Timeframe for diving post covid +

[kinoons]

Omicron drove a huge spike in daily number of positive cases, roughly four times that of Delta, but the number of hospitalizations was roughly similar. Most recently, US hospitals (including ours) saw a huge spike in flu and RSV in pediatric patients, far above the number of COVID patients we had. This does not mean that COVID acts like those other illnesses. In many cases it does, but in enough cases to matter, it does not. I agree that it doesn't impact "the masses", so to speak, but lung damage from COVID, even in relatively mild cases, is well-documented. This lung damage can lead to air trapping, which can lead to pulmonary barotrauma in diving. You and anyone else may feel free to follow your recommendations, but they are contrary to those of the highly-regarded UCSD diving medicine specialists, reproduced here for continuity (basically a chest x-ray series and pulmonary function testing for mild illness):

Category 1 Asymptomatic Diver who had a mild COVID-19-suspected illness
We define a mild illness as any patient who:
● Did not seek health care or received outpatient treatment only without evidence of hypoxemia.
● Did not require supplemental oxygen
● Imaging was normal or not required
● They have returned to their baseline exercise tolerance.

Commercial Divers/Scientific Divers/Recreational
● Initial/annual exam per ADCI/AAUS/NOAA/RSTC guidelines (DDM addition: for commercial or scientific divers only)
● Spirometry
● Chest radiograph (PA & Lateral)
● If chest radiograph is abnormal, obtain Chest CT scan
● If unknown (or unsatisfactory) exercise tolerance, perform exercise tolerance test with oxygen saturation

Best regards,
DDM

Does UCSD have any randomized controlled studies, or even non randomized studies to support these recommendations? How about randomizing some divers to the suggested evaluation and others to simply diving if they feel well and then seeing if there is a difference in barotrauma rates? They could even try to find folks who had never had Covid (good luck finding enough to power the study) or just compare to prior known rates. I’d hazard a guess that they didn’t, but I’ll admit I have not extensively looked.

If they don’t have randomized evidence then they are simply guessing. Simply guessing is unacceptable when offering guidance as a professional organization who is able to generate such evidence.

Never in the history of medicine would any of us accepted that a mild, minimally symptomatic, URI style viral infection, could cause long term health issues for any significant number of people. The majority of long Covid studies are garbage. They are not blinded, frequently self reported and Frequently ICD 10 codes are used to justify the symptoms. We all know ICD 10 codes are meant for billing, not treating, not data collection. Often times long Covid studies are studies of folks who present to the medical system, missing the total denominator of the cases. Additionally people who present to the medical system for a sniffle and Covid testing are often fundamentally different people than those who just walk off their cold.

I agree that people are suffering. I am not convinced that the Covid virus is the cause. As Dr. Prasad and his team suggests there are other potential causes.

 

[Duke Dive Medicine]

The 2nd time i had covid I went diving 2 days after the fever broke... The warm moist air from my CCR kept coughing at bay. TBH I felt better underwater than on land.

What was your pO2 setpoint?

Best regards,
DDM

 

[Whitrzac]

What was your pO2 setpoint?

Best regards,
DDM

1.1-1.2 for the bottom portion and 1.4-1.5 for deco.
Max of 290ft, 2:30 runtime

 

[Duke Dive Medicine]

1.1-1.2 for the bottom portion and 1.4-1.5 for deco.
Max of 290ft, 2:30 runtime

Thanks - so, you felt better diving a hyperoxic mix while recovering from COVID? While it's not possible to tell at this point, this might indicate that you were mildly hypoxemic.

Best regards,
DDM

 

[Duke Dive Medicine]

Does UCSD have any randomized controlled studies, or even non randomized studies to support these recommendations? How about randomizing some divers to the suggested evaluation and others to simply diving if they feel well and then seeing if there is a difference in barotrauma rates? They could even try to find folks who had never had Covid (good luck finding enough to power the study) or just compare to prior known rates. I’d hazard a guess that they didn’t, but I’ll admit I have not extensively looked.

If they don’t have randomized evidence then they are simply guessing. Simply guessing is unacceptable when offering guidance as a professional organization who is able to generate such evidence.

Never in the history of medicine would any of us accepted that a mild, minimally symptomatic, URI style viral infection, could cause long term health issues for any significant number of people. The majority of long Covid studies are garbage. They are not blinded, frequently self reported and Frequently ICD 10 codes are used to justify the symptoms. We all know ICD 10 codes are meant for billing, not treating, not data collection. Often times long Covid studies are studies of folks who present to the medical system, missing the total denominator of the cases. Additionally people who present to the medical system for a sniffle and Covid testing are often fundamentally different people than those who just walk off their cold.

