclusions. We reviewed the autopsy records for all bodies recovered from water in Friuli, northeastern Italy, over a 28-year period, focusing on death circumstances, autopsy findings and blood alcohol levels. Some unusual cases were examined separately. Among the 69 cases, there were 32 accidents, 13 suicides, 4 homicides, 6 natural and 14 undetermined deaths. Causes of death included 51 drownings, 6 undetermined, 5 cardiac deaths and 7 non-drownings. Six deaths in a bathtub and one diving-related death were also included. Acute alcohol intoxication was ascertained in 22 of 40 victims. Some significant limitations in the approach to water-related deaths have been highlighted: although emphysema aquosum and external foam resulted to be the most reliable indicators, a determination of drowning based exclusively on autopsy findings cannot be ascertained with certainty. Furthermore, it was found that the standard definitions of wet and dry drowning in the literature differ widely from a morphological perspective and this may lead to misleading outcomes. Post-mortem BAC changes have been critically analysed only in bodies found in cold water, and, in the absence of an alternative to blood specimens, the use of pre-set cut-off values is still necessary.

Applicable Forensic Biomarker for Drowning Diagnosis: Extracellular Signal-Regulated Kinase 2 (ERK2)

Drowning is a common cause of accidental death worldwide, and it continues to be a serious public health problem. However, diagnosing drowning is a challenging task in forensic investigation because it is difficult to prove actual drowning and other submerged deaths with the autopsy techniques that are currently in use. Here, we show biomarkers that may be helpful for the diagnosis of drowning. We divided the experimental animals into four groups (drowning, postmortem submersion, hypoxia, and control) to evaluate the expression patterns of extracellular signal-regulated kinase 1/2 (ERK1/2). On gene expression analysis, only ERK2 was found to be significantly increased in the drowning groups compared to the other cases. In the immunoblot analysis, phosphorylated ERK2 (p-ERK2) was found to be upregulated in the drowning groups. Immunohistochemical staining also showed that p-ERK in alveolar cells revealed a granular pattern in the drowning groups. However, the expression pattern of ERK2 over time after drowning differed between the freshwater and seawater drowning groups. Taken together, these results indicate that ERK2 may be useful for distinguishing between drowning and postmortem submersion if the postmortem interval (PMI) of drowning is short. Conversely, if the PMI is long from the time that death occurs until the discovery of dead bodies, it is possibly more helpful for identifying between freshwater and seawater drowning.

Potential of photoautotrophic microbial organisms in deciphering forensic issues

In forensic pathology, solving the crime mystery of death due to drowning still remains a challenging issue. The amalgamation of autopsy findings and comparative study of diatoms recovered from the victim's body organs and suspected drowning site help to decipher the cause of death due to drowning or post-mortem immersion. Since the correct interpretation of the cause of death is an important criterion to provide justice to the victim, therefore, the main objective of our study is to throw light on the application of photoautotrophic micro-algal organisms, known as Diatoms, in solving seven cases of victims whose bodies were recovered from various water bodies of Himachal Pradesh, India. The diatom test was conducted by using reverse aqua regia solution (15 ml HNO₃: 5 ml HCl) on the bone marrow extracted from the organs and water samples respectively. The informative outcomes of the experimental analysis demonstrated that the diatom test acts as a beneficial adjunct to solve drowning-related crimes where the exact cause of death remains hidden even after performing an autopsy of the victims. The protocol followed by the authors can be used conveniently to recover diatoms from bone marrow as well as from water samples. Our results showed that the maximum cases were of death due to accidental drowning but for one case of suicidal drowning in extremely cold water.

Application of the Drowning Index to Opioid & Multidrug Intoxication Deaths: A Retrospective Analysis

Introduction

Drowning deaths present a challenge for forensic pathologists, because the autopsy findings may occur in many nondrowning scenarios. Previous studies have attempted to identify patterns in organ weights that may be specific for drowning. The drowning index (DI) has been defined as the weight ratio of the lungs and pleural effusion fluid to the spleen. Studies have suggested DI may be useful in confirming drowning as the cause of death. No studies have yet compared autopsy findings in drownings to those in drug-related deaths, in spite of their qualitative similarities.

