Protective mask + surgical mask: is it feasible?
国家卫生健康委员会于昨日(2020年1月22日)组织制定了《医疗机构内新型冠状病毒感染预防与控制技术指南(第一版)》(以下简称“指南”)。今天,SIFIC团队为大家及时转载分享,具体见本公众号今日另一篇推文。
A novel coronavirus infection prevention and control technical guide (First Edition) of the medical institutions was formulated by the national health and Health Committee yesterday (January 22, 2020). Today, SIFIC team reproduces and shares in time for official account.
收到指南文件后,SIFIC团队连夜对原文进行了通读学习,可以说,在目前新型冠状病毒导致多名医务人员被感染“人人自危”的背景下,这个指南对医疗机构内的感染防控提供了极具操作性的指导,很多防控措施都有了更为具体和细致的指引。
The novel coronavirus was read through the original text by SIFIC team after receiving the guide document. It can be said that under the background of the current new coronavirus causing many medical staff to be infected with "everyone is in danger", this guide provides highly operational guidance for infection prevention and control in medical institutions, and many prevention and control measures have more specific and detailed guidelines.
但是,本指南的附件内容《医务人员穿脱防护用品的流程》中,众人对其中进入隔离病区穿戴防护用品的要求产生了困惑,我们先来看下这一段的原文:
However, in the attachment of this guide, "procedures for medical personnel to wear and take off protective equipment", people are confused about the requirements for wearing protective equipment when entering the isolated ward. Let's look at the original paragraph:
(一)医务人员通过员工专用通道进入清洁区,认真洗手后依次戴医用防护口罩、一次性帽子或布帽、换工作鞋袜,有条件的可以更换刷手衣裤。
(1) Medical personnel enter the cleaning area through the special passage for employees, and wear medical protective masks, disposable hats or cloth hats, and change work shoes and socks after washing hands carefully. If conditions permit, they can change hand washing clothes and pants.
(二)在进入潜在污染区前穿工作服,手部皮肤有破损或疑似有损伤者戴手套进入潜在污染区。
(2) Wear work clothes before entering the potential pollution area, and wear gloves to enter the potential pollution area if the hand skin is damaged or suspected to be damaged.
(三)在进入污染区前,脱工作服换穿防护服或者隔离衣,加戴一次性帽子和一次性医用外科口罩(共穿戴两层帽子、口罩)、防护眼镜、手套、鞋套。
(3) Before entering the contaminated area, take off the work clothes and change into protective clothing or isolation clothing, and wear disposable hat and disposable surgical mask (two layers of hat and mask), protective glasses, gloves and shoe covers.
从这个指南附件的描述中可以看到,指南推荐医务人员进入隔离病区时应佩戴“防护口罩+外科口罩”,即佩戴两层口罩,同时还应佩戴两层帽子,这一做法与感控人的既往观念有非常大的不同。众人主要对以下几个方面存在困惑:
It can be seen from the description of the annex to this guide that the guide recommends that medical personnel should wear "protective mask + surgical mask" when entering the isolated area, that is, two layers of masks and two layers of hats, which is very different from the previous concept of the sensory control person. People are confused about the following aspects:
过滤系数
Filter coefficient
众所周知,符合标准的医用防护口罩(包括我们常说的N95口罩)对非油性颗粒物的过滤效率可以达到95%,而外科口罩的过滤效率一般为30%,在防护口罩外面再加一层外科口罩,对提升细菌过滤性来说,作用微乎其微。
As we all know, the filtration efficiency of medical protective mask (including N95 mask as we often say) for non oil particles can reach 95%, while the filtration efficiency of surgical mask is generally 30%. Adding a layer of surgical mask outside the protective mask has little effect on improving the bacterial filtration.
所以,“外科口罩+防护口罩”的做法,真的能更好的保护佩戴者吗?
So, can the practice of "surgical mask + protective mask" really better protect the wearer?
来源:医用外科口罩(YY0469-2011)
Source: medical surgical mask (yy0469-2011)
脸部贴合
Face fit
影响一个口罩的防护性能,除了过滤性之外,还有一个非常关键的点就是口罩的密闭性,因为脸部肌肉与皮肤较为柔软,正常情况下,医用防护口罩边沿与脸部一般都能较好贴合。
In addition to the filter property, there is also a very key point to affect the protective performance of a mask, that is, the tightness of the mask, because the facial muscles and skin are relatively soft. Under normal circumstances, the edge of the medical mask and the face can generally fit well.
但是,如果在已经贴合完全的医用防护口罩外面再加一层外科口罩,就会给里层的防护口罩施加一个力,从而导致里层的防护口罩被压迫变形,这还能保证它的密闭性吗?是否会适得其反,反而让医用防护口罩的防护能力减弱呢?
