The course of respiration and circulation in death by carbon dioxide poisoning

To investigate the effects of very high concentrations of carbon dioxide (CO2) upon the course of respiration and circulation, dogs were allowed to breathe high concentrations of CO2 while intrathoracic pressure, blood pressure (BP) in the femoral artery, electrocardiogram and electroencephalogram readings were registered. The respiratory movements either increased just after inhalation of high concentrations of CO2 and then ceased in 1 min, or decreased and continued for a while according to the concentrations of CO2. The BP showed an initial depression, then returned to the original level, then fell again rapidly or maintained an appreciable level for a while until circulatory breakdown. In the dogs allowed to breathe the gas mixture of 80% CO2 with 20% O2, the respiratory movement ceased in 1 min, and the terminal respirations were seen with the circulatory breakdown after apnoea of several minutes. These findings showed that the cause of death in breathing high concentrations of CO2 is not hypoxia, but the CO2 poisoning.     

The course of respiration and circulation in 'toluene-sniffing'

To investigate the course of respiration and circulation in death by toluene inhalation, 25 dogs were allowed to rebreathe toluene vapor in a 1-1 plastic bag expanded with air, and electrocardiogram (ECG), electroencephalogram (EEG), blood pressure (BP) in the femoral artery and intrathoracic pressure (ITP) were registered. The respiratory movement continued two times longer than that of death by suffocation using a plastic bag of the same size. In the ECG, low voltage of R waves precipitously appeared several minutes after the beginning of the experiment and continued. The BP gradually reduced by half and kept the level for several minutes. The stage was considered toluene narcosis. Toward the end of the respiratory movement, the BP increased gradually. The analysis of the ECG complexes during the toluene inhalation revealed the direct effect of toluene to the septal and ventricular muscle of the heart. But in the end of the respiratory movement, it revealed ST segment elevation and upright T. In a few experimental animals, some of the transient arrhythmia with fluctuation of the BP appeared during the course, and in one of these dogs, fatal ventricular fibrillation occurred suddenly. These findings suggested that in most cases of sudden death in 'toluene-sniffing', the cause of death is severe hypoxia during toluene narcosis, but in a few cases, it is fatal arrhythmia due to the direct effect of toluene to the heart muscle.     

利多卡因硬膜外麻醉和静脉注射致死的动物模型

目的建立利多卡因硬膜外麻醉和静脉注射致死的动物模型。方法本地杂种犬18只其中6只经硬膜外腔、6只经股静脉注射利多卡因(63.35mg/kg体重),对照组3只经硬膜外腔、3只经股静脉按注射生理盐水(3.2ml/kg体重)。观察动物致死过程的生命体征变化及死后各组织器官的病理改变特点。结果硬膜外麻醉致死犬心电、血压和呼吸消失的平均时间分别为28 min(22~45 min)、23.6 min(20~42 min)、22 min(18~35 min);静脉注射致死犬血压、心电和呼吸消失的平均时间分别为6.5 min(5~8min)、8 min(6~10min)、7.2 min(4~9min);各器官病理改变均呈淤血、水肿等征象。结论该模型实验动物的表现和生命特征变化符合椎管内麻醉中毒、致死的表现,可用于利多卡因麻醉意外致死案件的法医学鉴定研究。     

体位性窒息对心、肺功能影响的实验研究

通过从股静脉将漂浮导管插入肺动脉的方法 ,检测悬挂前、悬挂期间和临终阶段呼吸、肺动脉压、心输出量的变化,探讨体位性窒息对心、肺功能影响及其在死亡中所起作用。结果:(1)悬挂前呼吸频率平稳 ,悬挂期间逐渐加快 ,临终前呈无规律状态 ;(2)悬挂期间及临终时肺动脉压比悬挂前明显升高;(3)悬挂前及悬挂期间的心输出量基本平稳 ,临终时比悬挂前及悬挂期间明显下降。本研究发现 ,悬挂可致呼吸失调 ,机体缺氧 ,导致心、肺功能障碍 ,属肺性死亡。其特征为呼吸停止是原发性的 ,心跳停止是继发的。     

利多卡因蛛网膜下腔麻醉致死的动物模型

目的 建立利多卡因麻醉致死的动物模型。方法 犬蛛网膜下腔注射利多卡因(37.01mg/kg体重),观察麻醉致死过程的生命体征变化及死后各器官的病理改变特点。结果 实验组犬心电、血压和呼吸消失的平均时间分别为23.8min(7-42min)、16.4min(7-35min)和18.6min(10～47min)。各器官病理改变均呈急死征象。结论 所建模型实验动物的表现和生命体征变化符合蛛网膜下腔麻醉致死的生前表现,可应用于利多卡因麻醉意外致死案件法医学鉴定的实验研究。     

