空气潜水减压病大鼠模型的建立

为建立空气潜水减压病大鼠模型,选用成年清洁级SD大鼠,以适当"压力-时程-减压速率"高气压暴露方案处理,分组如下:(1)600 kPa-90min暴露-200 kPa/min减压(n=8);(2)700 kPa-90min暴露-200 kPa/min减压(n=8);(3)700kPa-100min暴露-100kPa/min减压(n=8);(4)700 kPa-100min暴露-200kPa/min减压(n=37).出舱后置于转笼中以3m/min速度运动30min.从整体行为学、大体及显微病理学、炎症反应等方面筛选建立评估指标体系.通过控制高气压暴露的"压力-时程-减压速率"以及转笼运动方法,能制备出具有稳定发病率的大鼠减压病模型,并能很好地观测.建立了包括行为学、肺和中枢神经系统大体病理和显微病理以及炎性指标在内的模型评估体系.能根据需要建立特定发病率的减压病大鼠模型,建立的评估体系能很好地反映模型的病情.     

大连地区潜水捕捞作业人员急性减压病影响因素分析

目的 分析辽宁省大连地区潜水捕捞作业人员急性减压病发病情况及影响因素,为相关部门制定相应干预措施提供理论依据,控制和减少急性减压病的发生.方法 抽取大连地区沿海6个县区(旅顺口区、金州区、庄河地区、西岗区、甘井子区、长海县)共171家用人单位的642人进行问卷调查.结果 642名潜水作业人员,年度总下水次数392 845次,急性减压病的年发生次数507次,急性减压病的年平均发生率为1.3‰(人次);发病人数488例,占总人数的76％,其中轻度261例,占40.6％,中度91例,占14.2％,重度136例,占21.2％;潜水深度越深,潜水时间及潜水间隔时间越长,急性减压病的发病率越高;从事潜水作业之前对潜水知识非常了解以及潜水后严格规范减压的潜水作业人员急性减压病的发病频率低(P＜0.05或P＜0.01).潜水深度(OR=1.112)、潜水方式(OR=3.950)是急性减压病发病的主要危险因素.结论 潜水深度、潜水方式可能是大连地区潜水捕捞作业人员急性减压病的主要影响因素,潜水深度越深及重装潜水更易发生急性减压病.     

高压氧对减压病小鼠肺组织炎性细胞因子含量的影响

为探讨高压氧对减压病小鼠肺组织炎性细胞因子IL-1β和IL-10含量的影响,将小鼠随机分为正常对照组、减压病组和高压氧组。减压病组和高压氧组小鼠经600 kPa压缩空气暴露后,用1 m in快速减压至常压。高压氧组小鼠在快速减压1 h后接受高压氧处理。用酶联免疫吸附法检测减压病组和高压氧组小鼠在快速减压6 h后以及正常对照组小鼠肺组织IL-1β和IL-10含量。结果显示,减压病组小鼠肺组织IL-1β含量显著高于正常对照组(P<0.01);高压氧组小鼠肺组织IL-1β含量显著低于减压病组(P<0.05)。正常对照组、减压病组和高压氧组之间小鼠肺组织IL-10含量差异无统计学意义,均P>0.05,提示减压病早期小鼠肺组织存在促炎细胞因子和抗炎细胞因子之间的失衡,高压氧可有效降低促炎细胞因子水平,有助于减轻快速减压后继发性肺损伤。 更多还原     

医院工作效率指标的回归分析

医院管理中,平均病床周转次数、出院者平均住院日和平均病床工作日是评价医疗工作的效率指标。从理论上说,病床周转次数的多少.取决于出院者平均住院日和平均病床工作日的长短。但是,后两个指标对病床周转次数的快慢,影响的程度到底如何?相互之间的关系密切程度如何?本文对我院1980～1983年上述三个指标四十八个月的数据,运用多元回归分析法,计算出平均住院日、平均病床工作日与平均病床周转次数之间定量关系式——回归方程。通过回归方程,可用于计划预测和效率控制。     

一例急性脊髓型减压病分析

急性减压病较之减压性骨坏死发病急,但大多数经过减压治疗后可痊愈。急性脊髓型减压病是由于气泡侵犯神经系统,起病急,进展快,如延误治疗则易造成严重后遗症。本文通过对我院诊断的一例急性脊髓型减压病进行分析,旨在使大家对该病有一个了解并引起重视。     

