MASKS AND BREATHING AIDS | Updated June 2, 2021

June 2, 2021—The Centers for Disease Control has issued mask guidelines that supersede suggestions I posted here a year ago. Here are the latest guidelines: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/types-of-masks.html.

A Mechanical Ventilator. But we learned that
ventilators are a last resort, because 
intubation has serious risks of its own.

March 21, 2020–New York State Governor Andrew Cuomo today gave an enlightening speech about the COVID-19 challenges stressing the need for masks in the millions, and ventilators, of which the Governor says there are 6,000 in the State and 35,000 are needed. 

(Update October 21, 2020: A survey of more than 200 U.S. mayors earlier in 2020 indicated a shortage of 139,000 ventilators. 

But ventilators are no longer such a priority. Preferred treatment avoids using full-scale ventilators except as a last resort. Ventilators require intubation that is risky. Intermediate equipment such as use of oxygen or sleep apnea machines is less invasive and sometimes works. 

Masks are ranked here according to quality: https://bit.ly/2HmrnUu.)

New York State suffers from a shortage of both
I. Protective Devices (masks and face coverings) and
II. Mechanical Aids, i.e., devices for putting oxygen into the lungs.

This post details these two types of equipment.  This is a lay summary to fill an information vacuum that existed, when first posted, in a field replete with changing and contradictory instructions for hospital staff. If you have a better explanation of any of the equipment that follows, balancing simplicity with precision, or something else to add, please comment or send me a note – john @ cityeconomist.com.

I. PROTECTIVE DEVICES: (A) THE N95 MASK, (B) HIGHER-STANDARD MASKS AND (C) THE CLOTH FACE COVERING. 

A fabric mask is worn by three groups of people: (1) health-care workers and anyone with COVID symptoms, who are expected to wear an N95 mask if they can get them, (2) higher-standard masks for special situations, and (3) lower-standard masks of "cloth face coverings" for people with no symptoms who are in public places.

A. The N95 Mask. The top-quality commonly used working mask in the United States is the N95 mask. The "N" comes from the National Institute for Occupational Health and Safety (NIOSH), which sets standards for protective equipment in the workplace. The 95 references the fact that the mask filters out 95 percent of particulates. 3M makes a lot of them. The higher standard is N99. Availability: The shortage of masks is acute, but this shortage may ease in two weeks and be over (at least in New York State) in three weeks, because the call has gone out to collect and make these masks, and many groups and people are responding. Governor Cuomo of New York has been working on putting millions of masks in hospitals in New York City and the rest of the state. The masks are simple in concept, but the N95 standard requires (1) a tight fit, and (2) a very fine screen, because the coronavirus is microscopically tiny and can get past a casually handled mask. They are easy to put on and are used by both medical staff and patients, mostly to contain any viral infection they have as well as provide a defense against a virus from someone else. Governor Cuomo said that new masks are a priority for hospitals to meet the first waves of patients from their expanded testing.  There is already a shortage of masks in New York City. The N95 masks I have seen are supposed to be used only once (although they can be set aside for a month and then reused safely after the SARS-CoV2 virus has died), but doctors at Brooklyn's Kings County Hospital Center report that because of a lack of masks they have been reusing masks for up to a week, disinfecting them with hand sanitizer between shifts. The masks are relatively cheap to buy (prices have been as low as 80 cents each but, with the pandemic, Governor Cuomo says that he has had to pay as much as  $7 for an emergency order, as state governments have been bidding against one another for them. The Congress should pass a waiver of these masks from President Trump's new China tariffs – perhaps all medical supplies should be exempt from tariffs during a pandemic.

Other related masks are:

• The "N45" Mask. The "N45" mask, referred to in a tweet by Mia Farrow, is fictional. It does not exist.

It would mean a mask that filters out only 45 percent of particulates, which is not very effective. The origin of the "N45" mask reference appears to have been facetious, referencing that our current president is the 45th. Probably a lot of homemade masks for the public (see below) are as low as the N45 standard would be, but no manufacturer would advertise it.

• Masks Comparable to the N95. The equivalents of the N95 masks in Europe are the FFP2 and FFP3 face masks (see Postscript below for a test of the equivalence of the two standards). An Asian standard has been reported, KN95, which also screens out 95 percent of particulates; such masks are widely sold in the United States and have recently been accepted by the FDA as equivalent to N95 masks. (P.S. June 2021: The Centers for Disease Control says that perhaps 60 percent of KN95 masks currently sold in the United States are counterfeit and do not meet NIOSH N95 standards. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/types-of-masks.html .)