Identification of mechanical asphyxiation in cases of attempted masking of the homicide

Five homicides are described that had remained unexplained as to the causes of death after gross pathology. Although general signs of asphyxiation were present, they were lacking injuries specific of strangulation or oro-nasal occlusion. The diagnoses of asphyxiation were established by microscopical investigation of the lung and confirmed by subsequent police inquiries. An oro-nasal occlusion was involved in three cases, a strangulation or an oro-nasal occlusion, in another case. The victims were young and healthy. Toxicological investigations remained negative in four cases; one victim was anaesthetized by bromazepam and ether and had a blood alcohol concentration of 80 mg/100 ml. Lung histology and electron microscopy revealed acute emphysema, the development of a haemorrhagic-dysoric syndrome and a microembolism syndrome. With regard to the haemorrhagic-dysoric syndrome, the development of alveolar-interstitial edema is particularly important. This finding may also be diagnosed by light microscopy in semi-thin sections. It is emphasized that the combined action of several pathomechanisms is responsible for the rapid manifestation of the pulmonary lesions. Especially, the haemorrhagic-dysoric syndrome is brought about by the combined action of inspiratory intrapulmonary vacuum and raised intracapillary pressure. The complex pattern allows to compile the diagnosis of mechanical asphyxia even if there is no corresponding injury.     

Endobronchial/Tracheal Metastasis and Sudden Death

Endobronchial and endotracheal metastases are rare lesions that may cause acute occlusion of major airways. A case is reported of a 62‐year‐old man with history of renal cell carcinoma and hemoptysis who died after having suddenly become short of breath with cyanosis. At autopsy, recurrent renal cell carcinoma was identified with metastases to the lungs, pulmonary hilar lymph nodes, and brain. In addition, a solitary papillomatous metastasis arising from the mucosa of the carina was obstructing both the main bronchi and distal trachea. Death was due to acute airway obstruction by a metastatic deposit at the bifurcation of the trachea in a case of disseminated renal cell carcinoma. This case demonstrates an extremely rare cause of sudden death that may complicate disseminated malignancy.     

大鼠急性斑蝥中毒血流动力学研究

大鼠急性斑蝥中毒的血流动力学研究结果显示,灌胃后,大鼠左心室舒张末压(LVEDP)呈下降趋势,左心室内压(LVP)和左室压最大变化速率(±dp/dt max)变化不明显;心率(HR)在低剂量组加快,而大剂量组减慢;心电图(EKG)无明显改变;呼吸频率(RR)先快后慢,大鼠死亡时,呼吸比心跳早停止几分钟。提示斑蝥中毒死亡较快时,呼吸抑制作用是一个不容忽视的因素。     

Postmortem examination of transepithelial ion currents in rabbit colon and trachea in relation to temperature of storage and its importance for interlethal reactions

Electrical phenomena resulting from transepithelial ion transport have been a subject of clinical, physiological, pharmacologic and toxicologic studies. These examinations concern mainly electric phenomena in live organisms. The changes of transepithelial ion pathways which take place postmortem have not been yet established. The aim of the study was an attempt to trace variability of electrophysiological parameters related to transepithelial ion transport in specimens of rabbit trachea and colon depending on temperature at which specimens were stored after death. It was observed that postmortem electric phenomena in epithelium of airways and alimentary tract of rabbit occur well-ordered but with slower course in trachea samples and in tissues which were preserved at low temperature after death.     

Swimming and loss of consciousness

Under certain circumstances, even a good swimmer may drown during swimming exercise. Two cases of drowning, a survivor and a dead, during swimming exercise in swimming-pool are described. These cases and experimental researches with dogs indicate that the initial aspiration of water may cause extremely low heart rate and low blood pressure by reflex vagal inhibition, which deprive a good swimmer of his consciousness and make him drown.     

Intramuscular bleeding in deaths from an internal cause: forensically significant differential diagnosis between external trauma and hemorrhages occurring during agony

Five cases of death from an internal cause are described in which bleeding into the muscles of the neck, the region of the shoulder girdle, the back of the thorax and partly the arms occurred during agony. As the cause of death was unclear at first and a violent crime could not be ruled out, a forensic autopsy was ordered in the course of which hemorrhages were detected which raised the differential diagnostic question whether extravasation might have been caused by an impact of blunt force. However, thorough investigation of the macroscopic and especially the microscopic structure of the lesions provided clear evidence that all the hemorrhages were due to internal causes. The pattern of these muscular lesions suggests intensified breathing with dyspnea leading to ruptures of the accessory respiratory muscles. Intramuscular bleedings of this type are a well-known phenomenon in legal medicine in connection with death by drowning, but have not been described in the medicolegal literature in cases of natural death from an internal cause so far.     