急性故障性减压病在护理中注意的几个问题

减压病又称潜水员病。是指人体在高压环境下工作一定时间后,在转向正常气压时因减压过速, 气压幅度降低过大所引起的一种疾病,此时人体组织和血液中原来溶解的中性气体游离为气相,形成气泡,导致血液循环障碍和组织损伤。减压病护理与其它疾病护理有所不同,病情具有全身性、进展性特点,护理要特别注意以下几个问题,现介绍如下。     

脊髓型减压病13例临床分析

减压病发生于从事高气压下工作的潜水员、沉箱及隧道工人等,由于减压不当或根本不减压,体内原在高压下溶解的惰性气体形成气泡而引起的一种职业病,常侵犯皮肤、肌肉、关节及骨骼系统,但较少累及中枢神经系统,如一旦累及,即预示病情严重。目     

减压病加压治疗时的反常反应(附3例报告)

加压治疗的方法是目前治疗减压病最基本的措施,通常情况下,随着压力的升高和高压下停留时间的延长病人的临床症状逐步改善或消失。但是个别病例则相反,随着压力的增加症状反而加剧,这就是减压病再加压治疗时的反常反应,我们曾遇到3例,报告如下。病例介绍例1 男,36岁,某公社水产潜水员,工龄6     

慢性减压病101例分析

潜水减压病是因减压不当、体内原在高压下溶解的惰性气体形成气泡而引起的一种职业病.急性减压病处理的原则是立即加压使气泡消去,绝大多数可治愈。有人报道,发病后超过24～48h再进行治疗,治愈率将明显下降或不再会有多大效果。文献上关于发病后间隔较长时间才加压治疗的报道不多,究竟间隔多久还能治愈,未见专门研究. 1962及1963年作者曾单纯用加压治疗方法治愈过发病已136h及27个月的减压病患者各1例。根据气体定律,加压使症状迅即消去,这一特异效     

一次高气压暴露致减压性骨坏死2例报告

减压性骨坏死(Dysbaric osteonecrosis DON)最多发生于潜水、隧道和沉箱工人中~[1、2、3],也可见于航空减压病~[4]。一般认为该病是在多次减压不当之后发生,仅一次高气压暴露就导致发病的报道罕见,国内尚未见报道。现将两例和我们的体会报告如下。     

Decompression sickness and aseptic necrosis of bone: Investigations carried out during and after the construction of the Tyne Road Tunnel (1962-66): Report of Decompression Sickness Panel, Medical Research Council1

Report of Decompression Sickness Panel, Medical Research Council (1971). Brit. J. industr. Med., 28, 1-21. Decompression sickness and aseptic necrosis of bone: Investigations carried out during and after the construction of the Tyne Road Tunnel (1962-66). This paper describes investigations into the health of compressed air workers during and after the construction of a road tunnel under the River Tyne. Altogether 641 men were exposed to the compressed air environment over a period of approximately 31 months. The maximum working pressure was 42 psig (289·6 kN/m²), and the overall decompression sickness rate for work at pressures of 18 psig (124·1 kN/m²) and above was 2%.

Radiological examination of the chest was carried out on 183 men to detect lung cysts but only one was found. Thus lung cysts were not shown to be a common factor in the causation of decompression sickness but the possibility of small sub-radiological collections of trapped air being involved was not excluded.

Radiological examinations of the shoulders, hips and knee joints were carried out on 171 men. There was evidence of aseptic necrosis in one or more bones of 44 men (26%). Fifteen of the men with definite lesions of aseptic necrosis of bone and 7 of the men with suspected lesions had never worked in compressed air before this contract. The remaining 14 men with definite lesions and the 8 with suspected lesions had worked elsewhere in compressed air prior to this contract, but a definite lesion in one of these men and a suspected lesion in another can almost certainly be attributed to their work in compressed air on this contract.

     

Preemployment medical examinations in a compressed air tunneling project in Hong Kong

One thousand workers intended to be employed in a compressed air tunneling project in Hong Kong had preemployment medical examinations for fitness to work in compressed air. Only 69.3% were declared fit and the overall unfit rate was 22.1%. The major disqualifying medical conditions were lung and heart abnormalities and chronic otitis media. Chest x-ray was found to be the most useful procedure in detecting the disqualifying conditions. The type I bends rate of the contract during the same period of examination was low: 1.39% at maximum working pressure of 2.45 kg/cm2, and there was no case of type II decompression sickness. Although many factors may affect the bends rate, it is suggested that the strict criteria adopted in the selection of workers might have contributed to the satisfactory outcome in the prevention of decompression sickness.     

