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I want to inquire if CPAP devices can act as low performance ventilators, if they are connected to an oxygen source as well.

I am asking this question in regards to the covid-19 pandemic. There are only two websites which cover this in the entire web. One of them only suggests that CPAP devices may increase the risk of spreading. The other one notes similarities between these devices. Due to the lack of discussion reachable via google, even if the answer is "no", it might help many people.

I am looking for

  1. Scientific publications
  2. Conventions used in field hospitals/healthcare
  3. Your professional educated guess

in this order. Please include which category your answer falls into.

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    "if demand continues to grow, hospitals could use sleep apnea machines, suggests George Washington University Law professor John Banzhaf". This quote from the 2nd website highlights that this is a hypothesis from a non medical professor. It is thinking outside the box but not viable from my knowledge of CPAP machines. They take air from the surrounding air through a filter on the side of the machine. There is no way of connecting a bottled oxygen and air supply. Mar 21 '20 at 8:54
  • @ChrisRogers I checked that as well and there is an easy way to connect oxygen. If the CPAP is not oxygen compatible, you can add an oxygen bleed adaptor between the machine tubing and the mask tubing.
    – C.Koca
    Mar 21 '20 at 9:39
  • The air intake is not at the mask and machine tubing, and the way air is expelled would still spread the virus. See my answer Mar 21 '20 at 9:41
  • @ChrisRogers there is a way to connect bottled oxigen to them, in Apollo13 style but there is Mar 21 '20 at 19:10
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The software is very different. And the capabilities of the machine. The monitoring parameters within Ventilators are much more sensitive to pressure and volume than CPAP or BIPAP machines. Below are two pages from the manufacturer with setting capabilities for a BIPAP and a ventilator.

https://www.usa.philips.com/c-p/HH1460_00/dreamstation-cpap-with-humidifier

https://www.usa.philips.com/healthcare/product/HCNOCTN96/respironics-v60-non-invasive-ventilator/specifications

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The essence of protection is a physical barrier against air borne virus droplets splashing against your mucus membranes (eyes, nose, mouth), and against virus from being breathed in. A CPAP machine offers none of these. Even if connected to an oxygen supply some CPAP machines are just nasal and don't stop the person using their mouths. The oxygen supply needs to be mixed with air, and that air needs to be filtered for any kind of protection.

That is my educated guess.

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  • I am sorry, but I erroneously used respirator interchangeably with ventilator. I think you answered thinking I asked CPAP as a respirator, while in reality I meant for ventilator. I later edited the question.
    – C.Koca
    Mar 21 '20 at 0:14
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    I don't think OP was asking about protection, but rather about using CPAP devices as substitutes for unavailable ventilators.
    – Carey Gregory
    Mar 21 '20 at 4:27
  • Ok, then no idea but I suspect the pressures are way too low. Mar 21 '20 at 7:19
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    It's not down to the machine as to whether it is nasal only or full face mask. It is down to the mask and tubing set-up applied. All CPAP machines can use a full face mask. Mar 21 '20 at 8:50
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    This vendor of CPAPs and accessories offers a variety of full face masks cpapman.com/cpap-masks/full-face provided for reference; I have no interest in the company.
    – K7AAY
    Mar 21 '20 at 18:53
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The American Academy of Sleep Medicine (AASM) is correct in what they are saying when they said that

It is possible that using CPAP could increase the risk of spreading the virus to others around you.

If you are suffering from COVID-19 and use a CPAP machine, the air around you is sucked into the machine and blown out of the mask. Excess air pressure is blown out of outlet holes in the elbow joint between the tubing and mask. This can carry the COVID-19 pathogen out with it at force, spreading it further around the room.

Take this elbow joint as example, used on my CPAP mask. CPAP mask elbow joint

When you take where the idea of using oxygen and air supplies comes from

... if demand continues to grow, hospitals could use sleep apnea machines, suggests George Washington University Law professor John Banzhaf

This quote from the 2nd website (an article supposedly checked by an MD in Coronavirus Today) highlights that this is a hypothesis from a non medical professor. He may have experience working within the field of medicine but he is a medical negligence lawyer, not a medical practitioner, as highlighted by his George Washington University Law page

The idea of using an oxygen and air supply is "thinking outside the box" but not viable from my knowledge of CPAP/APAP machines. CPAP and APAP machines take air from the surrounding air through a filter on the side of the machine.

Take for example, my CPAP machine air intake photographed in this image

CPAP air intake

There is no way of connecting a bottled oxygen and air supply to this air inlet.

Using oxygen and air supply between the machine and mask

You said in the comments:

I checked that as well and there is an easy way to connect oxygen. If the CPAP is not oxygen compatible, you can add an oxygen bleed adaptor between the machine tubing and the mask tubing.

If you are looking to add oxygen within the air supplied to the patient, you are correct that you can connect an adaptor between the machine and the tubing to the mask.

If you are wanting to maintain a specific oxygen concentration, the way CPAP/APAP machines work is different to hospital ICU (Intensive Care Unit) ventilators.

Ventilators employed in NIV [Non-Invasive Ventilation] range from ICU ventilators with full monitoring and alarm systems normally employed in the intubated patient, to light weight, free standing devices with limited alarm systems specifically designed for non-invasive respiratory support. Life support ICU ventilators separate the inspiratory and expiratory gas mixtures. This prevents rebreathing and allows monitoring of inspiratory pressure and exhaled minute ventilation on which monitoring and alarm limits are based (British Thoracic Society Standards of Care Committee, 2002).

References

British Thoracic Society Standards of Care Committee. (2002). Non-invasive ventilation in acute respiratory failure. Thorax, 57(3), 192. DOI: 10.1136/thorax.57.3.192 PMCID: PMC1746282

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    I know for a fact that reason one definitely does not hold. You can connect oxygen to all CPAP devices. Reason two is reasonable as long as you care about spreading the disease. If you don't, if everybody has the disease, it is also rendered meaningless.
    – C.Koca
    Mar 21 '20 at 9:43
  • Mechanical devices can create aerosols which make the risk much much higher. Mar 21 '20 at 10:51
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    I have taken on board your comment about reason 2 in my previous edit @C.Koca and removed it as the question is asking about using CPAP machines in isolation units so spreading is not a big concern. Mar 21 '20 at 11:21

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