Materials and Methods

We compared the lung and pleural effusion weight, spleen weight, and DI from 536 autopsies ruled drowning, opioid, or multidrug intoxication, or hanging in Columbia, Missouri, from 2011 to 2016.

Results

Opioid overdoses result in heavier lungs and spleens than drownings, multidrug overdoses, or hangings. There is no DI value at which a death can be definitively ascribed to drowning. The median DI was significantly higher in drownings than in opioid intoxications, multidrug intoxications, or hangings (P < .0001; P = .001; P = .005). However, very few drowning cases (13.33%) had a DI >14.1. Additionally, many opioid and multidrug overdoses had a DI >14.1. The highest calculated DI value (DI = 33) was associated with multidrug intoxication.

Conclusion

In our opinion, the DI has little, if any, utility in distinguishing between drowning and drug-related deaths.

Immunohistochemical expression of P-selectin, SP-A, HSP70, aquaporin 5, and fibronectin in saltwater drowning and freshwater drowning

The diagnosis of drowning is one of the most difficult in forensic medicine. The aim of this study was to analyze pulmonary tissue reactions in death by drowning. In particular, we focused on the immunohistochemical expression of P-selectin, SP-A, HSP70, AQP-5, and fibronectin to investigate our expression in drowning and to understand whether there are differences between saltwater drowning (SWD) and freshwater drowning (FWD), which may indicate a different pathophysiology. We retrospectively investigated 10 cases of SWD (Mediterranean Sea) from the Institute of Legal Medicine of Genoa (Italy), and 10 cases of FWD (Lake of Geneva) from the University Center of Legal Medicine of Geneva (Switzerland). As control group, we examined 10 cases of death by acute external bleeding, characterized by minimal respiratory distress. As compared with controls, in SWD cases, the results showed a decrease of SP-A expression with membrane patterns. Furthermore, we observed a greater SP-A expression with granular pattern in drowning cases without statistically significant difference between SWD and FWD. For the markers AQP-5, HSP70, fibronectin, and P-selectin, no statistically significant differences were found between SWD, FWD, and controls.

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.

The derivation of predictive equations to speculate the post-mortem interval using cases with over 20-mL pleural effusion: A preliminary study

Often, pleural effusion is noted at autopsy when the cause of death is drowning or diseases such as heart, renal and liver failure. Several studies have established a correlation between the concentrations of electrolytes in pleural effusion and the post-mortem interval (PMI) or those concentrations and drowning site. The present study aims to investigate the relationship between the amount of pleural effusion, concentrations of electrolytes and total protein in pleural effusion, by integrated interpretation using various factors such as the deceased's gender, age, cause of death, drowning site, PMI and body temperature. We included 40 cadavers (26 male, 14 female) with >20-mL pleural effusion, which were categorised into four groups as follows: freshwater drowning; brackish water drowning; seawater drowning (drowning group); and not drowning. An equation derived to assess the lung weight revealed that the drowning site affected the lung weight. An equation for the amount of pleural effusion in the drowning group for the first time revealed that the amount of pleural effusion was directly proportional to the PMI. Using an equation to assess the PMI, we could estimate the PMI within 13.0-13.2 h in cases with >20-mL pleural effusion. Despite a small number of cases in the present study, we attained exciting results from the integrated statistical analysis.

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.

