氧化雾化吸入的临床应用观察

雾化吸入是治疗慢性呼吸系统疾病的主要方法之一，雾化吸入时雾滴的大小决定了它在呼吸道中的沉降部位。雾滴直径在1-5um沉积部位在细支气管及肺泡；5-20um沉积部位在支气管；2040um沉积部位在鼻、咽、喉及上部气管，故临床上，根据治疗呼吸道疾病的不同而选用不同的雾化器，一般临床所需雾滴直径以1-5um为宜。     

纳米二氧化钛微粒对肺组织的急性损伤作用

近年来,纳米材料作为一种新型材料,使用前景越来越广阔.当物质的粒径明显变短时,其理化性状也发生了根本性改变,对机体的生物效应和作用强度也发生本质上的变化.研究表明,直径小于5 μm的呼吸性粉尘的沉积效率与其粒径密切相关,1～100 nm的粒子可以自由进出肺组织而达到生物体内微米级颗粒所不能抵达的区域,在呼吸道的鼻咽部、气管支气管和肺泡区域均有沉积,并且可根据其粒径的大小不同而改变沉积部位[1],因而直接与细胞发生作用的机会更大.纳米粒子在肺部的沉积可引起炎症反应,肺上皮细胞的损伤,甚至肺组织的纤维化.     

血液透析室空气微生物气溶胶分布与医院感染的相关性及健康风险评价

目的 监测血液透析室空气微生物气溶胶的分布特性及其与医院感染的相关性分析,并评价环境健康风险。方法 选取2020年1月-2021年1月温州医科大学附属第二医院血液透析室收治的血液透析患者194例,根据是否发生感染分为研究组(n=10)和对照组(n=184),对血液透析室空气环境中的微生物进行采样,计算微生物气溶胶浓度与粒子中值直径。结果 两组的年龄、身体质量指数(BMI)、血液透析(HD)时间比较差异有统计学意义(P<0.05)。透析时,两组的微生物气溶胶浓度高于透析前和透析后(P<0.05);透析时和透析后,研究组的微生物气溶胶浓度高于对照组(P<0.05)。研究组透析时,血液透析室中不同等级的微生物气溶胶浓度、微生物气溶胶总浓度与粒子中值直径高于对照组(P<0.05);相关性分析结果显示,微生物气溶胶总浓度、不同种类微生物气溶胶浓度、微生物气溶胶粒子中值直径与血液透析患者医院感染相关(P<0.05)。患者经呼吸发生感染的风险大于经皮肤,且男性经呼吸、皮肤感染的风险大于女性(P<0.05)。结论 血液透析室空气环境中微生物气溶胶浓度在患者透析时浓度最高,微生物气溶胶浓度及粒子中值直径与血液透析患者医院感染相关,且血液透析室中男性呼吸和皮肤感染风险高于女性。     

健康和哮喘志愿者吸入不同粒径硫酸雾对呼吸反应的影响

为研究酸性雾粒大小对呼吸生理反应的影响,作者使哮喘和健康志愿者分别吸人体积中值直径为20、10和1μm、浓度为2000μg/m~3的硫酸气溶胶,并以相同方法吸去离子水气溶胶作对照。受试者每次接触上述气溶胶1小时,中间包括3次10分钟的运动和肺功能测定,通气率为40～45L/min。按随机顺序每隔7天试验一次。吸入室气温为10℃、吸入直径为20和10μm气雾时,相对湿度为100%;吸入直径为     

吸入氧化镍气溶胶的肺沉积和清除

本文叙述了大鼠吸入NiO气溶胶的实验结果。NiO的负荷是经化学分析测定的,以确定实际的沉积百分率。制备呼吸性NiO气溶胶并送进染毒室。用光散射法连续监测染毒室中NiO气溶胶浓度,用等动力法经玻璃滤料吸入空气,每隔一天用重量法加以测定。气溶胶的粒径分布,使用Andersen级联冲击器测定。进行了三个不同的接触实验。实验动物为Wistar雄性大鼠,每天接触NiO气溶胶6～7     

