Pulmonary Emphysema: Epidemiology, Pathology and Treatment

What is it, and what does it consist of?

It is defined as the permanent increase of air spaces distal to the terminal bronchioles, which are accompanied by the destruction of the alveolar wall and without evident fibrosis.

Emphysema is one of the entities grouped in chronic obstructive pulmonary disease. The emphysema is better evaluated in tomographies, although in the proportion of cases, indirect signs can be observed in conventional radiography.

Emphysema is a type of chronic obstructive pulmonary disease. The air sacs in the lungs are damaged and stretched, resulting in a chronic cough and shortness of breath.

Smoking is the most common cause, but emphysema can also be genetic. There is no cure, but quitting can stop the worsening of the disease.

In the United States, 3.5 million people, or 1.5 percent of the population, received a diagnosis of emphysema in 2016. The number of deaths from emphysema was 7,455, or 2.3 people per 100,000.

Facts about emphysema

Here are some critical points about emphysema:

 

  1. Most cases of emphysema are due to smoking.
  2. Shortness of breath and cough are the main symptoms of emphysema.
  3. Doctors diagnose COPD and emphysema with pulmonary function tests that measure lung capacity.
  4. The treatment includes medications, an inhaler, respiratory assistance, and possibly surgery.
  5. Treatment does not stop or reverse lung damage, but it can relieve symptoms and prevent attacks.
  6. Vaccines can help prevent other diseases that could become dangerous and emphysema.

Epidemiology

Approximately 210 million people are affected worldwide, with 3 million deaths annually. It is predominantly a disease that occurs during half of life due to the cumulative effect of smoking and other environmental risk factors.

Traditionally, it affects more men than women, but with greater exposure to smoke and environmental risk factors among women, the incidence is now equal between the sexes.

According to the phenotype, patients with genetic risk factors such as alpha-1-antitrypsin deficiency may develop this disease earlier.

Risk factor’s

  • Smoking: passive smoking is the most common.
  • Alpha-1 antitrypsin deficiency.
  • Intravenous injection of methylphenidate (Ritalin).

Clinical presentation

The clinical features of emphysema should be distinguished from the signs and symptoms of chronic bronchitis. Patients with emphysema are hypercapnic and may have a pink coloration on the skin. This compares with the cyanosis of chronic bronchitis and patients referred to as “blue.” In practice, the characteristics of these two syndromes coexist as chronic obstructive pulmonary disease.

Signs of emphysema include:

Patients usually report dyspnea without significant sputum production.

  • Tachypnea.
  • Absence of cyanosis.
  • Breathing with pursed lips.
  • Hyperinflation of the chest.
  • Reduction of respiratory sounds.
  • Living with a great noise.
  • Cor pulmonale.

Pathology

Emphysema is one of a heterogeneous group of pathological processes that form chronic obstructive pulmonary disease and is itself a relatively vague term encompassing several entities and morphological patterns, including:

Morphological subtypes:

Centrilobular emphysema (most common).

  • Emphysema panlobular.
  • Paraseptal emphysema.
  • Parametric emphysema
  • Localized emphysema.
  • Idiopathic giant bullous emphysema (or pulmonary syndrome).
  • Congenital lobular emphysema
  • Pulmonary interstitial emphysema

The three morphological subtypes of emphysema are named according to their relation to the secondary pulmonary lobe.

Centrilobular emphysema is the most common type and affects the proximal respiratory bronchioles, particularly the upper areas. It is strongly associated with the habit of smoking.

Panlobular emphysema, in contrast, affects the entire secondary pulmonary lobe and is more pronounced in the lower areas, coinciding with areas of maximum blood flow.

It is seen mainly in alpha-1-antitrypsin (AAT) deficiency (exacerbated by smoking), intravenous injection of methylphenidate (Ritalin), or Swyer-James syndrome.

Paraseptal emphysema affects the peripheral parts of the secondary pulmonary lobe and is usually located adjacent to the pleural surfaces (including pleural fissures). It is also associated with smoking and can lead to subpleural bullae and spontaneous pneumothorax formation.

Tests and diagnosis

A doctor will perform a physical examination and ask the patient about his symptoms and medical history.

Some diagnostic tests may also confirm that the patient has emphysema instead of asthma and heart failure.

If the patient has never smoked, a test can be performed to see if the person has an α1-antitrypsin deficiency.

Treatment and prognosis

The treatment of COPD and emphysema aims to stabilize the condition and prevent complications through medication and supportive therapy. Supportive therapy includes oxygen therapy and helps to quit smoking.

Unfortunately, once the lung tissue is lost, it does not occur again. Therefore, the treatment is supportive and aims to preserve the remaining lung parenchyma.

The interventions include:

  1. Give up smoking.
  2. Oxygen therapy (in chronic hypoxemia).
  3. Control of symptoms and exacerbations.
  4. Short-acting and long-acting beta-2 agonist drugs.
  5. Inhaled anticholinergics.
  6. Inhaled glucocorticoids.
  7. Antibiotics
  8. Pulmonary rehabilitation.

In patients with severe bullous alteration with compression resulting from normal lung parenchyma, pulmonary volume reduction therapy may be considered in selected patients.

Lung transplantation is considered in cases of alpha-1 antitrypsin deficiency.

The prognosis is worse in patients who continue to smoke, are deficient in alpha-1-antitrypsin, have low FEV1 at diagnosis, or have other comorbidities (e.g., heart failure, respiratory failure, frequent exacerbations).

Treatment of exacerbations

Complications can be managed using medication and oxygen therapy. Antibiotics can help in cases of bacterial infection.

Most exacerbations are treated with corticosteroids, such as prednisone and oxygen therapy.

Opioid drugs can relieve intense cough, and pain can be reduced with opioids.

In 2014, scientists at the University of Texas Medical Branch in Galveston achieved the growth of human lungs using stem cells. This could offer hope for people with emphysema and other lung conditions in the future.