COVID-19 has become a global pandemic, but some may wonder given most COVID-19 positive patients have only mild or even no symptoms. So what are we  afraid of? To understand the impact that COVID-19 can bring, let us begin with lung haziness.

“Lung haziness” means the appearance of shadows on chest X-ray. Sometimes, the haziness may not be that apparent, and the patient will need to have a computed tomography (CT) of the lungs to look for what is known as “ground glass” appearance. Those with lung haziness most commonly have lung damages, which can lead to shortness of breath, difficulty in breathing and even respiratory failure. Indeed, many of the COVID-19 patients in critical stage are have suffered from this situation. 

Patient with serious condition may need invasive ventilation and with high chance of complications

Once there is lung damage, patients often need oxygen to help them breathe. When a patient is on high concentration oxygen and still cannot maintain a blood oxygen saturation of over 90%, mechanical ventilation might be necessary.

If a patient is able to use non-invasive mechanical ventilation, he could still remain conscious during the treatment. However, if a patient’s condition is critical, or for other reasons that made him not suitable to use non-invasive mechanical ventilation, doctor might have to put in a tube into the patient’s lung and try invasive mechanical ventilation instead.

When a patient is on mechanical ventilation, he needs to be sedated or even anesthetised. Furthermore, there are complications associated with this treatment,such as secondary bacterial pneumonia or pneumothorax (lung burst).

If blood oxygen still cannot be maintained, then we might have to consider ECMO (extracorporeal membrane oxygenation). Also known as the artificial lung, ECMO is a method where oxygen is pumped into a patient’s blood outside his body. It is done through a machine connected via many tubes into the body of the patient. There are  about 20 artificial lungs in public hospitals, and in the beginning of April, Hong Kong has the first COVID-19 patient that had an artificial lung administered. This would be the worst scenario for COVID-19 patient and that’s why people fear of.  

No matter what method we use, the aim is to buy time to let the drugs take effect so that the patient can slowly recover. The patient can then gradually remove the ventilation support and breathe on his/her own.

Complications after recovery

When a patient recovers from COVID-19, will there be long term complications or side effect? From SARS experience, some survivors developed lung fibrosis. With that, a person’s exercise capacity may be reduced, and in more severe cases, they might need  oxygen in long term to help them breathing.

More importantly, we do not know what patients are more prone to lung damage up till this moment.Based on what we know now, it appears elderly and those suffering from chronic diseases are at higher risk. Prevention is better than cure. Rather than worrying about what damages COVID-19 can cause, we should instead focus on minimising the chance of getting infected. The golden rule is to wear mask, perform hand hygiene regularly and maintain social distancing.