EMPHYSEMA CAUSES SYMPTOMS AND TREATMENT!!!

EMPHYSEMA

DEFINITION

 Emphysema is characterized by permanent enlargement of the air spaces distal to the terminal bronchioles, accompanied by destruction of their walls without significant fibrosis.

It is one of the diseases that make up COPD . It is mostly caused by smoking and other reasons also which cannot be diagnosed.

EPIDEMIOLOGY

The prevalence of emphysema in the U.S is about 14 million.

There has been an increase in the cases of emphysema in the recent years due to the increase in the number of smokers.

Another factor that plays role is environmental pollution and sometimes genetic factors also come into play.

PATHOPHYSIOLOGY

Inhaled cigarette smoke and other noxious particles cause lung damage and inflammation, which, particularly in patients with a genetic predisposition, result in parenchymal destruction (emphysema) and airway disease (bronchiolitis and chronic bronchitis).

Factors that influence the development of emphysema include the following 

1. Inflammatory cells and mediators: A wide variety of inflammatory mediators have been shown to be increased (including leukotriene B4, IL-8, TNF, and others) that attract more inflammatory cells from the circulation (chemotactic factors), amplify the inflammatory process (proinflammatory cytokines), and induce structural changes (growth factors). 

2. Protease–anti-protease imbalance: Several proteases are released from the inflammatory cells and epithelial cells that break down connective tissues. 

3. Oxidative stress: Reactive oxygen species are generated by cigarette smoke and other inhaled particles and released from activated inflammatory cells such as macrophages and neutrophils. These cause additional tissue damage and inflammation

4. Airway infection: Although infection is not thought to play a role in the initiation of tissue destruction, bacterial and/or viral infections cause acute exacerbations.

5. Protease-mediated damage of extracellular matrix has a central role in the airway obstruction seen in emphysema. Small airways are normally held open by the elastic recoil of the lung parenchyma, and the loss of elastic tissue in the walls of alveoli that surround respiratory bronchioles reduces radial traction and thus causes the respiratory bronchioles to collapse during expiration.

CLASSIFICATION

It is classified according to its anatomic distribution within the lobule. There are four major types of emphysema:

(1) centriacinar

(2) panacinar,

(3) distal acinar, and 

 (4) irregular. 

Only the first two types cause clinically significant airway obstruction, with centriacinar emphysema being about 20 times more common than panacinar disease.

CENTRIACINAR OR CENTRILOBULAR EMPHYSEMA

The distinctive feature of centriacinar (centrilobular)emphysema is the pattern of involvement of the lobules: The central or proximal parts of the acini, formed by respiratory bronchioles, are affected, while distal alveoli are spared.

Thus, both emphysematous and normal air spaces exist within the same acinus and lobule.

The lesions are more common and severe in the upper lobes, particularly in the apical segments.

This type of emphysema is most commonly seen as a consequence of cigarette smoking in people who do not have congenital deficiency of α1-antitrypsin

PANACINAR OR PANLOBULAR EMPHYSEMA

In panacinar (pan lobular) emphysema, the acini are uniformly enlarged, from the level of the respiratory bronchiole to the terminal blind alveoli.

panacinar emphysema tends to occur more commonly in the lower lung zones and is the type of emphysema that occurs in α1-antitrypsin deficiency.

DISTAL ACINAR OR PARASEPTAL EMPHYSEMA

In distal acinar (paraseptal) emphysema, the proximal portion of the acinus is normal but the distal part is primarily involved.

Predisposes to spontaneous pneumothorax

Adjacent to foci of fibrosis

Least common

IRREGULAR EMPHYSEMA

Irregular emphysema, so named because the acinus is irregularly involved, is almost invariably associated with scarring, such as that resulting from healed inflammatory diseases.

It is although clinically asymptomatic, this may be the most common form of emphysema.

Common around scar tissue

CLINICAL FEATURES

Dyspnea

Weight loss

Cough with or without expectoration

Wheezing

Hypercapnia

Hypoxia 

Barrel chest

Death from emphysema occurs due to:

1. Pulmonary failure 

2. Respiratory acidosis

3. Hypoxia

4. Coma

5. Cor pulmononale( right sided heart failure)

CONDITIONS RELATED TO EMPHYSEMA

Several conditions resemble emphysema only superficially such as:

Compensatory emphysema

Obstructive over inflation

Bullous emphysema

Mediastinal (interstitial) emphysema

DIAGNOSIS

1. PFT

2. HRCT

3. Chest X Ray

4. Arterial blood gases analysis

5. Sputum examination

6. Alpha1 antitripsin serum levels

7. Complete blood count

8. Radiographic finding

DIFFERENTIAL DIAGNOSIS

The disease presents with nonspecific symptoms, and hence, it has broad differential diagnoses. These include:

• Chronic obstructive asthma

• Chronic bronchitis with normal spirometry

• Cystic fibrosis

• Bronchopulmonary mycosis

• Central airway obstruction

• Bronchiectasis

• Heart failure

• Tuberculosis

• Constrictive bronchiolitis

• Anemia

• Complications

• Pulmonary hypertension

• Cor pulmonale

• Chronic respiratory failure

• Spontaneous pneumothorax

TREATMENT

There is no known, definitive treatment that can modify the disease process. However, risk-factor modification and management of symptoms have been proven effective in slowing the disease progression and optimizing the quality of living.

Based on the symptoms and number of exacerbations, we can divide the disease into 4 COPD GOLD stages and modify the treatment accordingly.

1. Medical therapy

2. Supportive therapy

3. Interventional therapy

4. Management of a Patient with COPD Exacerbation.

just a short information on emphysema