There is an overall increase in the general prevalence of this disease all over the world and in India. Unlike many other diseases such as asthma, hypertension, diabetes, stroke or heart attacks, pulmonary fibrosis is a less well known entity. It requires a lot of understanding to manage the disorder and handle its morbidity. It is therefore important to know the basics of pulmonary fibrosis not only for the patients who suffer but also for their family members and other care-givers.
Pulmonary fibrosis in colloquial language is usually referred to as ‘shrinkage of lungs’ due to reduction in the lung volume. It keeps on progressing as the disease continues. In an advanced stage, the lungs are almost solid – air sacs are replaced by fibrous tissue with lungs giving the appearance of a honey-comb.
The lungs shrink whenever there is scarring of lung tissue due to a variety of diseases and disorders of lung parenchyma. Fibrosis is a pathological term which implies the formation of a scar. Scar formation follows the healing of an infection, inflammation or other form of injury. Pulmonary (or lung) fibrosis results from continued and progressive lung scarring. It generally occurs as the end-result of several different forms of inhalational and/ or immunological injuries of the lungs, collectively known as ‘interstitial lung diseases’ (ILD). Pulmonary fibrosis is also a type of ILD but all ILDs cannot be labeled as pulmonary fibrosis. Pulmonary fibrosis is usually idiopathic (i.e. cause not known or of unknown origin) while a secondary cause or an exposure is generally identifiable in most types of ILDs.
Lung scarring causes distortion and obliteration of lung alveoli as well as reduction in gaseous exchange responsible for oxygen deficiency (hypoxia). The patient develops breathlessness since his/ her lungs are not able to inhale the requisite amount of air, and hence the oxygen. Initially, the breathlessness occurs only on exertion but soon progresses to a stage when even the slightest amount of activity results in breathing difficulty. In an advanced stage, a patient may find it difficult to move out of the bed and later on, even to turn around in the bed.
It is important to emphasize that the diagnosis of pulmonary fibrosis requires to be established by a qualified physician. One must not presume the condition merely on the basis of cough and/ or breathlessness.
The final diagnosis of pulmonary fibrosis is made on the basis of clinical, radiological and histo-pathological findings. Repeated blood investigations, lung function tests and radiology are also required from time to time for follow-up assessments. Repeat biopsy and histopathological examination is not required most of the times unless there is strong indication.
Essentially speaking, it is for the treating physician to make the management-decisions. It is most crucial to decide whether the patient requires anti-fibrotic and/ or anti-inflammatory drugs. Such decisions are made according to the standard treatment-guidelines and clinical criteria. There is no definitive curative treatment of pulmonary fibrosis. Symptomatic and supportive treatment however helps to improve the quality of life. Antifibrotic drugs are shown to slow down the decline of lung function. Wherever appropriate, lung transplantation may be considered.