A novel method for the diagnosis of drowning by detection of Aeromonas sobria with PCR method

The acid digestion method has been widely used for the diagnosis of death by drowning, but it is not always sensitive. However, there has been no definitive method to replace acid digestion until now. We speculate that bacteria are more useful markers than plankton for the diagnosis of death by drowning. In this study, from the preserved blood samples of 32 freshwater drowning cases, specific DNA fragments of Aeromonas sobria, one of the most common aquatic bacteria, were examined using PCR. The DNA fragments of the bacterium were detected from 27 of 32 cases with first round PCR or nested-PCR. The remaining 5 cases in which bacterial DNA was not detected had longer storage periods for the blood samples and shorter time intervals from drowning to death. These results indicate that the present method can be applied to the diagnosis of death by drowning.     

Diatomeennachweis und -identifizierung

The diagnosis of death by drowning is one of the most difficult problems in forensic medicine, because it must be proven that covering of the airways by fluid has occurred by active aspiration of the drowning medium. The comparative identification which combines a qualitative and quantitative investigation of diatoms from tissues of the corpse with that of the drowning medium is a specific detection procedure which, by positive results, allows the diagnosis of typical drowning. The results of this detection must be assessed in combination with the autopsy findings, the toxicological analyses as well as the pathological-anatomical, biochemical and biophysical investigations. The cause and circumstances of death can be then be concluded from the combination of all these parameters     

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.     

Frequent detection of stomach contents in accidental drowning

We analysed forensic autopsies of 536 consecutive adults to determine the relationship between the presence of stomach contents and the manner of death. Stomach contents were identified in 27 (79.4%) of 34 accidental drownings and in 22 (43.1%) of 51 suicidal drownings (P < 0.01). Accidental drowning was the manner of death most frequently associated with the presence of stomach contents, and stomach contents were found significantly more often in this type of death than in suicidal drowning. These findings indicate that food intake is a factor possibly related to accidental drowning and suggest that fasting may be required before swimming or taking a bath to prevent accidental drowning.     

The number of diatoms recovered from the lungs and other organs in drowning deaths in bathwater

We assessed the plankton levels using the diatom test in the lungs and organs of the circulatory system of nine postmortem cases of bathwater drowning and one case of death due to ischemic heart disease (IHD) while bathing, as well as in the associated bathwater. The number of planktons detected in the lungs was not related to the postmortem period or the process of drowning, but was related to the plankton levels detected in the bathwater taken from the scene. In one case of bathwater drowning, the diatom distribution of the four pulmonary lobes (165.0-280.0planktons/100g sample) and other organs (3.6-13.6/100g) highly corresponded to the pattern of 'usual' drowning in water which contains a lot of diatoms. In this case, the bathwater taken from the scene contained a considerable amount of planktons (16.3/100ml water), which suggests that, when the bathwater is relatively 'dirty', the diatom test may be helpful in reaching a diagnosis of drowning. In another case of drowning, a considerable number of diatoms was detected relatively evenly in all four pulmonary lobes (58.3-141.7/100g), although no planktons were detected in distant organs. In this case, the bathwater also contained a substantial number of planktons (18.8/100ml), which suggests that a relatively even distribution of planktons in each pulmonary lobe may also support a diagnosis of drowning based on the autopsy findings when the bathwater is relatively 'dirty'. In the other seven cases of drowning, few planktons were detected in the lungs (0-18.2/100g) and other organs (0-9.1/100g) as well as in the associated bathwater (0-3.1/100ml). These cases suggest that if autopsy findings indicate drowning, the low levels of diatoms detected in both the pulmonary lobes and the bathwater may indicate drowning in clean water. In contrast, in one case of death due to IHD while bathing, no planktons were detected in the organs except for the lower lobe of the right lung (11.8/100g) and the left kidney (9.1/100g), although the bathwater contained a sufficient number of planktons by the diatom test (21.3/100ml). This case suggests that the diatom test may be helpful in distinguishing drowning and other causes of death in bathwater by comparison of the diatom levels in the organs and the bathwater. All of these results indicate that the diatom test may be helpful to differentiate ambiguous cases of drowning in bathwater. However, in this study, although special care and precautions were undertaken, contamination with some planktons could not be prevented. For accurate interpretation and diagnosis, examination and comparison of test results from all four pulmonary lobes, at least four distant organs, and the associated bathwater from the scene of death are necessary together with careful consideration of autopsy findings.     

