Pulmonary Disorders & Hypersensitivity Pneumonitis

Restrictive Pulmonary Disorders

• These disorders lead to decreased lung expansion.
• They also cause alterations in functional lung tissue, lung pleura, the chest wall, or neuromuscular functions.
• The two types include pulmonary and extrapulmonary disorders

Characteristics of Restrictive Pulmonary Disorders

• Involve decreased vital capacity
• Involve decreased total lung capacity
• Involve decreased functional residual capacity
• Involve decreased residual volume

Arterial Blood Gas Tests for Restrictive Pulmonary Disorders

• ABGs show decreased O2, normal or decreased CO2, and increased pH (alkalosis).

Interstitial Lung Disease

• Characterized by infiltration of alveolar walls.
• Alveolar cell wall infiltration can be caused by cells, fluids, and connective tissues.
• Infiltration includes acute, subacute, and chronic types.

Diffuse Interstitial Lung Disease

• Characterized by thickening of the alveolar interstitium.
• Begins due to injury to alveolar epithelial cells or capillary endothelial cells.
• Continuous inflammation of the alveoli causes destruction of the alveolar capillaries, thus tissue reorganization and irreversible scarring occur.
• The irreversible scarring and tissue reorganization leads to air-filled sacs and respiratory bronchioles, called honeycomb lung.
• There are three pathological patterns: inflammation, fibrosis, destruction
• Includes Dyspnea as a clinical manifestation.

Symptoms of Diffuse Interstitial Lung Disease

• Irritating, nonproductive cough
• Rapid, shallow breathing
• Nail bed clubbing
• Bibasilar expiratory crackles
• Cyanosis
• Anorexia
• Inability to increase cardiac output with exercise

Diagnosis of Diffuse Interstitial Lung Disease

• Chest x-ray
• Pulmonary functional testing
• Lung and transbronchial biopsy
• Gallium-67 scan
• CT scan

Sarcoidosis

• An acute or chronic systemic disease with idiopathic etiology, thought to be autoimmune.
• Triggers the alveolar macrophages.
• Pathogenesis involves the development of multiple granulomas in multiple organs and abnormal T-cell functionality.

Clinical Manifestations of Sarcoidosis

• Malaise
• Fatigue
• Weight loss
• Fever
• Insidious dyspnea
• Dry and nonproductive cough
• Erythema nodosum
• Macules, papules, hyperpigmentation, subcutaneous nodules
• Hepatosplenomegaly
• Lymphadenopathy

Diagnosing Sacroidosis

• CBC test can show leukopenia, anemia, increased eosinophils
• An elevated sedimentation rate
• Increased blood calcium
• Elevated liver enzymes
• Anergy with a limited response to allergens
• Elevated ACE enzyme
• Gallium-67 scan
• Pulmonary functional testing
• Transbronchial lung biopsy of granulomas

Hypersensitivity Pneumonitis

• A lung disease where the immune system overreacts to inhaled substances.
• Also known as extrinsic allergic alveolitis.
• Usually involves occupational allergens.
• Most dominant in nonsmokers.

Pathogensis of Hypersensitivity Pneumonitis

• Includes a genetic predisposition
• Antigens triggering Type III hypersensitivity reactions
• Antigen-antibody complexes causing hypersensitive granuloma inflammation
• Leads to diffuse pulmonary fibrosis in the upper lobes

Clinical Manifestations of Hypersensitivity Pneumonitis

• Can be acute, intermediate, or chronic
• Acute HP can include chills, sweating, shivering, myalgia, nausea, malaise, lethargy, and headache.
• Intermediate HP includes acute febrile episodes, pulmonary fibrosis with cough, dyspnea, fatigue, and cor pulmonale.
• Chronic HP includes progressive disease.

How to diagnose Hypersensitivity Pneumonitis

• Review the patient history
• Antibody serum test
• Skin testing for allergens
• Pulmonary functional testing
• Chest x-ray
• CBC, can show an increased white blood cell count, decreased O2, and increased sedimentation rate

Occupational Lung Diseases

• Diseases caused by inhalation of toxic gases or foreign particles, or exposure to pollutants.
• Pneumoconiosis is the inhalation of inorganic dust particles that cannot be easily broken down by the body.
• Anthracosis is coal miner's lung from inhaling carbon.
• Silicosis is the inhalation of silica.
• Asbestosis is the inhalation of asbestos.

Pathogenesis of occupational lung diseases

• Destruction or impairment of the pulmonary cilia so debris cannot be cleared.
• Macrophages try to engulf the particles for removal.
• Macrophages secrete lysozymes to control the particle.
• The lysozymes damage the alveolar walls and cause formation of fibrosis.