I agree that people are suffering. I am not convinced that the Covid virus is the cause. As Dr. Prasad and his team suggests there are other potential causes.

Unfortunately your post got hung up in moderation by an automatic system; we noticed that and fixed it. Apologies that it didn't appear as soon as you wrote it.

I don't know of an IRB that would approve the study that you recommend here. I suspect that there will be a lot of retrospective analyses in the years to come, but we're not at that point in the evolution of this disease and our understanding of it. TBH, I do hope that happens. I'm reminded a little bit of medications and diving here. There are probably a lot of divers who use medications that might give a diving medical examiner pause, but there's no data on who's actually taking what drug and what effects, if any, there are.

Absent RCTs demonstrating the validity of UCSD's recommendations, there are other levels of evidence, and I would submit that "expert opinion", while the lowest level of evidence on the pyramid, is valid and is much different than "simply guessing".

I agree that a significant number of people are not adversely affected by COVID. Lung damage from mild COVID is a low-probability event. Nevertheless, it has high potential consequences in divers, which is what drives UCSD's recommendations. Neither I nor UCSD nor anyone else is is in the business of preventing people from diving. We can make recommendations based on the best clinical and evidentiary information available at the time, and people can choose to follow them or not. The fact that nothing may happen afterwards as with our friends @Whitrzac and @Boarderguy is not a reflection on the validity of the recommendations.

Best regards,
DDM

 

[FabletheRaven]

Does UCSD have any randomized controlled studies, or even non randomized studies to support these recommendations? How about randomizing some divers to the suggested evaluation and others to simply diving if they feel well and then seeing if there is a difference in barotrauma rates? They could even try to find folks who had never had Covid (good luck finding enough to power the study) or just compare to prior known rates. I’d hazard a guess that they didn’t, but I’ll admit I have not extensively looked.

If they don’t have randomized evidence then they are simply guessing. Simply guessing is unacceptable when offering guidance as a professional organization who is able to generate such evidence.

Never in the history of medicine would any of us accepted that a mild, minimally symptomatic, URI style viral infection, could cause long term health issues for any significant number of people. The majority of long Covid studies are garbage. They are not blinded, frequently self reported and Frequently ICD 10 codes are used to justify the symptoms. We all know ICD 10 codes are meant for billing, not treating, not data collection. Often times long Covid studies are studies of folks who present to the medical system, missing the total denominator of the cases. Additionally people who present to the medical system for a sniffle and Covid testing are often fundamentally different people than those who just walk off their cold.

I agree that people are suffering. I am not convinced that the Covid virus is the cause. As Dr. Prasad and his team suggests there are other potential causes.

It's really hard to actually execute the trials you're suggesting. You will never get a RCT for people who dive according to reccomendation and those without because you can't get IRB approval to have people dive in a manner you deem unsafe. At best you're going to get retrospective data of people who dove according to recommendation and those who didn't, which is a much lower quality study. If THAT study turned out that there is no significant difference then you may be able to get approval for the first study.

So yes the long covid studies are garbage, but you will see better studies as time goes on. Right now the studies are really data mining because it doesn't require recruitment and follow up, which is REALLY hard.

 

[kinoons]

Unfortunately your post got hung up in moderation by an automatic system; we noticed that and fixed it. Apologies that it didn't appear as soon as you wrote it.

I don't know of an IRB that would approve the study that you recommend here. I suspect that there will be a lot of retrospective analyses in the years to come, but we're not at that point in the evolution of this disease and our understanding of it.

Absent RCTs demonstrating the validity of UCSD's recommendations, there are other levels of evidence, and I would submit that "expert opinion", while the lowest level of evidence on the pyramid, is valid and is much different than "simply guessing".

I agree that a significant number of people are not adversely affected by COVID. Lung damage from mild COVID is a low-probability event. Nevertheless, it has high potential consequences in divers, which is what drives UCSD's recommendations. Neither I nor UCSD nor anyone else is is in the business of preventing people from diving. We can make recommendations based on the best clinical and evidentiary information available at the time, and people can choose to follow them or not. The fact that nothing may happen afterwards as with our friends @Whitrzac and @Boarderguy is not a reflection on the validity of the recommendations.

