One of the possible consequences of COVID-19 is pulmonary fibrosis, and it is one of the most worrying long-term complications. This post-COVID complication disease is associated with long term, non-reversible lung dysfunction. This article highlights the diagnosis and management of the disease.

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Introduction

COVID-19 symptoms persist for months; worse, for 59% of patients, the risk of mortality is exacerbated for up to 6 months after infection, according to recent research published in the journal Nature. Ziyad Al-Aly, Yan Xie, and Benjamin Bowe of the Clinical Epidemiology Center, Research and Development Service, Virginia, and Saint Louis Health Care System in the United States conducted the study, which evaluated over 87,000 COVID-19 patients in that nation. Deaths caused by the long-term effects of COVID-19 are not directly attributable to this illness.

However, according to this new research, there were 'eight more fatalities per 1,000 patients over a six-month period'. "Over a six-month period, there were 29 extra fatalities per 1,000 patients among those who were hospitalised and died after more than 30 days. In terms of the entire pandemic death toll, these figures show that the deaths attributed to acute viral infection are merely the tip of the iceberg," senior author Ziyad Al-Aly, MD, stated in a news statement. Given the magnitude of the burden of chronic COVID-19, the disease's lasting consequences will echo for many years, if not decades.

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What are we dealing with?

The World Health Organisation (WHO) declared Coronavirus disease 2019 (COVID-19) a pandemic in March 2020, with the causal agent identified as the new severe acute respiratory illness coronavirus 2 (SARS-CoV-2). Months later, longer-lasting COVID-19 cases began to attract the attention of social support organisations such as the Long Haul COVID Fighters and the Body Politic COVID-19 Support Group.

Initially, physicians disregarded their worries as indicators of mental illness, such as worry- a practice known as 'medical gaslighting'. Early findings indicated a shorter recovery period (e.g., two weeks) for patients with moderate disease and a longer recovery period (e.g., two to three months or longer) for patients with more severe disease. This situation, however, quickly altered. The term long-haul COVID-19 (or post-acute COVID-19) has gained popularity in the scientific and medical sectors in recent years. The rehabilitation process from COVID-19 is a continuous procedure.

1. Acute COVID-19: COVID-19 symptoms lasting up to four weeks after the beginning of the sickness.
2. Ongoing symptomatic COVID-19: COVID-19 symptoms persisting four to twelve weeks after the beginning of the disease.
3. Post-COVID-19: Symptoms that emerge during or following COVID-19 persist for 12 weeks and are not explained by another diagnosis.

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Pathophysiology

The COVID-19 virus is an enclosed virus that infects the host via viral spike proteins. The fusion domain of the spike protein is revealed by the host protease TMPRSS2, which facilitates attachment to the angiotensin-converting enzyme-2 (ACE2) receptor on the host cell. It permits the viral DNA to be released into the host cell via endocytosis. Viruses target the host's cellular machinery in order to proliferate and discharge viral particles extracellularly, infecting nearby cells. The virus is thought to infect a variety of cells in the lungs, including type II pneumocytes and alveolar macrophages.

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Lung fibrosis occurrence post-COVID-19

Acute respiratory distress syndrome (ARDS) develops in 40% of COVID-19 pneumonia patients, with around 20% having severe ARDS. The duration and severity of the illness are important determinants in the development of pulmonary fibrosis after COVID-19 pneumonia. Lung fibrosis was seen in only 4% of patients with illnesses lasting less than one week, compared to 61% of individuals with illnesses lasting more than three weeks.

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Pulmonary fibrosis mechanisms

Several hypotheses for the development of pulmonary fibrosis in COVID-19 include the following:

• Cytokine release syndrome induced by the viral antigen
• Toxic effects of drugs on the lungs and increased airway pressure
• Acute lung damage caused by hyperoxia as a result of mechanical breathing

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Pulmonary fibrosis risk factors

The following are some of the risk factors for pulmonary fibrosis:

• Age
• Disease severity
• The length of time spent in the ICU and the need for ventilator support
• Cigarette use
• Alcoholism that has been present over an extended period of time

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Approaches for mitigating vulnerability

Because of the significant morbidity and low quality of life associated with pulmonary fibrosis, there should be a greater emphasis on risk-reduction efforts. The variables that aggravate the cycle of lung damage, inflammatory response, and fibroproliferation should be targeted using strategies.

1. The use of antiviral and immunomodulatory medicines is one of them.
2. Protective lung ventilation (low tidal volumes and low inspiratory pressures) to reduce ventilator-induced lung damage.
3. Continuous lung damage has long been thought to be a primary contributor to lung fibrosis. As a result, patients should be taught how to reduce their exposure to environmental influences and urged to quit smoking.

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Diagnosis and clinical track

COVID-19 clinical manifestations have spanned from asymptomatic/mild symptoms to severe sickness and death. The majority of mild and moderate patients recovered fully, while a small percentage of severe individuals with acute respiratory distress syndrome remained hypoxemic despite proper care.

There is a scarcity of evidence on the progression of post-COVID pulmonary fibrosis. Research done in Italy (from April to May 2020) looked at residual symptoms in 143 individuals who were released from the hospital after recovering from COVID-19. Patients were evaluated after a mean 60.3 days following the start of the first COVID-19 symptom; at the time of assessment, only 18 (12.6 per cent) were fully free of any COVID-19–related symptoms, while 32 per cent had one or two symptoms and 55 per cent had three or more. There was no fever or other indications or symptoms of acute illness in any of the individuals. In 44.1 per cent of patients, the quality of life had deteriorated.

Another research that followed up on the pulmonary function and associated physiological parameters of COVID-19 survivors three months after recovery involved 55 patients and discovered varying degrees of radiological abnormalities in 39 of them. Numerous investigations have demonstrated that the most prevalent aberration of lung function in discharged COVID-19 survivors is impaired diffusion capacity, followed by restricted ventilatory abnormalities, both of which are related to disease severity.

This group of patients had bronchial alterations such as traction bronchiectasis, architectural distortion, and septal thickening, which were comparable to those reported in other bronchial illnesses.

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Ways to manage fibrosis

Nintedanib and pirfenidone have both been found to reduce disease progression. COVID-19 and IPF have similar demographic characteristics. Autopsy examinations indicated SARS-CoV-2. COVID-19 lung fibrosis requires antifibrotic medications to be beneficial to patients.

India has failed to establish a strong surveillance system for the more than 15 million people who have recovered from the new coronavirus illness (COVID-19). Even though it is abundantly evident that the infection's effects last longer than previously thought.

The government maintains a policy for how and when to discharge a COVID-19-positive individual, as well as when to propose home or hospital care. On this, India adheres to the World Health Organisation's (WHO) guidelines. However, there is no clear strategy for doing health surveillance on persons who have recovered.

Thousands of healed patients are still experiencing lethargy, panic attacks, lung infections, and a variety of other symptoms. While India is presently grappling with the revival because, to an overburdened healthcare system, the healed patients might be the country's next significant health catastrophe.

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Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

The author is a practising super specialist from New Delhi.