Anecdotal increase of pneumothorax in COVID-19 survivors in hyperbaric enviorment

[ToddTheMechanic, EMT-I]

I'm a mechanic & rescueman (AEMT licensed) for very specialized industrial infrastructure. We regularly work in pressurized suits up to 4.5 bar (65psi) so one of the bigger medical concerns we have as rescueman is effects related to the pressurization (more specifically depressurization). One of those concerns is pneumothorax which we do see at least a few times a year and hear about it relatively frequently.  These mechanics are mostly very healthy, athletically fit people who are screened frequently by their doctors. They're also screened before, several times during, and after every single job regardless of if it's under pressurization or not. 

Just in the past month, I've seen 9 suprise pneumothoraces. Every single one has been in someone who was COVID-19 positive prior and has been healthy + negative for at least 3 months. There's only one that I'm not comfortable attributing entirely to COVID-19 because it happened in a rapid uncontrolled depressurization event during an emergency on that individuals first shift back after COVID-19, however the other 8 were all genuine suprises. 

Every person was properly & fully evaluated prior to pressurization. Each pressurization was without incident, each individual reported no concerns while pressurized until suddenly having classic pneumothorax symptoms mid-mission.

In all cases, our standard pneumothorax procedure was followed as soon as symptoms were reported. In all cases, the patient was immediately switched from air to medical O2. In all cases, the doctor was consulted and immediate slow decompression to minimum safe pressure was started. 3 of the 8 cases couldn't tolerate decompression due to gas expansion & tension pneumo, so we pressurized to maximum pressure for those. All cases met our emergency goals — were needle decompressed within 15 minutes of symptom onset, evacuated from the system within 25 minutes of symptom onset, and released to EMS within 45 minutes. Two cases required several needle decompressions, and everybody has recovered thus far. 

Even though this is very much an anecdotal, it's very concerning to me that all of these formerly COVID-19 positive patients are having these pneumothoraces at such a high rate under the same conditions other mechanics in our field are exposed too without nearly as high of a rate. 

[Corey Narry, MSN, RN, NP]

I think we're just seeing the long-term sequelae of COVID-19 infection and you may be seeing an actual trend that will be something to look out for in a post COVID-19 lung.  There are changes that happen in the lungs of patients even those who had a mild case of the disease.  We have admitted patients for other reasons who never were hospitalized for their initial infection and are now considered recovered.  Their chest x-rays commonly still show the infiltrative process that pneumonia leaves even when they never had an oxygen requirement during their illness.  As a result of that, I'm pretty sure there are some elasticity changes in their alveolar walls that lend itself more susceptible to barometric changes.  Again, studies in actual human subjects need to confirm this.