Best regards,
DDM

I would disagree that there are no IRBs who would approve such a study. Especially in the light that many divers are doing exactly what I suggested; if they feel well they are diving.

For example plenty of IRBs are approving cancer treatment studies with control arms that are receiving delinquent (not up to standard) care, or no control arm at all. It is impossible for those studies to inform the practice of oncologists since the control arm doesn’t meet the current standard of care. Any study that doesn’t actually improve practice is an immoral one prima facia.

As to expert opinion as a level of evidence - yes it’s on the pyramid. It’s also the least strong level and has proven to be wrong just as often, if not more so, than correct.

One easily accessible example was the expert opinion from the AAP regarding peanuts and allergies. TLDR version - they recommended avoiding peanuts and actually caused more allergies.

Peanut Allergy Prevention Advice Does a 180

New guidelines suggest that preventing peanut allergies may be as simple as giving peanut-containing food, beginning in infancy. How did old guidelines, which recommended avoidance, get it so wrong?

sciencebasedmedicine.org

At the time no one was clamoring the AAP to give a recommendation about peanuts and allergies. They easily could have performed the RTC and generated real evidence instead of simply offering an opinion with zero evidence to support it.

So no, I don’t accept the notion that UCSD can simply offer guidance based on their best guess because that’s the only avenue available to us.

 

[kinoons]

It's really hard to actually execute the trials you're suggesting. You will never get a RCT for people who dive according to reccomendation and those without because you can't get IRB approval to have people dive in a manner you deem unsafe. At best you're going to get retrospective data of people who dove according to recommendation and those who didn't, which is a much lower quality study. If THAT study turned out that there is no significant difference then you may be able to get approval for the first study.

So yes the long covid studies are garbage, but you will see better studies as time goes on. Right now the studies are really data mining because it doesn't require recruitment and follow up, which is REALLY hard.

Why no IRB approval? Does anyone have any actual hard evidence that diving post Covid is any more unsafe than diving after any other viral URI type illness? The recommendations (to my knowledge) are based on a perceived and theorized fear with no solid real world evidence to back it up.

It’s not like someone would be asking an IRB to approve a randomized study for a treatment or procedure that we know has harm and are looking for benefits that exceed that harm, like for cancer treatment.

Instead I’m asking for a RTC for a screening vs no screening for a theorized potential risk that has never actually been substantiated.

 

[Duke Dive Medicine]

Why no IRB approval? Does anyone have any actual hard evidence that diving post Covid is any more unsafe than diving after any other viral URI type illness? The recommendations (to my knowledge) ar based on a perceived and theorized fear with no solid real world evidence to back it up.

It’s not like someone would be asking an IRB to approve a randomized study for a treatment or procedure that we know has harm and are looking for benefits that exceed that harm, like for cancer treatment.

Instead I’m asking for a RTC for a screening vs no screening for a theorized potential risk that has never actually been substantiated.

Nobody in the present day is going to blindly randomize a post-COVID diver with (albeit small) potential for lung pathology into a study arm that recommends diving. Based on our current knowledge, that would be completely unethical. The best we're going to get is retrospective data, which again, I hope someone takes the time to gather. It may well happen that the overall risk is low enough that the recommendations can be modified.

Best regards,
DDM

 

[FabletheRaven]

Why no IRB approval? Does anyone have any actual hard evidence that diving post Covid is any more unsafe than diving after any other viral URI type illness? The recommendations (to my knowledge) ar based on a perceived and theorized fear with no solid real world evidence to back it up.

It’s not like someone would be asking an IRB to approve a randomized study for a treatment or procedure that we know has harm and are looking for benefits that exceed that harm, like for cancer treatment.

Instead I’m asking for a RTC for a screening vs no screening for a theorized potential risk that has never actually been substantiated.

Not that I'm a researcher in any sense, as someone who had to write an IRB application for truly benign stuff, you need to justify that what your doing is safe, they don't have to prove it's unsafe. If your study is trying to assert that you need xyz protocol to dive safely you can not in good conscious recommend the opposite for a control. What you need to do is show that the control is 'standard care' vs your new and better protocol. With Covid the conservative approach is 'standard care' so you can't experiment by telling a bunch of people to be 'unsafe' based on current protocols.

If you have a retrospective study that shows it IS safe to dive without xyz protocol THEN you can justify that it is safe to the IRB and conduct your study. Maybe. If they're nice.