应用ECMO救治一例吸入硫化氢气体中毒患者的护理体会

武汉大学中南医院于2021年12月23日收治1名职业性急性硫化氢中毒致呼吸衰竭患者,患者短期吸入较大量硫化氢,病情危重且进展迅速,医生团队及时给予体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)支持治疗及镇静镇痛等相关支持,早期请多学科会诊,控制患者精神症状,稳定其生命体征,稳定期康复团队给予患者康复指导,护理团队在患者行ECMO治疗期间,严控院感管理及管路护理,严密动态监测指标,重点交接班,实现了精准护理,并在后期人文关怀与线上追踪随访中达到了良好的效果,患者症状在短时间得到良好控制并逐步达到康复效果,于2022年1月15日顺利出院。综上,及时体外膜肺氧合急救及护理+多学科诊疗管理+线上指导随访的模式,有利于硫化氢急性中毒患者的治疗与康复,值得临床推广。     

Exercising animal models in inhalation toxicology: interactions with ozone and formaldehyde

Exercise during exposure to inhaled toxicants increases inhaled dose rate and alters dose distribution within the respiratory tract, and exercise has long been recognized as a critical exposure variable. While modern inhalation exposure studies with human subjects routinely use an exercise protocol, most investigations with animal models are performed with resting subjects. Animal inhalation exposures under exercising conditions frequently induce respiratory toxic effects well beyond that expected from the simple increase in ventilation dose rate. Different classes of irritants can induce different reflex breathing patterns, and small mammals have different capacities for hypothermic or hyperthermic responses to rest or exercise exposure. Respiratory tract injury and breathing pattern responses of rats to upper and lower airway irritants ozone and formaldehyde were measured under conditions of rest and exercise to illustrate the complexities of comparison to human exposures. In addition to the exercise effects on dose and dose distribution and the possibility of hypo- or hyperthermic responses, exercise enhancement of inhalation injury may also be related to a combination of toxicant-induced disruption of the pulmonary epithelial permeability barrier and exercise-induced pulmonary capillary stress failure.     

A review of inhalation toxicology studies with Para-aramid fibrils

The paper summarizes the results of inhalation toxicology studies associated with para-aramid (p-aramid) fibrils. The review is subdivided into two categories: the results of inhalation toxicity studies and mechanistic inhalation studies. Keratin-associated lesions were observed in the lungs of female rats following chronic exposure to high concentrations of p-aramid. These lesions were originally interpreted as cystic keratinizing squamous cell carcinomas (CKSCC). In recent years, this keratinizing lesion has been observed in the lungs of rats with greater regularity in numerous chronic inhalation studies following exposures to a variety of dusts. In an attempt to reach a consensus on an appropriate diagnosis for this lesion, an international panel of pathologists was convened to evaluate the morphological aspects of this lesion. The panel considered that the most appropriate diagnosis for this lesion was ‘proliferative keratin cyst’ (PKC). the biological potential of the PKC remains controversial, but it appears to be unique to the rat species and has little relevance for humans. Mechanistic studies with p-aramid have demonstrated that acute inhalation of high concentrations of fibrils produces a potent but transient pulmonary inflammatory and cell labelling response. The inhaled fibrils have low durability in the lungs of rats as evidenced by a progressive decrease in median fibre lengths with increasing residence time in the lung. In contrast, in a comparative study, size-separated chrysotile asbestos produced a sustained increase over controls in cellular proliferation responses of terminal airways, parenchyma, subpleural and mesothelial regions. In addition, while the short fibres were cleared at a normal or rapid rate, the long (i.e. > 5 μm) chrysotile fibres were retained in the lung or cleared at a slow rate, suggesting that this subpopulation of fibres is durable in the lungs of exposed rats. These results point out the differences in the lung responses between p-aramid fibrils when compared to chrysotile asbestos fibres, namely, that chrysotile produced enhanced and sustained cell proliferation responses, and that the long chrysotile fibres were retained in the lungs of exposed rats.     