Research on the incidence of decompression sickness in compressed air works. The development of its recent five years' study

Compressed air works have been used as the safest construction work for the basic underground or underwater compressed shield or caisson works in Japan; however, the workers who were exposed to the compressed fields must have put themselves at risk of decompression sickness. Decompression sickness is generally considered to be due to the bubble effects and the bubbles originate from the supersaturated gas dissolved in the blood and other tissues. The standard decompression schedule by the Ministry of Labor has been practically applied at the end of compressed air works, and the laborers decompress slowly from the bottom pressure to the surface according to the schedule. It is difficult to completely prevent the sickness and the average percentage of contracting "bends," using the Japanese standard decompression schedule, is considered to be 0.54%. But previous papers reported higher incidences from 1.42 to 3.3% or more. We have continued an actual investigation on the incidence, and the number of the exposed trials amounted to nearly a hundred thousand. These data were compared between recent five years' group and before. Eventually, it was ascertained that the incidence has been significantly decreased in the recent five years; however, greater care in occupational safety control is still needed.     

减压病小鼠血小板膜糖蛋白的表达

目的　探讨血小板膜糖蛋白CD31、CD61和CD62p表达在减压病发病机制中的作用。方法　 1 4只雌性昆明种小鼠随机分为减压病组和正常对照组。减压病组经 60 0kPa压缩空气暴露后 ,用 1min快速减压至常压。在减压后 60min时 ,用流式细胞术检测小鼠血小板膜糖蛋白CD31、CD61和CD62p表达。结果　减压病组小鼠血小板膜糖蛋白CD31的平均荧光强度 (1 8.64± 1 .0 1 )高于正常对照组 (1 6 .89± 1 .69) ,差异有显著性 (P <0 .0 5) ;减压病组小鼠血小板膜糖蛋白CD61的平均荧光强度 (2 71 .0 6± 2 4 .2 5)和CD62p的阳性百分数 (4.48%± 0 .43 % )均高于正常对照组 (分别为 2 34 .0 9± 1 5 .96、3 .0 0 %± 0 .66 % ) ,差异有非常显著性 (P <0 .0 1 )。结论　不适宜的快速减压可增强血小板膜糖蛋白CD31、CD61和CD62p的表达 ,促使血栓形成     

Analysis of some individual risk factors for decompression sickness in Hong Kong

Individual risk factors for decompression sickness (DCS) were studied in 932 men who had worked for 12 shifts or more at maximum working pressure (MWP) of 1 bar or above in a compressed air tunneling project in Hong Kong. Two dependent variables were used: presence or absence of bends and number of bends experienced by a man. Three hundred and fifty-six men (38.2%) had one or more bends. Univariate analysis showed that many variables were associated with presence or absence of bends. Logistic regression showed that the best equation included five independent variables: MWP, number of exposures, past number of bends, job (being a miner), and Quetelet Index (or Body Mass Index). The number of bends was also associated with many variables. Stepwise multiple regression revealed five important independent variables: ethnicity, MWP, Quetelet Index, number of exposures, and past number of bends. Obesity and past number of bends were therefore important risk factors for DCS after taking into account MWP and number of exposures. The age effect observed in univariate analysis could be due to obesity. Miners and Japanese had higher risks of DCS, probably due to their strenuous labor.     

Manifestations and treatment of 793 cases of decompression sickness in a compressed air tunneling project in Hong Kong

In the largest compressed air tunneling contract for the construction of the Island Line of the Mass Transit Railway system in Hong Kong, 154,390 man-decompressions occurred, of which 142,140 were after exposures to 1 bar (1.97 ATA, 14.7 psig) or above. The maximum working pressure (MWP) was 3.30 bar (4.26 ATA, 47.9 psig). There were 792 cases of type I and 1 case of type II decompression sickness. The manifestations of the cases were generally similar to those reported elsewhere. Oxygen treatment was given to 9 cases and all were successfully treated with no recurrence of symptoms. Minimum effective pressure treatment on 783 type I cases was successful, with 9.6% requiring two or more recompressions. The pressure required to relieve symptoms was more closely related to the interval between completion of decompression after work and commencement of treatment than to the delay between onset of symptoms and treatment. For every 1-h interval or every 1-h delay, an additional pressure of 0.04 bar (0.04 ATA, 0.58 psi) above MWP was required for pain relief. Step-wise multiple regression analysis showed that the four predictors for pressure of relief and the highest pressure used in recompression, respectively, were, in order of descending importance, maximum working pressure, interval before treatment, bends sequence (the nth attack of bends experienced in the present contract, i.e., the sum of previous attacks and the present attack), and duration of exposure.     

