A fundamental study on postmortem submersion interval estimation by metabolomics analyzing of gastrocnemius muscle from submersed rat models in freshwater.

In forensic practice, determining the postmortem submersion interval (PMSI) and cause-of-death of cadavers in aquatic ecosystems has always been challenging task. Traditional approaches are not yet able to address these issues effectively and adequately. Our previous study proposed novel models to predict the PMSI and cause-of-death based on metabolites of blood from rats immersed in freshwater. However, with the advance of putrefaction, it is hardly to obtain blood samples beyond 3 days postmortem. To further assess the feasibility of PMSI estimation and drowning diagnosis in the later postmortem phase, gastrocnemius, the more degradation-resistant tissue, was collected from drowned rats and postmortem submersion model in freshwater immediately after death, and at 1 day, 3 days, 5 days, 7 days, and 10 days postmortem respectively. Then the samples were analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate the dynamic changes of the metabolites. A total of 924 metabolites were identified. Similar chronological changes of gastrocnemius metabolites were observed in the drowning and postmortem submersion groups. The difference in metabolic profiles between drowning and postmortem submersion groups was only evident in the initial 1 day postmortem, which was faded as the PMSI extension. Nineteen metabolites representing temporally-dynamic patterns were selected as biomarkers for PMSI estimation. A regression model was built based on these biomarkers with random forest algorithm, which yielded a mean absolute error (± SE) of 5.856 (± 1.296) h on validation samples from an independent experiment. These findings added to our knowledge of chronological changes in muscle metabolites from submerged vertebrate remains during decomposition, which provided a new perspective for PMSI estimation.

Oxidative stress and NF-KB/iNOS inflammatory pathway as innovative biomarkers for diagnosis of drowning and differentiating it from postmortem submersion in both fresh and saltwater in rats.

BACKGROUND: Finding a dead body in water raises an issue concerning determining the cause of death as drowning because of the complex pathophysiology of drowning. In addition, the corpse may be submersed postmortem. OBJECTIVE: Evaluate the role of oxidative stress markers and NF-KB/iNOS inflammatory pathway as diagnostic biomarkers in drowning and whether they could differentiate freshwater from saltwater drowning. METHODS: This study included forty-five adult male albino rats classified into five groups: control group (C), Freshwater-drowned group (FD), Freshwater postmortem submersion group (FPS), saltwater-drowned group (SD), and saltwater postmortem submersion group (SPS). After the autopsy, the rats' lungs in each group were prepared for histological, immunohistochemical (caspase 3, TNF-α, NF-kB, COX-2 & iNOS), biochemical studies; MDA, NOx, SOD, GSH, VCAM-1, COX-2; and RT-PCR for the relative quantification of NF-kB and iNOS genes expression. RESULTS: Lung oxidative markers were significantly affected in drowned groups than in postmortem submersion groups. Inflammatory pathway markers were also significantly increased in the drowned groups, with concern that all markers were significantly affected more in saltwater than in freshwater drowned group. CONCLUSIONS: It is concluded that the tested markers can be used accurately in diagnosing drowning and differentiating it from postmortem submersion with a better understanding of the mechanism of death in drowning as both mechanisms, inflammatory and oxidative stress, were revealed and involved.

Submersion Injuries and the Cost of Injury Associated with Drowning Events in the United States, 2006-2015.

INTRODUCTION: The World Health Organization has reported submersion injuries as the third most common cause of death due to unintentional injury in the world. Greater detail in the rates, risk factors, and healthcare associated costs of submersion injuries could be instrumental in demonstrating the need for further funding and intervention. METHODS: The study was a cross-sectional analysis of a nationally representative dataset of inpatient and emergency department (ED) encounters between 2006 and 2015 in the United States (US). Healthcare utilization costs were provided within the datasets and adjusted to reflect actual charges and provider fees. Lastly, the final cost values were adjusted to the 2020 US dollar (USD) and summarized using a log adjusted mean. RESULTS: On average, there were 11,873 submersion injuries per year that presented to the ED in the US. Resulting in a rate where approximately 9 out of every 100,000 ED visits were associated with a submersion injury. Slightly more than 6% died in the ED, 24.2% were admitted, and 69.3% were discharged from the ED. In total, annual cost of submersion injuries in the US for ED care is approximately $12.5 million, inpatient care is approximately $27.5 million, and total annual healthcare cost exceeds $40 million. DISCUSSION: While these results only represent a fraction of the total cost associated with submersion injuries, it remains substantial and unchanged over the 10-year study period. Certain demographic groups showed higher rates of injury and disease burden, thus bearing a greater amount of the cost.

Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2024 Update.

The Wilderness Medical Society convened a panel to review available evidence supporting practices for acute management of drowning in out-of-hospital and emergency care settings. Literature about definitions and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded available evidence supporting practices according to the American College of Chest Physicians criteria and then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking. This is the second update to the original practice guidelines published in 2016 and updated in 2019.

Inhibition of acid rock drainage with iron-silicate or phosphate film: in rainy and submerged environments.

Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting effectiveness of coating agents on the oxidation of iron sulfide minerals was investigated using pyrite and rock samples resulting from acid drainage. The film formed with both surface-coating agents was identified by pyrite surface analysis. It was also confirmed that the formation of coatings varies depending on the crystallographic orientation. The inhibitory effects under rainy and submerged conditions were investigated using column experiments. Submerged conditions accelerated deterioration compared to that under rainy conditions. Iron phosphate coating had a significantly better oxidation-inhibitory effect (84.86-98.70%) than iron silicate coating (56.80-92.36%), and at a concentration of 300 mM, H+ elution was inhibited by more than 90% throughout the experiment. Furthermore, methods for effective film formation were investigated in terms of producing Fe3+; (1) application of coating agents mixed with oxidant (H2O2), (2) application of coating agent after the use of the oxidant. In a rainy environment, applying iron phosphate-based coating using the sequential method showed oxidation inhibition effects for cycles 1-9, whereas applying the mixed material showed effects for cycles 9-13. The use of a surface-coating agent after applying an oxidant did not inhibit oxidation. The surface coating agent and the oxidizing agent should be applied as a mixture to form a film.

Decomposition of partially submerged remains: a study on the reliability of insect colonisation for PMI/PMSI estimation.

The terrestrial decomposition of remains and associated insect colonisation have been highly researched, and recently studies have expanded to investigate the aquatic decomposition of remains. However, there are instances where remains may experience both terrestrial and aquatic conditions simultaneously due to partial submersion in tidal areas, or influx or efflux of water caused by flood or drought. Decomposition and post-mortem interval (PMI) research to date has focused on remains wholly exposed to either terrestrial or aquatic environments, with limited consideration of dual simultaneous exposure. This study was conducted in artificial lentic environments to ascertain how simultaneous zones of terrestrial and aquatic environments on a single body may impact decomposition. Three trials were completed over a period of 12 months, with each trial consisting of 12 stillborn piglets; three partially submerged head exposed, three partially submerged abdomen exposed, three fully submerged aquatic controls and three terrestrial controls. Decomposition stage and rate were inferred from physical characteristics and insect activity. The decomposition rate of the exposed region of each piglet was significantly faster than the submerged region. The exposed zone of each was colonised by insects and reached skeletonization, whereas the submerged zone without orifice exposure had no insect activity and had a significantly slower decomposition rate. This indicated the ability to utilise terrestrial entomological approaches to estimate a minimum PMI for the exposed portion of the remains. However, without the ability to determine the amount of time the remains may have been submerged for, this estimation represents only a minimum PMSI, with the possibility the remains were submerged for a period of time without insect access and colonisation.

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.

Long-term trends of salinity in coastal wetlands: Effects of climate, extreme weather events, and sea water level.

Coastal freshwater ecosystems play major roles as reservoirs of biodiversity and provide many ecosystem services and protection from extreme weather events. While they are of particular importance worldwide, they are affected by a large variety of anthropogenic threats, among which salinization has been less studied, particularly regarding large temporal and spatial data sets based on real case scenarios, while salinity can impact biodiversity and ecosystem functioning. In this study, we investigated the variations of salinity across long-term (1996-2020) and seasonal (monthly records) temporal scales and spatial (varying distance to the coastline) scales in water bodies of two typical temperate coastal wetlands situated on the Atlantic coast of France. We complemented our analyses with models of sea water levels computed at both sites across 2000-2020. Our detailed data set allowed for highlighting that salinity in ponds varied seasonally (higher during summer, due to decreased precipitation and higher temperature), but also spatially (higher closer to the seashore, which pattern increased through time). Over the long term, decreased precipitation but not increased temperature induced increasing salinity. We also highlighted contrasted long-term patterns of salinity changes on these two coastal wetlands, with one site were salinity decreased over time linked to the responses to marine flood, allowing to document the temporal dynamics of salinity following a massive intrusion of sea water. Complementarily, at both sites, water levels at high tides increased through time, a pattern which can induce additional salinization. To our knowledge, our study is the first to investigate long-term changes in salinity in coastal wetlands through natural processes (e.g. seaspray, seasonal variations) and ongoing climate perturbations (e.g. marine surges linked to extreme weather events, increased temperature and decreased precipitations).

