Really interesting article from an emergency physicians who helped 10 days at NYC hospital ICU.
Level 5 expert recommandations
Up to 30% false negative for COVID19 test
If flu-like or covid19 symptoms and tested -
Recommandation to take pulse oximetry for 2 weeks to find out asymptomatic hypoxemia
COVID19 affects surfactant production in lung alveoli, Causing secondary alveoli collapse, CO2 diffusion is not affected so no hypercapnea to increase respiratory drive from ongoing hypoxemia. Patients présents at the emergency department after 7-10 days when they are severely hypoxemic up to 50% blood O2 saturation and need intubation and subsequent high mortality rate.
If you monitor your O2 saturation as soon as you have symptoms you might find out earlier a progressive hypoxemia and have a longer time margin to seek support and try supportive measures earlier to lower lung swelling inflammation and stiffness.