SARS-CoV-2 / COVID-19 and Diving

[fxb]

Hi all, I apologize first of all if there is an existing thread on this topic, I did not see any after a quick search. I also would like to mention I am not a medical professional, so for any other non-experts who follow this thread please consider any of my opinions as nothing more than "educated musings". I do have some formal undergraduate education in human anatomy and physiology as well as all the dive physiology education you would expect from someone who is a DAN instructor and technical diver.

In this thread I am hoping to discuss the impact mild COVID-19 may have on safe diving. Specifically where there is no fever, congestion, pneumonia or other factors that are obviously incompatible with diving, but rather cases where a person only has mild symptoms associated with COVID-19 such as a dry cough, sore through, or lung irritation. Mild enough that a person still might consider diving. As far as I can tell those three symptoms alone are considered only relative or temporary risk factors, there are many reasons why you might have a slight sore throat or minor lung irritation (scuba gas is cold and dry after all), not all of which are necessarily incompatible with diving.

Now, given the current state of things I think it's reasonable not to rule out COVID-19 with the presentation of any of those three symptoms. With the assumption that in those cases a person might have COVID-19, it seems to me that any of the three "mild" symptoms mentioned above (dry cough, sore throat, lung irritation), should for now be considered as much more severe risk conditions.

My reasoning for this is that SARS-CoV-2 targets type II alveolar cells which are responsible for the secretion of pulmonary surfactant. It seems to me -- and please correct me if I am mistaken -- that degraded type II pneumocyte function and lower levels of pulmonary surfactant could have these effects which are undesirable for diving:

• Decreased alveolar tolerance for over-expansion, increasing possibility of lung over-expansion injury
• Decreased alveolar tolerance for the "harsh" quality of scuba breathing gas (cold and dry), possibly causing alveolar inflammation and increasing risk of developing more severe pneumonia
• Reduced alveolar volume, decreasing gas exchange efficiency which may increase risk of DCS

So in summary, given that absence of severe symptoms obviously incompatible with diving, should minor symptoms such as sore throat, lung irritation, or dry cough be considered much more severe risk conditions for diving when COVID-19 is a possible cause?

I am also hoping we can steer the discussion away from the topic of whether a person should be out and about in the first place.

Thanks! I am looking forward to hearing some experts chime in to point out any flaws in my reasoning or misconceptions I have about physiology and dive medicine.

 

[GJC]

Other physiologic responses that occur with respiratory tract infections include inflamation and swelling (and narowing) of the airways and increased secretion of fluid into the airways. This also increases the risk of air being trapped in alveoli with the consequences of lung over expansion injury while diving.

I don't think you would be more at risk with COVID-19 than any other respiratory problem like the flu, pneumonia or an unresolved asthma episode while diving. Your risk depends on what's going on in your lungs which is hard to determine by symptoms alone.

It's best not to dive if your lungs are infected or inflamed, so don't dive if you have any respiratory symptoms regardless of how mild it seems to be.

 

[Duke Dive Medicine]

Hi all, I apologize first of all if there is an existing thread on this topic, I did not see any after a quick search. I also would like to mention I am not a medical professional, so for any other non-experts who follow this thread please consider any of my opinions as nothing more than "educated musings". I do have some formal undergraduate education in human anatomy and physiology as well as all the dive physiology education you would expect from someone who is a DAN instructor and technical diver.

In this thread I am hoping to discuss the impact mild COVID-19 may have on safe diving. Specifically where there is no fever, congestion, pneumonia or other factors that are obviously incompatible with diving, but rather cases where a person only has mild symptoms associated with COVID-19 such as a dry cough, sore through, or lung irritation. Mild enough that a person still might consider diving. As far as I can tell those three symptoms alone are considered only relative or temporary risk factors, there are many reasons why you might have a slight sore throat or minor lung irritation (scuba gas is cold and dry after all), not all of which are necessarily incompatible with diving.

Now, given the current state of things I think it's reasonable not to rule out COVID-19 with the presentation of any of those three symptoms. With the assumption that in those cases a person might have COVID-19, it seems to me that any of the three "mild" symptoms mentioned above (dry cough, sore throat, lung irritation), should for now be considered as much more severe risk conditions.

My reasoning for this is that SARS-CoV-2 targets type II alveolar cells which are responsible for the secretion of pulmonary surfactant. It seems to me -- and please correct me if I am mistaken -- that degraded type II pneumocyte function and lower levels of pulmonary surfactant could have these effects which are undesirable for diving:

• Decreased alveolar tolerance for over-expansion, increasing possibility of lung over-expansion injury
• Decreased alveolar tolerance for the "harsh" quality of scuba breathing gas (cold and dry), possibly causing alveolar inflammation and increasing risk of developing more severe pneumonia
• Reduced alveolar volume, decreasing gas exchange efficiency which may increase risk of DCS

So in summary, given that absence of severe symptoms obviously incompatible with diving, should minor symptoms such as sore throat, lung irritation, or dry cough be considered much more severe risk conditions for diving when COVID-19 is a possible cause?

