Is it Bad News for Divers Who Suffer COVID-19?

The medical profession is still learning about COVID-19, but the first specific news related to divers comes from the Innsbruck University Clinic in Austria, where physicians have discovered lung damage in recovered COVID-19 sufferers. "COVID-19 is undisputedly a serious illness despite what some politicians might tell you, and the massive changes in the lungs can significantly increase the risk of scuba diving accidents." So says senior physician, dive medical officer, and diver Frank Hartig, MD.

However, as we report later in this article, other doctors believe these findings are premature, at best.

Doctors at the Innsbruck Clinic have treated dozens of coronavirus sufferers, from those who are symptom-free spreaders to intensive care patients saved by the use of heart/lung machines. Among those to have had the virus were six scuba divers, all of whom stayed at home in quarantine until they recovered. But Hartig believes they can no longer dive because the damage to their lungs appears irreversible. The bad news was revealed by lung CT scans.

"As an emergency doctor with 20 years' experience, you swallow when you see something like this in a 40-year-old patient," Hartig said in an interview first published in Italian RAI News and widely reported by diving media throughout the world.

After several weeks, two patients showed significant oxygen deficiency when under stress -- a typical sign of a persistent lung-shunt. In two, the bronchi were still very excitable under stress, as with asthmatic sufferers.

Hartig says it's difficult to believe these divers' lungs will heal, and says that after any COVID-19 infection, even after only mild symptoms, divers should definitely be subject to a thorough medical examination. Under no circumstances should former patients dive until fully examined.

As for using gases with elevated levels of oxygen, such as nitrox, some doctors feel this might trigger cascades of symptoms. Hartig reports that patients might come in with low oxygen saturation, and except for an increased respiratory rate, they appear to be fine. After being given two liters of oxygen, that saturation improves, but a few hours later, many are in intensive care with severe lung failure. "It is worrying that it is clear how little we know about this disease," suggests Hartig. "The use of nitrox by divers could be dangerous if the lung tissue is still sensitive."

Max Weinmann, MD, the director of acute Respiratory/COVID ICU at Emory University hospital (Atlanta, GA) and an Undercurrent subscriber, disagrees.

"The statement by Hartig that divers infected by COVID-19 will never be able to dive again due to irreparable lung damage is irresponsible and not based on scientific data. The fact that these cases were sufficiently mild to convalesce and recover at home indicates that at no time did they require supplemental oxygen, hospital care, or mechanical ventilator support. They were mild cases who never required hospitalization. It is not unusual in such situations to have bronchial hyper-reactivity or a 'viral-induced asthma' that can persist for around two months or so and may limit return to diving. This is usually temporary, but it can be distressing in a previously healthy individual. It typically responds to inhalers (bronchodilators, inhaled steroids, etc.) and hence, physician review.

"This is in stark contrast to those patients who develop Acute Respiratory Distress Syndrome, or ARDS. The latter is the condition which typically challenges us here in the ICU with a mortality of up to 50 percent. It is this aggressive systemic inflammatory situation which is associated with both tremendous lung and organ damage. In those patients who recover from ARDS, rehabilitation and healing is indeed prolonged, but lung function has [been] noted to return to near normal over time in up to 75 percent of patients."

In response to people posting on Facebook about the Innsbruck Clinic's findings, Doug Ebersole, an interventional cardiologist in Lakeland, FL, and a technical dive instructor who consults for Divers Alert Network (DAN), wrote: "I would not recommend making any firm conclusions or recommendations based on short-term results of six divers. I would especially refrain from using terms like the damage to the lungs is irreversible when they have only had a few weeks of follow-up.

"Apparently, two divers had exercise-induced hypoxemia while two others had exercise-induced reactive airway disease. They say four still had significant changes on CT scanning, implying that they were sick enough at one time, though apparently not hospitalized, that a physician had ordered a previous CT scan. Finally, any conclusions regarding the effects of increased partial pressures of oxygen in divers who have suffered COVID-19 is purely speculative.

"I would recommend taking the above information with a 'grain of salt' for now while awaiting further data. It is definitely interesting and is thought-provoking. We just need to wait for larger, more controlled studies with longer followup before becoming overly concerned.

"If a diver had a mild case of COVID-19 and is now back to jogging five miles per day without issues, they can probably return to diving without restrictions or further testing. However, if a diver had a prolonged ICU stay from the infection, especially if they required intubation, maybe they should have followup CT scans showing resolution of the changes and maybe even pulmonary function testing prior to resuming diving. Only time -- and, more importantly, data will tell. The Belgian Hyperbaric Medical Society has released some recommendations which are similar to what I stated above."

Ebersole is currently recovering from a COVID-19 infection he caught from a cardiology patient, despite wearing an N95 mask. He says he was lucky -- for him, it was like an extremely bad case of the flu.

The Undersea and Hyperbaric Medical Society has published a statement, which says, in part, "At the present time, we simply do not have sufficient data to support or refute the definitive proclamations made by this case series. Any attempt to generalize the effects of COVID-19 based upon a single case series (6 cases) published in the lay press should be met with appropriate scrutiny.

"The list of potential variables related to how this disease manifests, its clinical course, and long-term prognosis is lengthy and may include factors such as underlying medical conditions, age, disease severity, and secondary complications. Case reports suffer from multiple design weaknesses to include a lack of controls and randomization, which makes any conclusions that we may want to generalize to a larger population suspect. While these findings are indeed disquieting, it will take time before the potential impact on individual health, and any lasting effects on lung or heart function, are captured in the peer-reviewed literature." The full statement can be found here: https://tinyurl.com/yajv6eyf

Jim Chimiak, the Medical Director of Divers Alert Network, told Undercurrent, "COVID-19 shares many features with other serious viral pneumonias and requires a period of convalescence before returning to normal activities. The amount of time needed to recover will vary, as will the long-term effects of COVID-19, such as pulmonary function. As information becomes available, it will be incorporated into COVID-19 prevention, treatment, and follow-up guidelines.

"Determination of your fitness to return to diving after a COVID-19 infection will require assessment by your physician team confirming your full recovery and ability to safely perform unrestricted vigorous activity."

DAN's recommendations can be found here: https://tinyurl.com/yaf4uhjy

A final word from Dan Orr, former President Emeritus at DAN: "We all want to return to the sport we love, and it is always best to do so when and only when you are physically fit to do so. Only time and research will tell when that time is. In the meantime, a cautious and conservative approach is always a good idea."

As Dr. Hartig reaffirms, "At the moment, we are dependent on [different] expert opinions and studies will only be available in a year's time." Undercurrent reached out to Dr. Hartig for further comments, but at the time of writing had received no response.

So, self-isolate, shelter in place, stay home, stay safe . . . and wait for a data-based recommendations to emerge.