B. Higher-Standard Masks and Respirators.  The NIOSH N99 standard is higher but less commonly used, probably because such a fine screen might be hard to breathe through and might interfere with work. Respirators with Intake Filters: A respirator with a protective intake filter is used to protect a medical staff member working in an area with chemicals or germs.  It looks like a World War gas mask. It typically has a replaceable or cleanable filter. It is not something one sees on COVID patients, but people on the staff of an ICU might prefer to have a respirator with a mechanical filter than a mask. However, it is NOT recommended for the general public, because it may protect the user, but allowing exhalation means that other people are not protected.  Availability: There is no reported shortage of such respirators for a wide variety of uses. They are more expensive than surgical masks. They are bulky and require maintenance and training in use. Many are available online at a wide range of prices. They are not recommended for public use by the Centers for Disease Control: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/types-of-masks.html.

C. Cloth Face Coverings: Masks for the Public. In Asian countries, 80 percent of the public wear face masks in public. People are convinced that the masks make them safer, and indeed infection rates are much lower than in the West. A mask debate has been raging in the United States. Those who argue that containing the virus means everyone should wear a mask in public have been gaining adherents. One conclusion from the little research that has been done on mask-wearing is that if only 20 percent of the public wears a mask, it won't make much difference, but if 50 percent does, it will make a substantial difference. Masks for the public do not have to fit as tightly or have such a fine screen as the N95 mask. Their purpose is in part to remind people not to keep touching their face. These masks are simpler in design and can be made more cheaply, even homemade. The quality can be high if several layers of filtration are used. It is a good craft project for families. The CDC is now calling them "Cloth Face Coverings" to distinguish them from NIOSH-rated and similar quality masks. Availability. Simple versions of masks can be made by hand. YouTube videos show how; here's a link from the office of Rep. Carolyn Maloney, D-NY12 with ideas.

Resources. Below are some sources of information on creating or collecting masks and other equipment for coronavirus medical personnel, who are the priority at the moment:

• Governments and companies race to make masks for the coronavirus fight (NY Times): https://www.nytimes.com/2020/03/21/business/coronavirus-masks-hanes-trump.html.
• What coronavirus doctors and nurses fighting the pandemic wear (HuffPost): https://www.huffpost.com/entry/nurses-doctors-wear-coronavirus-pandemic_l_5e73bd19c5b6eab779447292. 
• Are homemade masks better than no protection? (Medscape): https://www.medscape.com/viewarticle/927259.
• The Netherlands recalled defective masks made in China, about 600,000 of which had been distributed to local hospitals, the health ministry said. Earlier, Spain and Turkey complained of faulty rapid-testing kits from China. (Medscape): https://www.medscape.com/viewarticle/927259.
• Austria makes masks compulsory as protection debate shifts.
• Four European countries make masks mandatory.
• The crucial missing Coronavirus Protection Guideline https://www.youtube.com/watch?v=hVEVve-3QeM
• How Czech Republic Maintains Low Contagion https://www.youtube.com/watch?v=T2dOs-LhJaQ
• How to make your own mask https://www.youtube.com/watch?v=4FB--BOyTiU

II. MECHANICAL BREATHING AIDS: (A) The Ventilator, (B) Oxygen Tank and mask, (C) CPAP machine, (D) BIPAP and Vapotherm machine.

A. The Ventilator (also called a "medical ventilator" or a "mechanical ventilator") provides breathing assistance to patients for whom providing oxygen is not enough. It's what is required for COVID-19 patients who have a serious case. Unlike previous flu infections, which did not require a ventilator for as long or as many people, the COVID virus can require use of a ventilator for many weeks and for a significant portion of those who are sick. A “ventilator” (mechanical ventilator) is a machine that takes over the work of breathing for a patient with primary respiratory failure due to lung disease or secondary respiratory failure due to central nervous system disease, anesthesia or drug overdose. Ventilators are connected to the patient via an endotracheal tube (“breathing tube”) that is placed in the patient's trachea (“wind pipe”). Ventilators remove carbon dioxide and deliver oxygen to maintain physiologic homeostasis (normal blood pH). Clearly, such a machine requires expertise to operate. New York startups are working hard to develop a simpler ventilator that will be cheaper and easier to use. Availability: Scarce. The cost for a ventilator is about $7,000, but prices vary widely based on location of manufacturer and demand. They are cheaper in China. In New York State some hospitals are already doubling up on ventilators because they are not just expensive but are hard to buy. Governor Cuomo suggested on March 21 that they might be adapted so that two patients can be on one machine, and some innovators are experimenting with more than two. They are also not easy to use and training staff takes time that no one has during the pandemic. If the hospitals are not ready, difficult triage decisions will have to be made. Governor Cuomo has put out a call for all medical ventilators not in use as he seeks to buy more and create more emergency beds. He has also noted that the competitive bidding among the states could be ended by invocation of the Defense Production Act by the President. He has said that the New York hospitals will run out of ventilators in the second week of April, right before Easter. Most recently he has been saying that only 20 (sometimes he says 20-30)  percent of ventilator patients survive. The National Health Service in Britain says that one-third survive. However, of those who survive, a large portion, perhaps one-third, suffer from trauma or scarred lungs or trachea.