A preliminary study on early postmortem submersion interval (PMSI) estimation and cause-of-death discrimination based on nontargeted metabolomics and machine learning algorithms.

Postmortem submersion interval (PMSI) estimation and cause-of-death discrimination of corpses in water have long been challenges in forensic practice. Recently, many studies have linked postmortem metabolic changes with PMI extension, providing a potential strategy for estimating PMSI using the metabolome. Additionally, there is a lack of potential indicators with high sensitivity and specificity for drowning identification. In the present study, we profiled the untargeted metabolome of blood samples from drowning and postmortem submersion rats at different PMSIs within 24 h by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 601 metabolites were detected. Four different machine learning algorithms, including random forest (RF), partial least squares (PLS), support vector machine (SVM), and neural network (NN), were used to compare the efficiency of the machine learning methods. Nineteen metabolites with obvious temporal regularity were selected as candidate biomarkers according to "IncNodePurity." Robust models were built with these biomarkers, which yielded a mean absolute error of 1.067 h. Additionally, 36 other metabolites were identified to build the classifier model for discriminating drowning and postmortem submersion (AUC = 1, accuracy = 95%). Our results demonstrated the potential application of metabolomics combined with machine learning in PMSI estimation and cause-of-death discrimination.

Taphonomic study on drowned victims in a non-sequestered aquatic environment in the Mediterranean Sea.

Human decomposition in sea water poses several challenges to forensic practitioners tasked with the analysis of drowned bodies. Postmortem changes in the marine environment have not been extensively investigated and the current literature is mainly based on bodies retrieved from shallow waters or on limited samples. On 18 April 2015, a fishing boat carrying allegedly 1,000 migrants sank in the Mediterranean Sea. In a fifteen-month time span, humanitarian missions were carried out to recover the bodies from the sea. The present study investigates postmortem changes on the drowned victims in a non-sequestered environment in the Mediterranean Sea. A retrospective study was performed by two observers on the autopsy photographic records in the series of bodies recovered from the open sea. For 184 bodies, the postmortem changes were evaluated according to facial, body, limb, and total aquatic decomposition score (FADS, BADS, LADS, TADS, respectively). Furthermore, a modification to the current scoring system that divides upper and lower limbs was suggested. The interobserver agreement was assessed using Krippendorff's alpha coefficient. Possible relations between the decomposition scores and PMSI were investigated with Pearson correlation analysis. According to the sequence of the recovery missions, increasing FADS, BADS, LADS, and TADS were observed. The modified scoring system showed a strong agreement between observers, allowing a more accurate description of the actual extent of decomposition. The scores showed a significant relation with the PMSI (p < 0.01). Prolonged submersion in the open marine environment was confirmed to show increasing decomposition rates, from moderate decay to full disarticulation. This study provides a descriptive unicum of the postmortem changes in the open sea, which may contribute to strengthen the discipline and aid description of bodies recovered in similar circumstances, especially if a body needs to be associated to a disaster or period with respect to another, thus facilitating families or authorities in the search for specific victims.

6-Year-Old Male Drowning Complicated by Cardiac Arrest and Ensuing Metabolic and Respiratory Acidosis: Should Presence of Pulses Lead Clinicians to Pursue Prolonged Cardiopulmonary Resuscitation?

BACKGROUND: Drowning is one of the leading causes of death in the pediatric population. Patients arriving to the emergency department (ED) with submersion injuries are often asymptomatic and well-appearing, but can sometimes present critically ill and require prolonged resuscitation. The question of how long to continue resuscitation of a pediatric patient with a submersion injury is a difficult question to answer. CASE REPORT: We present a case of 6-year-old boy was found by his friends submerged in sea water for 10-15 min. The patient was rescued by lifeguards and evaluated by emergency medical personnel, who found him breathing spontaneously but unresponsive. En route to hospital, the patient became apneic, cardiopulmonary resuscitation (CPR) was started, and the patient was intubated. The patient arrived to the ED in cardiopulmonary arrest, CPR was continued and epinephrine was administered. Return of spontaneous circulation was achieved after 42 min in the ED. Initial laboratory test results showed severe acidosis and chest x-ray study showed diffuse interstitial edema. Ventilator settings were adjusted in accordance with lung protective ventilation strategies and the acidosis began to improve. Over the next several days, the patient was weaned to noninvasive ventilation modalities and eventually made a complete neurologic recovery and continued to be a straight-A student. Why Should an Emergency Physician Be Aware of This?We make the case that, in select drowning patients, duration of CPR longer than 30 min can potentially result in favorable neurologic outcomes. Prolonged CPR should be especially strongly considered in patients with a pulse at any point during evaluation. With the combination of prolonged CPR and judicious use of lung protective mechanical ventilation strategies, we were able to successfully treat the patient in our case.