Clinical Manifestations of occupational lung diseases

• Usually no onset occurs until after years of chronic exposure.
• Progressive productive cough
• Dyspnea with exercise
• Chronic hypoxemia
• Cor pulmonale
• Respiratory failure

Diagnosis of occupational lung diseases

• Chest x-ray
• Pulmonary functional testing
• Arterial Blood Gas test

Pneumothorax

• Accumulation of air in the pleural space.
• The two types of pneumothorax are primary and secondary.
• Primary pneumothorax is spontaneous and occurs in tall, thin men with no underlying disease factors.
• Secondary pneumothorax is a result of complications from preexisting pulmonary disease.

Types of pneumothorax

• Catamenial pneumothorax is associated with menstruation and endometriosis, causing fluid buildup in the right hemothorax.
• Tension pneumothorax results from injury of traumatic origin and is a medical emergency.

Pathogenesis of pneumothorax

• Primary pneumothorax results from the rupture of blebs, allowing air to enter the pleural space which collapses the lung and causing the ribcage to spring outward.
• Secondary pneumothorax results from other underlying lung conditions, or can be a result of a rupture of a bleb.
• Tension pneumothorax results when air enters the pleural space but cannot exit during expiration which forces the lung to collapse and the mediastinum to shift, causing decreased venous return and decreased cardiac output.

Clinical manifestations of pneumothorax

• Tachycardia
• Decreased or absent breath sounds
• Hyperresonance
• Sudden chest pain
• Dyspnea
• Can also cause tracheal shift, neck vein distention, and subcutaneous emphysema

Diagnosis of pneumothorax

• Arterial Blood Gas tests which show Decreased O2 and Acute respiratory alkalosis
• ECG
• Chest x-ray

Pleural Effusion

• The collection of fluid or pus in the pleural cavity from some other disease process.
• The five types of effusion are: transudates, exudates, empyema, hemothorax, chylothorax/lymphatic.
• Transudates include protein and are associated with heart failure.
• Exudates include protein from infections, embolism, postmyocardial infarction syndrome, sarcoidosis, or pancreatic disease.
• Empyema is protein exudate caused by infection.
• Hemothorax includes blood in the pleural space from chest trauma.

Pathogenesis of Pleural Effusion

• Change in pressure affecting hydrostatic pressure, oncotic pressure, and intrapleural pressure.
• Essentially there is a pressure gradient where fluids are being driven from their location into the pleural cavity, since the pleural cavity is lower pressure for some reason.

Clinical manifestations of pleural effusion

• Dyspnea
• Decreased chest wall movement
• Pleuritic pain that worsens with inspiration
• Dry cough
• Absence of breath sounds
• Dullness to percussion
• Tracheal shift

Diagnosis of pleural effusion

• Chest x-ray for observation of densities and infiltrates, signs of chronic heart failure, and fluid location
• Thoracentesis
• CT or ultrasound

Pneumonia

• An inflammatory reaction in the alveoli caused by infection
• The infection is usually from normal bacterial flora or contamination that can enter systemic circulation.
• The there are types of pneumonia are: community acquired, hospital acquired, bacterial, atypical, viral.
• Affects the elderly, those with a limited gag reflex, the seriously ill, hospitalized patients, hypoxic patients, and immunocompromised patients

Types of Pneumonia

• Anaerobic bacterial
• Mycoplasma pneumonia
• Legionnaire's disease
• Pneumocystis jirovecii – fungal
• Aspergillus - fungal

Clinical manifestations of pneumonia

• Crackles
• Chills
• Fever
• Cough
• Purulent sputum

Diagnosis of pneumonia

• Chest x-ray for observation of parenchymal infiltrates
• Sputum tests
• CURB-65 test
• CBC, shows an increased white blood cell count for bacterial infections

Pulmonary Tuberculosis

• Infection caused by the mycobacterium tuberculosis
• Is an acid-fast aerobic bacillus that affects the lungs and lymph nodes
• Transmitted by droplets
• Common in malnourished, immunosuppressed, those living in crowded conditions, incarcerated, and immigrants

Classifications of tuberculosis

• Primary - which may lie dormant
• Reactivating - occurs after primary infection due to impaired immune system: HIV, corticosteroid use, silicosis, diabetes mellitus

Pathogenesis of tuberculosis

• If not destroyed by alveolar macrophages, tuberculosis multiplies and travels through the body through lymphatic dissemination and hematogenous dissemination.

Tuberculosis

Formation of Ghon tubercules is an indicative sign of infection

• Necrotic nodules that are well defined that become fibrotic and calcified

Clinical manifestations of tuberculosis

• Contact with infected person
• Low-grade fever
• Chronic cough
• Purulent sputum
• Night sweats
• Fatigue
• Weight loss
• Malaise
• Anorexia
• Crackles
• Malnourishment

Diagnosing tuberculosis

• Sputum culture
• DNA or RNA amplification
• Pulmonary functional tests
• Chest x-rays for observation of nodules with infiltrates
• Mantoux or PPD test

Explore restrictive pulmonary disorders, including spinal cord injury-induced issues. Learn about their impact on breathing & diagnostic tests for evaluation. Discover Hypersensitivity Pneumonitis (HP), its causes, and immunological mechanisms.