What is the treatment for pulmonary fibrosis after COVID-19?

Treatment for Pulmonary Fibrosis After COVID-19

Pulmonary rehabilitation is the primary recommended treatment for post-COVID-19 pulmonary fibrosis, combined with corticosteroids for patients with persistent symptoms and abnormal CT findings. 1

Diagnosis and Assessment

• Diagnosis of post-COVID pulmonary fibrosis is based on:
  • Persistent respiratory symptoms (cough, dyspnea, exertional dyspnea) lasting at least 12 weeks after COVID-19 diagnosis 2
  • Abnormal chest CT showing fibrotic changes
  • Pulmonary function tests showing restrictive pattern and reduced diffusion capacity
  • Functional impairment (desaturation on exertion)

Treatment Algorithm

First-Line Treatment: Pulmonary Rehabilitation

1. Pulmonary rehabilitation should be initiated as soon as possible for patients with severe COVID-19 1

   • Combined exercise (aerobic with strength training)
   • Specific respiratory exercises
   • Respiratory muscle training

2. Breathing exercises and techniques:

   • Breathing control techniques (high side lying, forward lean sitting)
   • Pursed lip breathing and square box breathing
   • Appropriate walking pace regulation to prevent oxygen desaturation 1

3. Traditional Chinese Medicine exercises (if available):

   • Baduanjin
   • Tai-chi
   • 6-character breathing exercise 1

Pharmacological Treatment

For patients with persistent symptoms, functional/physiological abnormalities, and parenchymal abnormalities on CT:

1. Corticosteroids:

   • Initial dose: 0.5 mg/kg prednisolone for 3 weeks 1
   • Has shown significant improvement in symptoms, gas transfer, forced vital capacity, and radiologic findings in small studies 1

2. Traditional Chinese Medicine decoctions (if available):

   • Based on syndrome differentiation following the therapy strategy of "reinforcing earth (spleen) to strengthen metal (lung), eliminating phlegm to dredging collaterals" 1
   • Shown to improve chest x-ray manifestations of pulmonary fibrosis, total lung capacity, and diffusion capacity 1

3. Antifibrotic agents:

   • Currently being tested in clinical trials (nintedanib and pirfenidone) 1
   • Recent evidence suggests pirfenidone may not provide significant benefit over placebo after 6 months of treatment 3

Supportive Care

• Long-term oxygen therapy for patients with persistent hypoxemia 4
• Education on resuming daily activities at an appropriate pace 1
• Gradual increase of exercise based on symptoms 1

Risk Factors for Post-COVID Pulmonary Fibrosis

• Older age
• Severe COVID-19 requiring ICU care
• Mechanical ventilation
• Chronic comorbidities
• Female sex 2, 5

Monitoring and Follow-up

• Regular assessment of pulmonary function tests
• Follow-up chest CT to evaluate fibrotic changes
• Oxygen saturation monitoring, especially during exertion
• Discharge criteria should include:
  • Temperature returned to normal for more than 3 days
  • Respiratory symptoms significantly improved
  • Significant absorption of pulmonary chest lesions on CT imaging
  • Two consecutive negative nucleic acid tests from respiratory tract samples (at least 24 hours between samples) 1

Important Caveats

• Most patients with post-COVID pulmonary changes show improvement over time, with significant recovery often occurring within the first year 6
• Approximately 20% of patients may experience progression of fibrosis over 5-10 years, based on data from SARS 6
• The overall incidence of post-COVID lung fibrosis is estimated at 2-6% after moderate illness 6
• There is currently insufficient evidence to recommend any specific pharmacological intervention with high certainty 1

Pulmonary rehabilitation remains the cornerstone of treatment, with corticosteroids considered for patients with persistent symptoms and abnormal imaging findings. The management should be adjusted based on the severity of fibrosis and patient response to treatment.