病区医务人员呼吸道感染与应用一次性口罩应用的相关性研究与分析

目的研究病区内医务人员呼吸道感染与一次性口罩应用的相关性分析。方法于2009年1月～2011年1月,选取某院1 221名医务人员作为研究对象,包括医生和护士。按照是否有佩戴一次性口罩习惯分为两组,A组平时有佩戴一次性口罩习惯,共831名医务人员,B组平时无佩戴一次性口罩习惯,共390名。调查两组医务人员呼吸道感染发生的情况,并对所有发生呼吸道感染的医务人员进行病原学实验室检查。结果对于4种不同的疾病指标,A组呼吸道感染发病率均低于B组,差异具有统计学意义(P﹤0.05)。A组医务人员出现急性呼吸道感染和呼吸道病毒感染的风险显著低于B组。结论医务人员院内呼吸道感染的发生与口罩的佩戴习惯有密切关系,医院应该首选佩戴一次性口罩,并对医务人员进行口罩佩戴方法的培训,并进行适合性检验。提高医务人员正确选择、佩戴口罩的意识,对降低呼吸道感染发生率有重要意义。     

Do we have enough evidence how seasonal influenza is transmitted and can be prevented in hospitals to implement a comprehensive policy?

PurposeTo identify if there is enough evidence at low risk-of-bias to prevent influenza transmission by vaccinating health-care workers (HCWs), patients and visitors; screening for laboratory-proven influenza all entering hospitals; screening asymptomatic individuals; identifying influenza supershedders; hand-washing and mask-wearing by HCWs, patients and visitors; and cleaning hospital rooms and equipment.Principal ResultsVaccination reduces influenza episodes of vaccinated (4.81/100 HCW) compared to unvaccinated (7.54/100) HCWs/influenza season. A Cochrane review found for inactivated vaccines the Number Needed to Vaccinate (NNV) = 71 (95%CI 64%, 80%) for adults 18–60 (same age as HCWs) to prevent laboratory-proven influenza. There are no RCTs of screening HCWs, patients, visitors and influenza supershedders to prevent transmission. None of four RCTs of HCWs mask-wearing (two directly observed, two not) showed an effect because they were underpowered either due to small size or low circulation of influenza. Hospital rooms and equipment can effectively be cleaned of influenza by many chemicals and hydrogen peroxide vapor machines but the cleaning cycle needs shortening to increase the likelihood of adoption.Major ConclusionsHCW vaccination is a partial solution with current vaccination levels. There are no RCTs of screening HCWs, patients and visitors demonstrating preventing influenza transmission. Only one study costed furloughing HCWs with influenza and no RCTs have identified benefits of isolating influenza supershedders. RCTs of directly- and electronically continuously-observed mask-wearing and hand-hygiene and RCTs of incentives for meticulous hygiene are required. RCTs of engineering solutions (external venting, frequent room air changes) are needed. A wide range of chemicals effectively cleans hospital rooms and equipment from influenza. Hydrogen peroxide vapor is effective against influenza and a wide range of bacterial pathogens with patient room changes, and clean areas cleaners do not clean but its cleaning cycle needs shortening to increase the likelihood of adoption of cleaning rooms vacated by influenza patients.     

面罩双水平气道内正压联合重组人脑利钠肽对急性心力衰竭的短期及长期影响

目的 观察面罩双水平气道内正压(BiPAP)联合重组人脑利钠肽(rhBNP)对急性心力衰竭治疗的短期及长期影响.方法 100例急性心力衰竭患者按随机数字表法分为BiPAP联合rhBNP组(51例)和常规治疗组(49例).常规治疗组给予常规抗心力衰竭药物治疗,BiPAP联合rhBNP组在常规治疗的基础上,给予BiPAP联合rhBNP治疗,观察记录两组患者治疗前及治疗后30 min、2h的动脉血氧分压(PaO2)、动脉血氧饱和度(SaO2)、临床表现的变化,随访3个月,比较两组心血管事件发生率、超声心动图相关指标及6 min步行试验距离的差异.结果 两组患者治疗后临床症状(呼吸频率、心率)及血气分析指标(PaO2、SaO2)均显著改善,并且BiPAP联合rhBNP组改善更显著,差异均有统计学意义(P＜0.05).随访3个月后,BiPAP联合rhBNP组心血管事件发生率[17.6％(9/51)]显著低于常规治疗组[38.8％(19/49)],差异有统计学意义(P＜0.05).BiPAP联合rhBNP组左室舒张末期内径(LVEDd)、左室射血分数(LVEF)较常规治疗组有明显改善[(55.0±6.1)mm比(63.3 ±6.5) mm,(52.5±7.2)％比(44.7±6.8)％],差异有统计学意义(P＜0.05).BiPAP联合rhBNP组6min步行试验距离显著高于常规治疗组[(325.6±36.4)m比(210.2±34.1) m],差异有统计学意义(P＜0.05).结论 BiPAP联合rhBNP治疗急性心力衰竭短期疗效显著,安全性高,而且可以改善患者的长期预后.     