A Smart Multi-Sensor Device to Detect Distress in Swimmers.

Drowning is considered amongst the top 10 causes of unintentional death, according to the World Health Organization (WHO). Therefore, anti-drowning systems that can save lives by preventing and detecting drowning are much needed. This paper proposes a robust and waterproof sensor-based device to detect distress in swimmers at varying depths and different types of water environments. The proposed device comprises four main components, including heart rate, blood oxygen level, movement, and depth sensors. Although these sensors were designed to work together to boost the system's capability as an anti-drowning device, each could operate independently. The sensors were able to determine the heart rate to an accuracy of 1 beat per minute (BPM), 1% SpO2, the acceleration with adjustable sensitivities of ±2 g, ±4 g, ±8 g, and ±16 g, and the depth up to 12.8 m. The data obtained from the sensors were sent to a microcontroller that compared the input data to adjustable threshold values to detect dangerous situations. Being in hazardous situations for more than a specific time activated the alarming system. Based on the comparison made in the program and measuring the time of submersion, a message indicating drowning or safe was sent to a lifeguard to continuously monitor the swimmer' condition via Wi-Fi to an IP address reachable by a mobile phone or laptop. It is also possible to continuously monitor the sensor outputs on the device's display or the connected mobile phone or laptop. The threshold values could be adjusted based on biometric parameters such as swimming conditions (swimming pool, beach, depth, etc.) and swimmers health and conditions. The functionality of the proposed device was thoroughly tested over a wide range of parameters and under different conditions, both in air and underwater. It was demonstrated that the device could detect a range of potentially hazardous aquatic situations. This work will pave the way for developing an effective drowning sensing system that could save tens of thousands of lives across the globe every year.

Exercise during hot-water immersion in divers habituated to hot-dry and hot-wet conditions.

Purpose: Diving in warm water increases thermal risk during exercise compared to thermoneutral waters. The purpose of this study was to evaluate exercise endurance in warm- and hot-water conditions in divers habituated to wet or dry heat. Methods: Nineteen male divers completed this study at the Navy Experimental Diving Unit. Subjects were assigned DRY or WET heat habituation groups. The DRY group (n=9) cycled at 125-150W for one hour in a non-immersed condition (34.4˚C, 50%RH), while the WET group (n=10) cycled at 50W for one hour while immersed in 34.4˚C water. Exercise time to exhaustion was tested on an underwater cycle ergometer in 35.8˚C (WARM) and 37.2˚C (HOT) water at 50W. Core temperature (Tc) was continuously recorded and for all dives. Results: Time to exhaustion was reduced in HOT compared to WARM water (p ≺0.01) in both DRY (92.7 ± 41.6 minutes in 35.8°C vs. 43.4 ± 17.5 minutes in 37.2°C) and WET (95.9 ± 39.2 minutes in 35.8°C vs. 53.4 ± 27.5 minutes in 37.2°C) groups, but did not differ between groups (p=0.62). Rate of Tc rise was greater with higher water temperature (p ≺0.01), but was not different between groups (p=0.68). Maximum Tc (p=0.94 and p=0.95) and Tc change from baseline (p=0.38 and p=0.34) was not different between water temperatures or habituation group, respectively. Conclusion: Endurance decreased with increased water temperature but was not different between WET and DRY. Divers became exhausted at a similar core temperature during WARM- and HOT-water exercise. Mechanisms and applications of heat acclimation for warm-water diving should be further explored.

Review and Prospect of Diagnosis of Drowning Deaths in Water.

Drowning is the death caused by asphyxiation due to fluid blocking the airway. In the practice of forensic medicine, it is the key to determine whether the corpse was drowned or entered the water after death. At the same time, the drowning site inference and postmortem submersion interval (PMSI) play an important role in the investigating the identity of the deceased, narrowing the investigation scope, and solving the case. Based on diatoms testing, molecular biology, imaging and artificial intelligence and other technologies, domestic and foreign forensic scientists have done relative research in the identification of the cause of death, drowning site inference and PMSI, and achieved certain results in forensic medicine application. In order to provide a reference for future study of bodies in the water, this paper summarizes the above research contents.