Sudden death in an adolescent due to undiagnosed classic Hodgkin lymphoma

Few cases of natural sudden death presenting as an undiagnosed lymphoma have been reported in the literature, especially in adolescents. Herein we provide a report of sudden death caused by undiagnosed classic Hodgkin lymphoma (cHL). We describe an 18-year-old female who collapsed after several weeks of weight loss, decreased appetite, and dyspnea. At autopsy, a bulky mass arising in the mediastinum and neck compressed the esophagus and trachea, surrounded the great vessels, obliterated the pericardial sac, and infiltrated the myocardium. The lungs were collapsed and large pleural effusions were present. The tumor burden, which weighed at least 2710 g in aggregate, was entirely above the diaphragm. Microscopic examination of the masses showed features typical for nodular sclerosis cHL including large bands of sclerosis, numerous Hodgkin/Reed-Sternberg (HRS) cells, and an eosinophil-rich mixed inflammatory cell infiltrate. Immunohistochemical stains showed the HRS cells to be uniformly positive for CD30 and CD15 and negative for CD3, CD20, CD45, and PAX5. This case exemplifies a rare sudden natural death due to previously undiagnosed cHL in a young patient.     

Radiographic demonstration of esophageal and tracheal fistulas at autopsy using a contrasting medium that vulcanizes at room temperature

Esophageal and tracheal fistulas, which occur in 0.05% of medicolegal autopsies, were demonstrated in three cases by a postmortem radiographic technique using silicone rubber/lead oxide as a contrasting medium that vulcanizes at room temperature. In one 83-year-old male, a tracheoesophageal fistula was detected, which had developed after surgical repair of an esophageal rupture caused by a flexible fiberoptic endoscope. In a second case, carcinoma of the esophagus in a 78-year-old male had eroded the trachea and arcus of the aorta creating a fatal tracheoesophagoaortic fistula. In a third case, 55-year-old female developed a tracheobrachicephalic artery fistula as a result of an infiltrating cystic adenocarcinoma of the trachea, resulting in a fatal hemorrhage into the trachea. The results of this study indicate that diagnostic radiologic methods using a vulcanized contrasting medium are useful in supplementing normal dissection in autopsy cases with suspected fistulas of the esophagus or trachea.     

关于建立侦查讯问中律师在场制度的尝试与思考

业已进行的讯问犯罪嫌疑人律师在场制度的试验表明:犯罪嫌疑人对此一般表示欢迎,他们在侦查中形成的口供比较稳定,此后没有翻供现象;而另一组没有律师参加讯问的犯罪嫌疑人,侦查终结后有的人进行翻供,并把原因归咎于侦查人员的不当讯问。同时,大多数侦查人员对试验表示理解和支持,并认为对侦查活动没有负面影响,反而有积极意义。试验还表明,建立讯问犯罪嫌疑人律师在场制度,并不需要“一刀切”,且我国目前及今后相当长一段时期也难以做到“一刀切”,因此,需要探索、建立替代性制度,如讯问时录音、录像制度。     

Iatrogenic tracheal laceration causing asphyxia

Endotracheal intubation is a simple, rapid, and safe technique that is being used as a standard procedure for airway management. However, airway injury during endotracheal intubation could be a significant source of morbidity or even mortality for patients and a source of liability for physicians as well. We report an unusual case of fatal tracheal occlusion by intraluminal blood clot complicating endotracheal intubation. The patient, a 62-year-old woman, with renovascular hypertension and incipient renal failure was scheduled for renal autotransplantation. The surgery was uneventful but the postoperative course was complicated with a lethal airway obstruction. At autopsy a linear longitudinal tracheal laceration was identified with an intraluminal blood clot obstructing the tracheal lumen. Tracheal laceration as a cause of death is a rare and potentially fatal complication of endotracheal intubation with intratracheal bleeding, clot formation, tracheal occlusion, and subsequent asphyxia.     