Performance of ICU ventilators during noninvasive ventilation with large leaks in a total face mask: a bench study

Objective:

Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO₂ rebreathing, their orifices allow proximal leaks to enhance CO₂ elimination. The ventilators used in the ICU might not adequately compensate for such leakage. In this study, we attempted to determine whether ICU ventilators in NIV mode are suitable for use with a leaky TFM.

Methods:

This was a bench study carried out in a university research laboratory. Eight ICU ventilators equipped with NIV mode and one NIV ventilator were connected to a TFM with major leaks. All were tested at two positive end-expiratory pressure (PEEP) levels and three pressure support levels. The variables analyzed were ventilation trigger, cycling off, total leak, and pressurization.

Results:

Of the eight ICU ventilators tested, four did not work (autotriggering or inappropriate turning off due to misdetection of disconnection); three worked with some problems (low PEEP or high cycling delay); and one worked properly.

Conclusions:

The majority of the ICU ventilators tested were not suitable for NIV with a leaky TFM.     

Impact of the type of mask on the effectiveness of and adherence to continuous positive airway pressure treatment for obstructive sleep apnea

Continuous positive airway pressure (CPAP) is the gold standard for the treatment of obstructive sleep apnea (OSA). Although CPAP was originally applied with a nasal mask, various interfaces are currently available. This study reviews theoretical concepts and questions the premise that all types of interfaces produce similar results. We revised the evidence in the literature about the impact that the type of CPAP interface has on the effectiveness of and adherence to OSA treatment. We searched the PubMed database using the search terms "CPAP", "mask", and "obstructive sleep apnea". Although we identified 91 studies, only 12 described the impact of the type of CPAP interface on treatment effectiveness (n = 6) or adherence (n = 6). Despite conflicting results, we found no consistent evidence that nasal pillows and oral masks alter OSA treatment effectiveness or adherence. In contrast, most studies showed that oronasal masks are less effective and are more often associated with lower adherence and higher CPAP abandonment than are nasal masks. We concluded that oronasal masks can compromise CPAP OSA treatment adherence and effectiveness. Further studies are needed in order to understand the exact mechanisms involved in this effect.     

Fit Test for N95 Filtering Facepiece Respirators and KF94 Masks for Healthcare Workers: a Prospective Single-center Simulation Study

BackgroundFor protection against coronavirus disease 2019 (COVID-19), the Korean government recommended the KF94 mask or that a mask at the same level as the KF94 should be worn when contacting a patient with COVID-19. Furthermore, adequately fitted N95 respirators and KF94 masks are essential. We investigated the fit tests to determine whether healthcare workers had adequate protection with N95 respirators and KF94 masks.MethodsIn this prospective single-center simulation study, five N95 respirators (two made in the USA by 3M and three made in Korea) and six KF94 masks, the Korean standard medical masks, were tested. The fit factor (FF) and leakage rate were evaluated using a two-fit test device. Adequate protection (defined as FF ≥ 100 or leakage rate ≤ 5) rates were compared between N95 respirators and KF94 masks, and between made in Korea and the 3M N95 respirators. For KF94 masks, adequate protection rates were compared before and after ear strap fixation.ResultsOverall, 30 participants were enrolled, and 330 fit tests were performed for FF and leakage rate. Adequate protection rates of all tested N95 respirators and KF94 masks were 22.7% (n = 75) by FF and 20.6% (n = 68) by leakage rate. N95 respirators showed a significantly higher adequate protection rate than KF94 masks for FF (48.7% vs. 1.1%, P < 0.001) and leakage rate (42.0% vs. 2.8%, P < 0.001). Adequate protection rate of 3M-made N95 respirators was significantly higher than that of those made in Korea (83.3% vs. 25.6% in FF, P < 0.001; 73.3% vs. 21.1% in leakage rate, P < 0.001). In KF94 masks, after fixation of ear strap with a hook, adequate protection rate improved significantly (1.1% vs. 12.8% in FF, P < 0.001; 2.8% vs. 11.1%, P < 0.001).ConclusionAlthough adequate protection rate of N95 respirators was higher than that of KF94 masks, N95 respirator protection rate was not optimum. Thus, it is necessary to minimize exposure to risk by selecting an appropriate mask or respirator that adequately fits each person, and by wearing respirators or masks appropriately, before contacting the patients. With their superior protection rate, wearing N95 respirators is recommended instead of KF94 masks, especially when performing aerosol-generating procedures.     

