RESEARCH BRIEFING

Does using "high-flow" nasal oxygen coronavirus patients expose health care workers?

We treat asthma and emphysema with inhalers, steroids, and oxygen. When breathing gets worse, we escalate. First. we increase the amount of oxygen, using various types of masks. If we must, we resort to using masks that actively push pressurized air into the patient's mouth and down the windpipe. This is called "positive pressure" and it is how CPAP machines work for people with sleep apnea. Collectively, these machines are referred to as non-invasive ventilation. In ERs and hospitals, we use fancier machines. BiPAP machines are used in hospitals and similar to CPAP, but instead of only setting (CPAP), BiPAP has the ability to deliver two different pressures, one for inhaling and one for exhaling. This makes it more comfortable and more effective. Recently, health care workers became worried that SARS-nCov-2 particles might briefly be suspended in the air (while it is not "airborne," the droplets take time to fall to the ground. Therefore, the use of BiPAP as a last-ditch effort prior to intubation (inserting a breathing tube) is not currently recommended. This means we're intubating asthmatics and emphysema patients with suspected covid-19, and far more frequently and much earlier than we would have just weeks ago. Without our intermediate steps, such as BiPaP, it's harder to know when a patient's oxygen status is about to rapidly deteriorate. That's compounded by our knowledge that SARS-nCov-2 causes decreased oxygen levels without obvious signs of respiratory distress (the expert's jargon for this is "silent hypoxemia and atelectasis."

A work-around? High-flow nasal cannula (HFNC), which provides rushes of air into the nose---almost like a nasal BiPAP. HFNC provides heated and humidified oxygen at very high rates (up to 60 liters per minute) through a two-port tube that is placed into the nostrils. The question is, does that rush of air mean that when a patient exhales or coughs, that it pushes viral particles further out, thereby exposing health care workers to more virus. A paper published in an anesthesia journal on March 18 simulated a patient coughing while using HFNC to determine the maximum distance cough-generated droplets would travel. In this paper, five healthy volunteers were given HFNC, gargled a cup of diluted red food dye and then blue food dye, and were told to cough twice. The furthest distance that a visible food dye droplet travelled on the ground was measured. Without HFNC, cough-generated droplets traveled an average of over 8 feet. With HFNC cough-generated droplets traveled an average of over 9.5 feet with a maximum distance of 14.7 feet. What does this study tell us? It tells us there is no "safe" way to treat covid-19. It also tells us that healthcare providers need to use personal protective equipment, such as N95 masks and face shields, when treating patients with suspected SARS-nCov-2 virus, regardless of whether supplemental oxygen is being given. 

Research Section Editor

POLICY BRIEFING

Rapid coronavirus testing

The US Food and Drug Administration has granted Emergency Use Authorization (EUA) to Cepheid, an American diagnostics company, to produce and distribute a new rapid test for SARS-nCoV-2, the virus that causes covid-19. The FDA can approve medical products through the EUA when immediate chemical, biologic, nuclear, or radiological threats exist. The EUA was activated in February, in anticipation of SARS-CoV-2 here. Tests can be run on fully automated machines, many of which are already in use for other assays in hospitals across the country, thereby reducing the need for new and often expensive equipment. Test results are available in under forty-five minutes. Shipping begins next week. Cepheid.

Elective—what's in a name?

Across the country, elective medical and surgical procedures are being postponed to reduce patient exposure to SARS-nCoV-2, and to conserve personal protective equipment. Many state governments have ordered such procedures be postponed or canceled. Today, Ohio attorney general David Yost ordered that all elective terminations of pregnancy be halted in compliance with these orders. However, the word "elective" may not mean the same thing to everyone. In gynecological contexts, the word "elective" is used to differentiate between patients who have spontaneous abortions ("miscarriages") and those who do not with to carry their pregnancy further. In most other medical contexts, the word elective is used to describe a procedure that is "not time sensitive," or in some cases, merely optional. The two meanings of "elective" seem to be conflated here, and many women seeking to end their pregnancies could be forced to wait until it is too late to legally receive an abortion, if these orders go into effect. Business Insider.

Uniform medical licensing. Is it here?

No. But, states are starting to relax licensing requirements allowing physicians to practice across state lines without obtaining new licensure. Normally, to practice medicine in a second state, even via telemedicine, physicians are required to obtain a license in the second state. Earlier this week, the Centers for Medicare and Medicaid Services approved the practice of telehealth across state lines without obtaining a second license. However, this rule applies only to Medicare and Medicaid beneficiaries. Some states already have a standing policy allowing the practice of medicine across state lines in cases of emergency and have been putting those policies into practice. Others are moving towards passing new administrative rules or legislation that would allow this practice. FierceHealthcare.

Physicians call on President Trump to use Defense Production Act powers

As we wrote yesterday, President Trump has invoked the Defense Production Act which allows Health and Human Services Secretary Alex Azar to take control of certain elements of the private sector, if exercised. The powers allow the federal government to compel private manufacturers to produce goods needed to combat an emergency. In this case, the government has contemplated using these powers to direct the production of mechanical ventilators and personal protective equipment. To date, the government has not elected to exercise these powers, at least not publicly, though officials have described some degree of communication with certain companies. This raises the possibility that the administration is quietly leaning onto companies, if not directly coercing them. However, the shortage of equipment has become more dire. The American Heart Association, the American Medical Association, and the American Nurses Association joined in a letter calling for the administration to exercise these powers to compel production of PPE. American Medical Association.

Policy Section Editor