Lekcja 7: Kliniczne aspekty chorób układu oddechowego 2 | Clinical Aspects of Respiratory System Diseases 2

Pneumonia

Pneumonia is an infectious inflammation of the lung tissue caused by a variety of pathogens, including bacteria, viruses, fungi, or, rarely, parasites. It leads to fluid accumulation and pus in the alveoli, which interferes with gas exchange, resulting in respiratory distress.

Causes and Types

  • Bacterial Pneumonia: Most commonly caused by Streptococcus pneumoniaeHaemophilus influenzae, and Staphylococcus aureus.
  • Viral Pneumonia: Typically caused by respiratory viruses like influenza, RSV (respiratory syncytial virus), and coronaviruses.
  • Fungal Pneumonia: More common in immunocompromised patients; AspergillusHistoplasma, or Pneumocystis jirovecii are typical pathogens.
  • Aspiration Pneumonia: Caused by inhalation of food, liquid, or vomit into the lungs.

Clinical Manifestations

  • Fever: Often accompanied by chills.
  • Cough: Productive, typically with yellow or green sputum, though it may be dry in viral cases.
  • Shortness of Breath: Breathing difficulty is a hallmark symptom.
  • Chest Pain: Sharp pain that worsens with deep breathing or coughing.
  • Fatigue and Malaise: Due to the body fighting off infection.
  • Confusion in Elderly Patients: This may be the primary symptom in older individuals.

Diagnosis

  • Chest X-Ray: Shows infiltrates or consolidation in the lungs.
  • Blood Tests: Elevated white blood cells, increased C-reactive protein (CRP), and procalcitonin levels.
  • Sputum Culture: Helps identify the causative organism for tailored antibiotic therapy.
  • Pulse Oximetry: Monitors blood oxygen levels, with decreased saturation indicating respiratory compromise.

Treatment

  • Antibiotics: The cornerstone of treatment for bacterial pneumonia. Common agents include macrolides (e.g., azithromycin) or beta-lactams (e.g., amoxicillin).
  • Antivirals: Used in viral pneumonia, particularly for influenza (e.g., oseltamivir).
  • Oxygen Therapy: For patients with hypoxemia to maintain oxygen saturation levels above 90%.
  • Supportive Care: Includes fluids to maintain hydration, antipyretics for fever, and rest.

Complications

  • Pleural Effusion: Accumulation of fluid around the lungs.
  • Sepsis: Systemic infection leading to organ failure.
  • Acute Respiratory Distress Syndrome (ARDS): Severe lung inflammation requiring intensive care.

Pulmonary Embolism (PE)

Pulmonary embolism is a life-threatening condition where a blood clot, often originating from the deep veins of the legs (deep vein thrombosis or DVT), travels to the lungs and blocks a pulmonary artery. This obstruction limits blood flow to the lungs, impairing gas exchange and straining the heart.

Causes and Risk Factors

  • Deep Vein Thrombosis (DVT): The primary source of emboli in PE.
  • Prolonged Immobilization: Long flights, bed rest after surgery, or hospitalization.
  • Hypercoagulable States: Including pregnancy, cancer, and genetic disorders like factor V Leiden.
  • Trauma or Surgery: Especially orthopedic procedures, such as hip or knee replacement.

Clinical Manifestations

  • Sudden Onset of Shortness of Breath: The hallmark symptom, often without warning.
  • Chest Pain: Sharp and pleuritic (worsens with deep breaths).
  • Tachycardia: A rapid heart rate as the body tries to compensate for reduced oxygen.
  • Hemoptysis: Coughing up blood, though less common.
  • Syncope (Fainting): Due to sudden drops in blood pressure.

Diagnosis

  • CT Pulmonary Angiography (CTPA): The gold standard for diagnosing PE, visualizing the clot in the pulmonary arteries.
  • D-Dimer Test: Elevated levels indicate clot formation but are non-specific.
  • Ventilation-Perfusion (V/Q) Scan: Measures airflow and blood flow in the lungs, particularly in patients who cannot tolerate CT contrast.
  • Ultrasound of the Legs: To detect DVT, which often precedes PE.

