This archive report was first published on 21 April 2020.
As a seasoned doctor, I've seen my fair share of critically ill patients. However, the Covid-19 pandemic has brought a new and alarming trend to our emergency departments. Patients are coming in with low oxygen levels, yet they're not showing the typical signs of distress that we'd expect to see in someone in such a critical condition.
According to my 30 years of practice, most patients requiring emergency intubation are in shock, have altered mental status, or are struggling to breathe. But Covid-19 patients are different. They're often unconscious or using every muscle to take a breath, and yet they're not showing the same level of distress as other critically ill patients.
What's even more concerning is that these patients are using their cellphones as we put them on monitors, despite having dangerously low oxygen levels and terrible pneumonia on chest X-rays. It's as if their bodies are compensating for the low oxygen levels without them even realizing it.
Research suggests that the coronavirus attacks lung cells that produce surfactant, a substance that helps the air sacs in the lungs stay open between breaths. As the inflammation from Covid-19 starts, it causes the air sacs to collapse, leading to low oxygen levels. But what's unique about Covid-19 is that the lungs initially remain 'compliant,' not yet stiff or heavy with fluid. This means patients can still expel carbon dioxide without feeling short of breath.
However, this silent hypoxia can have devastating consequences. Patients compensate for the low oxygen levels by breathing faster and deeper, which causes even more inflammation and air sacs to collapse. This can lead to a second and deadlier phase of lung injury, where fluid builds up and the lungs become stiff, carbon dioxide rises, and patients develop acute respiratory failure.
By the time patients have noticeable trouble breathing and present to the hospital with dangerously low oxygen levels, many will ultimately require a ventilator. It's a stark reminder of the importance of seeking medical attention early on, even if symptoms seem mild.
