Post-COVID Symptoms in Respiratory System

A few individuals develop long-term clinical residua following acute coronavirus 2019 (COVID-19) infection, sometimes persisting for months. Officially called post-acute sequelae of SARS-CoV-2 (PASC), it more commonly is referred to as “Long COVID (LC).”.

Postviral syndromes are defined as the sustained presence of symptoms after an acute viral infection. These symptoms can vary in severity; another good example other than COVID is the Epstein-Barr virus (human herpesvirus 4) which causes infectious mononucleosis. The symptoms can linger for weeks or even years.

Long Covid has not been officially defined, but the unique features of COVID may shed some light. Many people experience fatigue, loss of taste and smell, loss of memory, difficulty with orthostasis or dropping their blood pressure upon standing, cardiac dysrhythmias, and shortness of breath. This article aims to explore long-term respiratory insufficiency after COVID infection.

What happened to my lungs during my COVID infection?

The incidence of viral pneumonia has increased over the past decade in part to influenza and now COVID. Virulent organisms, such as the delta strain of SARS-CoV-2, can cause varying degrees of illness, from mild and self-limiting to life-threatening, causing respiratory failure.

X-rays typically demonstrate bilateral lung involvement, but there are no hard, fast rules on the appearance of radiography. On chest X-rays, many patients with COVID pneumonia can have a whitish or ground-glass appearance at the bases of the lungs.

It is widely accepted that the COVID virus, like most respiratory viruses, multiplies in the epithelium or top layers of the upper airway and secondarily infects the lung using airway secretions or spreads through the blood. Severe infections can result in extensive consolidation of the lungs, and diffuse damage to the small air sacs called alveoli.

In the case of COVID pneumonia, it is likely the overexuberant inflammation from the robust immune response is the mainstay of the pathologic process. Respiratory viruses damage the respiratory tract and stimulate the host to release various humoral or immunologic factors, which can take a long time to resolve.

What are the symptoms of lingering COVID?

Both children and adults can suffer from post-COVID symptoms for up to 3 months. Those who suffer for prolonged periods are considered to have LC (long COVID).

Although COVID-19 primarily affects the lungs, it can also damage many other organs, including the heart, kidneys, and brain, which is not apparent until weeks after infection. Patients with organ damage can suffer from long-term respiratory illness, such as heart complications, kidney impairment, stroke, and other neurological disorders.

How can I tell if my symptoms are from COVID or my hospitalization?

The short answer is you cannot tell. If you were unfortunate enough to become sick enough for hospitalization, you likely experienced severe weakness, exhaustion, and respiratory failure. Effects of hospitalization for long COVID can result in post-intensive care syndrome, which occurs after a person has required an intensive care unit (ICU) setting.

Patients suffering from COVID pneumonia but do not need the ICU or hospitalization can still have long COVID. The key to recovery appears to be time and supportive care. Even those who slowly recover from their shortness of breath or chest pain can struggle with chronic fatigue, headache, trouble sleeping, trouble concentrating, muscle and joint pain, and persistent cough.

How is chronic fatigue defined?

Chronic Fatigue Syndrome, also called Myalgic Encephalomyelitis, has considerable overlap with long COVID. Many patients have these symptoms along with respiratory ones such as shortness of breath, cough, difficulty with exertion, and chest pain.

The three required symptoms are:

1. A reduction or impairment of greater than 50% in the ability to perform at pre-illness levels of essential work-related, educational, social, and personal activities.
2. Post-exertional malaise—worsening of symptoms after physical, mental, or emotional exertion that was not experienced before the onset of the current changes.
3. Unrefreshing sleep—patients may not feel better or less tired even after a full night of sleep despite the absence of specific objective sleep alterations.

At least one of the following two additional manifestations must be present:

1. Cognitive impairment—patients have problems with thinking, memory, executive function, and information processing, as well as attention deficit and impaired psychomotor functions.
2. Orthostatic intolerance—patients develop a worsening of symptoms upon assuming and maintaining upright posture as measured by objective heart rate and blood pressure abnormalities during standing, bedside orthostatic vital signs, or head-up tilt testing.

What is the prognosis for my lungs after COVID?

In general, patients who recover from viral pneumonia have a good prognosis. It is more guarded in those who have immunocompromise or are elderly.

Some viruses, such as adenovirus and COVID, can cause serious chronic morbidity after an acute respiratory illness. There can be irreversible lung changes seen on chest radiography, meaning permanent lung damage. Fortunately, this is not common for most patients.

It is possible, however, that viral pneumonia from COVID may leave patients with residual disability from what is called interstitial fibrosis. This is a general term for scarring (fibrosis), making breathing difficult and getting oxygen difficult. Again, this is not that common, fortunately.

Most patients with COVID pneumonia recover. The hope is that the lungs will return to normal like after smoking which is known to take ten years or more. There just has not been enough time since the pandemic began.

There are some investigational drug trials for long COVID that are worth mentioning: Leronlimab (CytoDyn), RSLV-132 (Resolve Therapeutics), Zofin (Organicell Regenerative Medicine), and Ampion (Ampio Pharmaceuticals). The references are listed below.