How COVID-19 Kills Patients?
COVID-19 has wreaked havoc across the world since January, infecting more than 4.5 million people in212 countries and killing at least 272,000. It has impacted the world socially and economically. But besides the daily flood of news on coronavirus, a very few people know that COVID-19 mostly kills through an overreaction of the immune system.
A team of experts from Zunyi Medical University recently published a review article in Frontiers in Public Health about the disease pathway, epidemiology, diagnosis, symptoms, and current treatment available for COVID-19. They highlight the role of the potentially lethal overreaction of the immune system in the progression of the COVID-19 disease.
In the review paper, they describe how the virus infects the airways, replicates inside cells, and how it causes the immune system to overshoot with a “cytokine storm” in severe cases. This overreaction of the immune system is caused by the activation of white blood cells, which release a huge amount of inflammation, stimulating cytokines into the blood.
Data show that patients with severe COVID-19 may have cytokine storm syndrome, similar to what happens after the infection of MERS and SARS. This can result in the infiltration of an excess of immune cells like neutrophils and lymphocytes into the lung tissue causing damage to lung tissue.
Excessive weakness of blood vessels, high fever, extremely low blood pressure, lack of oxygen and excess acidity of the blood, blood clotting inside the body, and build-up of fluids in the lungs (“pleural effusion”) can be caused from the cytokine storm.
Failure of heart, lungs, intestines, liver, genitals, and kidney may occur due to the misdirected attack of white blood cells with healthy tissue. The formation of a so-called hyaline membrane, composed of the debris of proteins and dead cells, lining the lungs, may worsen and shut down of the lungs, as it makes absorption of oxygen difficult. And this is mostly how COVID-19 kills patients.
The goal of the treatment should be to fight the symptoms in the absence of a specific antiviral cure for COVID-19. The mortality rate could be lowered through intensive maintenance of the organ function, for example, a renal replacement therapy or an artificial liver blood purification system to filtrate the blood through mechanical means.
Methods to replace or supplement lung function is especially important, for example, ventilation through a tube into the windpipe, administration of heated and humidified oxygen via a tube in the nose (“transnasal high-flow oxygen,” non-invasive mechanical ventilation through a mask or a heart-lung bypass.
It is important to prevent secondary infections also. COVID-19 can cause inflammation and leakiness of gut lining, creating an opportunity for other pathogens to enter. This could be prevented with nutritional support like amino acids and nutrients to improve the function and defense system of the intestine and probiotics that can prevent the entry of harmful bacteria.
Since the current treatment relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition,” concludes Liu.
Editor’s Note; How Covid-19 kills patients, Review Article, Zunyi Medical University, Frontiers in Public Health