Circumstances and autopsy findings in drownings, Department of Forensic Medicine, Aarhus University, 2006-2015

The purpose of this study was to examine the demographic circumstances and the autopsy findings regarding drowning deaths autopsied at the Department of Forensic Medicine, University of Aarhus. The study is based on autopsy reports from the Department of Forensic Medicine in Aarhus, 2006-2015 with drowning as a cause of death. Among the 135 cases of the study, 87 (64.4%) were accidents versus 33 (24.4%) suicides. The study showed, that the majority of the drowned 73,3% were males, especially pronounced in the accidents (81.6% were males). In 60.7% victims, there was a positive blood alcohol analysis, most often in males. Females with positive alcohol analyses did however have the highest mean alcohol blood level (1.65 versus 1.47 per mile). The most frequent place of the submersions was docks (24.4%) and the most frequent time of day was in the evening (18.00 – 23.59; 19.3%) and at night (00.00 – 05.59; 20.0%). The study shows no significant connection between adipocere and type of water (OR=1.21, 95% CI (0.49;2.99), p=0.68), bulging lungs and type of water (OR=1.18, 95% CI (0.52;2.70), p=0.69), lung weight and type of water (z-test, p=0.38) and the amount of pleural effusion and water type (z-test, p=0.16). A significant connection between the presence of pleural effusion and type of water cannot discounted (OR=2.37, 95% CI (1.06;2.44), p=0.02).

Forensic Case Reports Presenting Immersion Pulmonary Edema as a Differential Diagnosis in Fatal Diving Accidents

Immersion Pulmonary Edema (IPE) reduces the transport of gases over the respiratory membrane due to edema in the interstitium and respiratory zones. IPE has previously been described in both swimmers and divers, with a few known fatal cases. We have reviewed 42 SCUBA and snorkeling-related drowning deaths, and through a thorough analysis of each case, including both diving physiology and forensic pathology, we present IPE as a differential diagnosis to drowning in four cases. Our findings propose that; absence of watery content in the stomach and conducting airways, and liquid filled lungs without hyperexpansion, may be compatible with IPE. We suggest that IPE should be considered in cases where witness testimony reveals; no obvious signs of aspiration and rapid respiratory deterioration despite continuous breathing through an appropriate air source. The diagnosis should be based on the overall impression, including both the autopsy findings and the circumstances regarding the accident.

Post-mortem evaluation of drowning with whole body CT

PURPOSE

The aim of this study is to investigate the value of whole body computed tomography (WB-CT) in bodies recovered from water by analysis of the imaging findings after drowning.

METHODS

The bodies of 41 drowning victims and 9 persons who died from mechanical asphyxia by hanging underwent post-mortem whole body computed tomography.

RESULTS AND CONCLUSIONS

Excessive fluid in the paranasal sinuses (98%), nasal pharynx (98%), oropharynx (95%), trachea (83%), ground glass opacities in the lung (89%), pleural fluid (71%), pericardial fluid (59%), esophageal fluid (81%), stomach fluid and distension (71%), duodenal (34%) and jejunal distension (31%) were the most frequent drowning related imaging findings which significantly differed from the group of mechanical asphyxia by hanging. In cases of fresh water drowning hemodilution was present in 79%. New and up to now unpublished findings were lower density in the spleen, indicative for hemodilution and detection of a pronounced amount of pericardial fluid, only seen in drowning victims.

The Forensic Pathology of Drowning and Pulmonary Overexpansion Injury

Drowning deaths are commonly seen in most forensic pathology practices. Experienced forensic pathologists perform autopsies and assign a cause and manner of death in such cases as a matter of routine. Deaths due to pulmonary overexpansion injury and subsequent air embolism are far less common and typically involve individuals who have been breathing compressed gas at depth, generally SCUBA (self-contained underwater breathing apparatus) divers. This review outlines the pathophysiological basis of these two forensic pulmonary issues and recommends an approach to performing and interpreting the results of a forensic autopsy when faced with such cases.

Examination of histological samples from submerged carrion to aid in the determination of postmortem submersion interval

The use of histology in the as a tool for estimating postmortem intervals has rarely been explored but it has the potential for offering medical examiners an additional means for estimating the postmortem submersion interval (PMSI) during a death investigation. This study used perinatal piglets as human analogs which were submerged in freshwater for various time intervals. Each piglet was extracted from the water and underwent a necropsy examination during which histological samples were collected. The samples revealed that the necrotic tissue decomposed relatively predictably over time and that this decompositional progression may have the potential to be used via a scoring system to determine or aid in determining the PMSI. This method for calculating PMSI allows for normalization between piglets of various mass and body types. It also prevents any contamination of the remains via algae growth and animal activity that may exacerbate and possibly exaggerate PMSI calculation.