Inferring Postmortem Submersion Interval in Rats Found in Water Based on Vitreous Humor Metabolites.

OBJECTIVES: The metabolomics technique of LC-MS/MS combined with data analysis was used to detect changes and differences in metabolic profiles in the vitreous humor of early rat carcasses found in water, and to explore the feasibility of its use for early postmortem submersion interval (PMSI) estimation and the cause of death determination. METHODS: The experimental model was established in natural lake water with 100 SD rats were randomly divided into a drowning group (n=50) and a postmortem (CO2 suffocation) immediately submersion group (n=50). Vitreous humor was extracted from 10 rats in each group at 0, 6, 12, 18 and 24 h postmortem for metabolomics analyses, of which 8 were used as the training set to build the model, and 2 were used as test set. PCA and PLS multivariate statistical analysis were performed to explore the differences in metabolic profiles among PMSI and causes of death in the training set samples. Then random forest (RF) algorithm was used to screen several biomarkers to establish a model. RESULTS: PCA and PLS analysis showed that the metabolic profiles had time regularity, but no differences were found among different causes of death. Thirteen small molecule biomarkers with good temporal correlation were selected by RF algorithm. A simple PMSI estimation model was constructed based on this indicator set, and the data of the test samples showed the mean absolute error (MAE) of the model was 0.847 h. CONCLUSIONS: The 13 metabolic markers screened in the vitreous humor of rat corpses in water had good correlations with the early PMSI. The simplified PMSI estimation model constructed by RF can be used to estimate the PMSI. Additionally, the metabolic profiles of vitreous humor cannot be used for early identification of cause of death in water carcasses.

Mussel acclimatization to high, variable temperatures is lost slowly upon transfer to benign conditions.

Climate change is increasing the temperature variability animals face, and thermal acclimatization allows animals to adjust adaptively to this variability. Although the rate of heat acclimatization has received some study, little is known about how long these adaptive changes remain without continuing exposure to heat stress. This study explored the rate at which field acclimatization states are lost when temperature variability is minimized during constant submersion. California mussels (Mytilus californianus) with different acclimatization states were collected from high- and low-zone sites (∼12 versus ∼5°C daily temperature ranges, respectively) and then kept submerged at 15°C for 8 weeks. Each week, the cardiac thermal performance of mussels was measured as a metric of acclimatization state: critical (Tcrit) and flatline (Tflat) temperatures were recorded. Over 8 weeks of constant submersion, the mean Tcrit of high-zone mussels decreased by 1.07°C from baseline, but low-zone mussels' mean Tcrit was unchanged. High- and low-zone mussels' mean maximum heart rate (HR) and resting HR decreased ∼12 and 35%, respectively. Tflat was unchanged in both groups. These data suggest that Tcrit and HR are more physiologically plastic in response to the narrowing of an animal's daily temperature range than Tflat is, and that an animal's prior acclimatization state (high versus low) influences the acclimatory capacity of Tcrit Approximately 2 months were required for the cardiac thermal performance of the high-zone mussels to reach that of the low-zone mussels, suggesting that acclimatization to high and variable temperatures may persist long enough to enable these animals to cope with intermittent bouts of heat stress.

Correlation of clinical and chest radiograph findings in pediatric submersion cases.

BACKGROUND: Submersion injuries are a leading cause of injury death in children in the United States. The clinical course of a submersion patient varies depending on the presence of anoxic brain injury and acute respiratory failure. OBJECTIVE: We studied changes in clinical findings and chest radiograph findings and determined the sensitivity/specificity of the presenting chest radiograph in predicting clinical improvement within the first 24 h in pediatric submersion cases. MATERIALS AND METHODS: We conducted a cross-sectional study of pediatric submersion patients through age 18 years treated at a children's hospital from 2010 to 2013. We reviewed demographics, comorbidities, prehospital/hospital course and chest radiographic findings. Clinical improvement occurred when a child demonstrated normal vital signs and mentation. We compared radiographic findings among children based on clinical improvement up to 24 h post submersion. Using odds ratios, we calculated associations between radiographic findings and clinical improvement. We studied the sensitivity/specificity of the presenting chest radiograph in predicting clinical improvement within 24 h. RESULTS: One hundred forty-two of 262 (54%) patients had initial chest radiographs; 41% had follow-up radiographs. The odds of an abnormal initial chest radiograph were 4 times higher in children with respiratory distress or abnormal mentation at emergency department (ED) presentation compared to children without these findings (odds ratio [OR]=4.83; 95% confidence interval [CI]=2.1-10.85; P<0.001). Improvement in radiographic findings occurred in 85% of children within 24 h. Children with an abnormal initial chest radiograph were 87% less likely to improve clinically by 24 h (P<0.001). A presenting chest radiograph that was normal or with mild pulmonary edema/atelectasis predicted clinical improvement within 24 h (sensitivity 95%, specificity 57%). CONCLUSION: Most chest radiographic findings improve in pediatric submersion patients who recover within the first 24 h. An initial chest radiograph that is normal or with mild pulmonary edema/atelectasis satisfactorily predicts clinical improvement by 24 h post submersion.