粉尘测定的采样方法及其结果的可比性

随着我国加入世界贸易组织 (WTO)并颁布了职业病防治法 ,我国的劳动卫生标准也作了相应的变动 ,如 :时间加权平均浓度 (TWA)成为接触限值的主体性单位 ;要求测定作业场所的呼吸性粉尘浓度。我们历史上积累了大量总粉尘和瞬时粉尘浓度的测定数据 ,怎样把它们转换和利用 ,需要研究。本文介绍德国及欧洲关于气溶胶组分的采样技术、规范和仪器 ,以及不同检测方法及其结果的比较。气溶胶测定依然是空气监测的一项重要任务。医学上主要考虑吸入的气溶胶颗粒在呼吸道沉积的部位。图 1[1 ] 显示了气溶胶各组分与其空气动力学直径的关系。空气中直…     

氧气驱动雾化吸入在儿科的应用和护理

近年来氧气驱动雾化吸入治疗是小儿呼吸系统疾病的主要治疗方法之一。应用氧气驱动雾化药液产生直径2—4μm雾液颗粒，主要为沐舒坦等湿化去痰剂、支气管扩张剂（万托林、爱全乐等）、抗病毒药物病毒唑等，吸入后大多数雾滴可较好地沉积在细支气管内、终末细支气管黏膜表面，     

42例气管结核气管镜下冷冻治疗联合镜下给药疗效观察

目的探讨经气管镜介入冷冻联合雾化吸入治疗气管支气管结核的临床效果。方法 2015年3月~2016年3月期间诊治的气管支气管结核患者中抽取42例作研究对象,对其采取经气管镜介入冷冻联合雾化吸入治疗,评估其治疗效果、痰菌阴转率、病灶吸收率以及不良反应情况。结果本组患者的治疗总有效率是97.6%,痰菌转阴率是92.9%,病灶吸收率是90.5%,无明显不良反应。结论经气管镜介入冷冻联合雾化吸入治疗气管支气管结核的临床效果确切,可有效消除患者临床症状和体征,并提升其痰菌阴转率,促进其病灶吸收,无明显不良反应,值得借鉴。     

小儿气管异物的护理

气管异物是耳鼻喉科急危症之一,多发生于3岁以下儿童.因小儿咳嗽反射及喉的保护作用不健全,在进食时哭笑、逗玩、惊吓等诱因,促使异物吸入气管及支气管内,可出现呼吸窘迫甚至危及生命.     

城市大气中气溶胶的毒性—粒子大小的影响

目前,一般认为空气中飘尘的毒性作用主要取决于粒子的大小。例如,吸入硫酸锌铵气溶胶所致肺通气障碍,微粒直径在1.4～0.29微米的范围内,随粒子直径的减小而增加。同样,二氧化锰的粗粒粉尘可被耐受多年而无不良反应,但其微粒烟尘(80%的粒子直径小于0.2微米)则能引起肺炎。最近的研究表明,一些具有潜在毒性的微量物质,包括:铅、镉、锑、硒、镍、钒、锌、钴、溴、锰、硫酸盐和苯并芘,主要存在于能沉着于肺的城市大气气溶胶     

Performance of personal inhalable aerosol samplers in very slowly moving air when facing the aerosol source

