The main symptom in patients with novel coronavirus pneumonia is a dry cough with little sputum. If there is a lung infection, CT reveals a lung shadow, which is an exudate in the lung. Usually all types of pneumonia require a focus on sputum drainage, and once there is sputum, the sputum can expel inflammatory secretions with pathogens and the inflammation in the lungs can improve as quickly as possible. The reason why the new coronavirus is particularly prone to evolve into a severe or critical illness is mainly because of the difficulty in expelling sputum from the patient’s lungs. Autopsy reveals the presence of large amounts of mucus in the lungs of patients with new coronavirus, which is extremely viscous. Therefore, patients have difficulty expelling the sticky sputum. Expulsion of sputum is the top priority in the treatment of pneumonia. If sputum can be expelled, it does not affect oxygen uptake and does not trigger respiratory failure. Patients with viral pneumonia usually do not easily eliminate sputum, which cannot be expelled, making it difficult to inhale oxygen and only increasing oxygen flow. However, as the exudate gradually increases, it will resist the increased flow rate and make it difficult to take in oxygen even with a ventilator. Patients who are particularly critical will eventually need to use extracorporeal membrane oxygen therapy, or ECMO therapy. Content source: Dr. You Lai