I am also hoping we can steer the discussion away from the topic of whether a person should be out and about in the first place.

Thanks! I am looking forward to hearing some experts chime in to point out any flaws in my reasoning or misconceptions I have about physiology and dive medicine.

Hi @fxb ,

The problem as I see it is that there are reports about people walking around asymptomatic who have incidental findings of whited-out lungs on radiographic exam, e.g. after a trauma, and it's discovered they have the virus at that point. I think if an individual is at all symptomatic or even has had an exposure to a person known to have COVID-19, he or she should refrain from diving until deemed free and clear by a health care professional. There are too many unknowns, and even the knowns as @GJC pointed out are contraindications to diving.

Best regards,
DDM

 

[Ukmc]

Hi @fxb ,

The problem as I see it is that there are reports about people walking around asymptomatic who have incidental findings of whited-out lungs on radiographic exam, e.g. after a trauma, and it's discovered they have the virus at that point. I think if an individual is at all symptomatic or even has had an exposure to a person known to have COVID-19, he or she should refrain from diving until deemed free and clear by a health care professional. There are too many unknowns, and even the knowns as @GJC pointed out are contraindications to diving.

Best regards,
DDM

Are you suggesting that every diver gets a chest X-ray to get cleared for diving? COVID-19 is likely to persist for 12-18 months or longer (although the epidemic scare hopefully will subside by May/June). The risk of truly asymptotic patients is actually a lot less than initially reported 20%. However, it may not be a bad idea to get a medical clearance with CXR to be safe over the next year or two.

 

[Duke Dive Medicine]

Are you suggesting that every diver gets a chest X-ray to get cleared for diving? COVID-19 is likely to persist for 12-18 months or longer (although the epidemic scare hopefully will subside by May/June). The risk of truly asymptotic patients is actually a lot less than initially reported 20%. However, it may not be a bad idea to get a medical clearance with CXR to be safe over the next year or two.

Hi @Ukmc , absolutely not. I do think that if a diver is confirmed to have COVID-19, he or she should be cleared by a physician who specializes in diving medicine before returning to diving; and if exposed to the virus, should refrain from diving until he or she is determined not to have it.

Best regards,
DDM

 

[Ukmc]

Hi @Ukmc , absolutely not. I do think that if a diver is confirmed to have COVID-19, he or she should be cleared by a physician who specializes in diving medicine before returning to diving; and if exposed to the virus, should refrain from diving until he or she is determined not to have it.

Best regards,
DDM

DDM, thank you for your response. I apologize that I misconstrued what I thought you implied when you said that some people do not show symptoms at all but have quite significant radiologic changes. My worry would be that if this is the case and a diver has bronchial and alveolar changes without exhibiting symptoms, they may not know that they are exposing themselves to a possibility of over-expansion lung injury. But once again, COVID positive without any symptoms is a rare occurrence.

 

[Duke Dive Medicine]

DDM, thank you for your response. I apologize that I misconstrued what I thought you implied when you said that some people do not show symptoms at all but have quite significant radiologic changes. My worry would be that if this is the case and a diver has bronchial and alveolar changes without exhibiting symptoms, they may not know that they are exposing themselves to a possibility of over-expansion lung injury. But once again, COVID positive without any symptoms is a rare occurrence.

No problem at all. I would worry about the same, and I honestly don't know how rare it is. There are just anecdotal reports coming out of the hard-hit areas at this point, but it seems to be more common than one would think. This is not to say that everyone walking around right now should be concerned about having lung issues related to COVID-19 and should avoid diving because of this, but it's certainly a good reason to be cautious if exposed and even more cautious if one has the illness.

Best regards,
DDM

 

[pepperbelly]

If someone has a mild undiagnosed asymptomatic case of Covid-19 is there any way to tell?
I understand asymptomatic means no symptoms, but I’m not sure if that means zero signs.
For instance could someone be able to exercise with no breathing issues if they had a mild case?

 

[Duke Dive Medicine]

If someone has a mild undiagnosed asymptomatic case of Covid-19 is there any way to tell?
I understand asymptomatic means no symptoms, but I’m not sure if that means zero signs.
For instance could someone be able to exercise with no breathing issues if they had a mild case?

Not to get too technical, but a symptom is something that the patient feels that the practitioner may not be able to assess directly, e.g. nausea. A sign is something that a practitioner can perceive, like pulse oximetry, lung sounds, fever, etc. though again technically a fever could be both a sign and a symptom.

Anyway, I think what you're asking is whether there are people walking around carrying the SARS CoV-2 virus without signs or symptoms of COVID-19, and anecdotally at least, the answer is yes.

Best regards,
DDM

 

[pepperbelly]

I wasn’t very clear. I do understand that there are people walking around with it and don’t know.
I was wondering, for instance, if I had it but wasn’t coughing or showing any other signs and I got on a treadmill would I notice?