纳米硫化镉呼吸道亚慢性暴露对雄性大鼠的生殖毒性

目的探讨纳米硫化镉(CdS)对大鼠睾丸的氧化损伤及对精子的影响。方法 32只雄性清洁级SD大鼠随机分为对照组(蒸馏水)、10 mg/kg、20 mg/kg和30 mg/kg的纳米CdS组,每组8只。采用肺灌注方法染毒,2次/周,持续染毒12周。计算睾丸脏器系数,测定睾丸组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力和丙二醛(MDA)含量,观察精子数量、畸形率、活动度和睾丸的病理学变化。结果与对照组相比,30 mg/kg染毒组精子数量、精子活动度降低,10、20、30 mg/kg染毒组精子畸形率增高(P<0.05)。与对照组相比,30 mg/kg染毒组的大鼠睾丸SOD、GSH-Px活力降低(P<0.05),10、20、30 mg/kg染毒组的大鼠睾丸MDA含量增高(P<0.05)。染毒组生精小管内生精细胞脱落,层次减少,各级生精细胞排列紊乱,管内生精细胞疏松、排列紊乱、上皮变薄,管腔内可见脱落的精子细胞。结论纳米硫化镉经呼吸道染毒可致大鼠睾丸病理改变,氧化损伤,并且引起精子数量减少,活动度降低,畸形率增加。     

Effect of Chlorella vulgaris intake on cadmium detoxification in rats fed cadmium

The aim of this study was to investigate if dietary Chlorella vulgaris (chlorella) intake would be effective on cadmium (Cd) detoxification in rats fed dietary Cd. Fourteen-week old male Sprague-Dawley (SD) rats weighing 415.0 ± 1.6 g were randomly divided into two groups and fed slightly modified American Institute of Nutrition-93 Growing (AIN-93G) diet without (n=10) or with (n=40) dietary Cd (200 ppm) for 8 weeks. To confirm alteration by dietary Cd intake, twenty rats fed AIN-93G diet without (n=10) and with (n=10) dietary Cd were sacrificed and compared. Other thirty rats were randomly blocked into three groups and fed slightly modified AIN-93G diets replacing 0 (n=10), 5 (n=10) or 10% (n=10) chlorella of total kg diet for 4 weeks. Daily food intake, body weight change, body weight gain/calorie intake, organ weight (liver, spleen, and kidney), perirenal fat pad and epididymal fat pad weights were measured. To examine Cd detoxification, urinary Cd excretion and metallothonein (MT) concentrations in kidney and intestine were measured. Food intake, calorie intake, body weight change, body weight gain/calorie intake, organ weight and fat pad weights were decreased by dietary Cd intake. Urinary Cd excretion and MT concentrations in kidney and small intestine were increased by dietary Cd. After given Cd containing diet, food intake, calorie intake, body weight change, body weight gain/calorie intake, organ weights and fat pad weights were not influenced by dietary chlorella intake. Renal MT synthesis tended to be higher in a dose-dependent manner, but not significantly. And chlorella intake did not significantly facilitate renal and intestinal MT synthesis and urinary Cd excretion. These findings suggest that, after stopping cadmium supply, chlorella supplementation, regardless of its percentage, might not improve cadmium detoxification from the body in growing rats.     

锌镉毒性研究进展

目的:总结近年来国内外对于锌镉毒性的研究进展。方法:搜集、分析国内外相关文献。结果:动物实验研究表明:镉对鼠类的生殖系统、骨骼发育以及听力系统均有毒作用,镉可引起鱼类卵壳破裂,锌能拮抗镉对动物的毒性作用。人体研究表明:锌不仅能提高人体免疫力而且能拮抗镉对人体的毒性作用,镉对人体的健康效应主要表现在对人体呼吸、泌尿、消化、运动、生殖系统等方面的毒性作用。结论:锌镉相互拮抗,锌可预防和减轻镉中毒的危害。     

Biopersistence of man-made fibers by animal inhalation experiments in recent reports

Biopersistence of man-made fibers by animal inhalation experiments was mainly reviewed. This report showed that the biopersistence and maximum tolerated dose are significantly important factors for hazard assessment for man-made fibers as well as fiber size (diameter/length), chemical compositions and surface properties.     