Increased blood-brain barrier permeability to tetracycline in rabbits under dysbaric conditions

Alteration of the blood-brain barrier (BBB) by dysbaric exposure may have relevance in several areas of hyperbaric medicine. Drugs administered to persons exposed to dysbaric conditions, e.g., divers, compressed air workers, may penetrate the brain in amounts that could produce toxic or undesirable effects. Modification of the BBB may also have pathogenetic implications in decompression sickness. Furthermore, increased BBB permeability to certain potentially useful antitumor agents, antibiotics, and other compounds under dysbaric conditions may provide the basis for a new therapeutic approach. This report concerns the influence of dysbaric exposure on BBB permeability to an antibiotic. Tetracycline (5-40 mg/kg) was intravenously injected in 22 experimental rabbits (subjected to air compression-decompression) and 17 controls (kept at ambient pressure). Fluorescence microscopy and spectrometry revealed significantly greater tetracycline concentrations in 72.7% of the experimental brains. With the 5 mg/kg dose, the mean tetracycline concentrations was 0.17 micrograms/g in control brains and 0.33 micrograms/g in experimentals. These results indicate that dysbaric exposure increases BBB permeability to tetracycline. It appears that BBB alteration is related to intravascular gas bubbles but is independent of the development of decompression sickness. The conclusions of this investigation are pertinent to brain pharmacotherapy and may provide some new insight into the mechanism of decompression sickness. They also point to potential risks connected with drug administration under dysbaric conditions that can alter BBB permeability.     

Fetal and maternal bubbles detected noninvasively in sheep and goats following hyperbaric decompression

Pregnant sheep and goats were compressed with air to an equivalent depth of 49 msw (160 fsw) for bottom times ranging from 5 to 15 min. Maternal (precordial) and fetal (umbilical artery) circulation were monitored transcutaneously with a Doppler ultrasound flowmeter to determine the presence of decompression gas bubbles. It was found that the number of bubbles detected precordially in the maternal circulation exceeded the number detected in the fetal umbilical artery for any given bottom line. Additionally, bubbles were found in the fetal circulation even when the mother did not display signs of decompression sickness. Thus, avoidance of symptoms of pain-only decompression sickness in the mother is not sufficient to preclude gas phase formation in the fetus.     

Medical aspects of the environmental sanitation of workplaces in compressed air work in Japan

Actual follow-up investigations were made for a period of 5 yr and 10 months since February 1980 on 55 places of caisson and shield work. The maximum bottom pressure in caisson work was 3.6 kg/cm2 (4.6 ATA) and that of shield work was 1.6 kg/cm2. The number of exposures of workers was 23,737 in caisson work and 75,244 in shield work. The items of geomedical measurements were temperature (degrees C), humidity, dust, illumination, noise, oxygen, carbonic acid gas and others. In compressed air work, it is most important to prevent decompression sickness (bends) from the view of occupational health. The incidence of bends has decreased in recent years because of strict control by regulations. Environmental hygiene, however, has seldom been discussed in this field and little geomedical control has been made on compressed air work. In view of this situation, we have, therefore, studied, observed, and measured the hygienic factors of this work during the past five years. This investigation is without doubt the first of its kind in Japan and the areas covered most of the regions where compressed air works have been made in the past. From these results, it can be concluded as follows: The working temperature was controlled, but humidity was too high (nearly 90%). Illumination was insufficient. Dust was a problem, but high humidity played an important role in decreasing the volume. The environment was noisy. It is therefore natural that environmental studies should be continued and hygienic consideration be further emphasized in compressed air work.     

Central nervous system involvement in patients with decompression illness]

Dysbarism or decompression illness (DCI), a general term applied to all pathological changes secondary to altered environmental pressure, has two forms decompression sickness (DCS) and arterial gas embolism (AGE) after pulmonary barotrauma. Cerebral and spinal disorders have been symptomatically categorized as AGE and DCS, respectively. Magnetic resonance images (MRIs) of divers with DCI showed multiple cerebral infarction in the terminal and border zones of the brain arteries. In addition, there were no differences between MRI findings for compressed air and breath-hold divers. Although the pathogenesis of the brain is not well understood, we propose that arterialized bubbles passing through the lungs and heart involved the brain. From the mechanisms of bubble formation, however, this disorder has been classified as DCS. We propose that there is a difference between clinical and mechanical diagnoses in the criteria of brain DCI. In contrast to brain injury, the spinal cord is involved only in compressed air divers, and is caused by disturbed venous circulation due to bubbles in the epidural space. The best approach to prevent diving accidents is to make known the problems for professional and amateur divers.