What your doctor is reading on Medscape.com:
APRIL 21, 2020 — For Luanne Freer, MD, an expert in high-altitude pulmonary edema (HAPE) and founder and director of Everest ER, a nonprofit seasonal clinic at the Mt. Everest base camp in Nepal (elevation, 17,600 ft), a sudden flurry of messages and questions she received about a possible COVID-19/HAPE link was startling.
“That’s why it kind of poked me in the eye,” she said, referencing her extensive experience treating HAPE, which she described as a pressure-related phenomenon. “My goodness, they are so completely different.”
Dr. Freer, an emergency physician, reached out to several pulmonary intensivists with experience treating both HAPE and COVID-19 to gauge their reactions, and within 36 hours, they had drafted their response. In the commentary, published in High Altitude Medicine & Biology, the clinicians note that the comparison between HAPE and COVID-19 is potentially risky.
“As a group of physicians who have in some cases cared for patients with COVID-19 and in all cases cared for patients with HAPE and studied its pathophysiology and management, we feel it important to correct this misconception, as continued amplification of this message could have adverse effects on management of these patients,” they wrote.
The suggestion that COVID-19 lung injury sometimes looks more like HAPE than like acute respiratory distress syndrome (ARDS) appeared in a journal review article in late March and was put forth by medical professionals on social media where it gained traction in recent weeks and was amplified in multiple media outlets, including this one.
“With COVID, we don’t understand everything that’s going on, but we know for sure it’s an inflammatory process – not a pressure-related problem,” Dr. Freer said. “I thought … this could be so dangerous to load the medicines that we use when we’re treating HAPE onto patients with COVID-19.”
The pathophysiological mechanisms in HAPE are different than those in other respiratory syndromes, including those associated with COVID-19, said Andrew M. Luks, MD, of the UW Medicine, Seattle, and the first author on the commentary.
“HAPE is a noncardiogenic form of pulmonary edema, as are ARDS due to bacteria or viral pneumonia, re-expansion pulmonary edema, immersion pulmonary edema, negative pressure pulmonary edema, and neurogenic pulmonary edema,” Dr. Luks, Dr. Freer, and colleagues wrote in the commentary, explaining that all of these entities cause varying degrees of hypoxemia and diffuse bilateral opacities on chest imaging. “Importantly, in all of these cases, edema accumulates in the interstitial and alveolar spaces of the lung as a result of imbalance in Starling forces.”