B. The oxygen tank doesn't reliably get oxygen to a COVID patient. It is the first mechanical resource for a person who has trouble breathing. But a COVID patient's problems are all the way in the lung, and the oxygen from a tank is is fed through the nose or mouth with plastic tubing, a regulator and a face mask or nasal prongs. The good news is that it is relatively inexpensive ($1,000-$2,500 range) and is relatively easy to learn to use. One of my late uncles had his own oxygen tank for years.  Availability: There seems to be no shortage of oxygen tanks in the United States, or of people who know how to use them, but they are not ideal for treating a COVID patient because the virus finds its way to the lungs. If and when ventilators are scarce, oxygen tanks might have some role.

C. A sleep apnea or CPAP machine blows ambient air into the lung like an oxygen machine. (CPAP stands for "continuous positive airway pressure.") It can be a lifesaver for someone who has breathing problems at night in bed. It has a computer-chip-controlled air flow regulator, a tube and a mask; many models include a humidifier. It is not a substitute for an oxygen tank, which in turn is not a substitute for a ventilator. However, conceivably innovators will be at work adapting equipment where there are shortages of ventilators. (A problem with CPAP machines, as David notes below in a comment, is that the exhale part of the cycle would spew viruses into the air; this would have to be modified.) Some new models might replace an oxygen tank regulator, for example. Meanwhile, it is not an alternative to a ventilator for someone hospitalized with COVID-19. Availability: Too bad the CPAP machine isn't ready yet to replace oxygen tanks or ventilators, because these machines are much less expensive, about $1,000, and are widely available. Reportedly some innovators are working on bridging the gap between the CPAP machine and the oxygen tank, and the CPAP machine and ventilator.

D. BiPAP and Vapotherm machines. When patients with respiratory illness need assistance to breathe, multiple respiratory care options are available before physicians resort to intubation and use of a ventilator—including nebulizers, high flow nasal cannulas and bi-level positive airway pressure (BiPAP) machines. The risk from them again is airborne transmissions to healthcare workers. Vapotherm's high velocity therapy provides mask-free non-invasive ventilatory support," says  the product's website. High velocity/high flow therapy, properly fitted and applied, is associated with a low risk of airborne transmissions. A North Fork, L.I. hospital worker has laid out $10,000 to purchase such a machine for her hospital's ICU. (I have no idea whether the Vapotherm machine does the job and is appropriately priced; I am still trying to find out.)

Three general comments:

• Experimentation with several breathing aids will surely generate gradations that could reduce the excess demand for ventilators.
• For the moment, the challenge is to get something basic to hospitals. Some day maybe engineers who design these products so they are easier to use and designers will make them look better. Maybe they could help make ventilators look less like a gas pump and more friendlier both for the patient and the person who operates it. 
• Meanwhile, the pandemic will provide lots of time for families to experiment with interesting fabrics for their homemade masks and for medical-device people and apparel designers to work together on Zoom to make the look of the business of defeating illness more imaginative.

Postscript 1: The big brands have been stepping up to make the N95 and other masks that are in short supply. LVMH is using a Chinese distributor to order 40 million FFP2 (European standard) for France. https://www.businessoffashion.com/articles/news-analysis/lvmh-to-supply-france-with-40-million-surgical-masks-to-tackle-shortage. 

Postscript 2: Here is a 2009 study comparing the filtration effectiveness of NIOSH N95 and the European-standard FFP2 and FFP3 masks. https://www.ncbi.nlm.nih.gov/pubmed/19261695

Ann Occup Hyg. 2009 Mar;53(2):117-28. doi: 10.1093/annhyg/men086.

Comparison of nanoparticle filtration performance of NIOSH-approved and CE-marked particulate filtering facepiece respirators.

Rengasamy S1, Eimer BC, Shaffer RE.

Abstract

The National Institute for Occupational Safety and Health (NIOSH) and European Norms (ENs) employ different test protocols for evaluation of air-purifying particulate respirators commonly referred to as filtering facepiece respirators (FFR). The relative performance of the NIOSH-approved and EN-certified 'Conformité Européen' (CE)-marked FFR is not well studied. NIOSH requires a minimum of 95 and 99.97% efficiencies for N95 and P100 FFR, respectively; meanwhile, the EN requires 94 and 99% efficiencies for FFRs, class P2 (FFP2) and class P3 (FFP3), respectively. To better understand the filtration performance of NIOSH- and CE-marked FFRs, initial penetration levels of N95, P100, FFP2 and FFP3 respirators were measured using a series of polydisperse and monodisperse aerosol test methods and compared. Initial penetration levels of polydisperse NaCl aerosols [mass median diameter (MMD) of 238 nm] were measured using a method similar to the NIOSH respirator certification test method. Monodisperse aerosol penetrations were measured using silver particles for 4-30 nm and NaCl particles for 20-400 nm ranges. Two models for each FFR type were selected and five samples from each model were tested against charge neutralized aerosol particles at 85 l min(-1) flow rate.