Idiopathic Pulmonary Fibrosis - Symptoms, Complications, Investigations, and Treatment

Introduction:

Idiopathic pulmonary fibrosis refers to the specific form of chronic, irreversible scarring of the lungs resulting in stiffness and breathing difficulty. This disease usually affects mid-aged people of ages ranging from 50 to 70. Idiopathic pulmonary fibrosis belongs to a group of conditions known as interstitial lung diseases, which include both the inflammation and scarring of the lungs.

What Are the Signs and Symptoms of Idiopathic Pulmonary Fibrosis?

The clinical manifestations of idiopathic pulmonary fibrosis are non-specific and similar to pulmonary and cardiac diseases. The symptoms may include:

• Low-grade fever.

• Weight loss.

• Arthralgias.

• Fatigue.

• Myalgias.

• Non-productive cough.

• Dyspnea (on exertion).

• Prevalence of obstructive sleep apnea.

• Clubbing.

• Scarring or fibrosis of lung tissue increases gradually, resulting in the lack of oxygen in the body.

What Are the Complications of Idiopathic Pulmonary Fibrosis?

Patients with idiopathic pulmonary fibrosis may present with the following complications, and these include:

• Pulmonary hypertension.

• Respiratory infection.

• Acute exacerbation of pulmonary fibrosis.

• Acute coronary syndrome.

• Adverse medication effects.

• Thromboembolic disease.

• Lung cancer.

What Are the Investigatory Procedures of Idiopathic Pulmonary Fibrosis?

Laboratory Findings:

• The results of laboratory studies are considered to be non-specific, but some laboratory studies may help in ruling out the causes of interstitial lung diseases.

• The high titer values of antinuclear antibodies suggest the presence of connective tissue disease. About 30 % of patients with idiopathic pulmonary fibrosis test positive for rheumatoid factor or antinuclear antibodies with no records of high titer values.

• Both the values of C-reactive protein and erythrocyte sedimentation rate are elevated in patients with idiopathic pulmonary fibrosis.

• Though hypoxemia is a common finding in idiopathic pulmonary patients, polycythemia is found to be rare in laboratory studies.

Imaging Studies:

• Chest Radiography:

  • The chest radiography reveals abnormal radiograph findings at the time of diagnosis.
  • Peripheral reticular opacities (netlike linear and curvilinear densities) are more common in the base of the lungs. The honeycomb pattern (coarse reticular pattern) is the distinguishing radiological finding, and lower lobe loss is also noticed.

• High-Resolution Computed Tomography:

  • High-resolution computed tomography findings reveal patchy, subpleural, peripheral, and bibasilar reticular opacities.
  • These findings are a more specific, sensitive, and important component in the diagnosis of idiopathic pulmonary fibrosis.
  • Reticular opacities appear as a fine network of lines that include interlobular septal thickening and intralobular lines.
  • The severely affected areas are involved with reticular markings, which also demonstrate traction bronchiectasis.
  • Subpleural honeycombing appearance is a characteristic feature of idiopathic pulmonary fibrosis.
  • Ground glass opacities can also be found but appear less compared to reticular abnormalities.
  • The subpleural honeycombing, thickened interlobular septae, and traction bronchiectasis findings obtained from high-resolution computed tomography increase the specificity for diagnosing idiopathic pulmonary fibrosis.

Pulmonary Function Testing:

• The restrictive ventilatory defect and a reduced diffusion capacity for carbon monoxide are the typical findings of pulmonary tests with idiopathic pulmonary fibrosis.

• These findings are non-specific and used in reference to radiologic, clinical, and pathological details to achieve an accurate diagnosis of this condition.

• In patients with idiopathic pulmonary fibrosis, pulmonary functions like functional residual capacity, total lung capacity, vital capacity, and forced vital capacity activities are decreased.

• The obstructive ventilatory defects are not common; if present, it is suggestive of chronic obstructive pulmonary disease.

• In addition, the diffusion capacity of carbon monoxide is also decreased to a greater extent in this condition.

Six-Minute Walking Test:

• This test is an indicator of functional exercise capacity that is performed during the initial and longitudinal clinical assessment of patients with idiopathic pulmonary fibrosis.

• Patients showing desaturation levels of less than 88 % during a six-minute walking test and a decline in diffusion capacity of carbon monoxide reveal a strong prediction of increased mortality.

Bronchoalveolar Lavage:

• The use of bronchoalveolar lavage in the diagnosis of idiopathic pulmonary fibrosis is limited.

• The findings reveal that there are an increased number of neutrophils in bronchoalveolar lavage fluid in about 70 to 90 % of patients and an increased number of eosinophils in about 40 to 60 % of patients with idiopathic pulmonary fibrosis observed, respectively.

• This test is used to eliminate other alternative diagnoses.

• Bronchoalveolar lavage fluid neutrophilia value is determined in the prediction of early mortality.

Transthoracic Echocardiography:

• In 20 % to 40 % of patients, pulmonary hypertension is present at rest approximately.

• Transthoracic echocardiography is an excellent method to detect pulmonary hypertension. Reports suggest that variable performances are determined by thoracic echocardiography in patients with chronic lung disease, including idiopathic pulmonary fibrosis.

How to Treat Idiopathic Pulmonary Fibrosis?

Medical Care :

• The primary objective of any treatment plan includes the proper assessment and treatment of associated comorbid medical conditions. Common medical conditions associated with idiopathic pulmonary fibrosis include chronic obstructive pulmonary disease, gastroesophageal reflux disease, obstructive sleep apnea, and coronary artery disease. The treatment modalities should be managed accordingly.

• These patients with a positive history of smoking are strictly advised to quit smoking, and drug therapy is provided if necessary.

• Oxygen supplementation therapy should be administered in patients with severe hypoxemia at rest or with exercise to manage the oxygen saturation of 90 % at rest and with exertion.

Palliative Care:

• Early palliative care should be recommended, along with disease-focused care in idiopathic pulmonary fibrosis.

• Palliative care refers to psychological support, patient and caregiver involvement, symptom management, and spiritual support.

• By providing excellent palliative care, the prognosis and mortality rate have been decreased.

• In the absence of this support, more patients with severe or final-stage lung diseases die in the critical care environment.

Lung Transplantation Therapy:

• Lung transplantation is only the final choice of treatment based on the severity and the disease progression.

• Certain guidelines are followed for the evaluation to perform lung transplantation procedure:

• A decrease in pulse oximetry below 88 % during a six-minute walk test.

• Honeycomb appearance on high-resolution computed tomography.

• The diffusion capacity of carbon monoxide is less than 39 %.

• A continuous or greater level of decrement in forced vital capacity during six months of follow-ups.

Conclusion:

Patients with idiopathic pulmonary fibrosis can survive three to five years after their diagnosis. But the course of the disease is highly variable; some people may become seriously ill within a few months, and others may live more than a decade or longer. Only a few cases of idiopathic pulmonary fibrosis appear to run in families. An interprofessional team approach is necessary for the proper diagnosis and timely management of the disease.