动式吸入纳米二氧化硅的大鼠肺毒性研究

目的 探讨连续动式吸入条件下不同浓度的纳米二氧化硅(SiO2)是否可以导致大鼠肺部明显的毒性作用.方法 48只雄性SD大鼠按体重随机分成4组,包括分散剂对照组(对照组,生理盐水)和纳米SiO2低剂量组(质量浓度为0.3％)、中剂量组(质量浓度为1.0％)和高剂量组(质量浓度为3.0％).于动式染毒28 d后(每天染毒2h)处死动物,采集肺泡灌洗液(BALF)和肺组织,观察肺脏器系数、BALF中白细胞总数及分类、总蛋白含量、乳酸脱氢酶(LDH)活力、肺组织病理改变(HE染色)和肺纤维化形成情况(VG染色).结果 与对照组相比,纳米SiO2组肺脏器系数的差异无统计学意义(P＞0.05).1.0％和3.0％纳米SiO2组BALF中的白细胞总数明显高于对照组,差异有统计学意义(P＜0.05).各剂量纳米SiO2组的总蛋白含量和LDH活力与对照组比较,差异均无统计学意义(P＞0.05).与对照组相比,各剂量纳米SiO2组淋巴细胞的比例明显降低,单核和巨噬细胞的比例明显升高,差异有统计学意义(P＜0.05).HE染色显示,纳米SiO2组肺泡壁明显增厚,支气管和血管壁周围发生明显的炎性细胞浸润,各纳米SiO2组肺纤维化VG染色均未见胶原纤维分布的明显增加.结论 本实验条件下,连续28d动式吸入纳米SiO2只引起大鼠肺部显著的炎症反应,未出现肺纤维化现象.     

镉对大鼠睾丸的影响

本文报告饮水中含镉对大鼠睾丸的慢性损害实验，并作有关酶组织化学活性检查。结果：大鼠连续饮用含ＣｄＣｌ２（氯化镉）３００ｍｇ／Ｌ水，其睾丸曲精小管内各级生精细胞损害严重。曲精小管和附睾内精子完全消失；曲精小管各级生精细胞核呈固缩状，残留甚少且难以区别。腔内可见较多多核聚体，嗜伊红团块和网状结构等坏死组织产物。糖原ＰＡＳ反应减弱；ＳＤＨ（琥珀酸脱氢酶）、Ｍｇ２＋－ＡＴＰａｓｅ（镁激活三磷酸腺苷酶）的活性明显减弱；ＬＤＨ（乳酸脱氢酶）、ＡＣＰ（酸性磷酸酶）的活性增强。提示：以含ＣｄＣｌ２３００ｍｇ／Ｌ染毒饮水已引起睾丸曲精小管上皮严重损坏。     

Estimating cadmium absorption rate in digestive organs calculated from information of studies on cadmium conducted in Japan

The absorption rate of cadmium (Cd) in the digestive organs is reported to be 0.5-8% in Friberg's textbook. This value was obtained from experimental studies. The object of the present study is to obtain the value from the Cd intake amount by ingestion, the Cd absorption amount by respiration and smoking, and the total Cd absorption amount calculated from the Cd accumulation amount in organs reported in articles including not only experimental but also epidemiologic studies conducted in Japan. The oral intake amounts of Cd in Japan were obtained from a published article to be 48 micrograms/day for males in the 1970s. The total Cd absorption amount that was calculated from the Cd accumulation amount in organs of 223 male subjects autopsied following sudden death was found to be 6.8 micrograms/day for male adults in the 1970s. The Cd exposure before the 1970s reflected the Cd absorption amount calculated from the Cd accumulation amount in the 1970s. The Cd absorption amount by respiration and smoking for males in the 1960s was 1.0 microgram/day, and the difference of 5.8 micrograms/day between the above two corresponds to the Cd absorption amount in digestive organs before the 1970s. The rice intake amount for Japanese in 1955-1965 was reported to be about 1.4 times as much as that in 1975. Therefore the Cd absorption rate in digestive organs was estimated to be about 10% from these values, assuming that most of the change in Cd intake from food is derived from the amount of rice eaten in Japan. This value is somewhat greater than the values published in the literature.