Action Plan for Near Drownings

In brief: The outcome of a near drowning depends on the patient's physical condition before the accident, the duration of submersion, the temperature of the water, and how much water entered the lungs and stomach. Dr. Podolsky describes the pathophysiology of drowning, a practical action plan for treating victims, and preventive measures. The key to successful management is shortening the duration and extent of hypoxemia. In addition, patients should be monitored in intensive care units for at least 24 hours, because potentially fatal complications may develop. Preventive measures include restricting access to unguarded pools and teaching the public basic cardiopulmonary resuscitation techniques.     

Postmortem lung weight in drownings: a comparison with acute asphyxiation and cardiac death

There are several controversial findings and arguments about the lung weight as a marker of drowning. The aim of the present study was to examine the difference in the lung weight and the amount of pleural effusion between freshwater and saltwater drownings (n=70 and n=75, respectively), in comparison with asphyxiation (n=85) and acute cardiac death (n=82), for the diagnosis of drowning. In drowning cases, a gradual postmortem time-dependent decrease in the lung weight and a reciprocal increase in the pleural effusion suggested postmortem transudation from the lungs. The decrease in the total value of the combined lung weight and the amount of pleural effusion was marked in saltwater immersion after 3 days postmortem, suggesting a leakage of the effusion out of the thoracic cavity under an osmotic effect of the immersion medium. In cases within 3 days postmortem, when the combined lung weight and amount of pleural effusion were added to estimate possible combined lung weight at the time of death, there was a gross difference among the causes of death: the value was the largest in saltwater drowning, followed by freshwater drowning, acute cardiac death and asphyxiation. However, the value depended on the gender and age of the subjects, suggesting a relation to the individual physical constitution and survival time or vital activity. These factors should be taken into consideration in evaluation of the lung weight in the diagnosis of drownings.     

Gastric mucosa lesions in drowning: its usefulness in forensic pathology

In a retrospective study of 52 autopsy cases of drowning fatalities, death circumstances, macroscopical and histological findings of the stomach mucosa were carefully studied. Results were compared with a control group, composed by 80 cases of different kinds of asphyxia (hanging, chocking and suffocation), skull injuries, sudden cardiac death and poisonings. The spectrum of gastric lesions observed during autopsy in drowning group, are presented. Stomach mucosa tears were found in 21.1% of the cases of drowning, preferably on fundus (54.5%). The control group does not show similar lesions. The physiopathological mechanism of its production, are also discussed. On sight of these results, it is concluded that the macro and microscopical examination of the stomach could be useful as an adjunct procedure for drowning diagnosis. The presence of gastric mucosa lesions has an intravital significance and could be correlated with other anatomical or histological signs of drowning for the diagnosis. In every case, necropsic examination must be carried out as soon as possible in order to avoid putrefactive artifacts.     

Determining the effect of water temperature on the T1 and T2 relaxation times of the lung tissue at 9.4 T MRI: A drowning mouse model

Japanese individuals have a unique culture of soaking in a bathtub, and forensic pathologists have experienced fatal cases due to drowning. However, T1 and T2 relaxation times of a drowning lung are poorly documented.In the present study, we investigated the relationship between drowning water temperature and T1 and T2 relaxation times of drowning lung tissues at 9.4 T MRI (Bruker, BioSpec94/20USR). The mice used as animal drowning models were directly submerged in freshwater. Water temperature was set to 8 °C–10 °C (cold), 20 °C–22 °C (normal), 30 °C, and 45 °C. The regions of interest (ROIs) on the axial section of the third slice were set at the central and peripheral areas of each—the left and the right—lung. T1 relaxation times measured immediately after death differed by the presence or absence of soaking water, except in case of cold water temperature. In the drowning groups, T1 relaxation time showed a linear dependency on water temperature. By contrast, T2 relaxation time was almost constant regardless of the presence of drowning under the same temperature condition; when compared in the lung areas of the same individuals, the times were uniformly reduced in drowning models. To minimize the effects of hypostasis and decomposition, we performed measurements immediately after death and were able to determine the noticeable difference in drowning water temperature. These results may be useful for qualitative assessments of a drowning lung and may serve as a basis when imaging the human body during forensic autopsy cases.     

Der Tod im Wasser

Death occurring in water is not always caused by drowning. There are many different pathophysiological mechanisms responsible for these fatalities. This educational article first describes the diversity of "death in the water," i.e., typical drowning, atypical drowning, or immersion death. The pathophysiology and pathology of typical and atypical drowning are described. The macromorphological and histological findings in cases of drowning are discussed as to their significance for the diagnosis of drowning. Immersion death is most often caused by autonomous neural reflexes due to water exposure. Finally, the changes due to immersion in water and possible injuries to the body after death are described, followed by explanations regarding bodies found in the bath tub and different kinds of diving accidents.     

