The effect of ethanol or long-time reaction on the diatom test in water samples using sodium hypochlorite

BackgroundThe diatom test method using sodium hypochlorite (NaClO) was equivalent to the conventional method in water samples. However, the method using NaClO was inferior to the conventional method in lung samples, in which ethanol was used and the reaction with NaClO was longer compared with the method in water samples. Using water samples, we aimed to clarify whether these differences affect the diatom test result.Materials and methodsThirteen water samples from natural water sources were each divided into four parts corresponding to four (2 × 2) digestion methods: 3 “digestion” vs. 1 “digestion” and with ethanol vs. without ethanol. After the base-2 logarithmic transformation, the diatom counts were analyzed using three-way analysis of variance (ANOVA); factor 1 was “digestion times,” factor 2 was “ethanol,” and factor 3 was “sample number,” and the interaction between factors 1 and 2 was also analyzed.ResultsThe geometric means of the diatoms from the 3 “digestion” with ethanol method, the 3 “digestion” without ethanol method, the 1 “digestion” with ethanol method, and the 1 “digestion” without ethanol method were 373.5, 551.8, 436.6, and 522.0, respectively. ANOVA showed a significant difference in factor 2 (P = 1.7 × 10^-4). There was no significant difference in factor 1 (P = 0.46), and no significant interaction between factors 1 and 2 (P = 0.13).ConclusionEthanol may decrease the diatom count in the diatom test using NaClO. In contrast, the diatom frustules do not dissolve through three-times digestion using NaClO.     

Characteristics of drowning deaths in an inner city river

A study was undertaken of all drowning deaths that occurred over a 30-year period from 1988 to 2017 in the urban section of the River Torrens, Adelaide, South Australia, an augmented waterway that runs through the central business district. Autopsy records from Forensic Science South Australia (FSSA) were reviewed. There were 34 drownings (0–5 cases/yr) with 28 males and 6 females (M;F = 4.6:1), with an age range for males of 18-76yrs (mean 42.0; SD 18.0) and for females of 20-84yrs (mean 69.3; SD 24.5). There were 15 (44%) accidents, 11 (32%) suicides, 1 (3%) homicide and 7 (21%) undetermined. Of the 22 cases during or after 1994 with complete toxicology reports, 10 (45%) had a blood alcohol concentration (BAC) of greater than 0.05% (g/100 mL) with an illicit substance detected in 4 (18%) cases: (MDMA (3,4-methylenedioxymethamphetamine), methylamphetamine and THC (delta-9-tetrahydrocannabinol) acid). The presence of various therapeutic drugs was also detected in 10 cases (45%) including temazepam, fluoxetine, diazepam, olanzapine, amitriptyline, carbamazepine, codeine, citalopram and valproate. Although the numbers of cases were not high, the urban portion of the River Torrens had a much higher number of drowning events per kilometre compared to other inland waterways in South Australia such as the Murray River. This is most likely due to the vulnerability that exists for intoxicated individuals in the city from falls into the water and to the availability of the river as a means of suicide to members of the adjacent urban population.     

Is it feasible “scoop and run while playing” resuscitation on a rescue water craft? A randomized simulation study with lifeguards

ObjectiveResponse time is a predictive factor for survival of drowning victims and lifesaving. Rescue Water Craft (RWC) are lifeboats very common in lifeguards operations. The aim of this study was to analyze the feasibility of providing effective mouth-to-mouth ventilations and/or cardiopulmonary resuscitation (CPR) on the RWC while sailing at different speeds.MethodA quasi-experimental cross-over block design was used to test during one minute efforts the effectiveness of Mouth to Mouth ventilation (MM-only) and CRP, at the beach and sailing at two diferents speeds 5 knots(kn) and 10 kn with calm sea. Quality CPR reference were 2015 ERC guidelines.ResultsThe data obtained from 13 lifeguards were included, that means that 78 resuscitation test were completed. The MM-only performance skills reached 69.7% ± 40.4 for 5 kn and 60.0% ± 41.8 for 10 kn (p = .59). For full CPR, performance was 74.4% ± 24.2 and 68.5% ± 23.9 respectively. Quality of MM and CPR decreased, not significantly, while sailing at 5 kn and 10 kn [(Q-MM; 5 kn: 59.9% ± 37.8 vs. 10 kn: 43.2% ± 41.4, p = .42)(Q-CPR; 5 kn: 64.8% ± 21.2 and 10 kn: 60.6% ± 21.0, p = .44)]. MM-only and CC variables were significantly worse on RJS when compared with resuscitation at the beach (p < .05). A trend for better results by lifeguards previously training on RJS was observed.ConclusionsResuscitation techniques on board of a RWC are feasible and therefore they could be an option for lifeguards when their training, sea conditions, distance and the victim's characteristics allow it. CPR maneuvers may be highly effective at 10 kn, both for MM-only and CPR, however, the quality of the ventilations dramatically worsen with increasing speed.     