While personal aerosol samplers have been characterized primarily based on wind tunnel tests conducted at relatively high wind speeds, modern indoor occupational environments are usually represented by very slow moving air. Recent surveys suggest that elevated levels of occupational exposure to inhalable airborne particles are typically observed when the worker, operating in the vicinity of the dust source, faces the source. Thus, the first objective of this study was to design and test a new, low cost experimental protocol for measuring the sampling efficiency of personal inhalable aerosol samplers in the vicinity of the aerosol source when the samplers operate in very slowly moving air. In this system, an aerosol generator, which is located in the centre of a room-sized non-ventilated chamber, continuously rotates and omnidirectionally disperses test particles of a specific size. The test and reference samplers are equally distributed around the source at the same distance from the centre and operate in parallel (in most of our experiments, the total number of simultaneously operating samplers was 15). Radial aerosol transport is driven by turbulent diffusion and some natural convection. For each specific particle size and the sampler, the aerosol mass concentration is measured by weighing the collection filter. The second objective was to utilize the new protocol to evaluate three widely used aerosol samplers: the IOM Personal Inhalable Sampler, the Button Personal Inhalable Aerosol Sampler and the 25 mm Millipore filter holder (closed-face C25 cassette). The sampling efficiencies of each instrument were measured with six particle fractions, ranging from 6.9 to 76.9 micro m in their mass median aerodynamic diameter. The Button Sampler efficiency data demonstrated a good agreement with the standard inhalable convention and especially with the low air movement inhalabilty curve. The 25 mm filter holder was found to considerably under-sample the particles larger than 10 micro m; its efficiency did not exceed 7% for particles of 40-100 micro m. The IOM Sampler facing the source was found to over-sample compared with the data obtained previously with a slowly rotating, freely suspended sampler in a low air movement environment. It was also found that the particle wall deposition in the IOM metallic cartridge was rather significant and particle size-dependent. For each sampler (IOM, Button and C25) the precision was characterized through the relative standard deviation (RSD) of the aerosol concentration obtained with identical samplers in a specific experiment. The average RSD was 14% for the IOM Sampler, 11% for the Button Sampler and 35% for the 25 mm filter cassette. A separate set of experiments, performed with the Simplified Torso showed that in very slowly moving air a personal sampler can be adequately evaluated even when it is not attached to a body but freely suspended (confirming the data reported previously).     

Personal sampling for inhalable aerosol exposures of carbon black manufacturing industry workers

The study was concerned with the measurement of inhalable aerosol exposures in the carbon black production industry. The primary goal of the study was to determine the extent to which inhalable aerosol exposure, as measured by the Institute of Occupational Medicine (IOM) personal inhalable sampling head, compared to "total" aerosol exposure, as measured by traditional methodology. A secondary objective was the evaluation of another inhalable aerosol sampler for carbon black aerosol measurement. In addition, an exploratory evaluation of the applicability of the National Institute for Occupational Safety and Health (NIOSH) analytical method (Method 5040) for the determination of carbon black, measured as elemental carbon, was conducted. A field study was carried out in a number of North American carbon black production plants using three samplers: the 2 Lpm IOM sampler as a reference sampler for the inhalable fraction, the 2 Lpm closed-face 37-mm plastic cassette that has been used for many years for total aerosol, and the 3.5 Lpm GSP sampler that has recently been identified by some as a possible candidate for inhalable aerosol. No such studies have previously been reported for the carbon black industry. Further, there have been no reports of the GSP performance in direct comparison to a reference instrument like the IOM sampler. The results showed that inhalable aerosol exposures for workers in carbon black production and packing areas were higher than the corresponding total aerosol exposures by a factor of nearly three, implying the presence of significantly coarser aerosol than previously thought based simply on knowledge of the carbon black production process. The fact that the aerosols collected in portions of the process comprised high proportions of non-elemental carbon particulate was thought likely to be responsible, underlining the need to consider whether gravimetric assessment for such exposure is the most appropriate metric. In addition, and somewhat surprisingly, the GSP sampler emerged clearly as a good alternative to the IOM sampler for collecting inhalable aerosol in carbon black industry workplaces like those studied (although this conclusion cannot yet be extended to other workplaces).     

Relationships between inhalable, thoracic, and respirable aerosols of metalworking fluids

The aim of the study described in this companion paper was to assesses relationships among inhalable, thoracic, and respirable aerosol fractions of metalworking fluids. A RespiCon sampler, which simultaneously collects all three fractions, was used at four Ontario plants to collect 37 samples of 120 to 400 min duration. The ratios of the slopes of the lines of a regression model forced through the origin between inhalable and thoracic, inhalable and respirable, and thoracic and respirable were 1.38, 1.51, and 1.13, respectively. These ratios would be useful in assessing metalworking fluid airborne exposure data based on different aerosol fractions and for interpreting occupational exposure standards based on different fractions.     