Sudden suffocation by surgical sponge retained after a 23-year-old thoracic surgery

A 70-year-old male patient with a 23-year-old history of right lower lung lobectomy for primary pulmonary adenocarcinoma (T1 N0 M0) presented with recurrent bronchopneumonia and purulent sputum. Pleural callus, lung abscess, bronchopleural fistula, and stitch granulomas were confirmed by chest x-ray, computed tomography scan, and bronchoscopy in the background of his complaints. An attempt to remove the bronchial purulent discharge and tissue sampling was made by using a flexible bronchoscope. The area of the lower trachea suddenly became clogged during bronchoscopic removal of the suspected piece of tissue (which later turned out to be organizing surgical gauze). The resuscitation following ventricular fibrillation failed to save the patient's life. The forensic postmortem examination confirmed the position of the foreign body extending from the abscess cavity, crossing the midline at carina and obstructing the lower trachea. This foreign body was a remnant of the surgical gauze left behind during a thoracic surgery 23 years ago.     

An experimental study of death in a reverse suspension.

To investigate the course of respiration and circulation in a head-down position, 14 rabbits were set in reverse suspension. The respiratory rate increased a little, but the amplitude of the respiratory movements did not change in the beginning of the experiment. The amplitude of respiratory movements then began to reduce gradually, and toward the end of the experiment, it reduced suddenly. PaO2 increased in the beginning of the experiment and then began to decrease in accordance with the reduction of the amplitude of the respiratory movements. The blood pressure decreased with relation to the decrease of PaO2 resulting from the reduction of the amplitude of the respiratory movements. All rabbits died in 17 to 44 hours (average, 26 hours). The results suggested that the cause of death in a head-down position is due to postural asphyxia resulting from hindered respiratory movements, and that it is possible to survive for at least half a day in a head-down position.     

Evolution of the content of THC and other major cannabinoids in drug-type cannabis cuttings and seedlings during growth of plants

In Europe, authorities frequently ask forensic laboratories to analyze seized cannabis plants to prove that cultivation was illegal (drug type and not fiber type). This is generally done with mature and flowering plants. However, authorities are often confronted with very young specimens. The aim of our study was to evaluate when the chemotype of cannabis plantlets can be surely determined through analysis of eight major cannabinoids content during growth. Drug-type seedlings and cuttings were cultivated, sampled each week, and analyzed by high-performance liquid chromatography with diode array detection. The chemotype of clones was recognizable at any developmental stage because of high total Δ(9)-tetrahydrocannabinol (THC) concentrations even at the start of the cultivation. Conversely, right after germination seedlings contained a low total THC content, but it increased quickly with plant age up, allowing chemotype determination after 3 weeks. In conclusion, it is not necessary to wait for plants' flowering to identify drug-type cannabis generally cultivated in Europe.     

家兔烧死后气管、肺及心肌的病理形态学观察

目的探讨烧死的病理形态学依据。方法建立家兔烧死动物模型,用光镜、透射及扫描电镜观察10只生前烧死家兔气管、肺及心肌的病变;并与死后焚尸及非烧死的正常组(各5只)对照。结果透射电镜下,气管粘膜上皮完全脱落,成堆红细胞和纤维蛋白成分粘附在平滑肌表面。肺Ⅰ型上皮细胞结构基本完整连续,线粒体嵴有断裂、缺失;Ⅱ型肺泡上皮细胞微绒毛消失,多数细胞线粒体、板层小体、高尔基体未见异常,少数Ⅱ型肺泡上皮细胞质膜破损、染色质浓集、胞质内容丢失。心肌严重变性坏死,细胞膜破坏,线粒体极度肿胀,肌丝溶解并出现收缩带坏死。扫描电镜下,气管粘膜上皮有完整纤毛,但上皮大片脱落,少数区域纤毛上皮稀疏排列,有脱落柱状上皮附着在纤毛上;肺间皮细胞结构基本完整,微绒毛数量不一致;心内膜的内皮细胞大部脱落,暴露内皮下结缔组织,心肌纤维呈扭曲排列。死后焚尸及正常组对照组未见上述变化。结论烧死兔的光镜和电镜下气管、肺及心肌的病理形态学变化,能为生前烧死与死后焚尸的鉴别提供依据。     

Mechanism of Death in Hanging: A Historical Review of the Evolution of Pathophysiological Hypotheses

Abstract: In cases of hanging, the exact mechanism leading to death has yet to be elucidated. Most of our contemporary knowledge is still based on writings from the end of the 19th and the beginning of the 20th century. This article reviews the historic experiments that shaped our current theories. Medico‐legal textbooks written in English and French from 1870 to 1930 were reviewed. Various animals, such as rabbits, mice, and dogs, have been used to develop animal models of hanging. Limited human studies on cadavers and judicial hangings have provided some additional insight into the pathophysiology of death by hanging. The main pathophysiological theories described were respiratory asphyxia, interruption to cerebral blood flow because of occlusion of vessels in the neck, and cardiac inhibition secondary to nerve stimulation. The relative contributions of each of these theories to death in cases of hanging is still debated today.