However, if a surgical mask is added outside the medical protective mask that has been fully fitted, a force will be exerted on the inner protective mask, which will cause the inner protective mask to be compressed and deformed. Can this ensure its tightness? Will it backfire and weaken the protective ability of medical protective masks?
来源:SIFIC版主分享
Source: shared by sific moderator
舒适通气
Comfortable ventilation
如果您真的佩戴过医用防护口罩,您就会知道,规范佩戴的防护口罩会给人的呼吸增加多大的阻力,一个正常人佩戴2-3个小时就已经非常吃力。再加上一身的防护服,和紧张的工作氛围与心理压力,对于佩戴者来说,医用防护口罩的舒适性也是非常重要的一点。
If you have ever worn a medical protective mask, you will know how much resistance it will add to people's breathing. A normal person has been very hard to wear it for 2-3 hours. In addition to a body of protective clothing, and tense working atmosphere and psychological pressure, for the wearer, the comfort of medical protective mask is also very important.
但是,如果我们还在医用防护口罩外面再加一层外科口罩,这对佩戴者来说无疑是雪上加霜。
However, if we add a surgical mask to the medical protective mask, it will definitely make the wearer worse.
来源:新京报社
Source: Xinjing News Agency
内层保护
Inner layer protection
讨论中,也有同行提到,根据本次指南中的穿脱流程整体来看,本指南中推荐的“脱卸”流程与以往有较大不同,本指南是要求将防护镜、手套、防护服在污染区脱卸并丢弃(以往一般推荐在潜在污染区(如缓冲区)脱卸),而外层的外科口罩和帽子也被要求在污染区中脱卸,不能离开污染区。
During the discussion, some colleagues also mentioned that according to the whole process of wearing and taking off in this guide, the recommended "taking off" process in this guide is quite different from that in the past. This guide requires that protective glasses, gloves and protective clothing be taken off and discarded in the contaminated area (it is generally recommended that they be taken off in the potential contaminated area (such as buffer area), while the outer surgical masks and hats are also required to be taken off in the contaminated area Take off in the dyeing area and do not leave the contaminated area.
因此,有同行觉得:其目的是希望在脱掉外层所有物品后,可使用内层的防护口罩和帽子来保护操作者安全进入潜在污染区,最大可能避免潜在污染区的交叉污染。也就是说,外层外科口罩和帽子的真实目的,并不仅仅为了加强口罩的“过滤性”,还希望其能保障内层防护口罩和帽子的“不被污染”。
Therefore, some colleagues think that the purpose is to use the inner protective mask and hat to protect the operator from entering the potential pollution area safely after removing all the outer objects, and to avoid cross pollution in the potential pollution area as much as possible. In other words, the real purpose of the outer surgical mask and hat is not only to enhance the "filterability" of the mask, but also to ensure that the inner protective mask and hat are "not polluted".
可操作性
Operability
上述观点,得到了部分同行的认同,但也有其它同行提出了异议。
These views have been approved by some peers, but others have raised objections.
昨日,大家应该已经在网上看到,湖北省已向国家发起紧急求助,希望国家能支援4000万个口罩,500万套防护服,以解决疫情防控的物资短缺问题。感染防疫就是一场没有硝烟的战争,如果说各类治疗药品是战争中的子弹和大炮的话,那应急防护物资就是战争中的粮库,是非常重要的后备辎重。
Yesterday, you should have seen on the Internet that Hubei Province has launched an emergency appeal to the state, hoping that the state can support 40 million masks and 5 million protective clothing to solve the material shortage of epidemic prevention and control. Infection and epidemic prevention is a war without gunpowder. If all kinds of therapeutic drugs are bullets and artillery in the war, then emergency protection materials are the granary in the war and are very important backup supplies.
任何一个口罩都是非常紧缺的物资,怎么能将如此重要而紧缺的外科口罩,仅仅是为了拿去当“挡溅牌”呢?!难道我们就不能用其它非紧缺物品代替吗?比如:防护面屏!
Any mask is a very scarce material. How can such an important and scarce surgical mask only be used as a "splash shield"?! Can't we replace it with something else that is not in short supply? For example: protective screen!
国际做法
International practice
感控措施的制定是一个循证的过程,任何指南都应该有循证依据的支持,或者借鉴国际通行做法,但不论是WHO还是美国CDC,或者其它国际组织发布的指南中,我们几乎
The development of the control measures is an evidence-based process, and any guide should be supported by evidence-based basis, or learn from international practices. However, in the guide issued by who, CDC of the United States, or other international organizations, we almost