Correction of sampler-to-sampler comparisons based on aerosol size distribution

This article explains a simple method for correcting a sampler-to-sampler ratio for changes in size distribution by computing a bias factor that relates the measured ratio with a ratio determined from equations that describe the collection efficiency curves of the samplers while taking size distribution into account. Laboratory trials were conducted to determine whether the resulting bias factor is independent of aerosol size distribution. During these studies, a 3-piece cassette and respirable cyclone were compared with an inhalable sampler in both a still-air chamber and a moving-air chamber operated at 0.2 m/sec and 1.0 m/sec. An ISO test dust of various size fractions was generated to produce an aerosol with mass median aerodynamic diameter ranging from 1.4 microm to 10.1 microm. An organic dust consisting of ground grain material was also applied to the still-air chamber to demonstrate differences between dust types. Results showed that the bias value was significantly different between dust types for both the cyclone/ inhalable (p=0.001) and cassette/inhalable (p=0.033) comparisons but was not different between wind conditions for either comparison. All but one comparison had insignificant slopes when comparing the bias value with median diameter, indicating that the bias value could be used to correct for size distributions in most conditions. However, bias values determined when comparing the cyclone with the inhalable sampler in the still-air condition produced a positive slope for median diameters less than 4 microm (p=0.008). Further research is needed to determine why the actual cyclone/inhalable ratio decreases relative to the expected ratio as the proportion of respirable particles increases. These results suggest that, for most conditions, the size-distribution compensation can be applied to sampler-to-sampler correlations provided that the original comparison was performed with the same dust type.     

Assessment of increased sampling pump flow rates in a disposable,inhalable aerosol sampler

A newly designed, low-cost, disposable inhalable aerosol sampler was developed to assess workers personal exposure to inhalable particles. This sampler was originally designed to operate at 10 L/min to increase sample mass and, therefore, improve analytical detection limits for filter-based methods. Computational fluid dynamics modeling revealed that sampler performance (relative to aerosol inhalability criteria) would not differ substantially at sampler flows of 2 and 10 L/min. With this in mind, the newly designed inhalable aerosol sampler was tested in a wind tunnel, simultaneously, at flows of 2 and 10 L/min flow. A mannequin was equipped with 6 sampler/pump assemblies (three pumps operated at 2 L/min and three pumps at 10 L/min) inside a wind tunnel, operated at 0.2 m/s, which has been shown to be a typical indoor workplace wind speed. In separate tests, four different particle sizes were injected to determine if the sampler's performance with the new 10 L/min flow rate significantly differed to that at 2 L/min. A comparison between inhalable mass concentrations using a Wilcoxon signed rank test found no significant difference in the concentration of particles sampled at 10 and 2 L/min for all particle sizes tested. Our results suggest that this new aerosol sampler is a versatile tool that can improve exposure assessment capabilities for the practicing industrial hygienist by improving the limit of detection and allowing for shorting sampling times.     

Airflow,transport and regional deposition of aerosol particles during chronic bronchitis of human central airways

In the present study, the effects of airway blockage in chronic bronchitis disease on the flow patterns and transport/deposition of micro-particles in a human symmetric triple bifurcation lung airway model, i.e., Weibel’s generations G3–G6 was investigated. A computational fluid and particle dynamics model was implemented, validated and applied in order to evaluate the airflow and particle transport/deposition in central airways. Three breathing patterns, i.e., resting, light activity and moderate exercise, were considered. Using Lagrangian approach for particle tracking and random particle injection, an unsteady particle tracking method was performed to simulate the transport and deposition of micron-sized aerosol particles in human central airways. Assuming laminar, quasi-steady, three-dimensional air flow and spherical non-interacting particles in sequentially bifurcating rigid airways, airflow patterns and particle transport/deposition in healthy and chronic bronchitis (CB) affected airways were evaluated and compared. Comparison of deposition efficiency (DE) of aerosols in healthy and occluded airways showed that at the same flow rates DE values are typically larger in occluded airways. While in healthy airways, particles deposit mainly around the carinal ridges and flow dividers—due to direct inertial impaction, in CB affected airways they deposit mainly on the tubular surfaces of blocked airways because of gravitational sedimentation.     