Decomposed and non-decomposed bodies retrieved from water: a comparative approach

The cause and manner of death in submersion cases are a routine challenge for forensic pathologists as they present considerable diagnostic difficulties. The present study was undertaken with a view to determine the characteristic pattern in bodies retrieved from water. From a total of 6779 medicolegal deaths reported at an Apex Medical Centre, Yeotmal, a rural district of Maharashtra over a 10-year study period, only 110 cases (1.6%) were decomposed and 243 cases (3.6%) were non-decomposed bodies retrieved from water with a rate of 0.6 decomposed body as compared with 1.4 non-decomposed bodies per 100,000 population per year. However, out of total 353 bodies retrieved from water, 31.2% were decomposed and 68.8% non-decomposed. Male predominance was seen in both groups with peak at 31-40 years. The cause and manner of death were ascertained as 89.9% and 82.7%, respectively, in decomposed bodies as compared with 100% and 96.3%, respectively, in non-decomposed bodies. Drowning was the commonest cause of death in both groups with suicide as the commonest manner of death in decomposed bodies in contrast to accidental in non-decomposed bodies. Excessive amount of pleural fluid, aquatic animal activity and mud/vegetation in lower respiratory tract was more commonly encountered in decomposed bodies. However, fine white froth was not seen in any of the cases in contrast to 81% non-decomposed bodies. Bodies were commonly recovered from wells in both groups. Most of the bodies were retrieved in the rainy season followed by summer and winter seasons in both groups.

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.

Predicting the postmortem submersion interval for human remains recovered from U.K. waterways

This article aims to increase accuracy in estimating the postmortem submersion interval (PMSI) for bodies recovered from rivers in the United Kingdom. Data were collected from closed case files, crime scene reports, and autopsy files concerning bodies recovered over a 15-year period from the River Clyde, Scotland, and the River Mersey and canals in northwest England. One hundred and eighty-seven cases met the study criteria and were scored by quantifying the overall amount of decomposition observed in each case. Statistical analysis showed that the duration of a body's submergence in water and the temperatures to which it was exposed, as measured in accumulated degree days (ADD), had a significant effect on the decay process. Further analysis indicated that there were no significant differences in decomposition between the waterways. By combining the data from all study samples, it was possible to produce a single linear regression model for predicting ADD from observed decomposition.

Forensic investigation of submersion deaths

CONTEXT

The diagnosis of the cause and the establishment of the manner of death in submersion cases are routine challenge for forensic pathologists as it presents considerable diagnostic difficulties.

OBJECTIVE

To concisely review the main questions during a submersion death investigation and to give the respective documented answers.

DATA SOURCES

The search strategy included a literature search of PubMed, Medline and Google Scholar databases, as well as a review of the cited references by the identified studies and a hand search of relevant textbooks and reference works.

CONCLUSIONS

A complete autopsy, histopathological examination and full toxicological screening are important to determine whether death indeed followed submersion in the water, or to see whether any natural disease or substance use have contributed or caused death. In ambiguous situations, the co-estimation of circumstantial evidence may be of invaluable importance toward the conclusion concerning the cause and the manner of death. The thorough forensic investigation of the submersion deaths not only serves the justice administration, but it also presents considerable benefits for the public health.

Presence of periorbital and conjunctival petechial hemorrhages in accidental pediatric drowning

The pathological findings of drowning are variable and non-specific. Petechial hemorrhages involving the periorbital region and the conjunctiva have been described in many causes of death, but are thought to be exceedingly uncommon in cases of drowning. However, such studies have not specifically addressed the pediatric population. The current study retrospectively examined 79 cases of accidental pediatric drowning for the presence of periorbital/conjunctival hemorrhages and analyzed factors that may have affected their presence. Ten victims had periorbital/conjunctival petechial hemorrhages (13%), with five having periorbital petechiae, three having conjunctival petechiae, and two having both periorbital and conjunctival petechiae. The age and gender of the victim, site of drowning, resuscitation history and the presence of other pathological findings were not significantly associated with the presence of periorbital/conjunctival petechiae. However, as the interval between the drowning episode and autopsy increased, the incidence of periorbital/conjunctival petechiae decreased (28% for <24h; 7% for >24h). The presence of periorbital/conjunctival hemorrhages in a significant proportion of pediatric drowning victims confirms that the pathologist must add this finding to the spectrum of changes seen in pediatric drowning.

