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COVID-19 and The Use of CPAP

Lisa Wolfe, MD, is an associate professor of Neurology and of Medicine in the Division of Pulmonary and Critical Care at Northwestern Medicine and an expert in respiratory devices used to treat patients with neuromuscular disorders and sleep-related breathing disorders. In this episode, Wolfe discusses key considerations for sleep medicine clinicians in the context of coronavirus disease 2019 (COVID-19), including continuous positive airway pressure (CPAP) use, CPAP as a ventilator alternative and strategies that Northwestern Medicine's sleep medicine team is implementing during this pandemic.
COVID-19 and The Use of CPAP
Featured Speaker:
Lisa Wolfe, MD
Lisa Wolfe, MD is an associate professor of Neurology and of Medicine in the Division of Pulmonary and Critical Care at Northwestern Medicine. 

Learn more about Lisa Wolfe, MD
COVID-19 and The Use of CPAP

Melanie Cole (Host):  This is the Northwestern Medicine podcast on COVID-19 dated April 6, 2020.

Welcome. This is Better Edge, a Northwestern Medicine podcast for physicians. I’m Melanie Cole and today, we’re discussing COVID-19 and the use of CPAP for patients with sleep apnea. Joining me is Dr. Lisa Wolfe. She’s an Associate Professor of Neurology and of Medicine in the Division of Pulmonary and Critical Care at Northwestern Medicine. Dr. Wolfe, I’m so glad to have you join us today in this unprecedented time. Let’s start with the risks of COVID-19 for patients with sleep apnea. Have we discovered a link at all?

Lisa Wolfe, MD (Guest):  There’s no link between sleep apnea and COVID-19. The infection is one that’s droplet mediated and it’s not something that you have to be at risk for in terms of the care or the use of the CPAP machine specifically.

Host:  Thank you for that answer. Should patients with sleep apnea who are showing symptoms or who are diagnosed with COVID-19 continue the use of CPAP? Shortness of breath and difficulty breathing have shown to be a symptom. Could CPAP help them breath? Tell us a little bit about that connection.

Dr. Wolfe:  So, there are two sides to this coin when we talk about the use of CPAP especially in the home for patients that are COVID-19 positive. We definitely know that positive pressure is beneficial to the lung especially as we pass through the early stages of COVID. And the use of the heated humidifier together with the pressure is also beneficial. Because we know that patients start to produce copious amounts of secretions and that heated humidification really helps to liberate those and help keep the lung open. The positive pressure is beneficial because it’s similar to the PEEP we would give had they been on mechanical ventilation. The only downside is that there will be an increased spread of droplet with the use of positive pressure in any noninvasive device. And that brings to the question caregivers, other members in the home, that kind of thing.

Because of that, if a patient has COVID-19, and they are on CPAP, we recommend that while they are using their CPAP at night, that they sleep by themselves in the room so that others are not exposed to those droplets and that the room be cleaned before anyone else would come in. Now in the morning, when the patient turns their PAP device off; you should wait about an hour or two before going in to clean the room and anyone who is cleaning the room should use a mask and gloves.

Host:  Well that’s great advice. So, what should sleep medicine clinicians be advising their patients with COVID-19? Basically what you just said but is there anything else they should advise their patients on at this time?

Dr. Wolfe:  I think the most important thing is to know that when the patient transfers from being at home using their PAP device to being in the hospital; you are going to see a variation from hospital to hospital and a variation given where we are in our curve between a flat curve in terms of the population expansion of COVID as we get into exponential increase in the number of patients. Initially, most hospitals will say we don’t want our patients using noninvasive ventilation while they are in the hospital and that would include a CPAP machine because of the risk of droplet spread and because of a preference for early intubation.

However, in patients who are very stable on their devices and who require them; we encourage patients to be their own advocate and explain that they need to use their equipment for their preexisting sleep disordered breathing. Oftentimes, that means a patient will be best off if they come to the hospital bringing their own equipment with them so that the hospital can’t say well, we have a reduction in supplies. As well as we see that significant take off in numbers of cases, what we will find is that hospitals and physicians will say look, we understand that there’s droplet spread in association with these devices, however, because of our lack of full mechanical ventilators, we would like to use noninvasive devices to help reduce the need for those mechanical ventilators and as that you’ll see a significant shift and change in attitude to the use of these devices in hospitalized COVID positive patients.

But again, hospital to hospital, these policies will differ and day to day, they’ll differ depending on where we are in the escalation of the crisis.

Host:  So, then along those lines, and such an interesting answer. An insufficient supply of ventilators has been a concern obviously facing the whole country and many hospitals as this virus continues to spread, what are your thoughts on using CPAP machines in the event of ventilator shortages? Could these be temporary solutions during this pandemic?