Giant intracranial arteriovenous malformation as a possibility of epileptic seizures in a case of drowning

A male in his late 50s had been complaining of headaches and dizziness for 25 years. He also had episodes of losing consciousness, but had not sought treatment because of financial hardship. He was found in the ocean. Autopsy revealed foamy liquid leaking from his nose and mouth, and pleural effusions. The trachea and bronchi contained the same foamy liquid. The lungs were swollen and edematous, and leaked a large amount of foamy liquid. His cause of death was diagnosed as drowning. In the brain, the veins on the frontal lobe and the temporal pole, each on the right cerebral hemisphere, were dilated. A vascular lesion measuring 5 × 5 × 8 cm was found on the bottom of the right frontal lobe, and was located between the right middle cerebral artery and those veins. This vascular lesion extended to the brain parenchyma, and the basal ganglia of the right cerebrum was displaced outward and upward. The vascular lesions in the brain showed blood vessels of various sizes and shapes, and some of the vessel walls were thickened. The vascular lesion on the right frontal lobe was diagnosed as an arteriovenous malformation (AVM). According to the police investigation, the harbor where his body was found was a place he often came for fishing and walking. The possibility of suicide cannot be ruled out. Moreover, it was considered that his AVM might have rendered him unconscious, causing him to fall into the ocean.     

Haematic silicon in drowning

The aim of this paper was to evaluate silicon (Si) concentration in human whole ventricular blood as a further potential chemical marker in the diagnosis of drowning. We employed an acidic digestion for the extraction of soluble Si, and an alkaline digestion for the determination of total Si, including particulate matter, both arising from drowning medium. 29 suspected drowning situations, 24 in fresh water (Fw) and 5 in seawater (Sw), were examined. The difference in Si concentration between the left and right ventricular blood (Si Δ_L–R) was measured and alkaline Si Δ_L–R seems, indeed, a potentially significant complementary tool in the diagnosis of Fw drowning, because insoluble silicon fraction does not undergo hemo-dilution or hemo-concentration, and the Δ_L–R is not affected by exogenous factors. In spite of the limited number of cases investigated, a good correlation was observed between the analytical results and the macro-microscopic autoptic findings.     

溺水后吸入性肺炎患儿的临床特征及病原分析北大核心CSCD

目的 分析溺水后吸入性肺炎患儿的临床特征及病原特点,为抗菌药物的经验性选择提供参考。方法 回顾性收集重庆医科大学附属儿童医院2010年1月至2020年10月收治的185例溺水后吸入性肺炎患儿的临床资料,按淹溺环境分为溺粪组(44例)、自然淡水组(69例)、游泳池组(41例)、污水组(31例),分析比较4组患儿的临床特征及病原结果。结果 185例患儿,年龄4月龄至17岁,中位年龄34月龄。共157例患儿完善痰培养,103例阳性(65.6%),检出革兰阴性菌87株(68.5%),革兰阳性菌37株(29.1%),真菌3株(2.4%)。溺粪组、污水组检出病原以革兰阴性菌为主,分别为88.2%(30/34)、78.3%(18/23)。自然淡水组革兰阳性菌检出比例高于溺粪组(P<0.008)。游泳池组革兰阳性菌与革兰阴性菌检出比例相等。结论 溺粪及污水溺水者考虑肺部细菌感染时可考虑选择对革兰阴性菌作用强的抗生素,游泳池及自然淡水溺水者可应用广谱抗生素,根据药敏试验结果进一步调整。     