Health and Economic Burden of Injurious Falls Into Irrigation Canals in Japan: A Retrospective Cohort Study.

BACKGROUND: Falls into small water bodies can cause drowning and trauma. Such falls, especially into irrigation canals, and the subsequent trauma are common in Japan. However, few studies have investigated their characteristics, costs, and prognosis. OBJECTIVE: Our aim was to clarify the characteristics, prognosis, and economic burden of trauma due to falls into irrigation canals in Kurashiki City, Japan. METHODS: This 4-year, single-center, retrospective cohort study was conducted at a Japanese tertiary care hospital between January 1, 2013 and December 31, 2016. We enrolled patients who had fallen into irrigation canals constructed more than 300 years ago, and transported to our hospital by ambulance. The study outcomes included the characteristics, prognosis, and health care costs of such trauma. RESULTS: We enrolled 266 patients with a median age of 66 years (range 19-64 years). Most patients fell into irrigation canals while walking (49.3%), riding a bicycle (35.0%), or driving or riding in a car (7.1%). Extremities were the most frequently affected body parts, and the head and chest were less frequently affected. Four patients (1.5%) died in the emergency department (ED), and 121 (45.5%) were hospitalized (109 in our hospital and 12 transferred to other hospitals). The total costs of ED and hospital stays were 777,625 US dollars (266 patients) and 712,059 US dollars (109 patients hospitalized in our hospital), respectively. CONCLUSIONS: Trauma due to falls into irrigation canals can be severe and even fatal, and the related costs are high. Our study highlights the importance of implementing appropriate measures to prevent falls into irrigation canals and of promoting awareness among citizens.

Trauma on the high seas: an overview of recreational water use injuries.

Recreational water use (RWU) injuries span from superficial lacerations to even death. Given the global popularity of RWU, radiologists should be aware of the common mechanisms and key imaging findings related to injuries in this setting. The goal of this article is to depict common RWU injuries and their emergent radiographic findings, which may have both important surgical and management implications. We present a broad review with case illustrations of these injuries seen at our level 1 trauma center showing the breadth of injury that can occur, general mechanisms and sample imaging findings.

Flush Drowning as a Cause of Whitewater Deaths.

INTRODUCTION: Most recreational whitewater fatalities are caused by fixed underwater entrapment or by "flush drowning," an obscure term frequently associated with high-volume rivers, continuous rapids, cold water, and a lack of prolonged underwater entrapment. Although entrapment drowning is typically associated with submersion hypoxia, flush drownings likely involve diverse mechanisms of death; as such, a concise definition is elusive. This said, certain risk factors may be predictively associated with flush drownings. We attempt to further characterize causes of fatal river accidents and possible effects of water temperature on injury pattern. METHODS: We reviewed river mortality data collected from the American Whitewater Association accident database comparing fatal whitewater accident trends in the Rocky Mountain region versus the Southeastern United States. We limited data from the Southeast to the months of June through August to create a warm water cohort. We then divided lethal accidents into flush drowning, entrapment submersion, or miscellaneous events, defining each category in specific terms. RESULTS: Flush drownings were more common in the Rocky Mountains than in the Southeast subgroup and involved older victims on average than entrapment drowning or miscellaneous events. Entrapment drownings were common in both regions, primarily occurring at fallen trees or rock formations. CONCLUSIONS: Flush drownings appear to occur more frequently in older persons. Although hypothetical, the relative increase in flush drowning in the Rocky Mountains might partly be the result of colder water temperatures. If the cause of flush drowning is better understood, safety in whitewater recreation may be improved.