Diatoms and drowning

Summary An examination is made of the applicability of quantitative and qualitative diatom analysis to the diagnosis of death by drowning, definition of the environment in which drowning occurred, and delimitation of the area where it occurred. The material comprises 107 bodies of subjects known or suspected to have died by drowning together with a control series of 15 bodies of subjects over 30 years of age who had died of various diseases on land.Whenever diatoms were found in the greater circulatory organs they were also found in the lungs, and when none were present in the lungs none were found in the other organs either. No diatoms or fragments of diatoms were found in the samples from the control subjects. All the fresh, well-preserved bodies for which death by drowning could be regarded as certain from the macroscopic autopsy findings and police reports, the cases used to test the method, gave quantitative diatom results that supported a diagnosis of water aspiration.The diatoms identified in the qualitative analyses served well to describe the ecological properties of the environments in which death had taken place, and the site of drowning could be defined by means of comparative water samples provided that sufficient diatoms were present, the local environment was not too homogeneous or the diatoms were not of quite different species due to a completely unknown location of death.     

Concordance analysis of diatom types and patterns in lung tissue and drowning medium in laboratory animal model

Diatom test has been widely used in the diagnosis of drowning and inferring the drowning site. One of the issues is whether the concordance of the diatom types and patterns between the drowning victim’s organs and media should be considered an essential requirement for the diagnosis of drowning. In this study, lung tissues from 20 rabbits and drowning media were studied by the Microwave Digestion–Vacuum Filtration–Automated Scanning Electron Microscopy method, and four methods, type consistency, coefficient of similarity, squared-chord distance, and cluster analysis, were introduced to analyze the diatom types and patterns for evaluating the value of diatom consistency in drowning cases. The results showed that diatom types and patterns in lung tissues do not perfectly match the drowning medium, and they are sometimes concordant with the drowning medium sampled from other than drowning site. We should be cautious when using diatom detection to infer drowning sites.

     

Atypisches Ertrinken bei anaphylaktischem Schock

Background

Anaphylactic shock is a life-threatening allergic reaction. Its incidence as a direct cause of death is very low; however, non-natural causes of death caused by an anaphylactic reaction are rarely documented in statistical evaluations. Surprisingly, to date, cases of drowning due to allergic shock have not been published.

Case report

We report the case of a young man who was found lying prone in a small river. A distinct laryngeal edema was detected during autopsy alongside typical signs of drowning. Additionally, it was determined that he had almost suffocated after a wasp sting 1 year before his death. Significantly increased values of tryptase and immunoglobulin E in serum were detected via postmortem biochemical analysis and many degranulated mast cells in heart and lung tissue were seen at immunohistochemical examination. The cause of death was diagnosed as atypical drowning due to anaphylactic shock.

Conclusion

Routine forensic investigations should include the determination of any known allergies and the circumstances of death in every case of suspected anaphylaxis. The results of additional postmortem examinations should be interpreted in the context of the findings from investigative and autopsy studies.

     

Electrolyte analysis of pleural effusion as an indicator of drowning in seawater and freshwater

It is important for forensic pathologists to determine the diagnosis of drowning as well as the site of drowning. In a previous study, we propose that analysis of electrolytes in pleural effusion from rats may be useful for determining whether drowning has occurred in seawater or freshwater. To test this proposal, we measured the concentration of sodium, potassium and chloride ions and total protein in pleural effusion from 40 autopsy cases: 24 involving seawater drowning, 9 freshwater drowning and 7 no drowning. The concentrations of sodium and chloride ions in pleural effusion showed a significant difference between seawater drowning and freshwater drowning. The concentration of potassium ions and total protein showed no difference between each group, although they increased in proportion to the postmortem interval in cases of both seawater and freshwater drowning. These results are almost same as our previous study and, thus, the quantitative analysis of electrolytes in pleural effusion may be useful for determining whether drowning has occurred in seawater or freshwater.     