Mechanical ventilation and resuscitation under water: Exploring one of the last undiscovered environments – A pilot study

IntroductionAirway management, mechanical ventilation and resuscitation can be performed almost everywhere – even in space – but not under water. The present study assessed the technical feasibility of resuscitation under water in a manikin model.MethodsTracheal intubation was assessed in a hyperbaric chamber filled with water at 20 m of depth using the Pentax AWS S100 video laryngoscope, the Fastrach™ intubating laryngeal mask and the Clarus optical stylet with guidance by a laryngeal mask airway (LMA) and without guidance. A closed suction system was used to remove water from the airways. A test lung was ventilated to a maximum depth of 50 m with a modified Oxylator^® EMX resuscitator with its expiratory port connected either to a demand valve or a diving regulator. Automated chest compressions were performed to a maximum depth of 50 m using the air-driven LUCAS™ 1.ResultsThe mean cumulative time span for airway management until the activation of the ventilator was 36 s for the Fastrach™, 57 s for the Pentax AWS S100, 53 s for the LMA-guided stylet and 43 s for the stylet without LMA guidance. Complete suctioning of the water from the airways was not possible with the suction system used. The Oxylator^® connected to the demand valve ventilated at 50 m depth with a mean ventilation rate of 6.5 min⁻¹ vs. 14.7 min⁻¹ and minute volume of 4.5 l min⁻¹ vs. 7.6 l min⁻¹ compared to the surface. The rate of chest compression at 50 m was 228 min⁻¹ vs. 106 min⁻¹ compared to surface. The depth of compressions decreased with increasing depth.ConclusionAirway management under water appears to be feasible in this manikin model. The suction system requires further modification. Mechanical ventilation at depth is possible but modifications of the Oxylator^® are required to stabilize ventilation rate and administered minute volumes. The LUCAS™ 1 cannot be recommended at major depth.     

Electrolyte analysis of pleural effusion for discrimination between seawater and freshwater drowning in decomposed bodies

ObjectiveThe diagnosis of drowning is an important issue in forensic investigations. Moreover, discriminating between seawater and freshwater drowning is crucial to identify where the drowning occurred. The present study aimed to investigate electrolyte concentrations in pleural fluid in decomposed bodies in late postmortem intervals and derive cut-off values for the diagnosis of seawater and freshwater drowning.Study designData were collected from 44 seawater drowning cases, 60 freshwater drowning cases, and 30 non-drowning cases with pleural effusion which served as controls. The levels of sodium ion (Na⁺), potassium ion (K⁺), and chloride ion (Cl⁻) of pleural fluid were measured, and two indices were calculated: summation of Na⁺ and K⁺ levels (SUM _Na + K), and summation of Na⁺, K⁺, and Cl⁻ levels (SUM _{Na + K + Cl}). The means of the three ion concentrations and two indices significantly differed between the three groups (p < 0.0001).ResultsThe receiver operating characteristic analysis revealed that the sensitivity and specificity were both 1.000 for SUM _{Na + K + Cl} of 288.3 mEq/L between the seawater and control groups. The Na⁺ value of 109.0 mEq/L also had a high sensitivity of 0.977 and a specificity of 0.933 in the seawater and control groups. The sensitivity and specificity were 0.967 and 1.000, respectively, for SUM _Na + K of 123.2 mEq/L between the freshwater and control groups.ConclusionThe electrolyte concentrations in pleural effusion may be useful for the diagnosis of drowning in decomposed bodies with a longer postmortem interval.     

Application of the microwave digestion-vacuum filtration-automated scanning electron microscopy method for diatom detection in the diagnosis of drowning

The cause of death for the decomposed corpses recovered from water is still a difficult issue in current forensic practice. In this article, we present two cases of bodies recovered from water with no positive findings to indicate the cause of their death. We apply both conventional acid digestion method as well as the microwave digestion-vacuum filtration-automated scanning electron microscopy method (MD-VF-Auto SEM) for diatom detection in different organs of both bodies. Our results indicate that MD-VF-Auto SEM method provide more accurate information and match further police investigation. This novel method would be a useful technique in assessing cause of death for body found in water.