Comparison between lung weight and blood strontium in bodies found in seawater

This paper examines the use of lung weight increase as an indicator of seawater drowning compared to the amount of Sr absorbed by the blood. The study population was limited to male victims older than 20 years. Significant differences between cases of drowning and "non-drowning" were detected in terms of the lung-heart weight ratio (L/H) (p<0.001) or lung-body weight ratio (L/B) (p=0.005). However, using lung weight (L), L/H or L/B to distinguish between seawater drownings and saltwater non-drownings some overlap was produced. The factor rendering least overlap was L/B, which also appeared to be non-dependent on the victim's age. Our findings suggest that a value of L/B higher than 19.5 g/kg could be a useful indicator of death by drowning, but that when a lower value is found, additional drowning diagnoses would be needed to establish the manner of death.

Pediatric drowning: a 20-year review of autopsied cases: II. Pathologic features

The pathologic findings in autopsies of drowning victims are nonspecific and vary from case to case. However, most reported pathologic series of drowning cases exclude children and do not take into consideration the unique circumstances surrounding bathtub drownings. In addition, the effect of resuscitation on the autopsy findings has not been studied in children. A retrospective review of autopsy records of non-bathtub drownings from a 20-year period (1984-2003) was performed and 63 cases were identified in 45 males and 18 females (age range 9 months to 17 years). The incidence of frothy exudate, pleural effusion, and increased lung weight was 43%, 36%, and 80%, respectively. The incidence of frothy exudate and the combination of all 3 factors was significantly higher in cases with no resuscitation compared with those cases with attempted resuscitation with or without delayed death. As the interval between the drowning episode and autopsy increased, the incidence of frothy exudate decreased significantly. There was no relationship between these findings and the age and sex of the decedent. Other clinical conditions or occult pathologic findings that may have contributed to death were found in 8 cases (13%). The findings highlight the need for thorough clinicopathologic correlation in cases of drowning to accurately interpret the pathologic findings.

Pediatric Drowning

Bathtub drownings are a significant cause of mortality in the pediatric population. Infants and preambulatory children are disproportionately affected, and several studies have suggested that preventative campaigns have been ineffective in the prevention of such deaths. To obtain a better understanding of the factors associated with bathtub drownings, a retrospective review of autopsy records over a 20-year period (1984-2003) was performed. Eighteen consecutive cases of bathtub drownings were identified in 8 males and 10 females (ratio, 0.8; P = 0.6374). The age ranged from 6 months to 70 months (mean, 17 months; median, 11 months), and most cases occurred in infants aged 12 months or less (72%). Males tended to be older than females (mean, 23 months versus 11 months; P = 0.1889). Associated factors included inadequate adult supervision (89%), cobathing (39%), the use of infant bath seats (17%), and coexistent medical disorders predisposing the infant or child to the drowning episode (17%). The pathologic findings included a frothy exudate (28%), pleural effusion (28%), and increased lung weight (61%). All toxicologic samples submitted for analysis were negative. The present study highlights the factors associated with bathtub drownings and may aid in the prevention of such deaths in the pediatric population.