Uncertainties in aerosol deposition within the respiratory tract using the icrp 66 model: a study in workers

This study estimates uncertainties in aerosol deposition within the main regions of the human respiratory tract calculated using the ICRP 66 model. Uniform, triangular, normal, or lognormal distributions were assigned to the model parameters, which involve physical properties of aerosols, their inhalability, their thermo- and aerodynamic deposition efficiencies, and the anatomy, physiology, and exertion level of the individuals. Calculations were performed over a range of aerosol sizes from 0.01 to 50 mum. Monodispersed aerosols were characterized by their aerodynamic diameter (dae). Polydispersed aerosols were characterized by their activity median aerodynamic diameters (AMADs) and the geometric standard deviation (GSD) in diameter. Lognormal distributions of particle deposition were generally observed with low GSD (< 2). The highest uncertainties were observed within the deep lung for the smallest and the largest aerosol sizes, which were mainly due either to particle density or to aerodynamic deposition efficiencies and anatomical and physiological variability, respectively. In the case of diameters larger than 5 mum, uncertainties in the deep lung deposition were much more important for monodispersed than for polydispersed aerosols. This was explained both by the size distribution of the deposited aerosol, the median of which corresponded to a maximal dae value of about 7 and 5 in bronchioles and alveoli, respectively, and by the absence of deposition, which occurs for dae equal to or larger than 50 mum, depending on the exertion level. Thus, in the range of AMADs considered, for the four default workers proposed by ICRP 66, uncertainties in aerosol deposition remain low, with GSD smaller than 3.     

Solid versus liquid particle sampling efficiency of three personal aerosol samplers when facing the wind

The objective of this study was to examine the facing-the-wind sampling efficiency of three personal aerosol samplers as a function of particle phase (solid versus liquid). Samplers examined were the IOM, Button, and a prototype personal high-flow inhalable sampler head (PHISH). The prototype PHISH was designed to interface with the 37-mm closed-face cassette and provide an inhalable sample at 10 l min(-1) of flow. Increased flow rate increases the amount of mass collected during a typical work shift and helps to ensure that limits of detection are met, particularly for well-controlled but highly toxic species. Two PHISH prototypes were tested: one with a screened inlet and one with a single-pore open-face inlet. Personal aerosol samplers were tested on a bluff-body disc that was rotated along the facing-the-wind axis to reduce spatiotemporal variability associated with sampling supermicron aerosol in low-velocity wind tunnels. When compared to published data for facing-wind aspiration efficiency for a mouth-breathing mannequin, the IOM oversampled relative to mannequin facing-the-wind aspiration efficiency for all sizes and particle types (solid and liquid). The sampling efficiency of the Button sampler was closer to the mannequin facing-the-wind aspiration efficiency than the IOM for solid particles, but the screened inlet removed most liquid particles, resulting in a large underestimation compared to the mannequin facing-the-wind aspiration efficiency. The open-face PHISH results showed overestimation for solid particles and underestimation for liquid particles when compared to the mannequin facing-the-wind aspiration efficiency. Substantial (and statistically significant) differences in sampling efficiency were observed between liquid and solid particles, particularly for the Button and screened-PHISH, with a majority of aerosol mass depositing on the screened inlets of these samplers. Our results suggest that large droplets have low penetration efficiencies through screened inlets and that particle bounce, for solid particles, is an important determinant of aspiration and sampling efficiencies for samplers with screened inlets.     