Dr. Wolfe:  So, I’m going to answer that in three parts. The first part is to say that there is a difference between using a CPAP device noninvasively and using it invasively. I’m going to take the noninvasive part first and then we’re going to come back to the invasive. When we look at noninvasive, if we look at models such as Italy and in China, as well as now models that are coming out of other countries who are under a significant stress because of large escalation in numbers of  patients; noninvasive ventilation becomes much more a part of what they need to do both on the front end to avoid intubation and on the back end to speed extubation and help to transition people off ventilators to get them out of ICUs and to free up those ventilators for the next patient.

And so, we will see that change and evolve as we are going forward. Now, within these machines, “CPAP” is frequently referred to as any device that’s used noninvasively for supportive breathing. But we really know that there are some devices that have just a continuous pressure and others that can augment ventilation with inspiratory support and even a back up rate. And you get significant differences in how efficacious these devices are depending on the technology that’s engaged in the device.

Now, initially, we thought that the only thing that would be helpful was devices that had inspiratory support because we know that in the setting of traditional respiratory failure due to say pneumonia, or COPD exacerbation, that those are the devices that have the greatest validity. What’s interesting now is that we are aware of the role of PEEP and how positive end expiratory pressure is fundamental to the treatment of those with COVID associated lung injury. And because of that, if we had a significant shortage of ventilators, the use of pure CPAP therapy as a way of providing PEEP has been looked at as an alternative and may play a role in that situation of device shortage.

Now, I’m going to get back to the invasive component. So, invasive mechanical ventilation is traditionally done with full scale ICU ventilators, all the buzzers and whistles. However, in the setting of an equipment crisis, we can use lower level bilevel PAP devices that provide inspiratory support and backup rate because that is the stripped down or naked as you would say version of mechanical ventilation. In testing these devices, both in the lab and on our patients; what we have found is that the biggest single limitation comes from total pressure. Because we need higher and higher levels of PEEP, 15-20 being not uncommon, if we have bilevel PAP devices who max out their pressures at 25 or even 30, we may not have the driving pressure we need during the acute phase of the COVID lung injury. However, when we have patients who are in the convalescent phase in which high levels of PEEP are not necessary; that is when using a bilevel PAP device adapted to be placed on either tracheostomy tube or an endotracheal tube can be an efficient alternative to full mechanical ventilation and will likely play a big role as we see a huge escalation in need for equipment that outstrips our traditional availability for mechanical ventilation.

Host:  So, interesting Doctor. Are there alternative treatments that should be considered in the case that it’s recommended to discontinue the use of CPAP for patients?

Dr. Wolfe:  Always for patients who can’t use their CPAP for whatever reason; we recommend that elevation of the head of the bed and staying off of their back makes a huge difference in keeping the upper airway open in a patient with traditional obstructive sleep apnea. That kind of small maneuver can make a big difference when no machine is available at all.

Host:  Well how are you and your team evolving care for your patients during this pandemic? Discuss a little bit about how your department is utilizing and optimizing Telehealth, at home testing, diagnostics. What are you doing for your patients right now?

Dr. Wolfe:  Well I think the important thing to know in terms of the at home component is that Medicare has now approved something that’s called the 1135 Waiver. Under that 1135 Waiver, face to face visits which traditionally had been the bedrock for how we delivered PAP therapy to patients in the past for new devices, for access to sleep medicine testing. That 1135 Waiver means that we can now do this with telephone visits or with video visits. And we’re using both in terms of getting that done. In addition, we’re doing home testing instead of in lab testing and our home testing is now using devices that may even be disposable. And so, this is allowing us to do sleep medicine without having a lot of face to face or at risk interactions keeping the patients at home and away from the hospital.

Host:  Well thank you so much for being on with us. As we wrap up, Dr. Wolfe, tell us a little bit about what you would like other providers to know about treating their patients during the COVID-19 pandemic. Are the any immediate actions they should be advising patients using CPAP to take?

Dr. Wolfe:  You know, I think the one thing I’m going to give as sort of a take home message is that we think a lot about obstructive sleep apnea as the indication for noninvasive home PAP therapy and it is the most commonly indicated use. That being said, I think it’s really important to understand that we do have patients at home on more advanced noninvasive ventilation due to conditions like neuromuscular diseases, scoliosis or conditions of hypercapnia. Even if your hospital has decided that the risk of COVID spread means that you don’t want to use noninvasive ventilation; we encourage you to understand that for those patients, it is such a fundamental part of their therapy that it is potentially life threatening to remove it given the risk of escalating hypercapnia and respiratory failure. And that it’s really important to understand that not all PAP machines are for the guy that snore and pisses off his wife. And so we encourage people to take a good complete history and for those in whom it’s appropriate, continue their home noninvasive ventilation.

Host:  Thank you so much Doctor, for joining us today. Really such important information. And that concludes this episode of Better Edge a Northwestern Medicine podcast for physicians. To refer your patient or for more information on COVID-19, please visit our website at to get connected with one of our providers. Please remember to subscribe, rate and review this podcast and all the other Northwestern Medicine podcasts. I’m Melanie Cole.