Weight ratio of the lungs and pleural effusion to the spleen in the diagnosis of drowning

An accurate and reliable method of diagnosing death by drowning is an important requirement in forensic autopsies. In this study, we compared the weight ratio of the lungs and pleural effusion to the spleen for 55 cases of drowning (37 males, 18 females), 36 cases of mechanical asphyxiation (16 males, 20 females), and 26 cases of acute cardiac death (19 males, 7 females). In the case of the males, there were significant differences in the weight of the spleen and the total weight of the lungs and pleural effusion between drowning and the other causes of death; however, there was no such significant difference in the females. We observed significant differences in the lungs and pleural effusion/spleen weight ratio between drowning and the other causes of death for both sexes. Therefore, these findings suggest that the ratio may be a useful index to accurately diagnose death by drowning, while ruling out mechanical asphyxiation and acute cardiac death in forensic autopsies.

Drowning: still a difficult autopsy diagnosis

Investigation of bodies recovered out of water comprises an important proportion of the medico-legal requests. However, the key question whether the victim died due to "true" drowning can frequently not easily be solved. In addition, the diagnosis of hydrocution is even more difficult. In this manuscript, a review of reported diagnostic methods is discussed in order to provide guidelines, which can be used in current forensic practice. In particular, the (dis)advantages of various biological and thanato-chemical methods, described in literature during the last 20 years, will be confronted with the classical techniques such as the detection of diatoms and algae. Indeed, the diatom test is still considered as the "golden standard". In conclusion, the ideal diagnostic test as definite proof for drowning still needs to be established. At present, the combination of the autopsy findings and the diatom test is a good compromise in arriving at a conclusion. Additional biochemical and technical methods could be useful. Unfortunately, the cost-benefit analysis in current practice could be hard to defend. However, the importance of this subject asks for further scientific approaches and research.

Electrolyte analysis in pleural effusion as an indicator of the drowning medium

In medico-legal autopsies for drowned bodies, the location of drowning needs to be determined. To investigate the usefulness of electrolyte analysis in pleural effusion as an indicator of the location where the deceased has drowned, we determined the concentrations of electrolytes in the pleural effusion of rats drowned in four kinds of water. The concentrations of sodium and chloride ions in the pleural effusion of rats that drowned in seawater were significantly greater than those of rats that drowned in freshwater at both 1 day and 3 days after drowning. The concentration of potassium ions in pleural effusion 1 day after drowning showed no difference between each group, although it then increased from 1 to 3 days after seawater drowning, whereas it decreased from 1 to 3 days after freshwater drowning. The concentration of total protein in pleural effusion increased from 1 to 3 days after drowning, however, there was no significant difference in the concentration of total protein in pleural effusion between each group at either 1 day or 3 days after drowning. These results suggest that analysis of electrolytes in pleural effusion may be useful for determining whether drowning has occurred in seawater or in freshwater.

What Is the Incidence and Significance of “Dry-Lungs” in Bodies Found in Water?

BACKGROUND

Drowning without aspiration of liquid, generally attributed to death from asphyxia while submerged and in laryngospasm, has been reported to occur in approximately 10% to 15% of drowning victims.

OBJECTIVES

The occurrence of "dry-drowning" recently has been questioned and the hypothesis developed that "dry-lungs" in bodies found dead in the water could conceal more natural deaths than previously recognized.

METHODS

Based on 578 selected adult victims who presumably drowned, we analyzed the correlation between the cases with a low combined lung/pleura liquid weight (< 1000 g and < 750 g) and a wide set of individual, circumstantial, and postmortem (PM) variables, using multivariate logistic regression analysis. Victims with lung weight < 1000 g were screened for long-QT syndrome (LQTS) founder mutations in KCNQ1 and KCNH2 genes.

RESULTS

Of the 578 victims, 120 (20.7%) had a lung weight of < 1000 g, and 22 of these (3.8%) of < 750 g. Multivariate analysis showed a significant correlation for women (P < 0.001), for women aged 65 years or older (P < 0.001), and for men with prolonged PM submersion time (P < 0.001). "Normal" lungs were found in only 8 (1.4%) victims. Low-weight (< 1000 g), overdistended lungs with no sign of liquid penetration were seen in 11 (1.9%). No LQTS founder mutations were detected.

CONCLUSIONS

The actual incidence of death of persons found in water who have normal lungs or do not have penetration of liquid into their airways, based on our study, is much lower (below 2%) than currently assumed.