Exposure to metalworking fluid aerosols and determinants of exposure

Metalworking fluid (MWF) aerosols are associated with respiratory disorders including asthma and hypersensitivity pneumonitis. The aims of this study were to describe exposure to inhalable MWF aerosols and volatile compounds in machine shops, to estimate the influence of important determinants of exposure and to compare different sampling techniques for MWF aerosols. Personal full-shift air samples of inhalable aerosol (PAS-6 sampler) and total aerosol (open-faced sampler) were collected on operators in five medium to big-sized machine shops in three companies. The filters were analysed gravimetrically and extracted by supercritical fluid extraction for MWF aerosol and triethanolamine content. In addition, personal measurements were taken for formaldehyde and volatile compounds on adsorbent samplers. Continuous dust measurements were performed with a real-time instrument (DataRAM) during 2 h periods, using 1-min average values. In total, 95 measurements of inhalable aerosol and extracted MWF aerosols on 51 operators were conducted. Within the companies, the average exposure to inhalable aerosol ranged from 0.19 to 0.25 mg m(-3) with geometric standard deviations from 1.56 to 1.79. On average, the extracted fraction of MWF aerosol was 67% of the inhalable aerosol concentration. The exposure levels of triethanolamine, formaldehyde and volatile compounds were generally low. About 45% of the between-worker variance could be explained by use of compressed air, lack of complete enclosure of machines or grinding as cutting task. In 21 workers with continuous aerosol measurements, short-term peak exposures during 6% of the work time contributed to approximately 25% of the average concentration of inhalable MWF aerosol. Inhalable MWF aerosol concentration measured with the PAS-6 sampler was a factor 2 higher than the concentrations derived from the open-faced sampler. These findings suggest that control measures, such as full enclosure of machines and the elimination of the use of compressed air as cleaning technique, are required to reduce the exposure to MWF aerosols to levels below the expected threshold for adverse respiratory health effects.     

A study of workers' exposures to the inhalable and 'total' aerosol fractions in the primary nickel production industry using mannequins to simulate personal sampling.

This paper describes a study that was carried out at work sites in the primary nickel production industry to investigate the difference between inhalable and 'total' aerosol exposures by using the mannequin sampling method, and to compare the results with those from an earlier study where actual workers' personal exposures were assessed in the same way. Experiments were carried out at 21 work sites located in mining, milling, smelting, and refining works of two primary nickel production companies. During sampling, mannequins were used to simulate the physical presence of workers and the 'exposures' of these were obtained for strategic positions at selected work sites. The orientations of each mannequin with respect to the wind were rotated through 90 degrees every hour in order to simulate the approximate orientation-averaging corresponding to actual workers. Two samplers were placed side-by-side on each mannequin: the Institute of Occupational Medicine (IOM) inhalable aerosol sampler, and the 37-mm plastic cassette widely used as a personal sampler for 'total' aerosol. Each collected sample was analyzed to obtain both overall dust and overall nickel content. A total of 116 such sample pairs were collected. The results show that inhalable aerosol exposure levels-for both overall dust and for total nickel content-were consistently and significantly higher than the corresponding total aerosol exposure levels. Weighted least squares linear regression yielded (inhalable/'total') aerosol ratios ranging from 1.38 to 3.90 and 1.20 to 4.01, respectively, for overall dust and for total nickel content for different work sites. Comparison of these results with those from the earlier study of actual workers' personal exposures were in good agreement for most of the work sites studies. However, the actual intensities of exposure using the mannequin sampling method were consistently lower than those obtained from actual workers' personal sampling in our earlier study. The consistency of the (inhalable/'total') ratios between mannequin and actual personal sampling strongly suggests that the characteristics of the aerosol sampled by the two methods, most notably the particle size distribution, were the same. This in turn suggests that mannequin sampling can be useful in occupational hygiene for determining such properties of personal workers' exposures. It certainly provides a useful and cost effective method for determining factors at work sites in individual industry settings by which to examine the impact of changing exposure assessment from one based on 'total' aerosol to the recommended new approach based on inhalable aerosol.