改进呼吸面罩在无创正压通气吸痰中的应用

目的探讨改进的纽式面罩在无创通气中的使用效果。方法选择慢性阻塞性肺部疾病并Ⅱ型呼吸衰竭行无创正压通气患者78例,按随机数字表法随机分为对照组4JD例和观察组38例,两组均使用纽式面罩,将吸痰管留置气管内,吸痰管尾端从纽式面罩下方与面部接合处穿出。对照组吸痰时,先停用无创通气,改用单侧鼻导管吸氧后吸痰;观察组吸痰时,不中断无创通气,通过面罩吸痰孔吸痰,比较两组吸痰效果。结果两组无创通气治疗24h,氧分压（PaO：）和二氧化碳分压（PaCO：）差异无统计学意义（t分别为0．84,1．07;P均〉0．05）;无创通气48h,观察组的Pa02和PaCO2分别为（61．53±9．94）、（64．02±10．37）mmHg,对照组分别为（56．57．4±11．19）、（69．55±12．73）nllnHg,两组比较差异有统计学意义（t分别为2．07,2．10;P均〈0．05）;无创通气96h,两组比较差异有统计学意义（t分别为3．87,3．03;P均〈0．01）。观察组累计应用正压通气总时间（152．23±25．91）h,少于对照组的（169．57±33．49）h,差异有统计学意义（t=2．54,P〈0．05）。结论无创正压通气的患者,选用带吸痰侧孔面罩进行通气,吸痰时不需中断无创通气,可减少并发症,恢复时间短,治疗效果好。     

Prevalence of sleep disturbances during COVID-19 outbreak in an urban Chinese population: a cross-sectional study

ObjectiveThe COVID-19 pandemic is a large-scale public health emergency that likely precipitated sleep disturbances in the community. This study aimed to investigate the prevalence and correlates of sleep disturbances during the early phase of COVID-19 pandemic.MethodsThis web-based cross-sectional study recruited 1138 Hong Kong adults using convenience sampling over a two-week period from 6th April 2020. The survey collected data on sleep disturbances, mood, stress, stock of infection control supplies, perceived risk of being infected by COVID-19, and sources for acquiring COVID-19 information. The participants were asked to compare their recent sleep and sleep before the outbreak. The Insomnia Severity Index (ISI) was used to assess their current insomnia severity. Prevalence was weighted according to 2016 population census.ResultsThe weighted prevalence of worsened sleep quality, difficulty in sleep initiation, and shortened sleep duration since the outbreak were 38.3%, 29.8%, and 29.1%, respectively. The prevalence of current insomnia (ISI score of ≥10) was 29.9%. Insufficient stock of masks was significantly associated with worsened sleep quality, impaired sleep initiation, shortened sleep duration, and current insomnia in multivariate logistic regression (adjusted OR = 1.57, 1.72, 1.99, and 1.96 respectively, all p < 0.05).ConclusionA high proportion of people in Hong Kong felt that their sleep had worsened since the COVID-19 outbreak. Insufficient stock of masks was one of the risk factors that were associated with sleep disturbances. Adequate and stable supply of masks may play an important role to maintain the sleep health in the Hong Kong general population during a pandemic outbreak.     

鼻咽部加压预防低压舱耳气压性损伤

目的在低压舱下降时,了解经面罩对鼻咽部加压大于咽鼓管通气阻力时能否预防耳气压伤。方法16名常发生耳气压伤的飞行员和10名志愿者,咽鼓管通气阻力<6kPa。低压舱以20m/s的下降率自3500m降到地面高度。受试者发生明显的"压耳"感时,进行面罩增压6kPa平衡耳鼓室压。飞行员模拟飞行条件平衡耳鼓室压时,低压舱中止下降高度;志愿者平衡耳鼓室压时,低压舱中止下降高度,并测面罩增压前后的耳鼓室压进行比较。结果在16名飞行员中,有11名需要借助鼻咽部增压才能平衡鼓室压。在11人中有3人为单耳咽鼓管主动通气不良。面罩充气平衡耳鼓室压的次数为2～3次,平均为2.36±0.48次。面罩充气前后的鼓室压分别是-2.04±0.58kPa和-0.09±0.05kPa,差异有统计学上的显著性意义(t=7.132,P<0.01)。志愿者感到"压耳"时耳鼓室压在-2.17±0.52kPa,面罩加压后耳鼓室压为-0.08±0.06kPa,差异有统计学上的显著性意义(t=6.836,P<0.01)。结论当人体的环境压力增加时,经面罩提供大于咽鼓管通气阻力的鼻腔充气可以预防耳气压伤的发生。     

加压供氧面罩无余压时呼气阻力的数值模拟

目的 用数值模拟的方法获得加压供氧面罩无余压状态下呼气活门的呼气阻力。方法 采用呼气活门静态特性方程与流场控制方程耦合求解的方法，计算加压供氧面罩呼气活门的呼气阻力。流场计算中，在同位网格上采用了SIMPLER方法和κ-ε两方程湍流模型，用QUICK格式对控制方程进行了离散。结果 数值模拟结果与实验结果吻合较好。结论 本文中提出的数值模拟方法正确，计算结果满足工程精度要求。