A quantitative comparison analysis of diatoms in the lung tissues and the drowning medium as an indicator of drowning

The presence of diatoms in the lung tissues, internal organs and bone marrow is considered as the supportive evidence in the diagnosis of death by drowning. Generally, the diatoms detected in the lung tissues are regarded as insignificant since these diatoms can be detected in the lung tissues of the postmortem immersion bodies. In this study, we analyzed the relationships between the numbers of the diatoms in the lung tissues and the drowning medium. We made a comparison analysis between the diatoms in the lung tissues and the drowning medium using the ratio of diatom numbers in both samples (L/D ratio), utilizing Microwave Digestion - Vacuum Filtration - Automated Scanning Electron Microscopy method. Our data indicate that the L/D ratios in victims of the drowning group were higher than the postmortem immersion group. A higher L/D ratio provides valuable information about the cause of death in drowning victims. Quantitative diatom analysis in the lung tissues, especially combined with the diatom analysis of the drowning medium, provides supportive evidence in determining if a body recovered in water was due to drowning or not.     

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.     

Recent modifications to the investigation of diving related deaths

The investigation of deaths that involve diving using a compressed breathing gas (SCUBA diving) is a specialized area of forensic pathology. Diving related deaths occur more frequently in certain jurisdictions, but any medical examiner or coroner’s office may be faced with performing this type of investigation. In order to arrive at the correct conclusion regarding the cause and manner of death, forensic pathologists and investigators need to have a basic understanding of diving physiology, and should also utilize more recently developed technology and ancillary techniques. In the majority of diving related deaths, the cause of death is drowning, but this more often represents a final common pathway due to a water environment. The chain of events leading to the death is just as important to elucidate if similar deaths are to be minimized in the future. Re-enactment of accident scenarios, interrogation of dive computers, postmortem radiographic imaging, and slight alterations in autopsy technique may allow some of these diving related deaths to the better characterized. The amount and location of gas present in the body at the time of autopsy may be very meaningful or may simply represent a postmortem artifact. Medical examiners, coroners, and forensic investigators should consider employing select ancillary techniques to more thoroughly investigate the factors contributing a death associated with SCUBA diving.     

大口径反坦克武器侵彻坦克后绵羊的致伤特点

观察某型大口径反坦克武器破甲后对绵羊的致伤特点和规律，为战时防护、救治提供依据。将16只绵羊平均分为4组布放在坦克内，用火炮发射破甲弹攻击坦克。在致伤的同时，测量坦克内冲击波超压，致伤后进行病理解剖等检查。结果16只羊有3只即刻死亡，其余13只都受到了不同程度的损伤，其致伤因素主要是破甲后产生的温度极高的金属射波和冲击波，说明大口径破甲弹致动物损伤严重，死亡率高，受伤器官多，致伤因素复杂。     

Can pulmonary foam arise after postmortem submersion in water? An animal experimental pilot study

It is difficult to differentiate drowning from postmortem submersion. Pulmonary foam can be found in bodies retrieved from water. It is unknown whether foam is a result of drowning or if it also forms after postmortem submersion. We divided deceased piglets into three groups: postmortem saltwater submersion (N = 20), postmortem freshwater submersion (N = 20) and dry-land controls (N = 20). All carcasses underwent endoscopic examination within 24 h of death and the presence of external and internal pulmonary foam was scored. No external foam was detected in the postmortem freshwater or the postmortem saltwater group. Internal foam was seen in 35% of the postmortem freshwater and 40% of the postmortem saltwater group. No external or internal foam was detected in the dry land control group. The literature shows external as well as internal foam in drowned humans. Internal foam is seen in postmortem submersion in the current piglet study and antemortem submersion in the literature in humans, and can therefore not be used to support/refute the diagnosis of drowning. No external foam was present in the postmortem submersed piglets, yet has been described in drowned humans. Hence the presence of external foam in bodies recovered from water may be indicative for drowning. The presence of external foam is a potentially valuable clinical sign in distinguishing drowning from postmortem submersion.     

Diatomological mapping of water bodies for the diagnosis of drowning cases

Forensic diatomology plays an important role in solving mysteries of drowning cases. The diatomology contributes significantly not only in determining the mode of death but also in determining the site of drowning. Presence of sufficient number of diatoms in vital distant body organs can establish ante-mortem drowning up to a certain extent. Question about the exact site of drowning is mostly raised particularly when circumstantial evidences are not clear about the drowning site or drowning site itself is not there. Distribution of diatoms in any water body, and their correlation with the diatom species recovered from the drowned body can be a method of choice to resolve the questions related to drowning site. Analysis was undertaken in order to record the significant variation in diatom diversity in the 10 (selected) different types of water bodies in Punjab (India) during different seasons (summer, autumn, winter and spring). This comparative study was conducted for two years. The data so obtained has been utilized to generate Diatomological Maps, which can be helpful in diagnosing the suspected drowning cases occurring in a particular area and characterization of different water bodies.