Treatment

  • Anticoagulation: Initial treatment with heparin, followed by long-term therapy with warfarin or direct oral anticoagulants (DOACs) like rivaroxaban.
  • Thrombolysis: For massive PE causing hemodynamic instability, clot-busting drugs (e.g., alteplase) are administered.
  • Inferior Vena Cava (IVC) Filter: For patients who cannot receive anticoagulation, this filter prevents clots from traveling from the legs to the lungs.

Complications

  • Pulmonary Hypertension: Chronic high blood pressure in the lungs due to unresolved clots.
  • Right Ventricular Failure: The heart’s right ventricle strains to pump blood against the blocked arteries.

Tuberculosis (TB)

Tuberculosis is a chronic bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs but potentially involving any organ. It remains a global health threat, particularly in developing countries.

Causes and Risk Factors

  • Airborne Transmission: TB spreads via inhalation of droplets from an infected person’s cough or sneeze.
  • Weakened Immune System: Conditions like HIV, diabetes, and malnutrition increase the risk.
  • Close Contact with an Infected Person: Especially in crowded environments.
  • Latent TB Reactivation: Latent TB can reactivate, particularly in immunosuppressed individuals.

Clinical Manifestations

  • Persistent Cough: Often lasting for more than three weeks, initially dry but may progress to producing sputum.
  • Hemoptysis: Coughing up blood is a hallmark of advanced disease.
  • Weight Loss: Unintentional and progressive, sometimes referred to as “consumption.”
  • Night Sweats: Profuse sweating that occurs during sleep.
  • Fever and Chills: Low-grade and often accompanied by malaise.

Diagnosis

  • Tuberculin Skin Test (TST): Measures delayed hypersensitivity response to injected tuberculin.
  • Interferon-Gamma Release Assays (IGRA): A blood test that detects TB infection, including latent TB.
  • Sputum Culture and Smear: For acid-fast bacilli (AFB), the gold standard for TB diagnosis.
  • Chest X-ray: Shows characteristic cavitations, particularly in the upper lobes of the lungs.

Treatment

  • Antibiotic Therapy: TB requires a prolonged, multi-drug regimen, typically consisting of isoniazid, rifampicin, pyrazinamide, and ethambutol (for at least six months).
  • Directly Observed Therapy (DOT): Ensures patient compliance by observing medication intake, reducing the risk of drug resistance.

Complications

  • Miliary TB: A disseminated form where the bacteria spread to multiple organs.
  • Drug-Resistant TB: Multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) pose significant treatment challenges.

Interstitial Lung Diseases (ILDs)

ILDs are a group of disorders that cause progressive scarring (fibrosis) of the lung tissue, which impairs the ability to breathe and absorb oxygen. Idiopathic Pulmonary Fibrosis (IPF) is a common example of ILD.

Causes

  • Idiopathic: Most commonly, no clear cause is found (IPF).
  • Occupational Exposures: Long-term inhalation of substances like asbestos, silica, and coal dust can lead to fibrosis (e.g., asbestosis).
  • Autoimmune Diseases: Conditions such as rheumatoid arthritis and scleroderma can cause secondary ILD.
  • Medications: Drugs like amiodarone and methotrexate can induce lung fibrosis.

Clinical Manifestations

  • Progressive Dyspnea: Worsening shortness of breath over time, particularly during exertion.
  • Chronic Dry Cough: Persistent and non-productive.
  • Fatigue and Weight Loss: Often seen in advanced disease.

Diagnosis

  • High-Resolution CT Scan (HRCT): Shows characteristic “honeycombing” and ground-glass opacities.
  • Pulmonary Function Tests (PFTs): Reveal restrictive patterns with reduced lung volumes and diffusion capacity.
  • Lung Biopsy: Sometimes needed to confirm diagnosis, particularly in atypical cases.

Treatment

  • Anti-fibrotic Agents: Medications like pirfenidone and nintedanib slow the progression of fibrosis in IPF.
  • Corticosteroids: Used in inflammatory forms of ILD, but less effective in fibrotic diseases.
  • Immunosuppressive Therapy: In cases of autoimmune-associated ILD, immunosuppressants such as azathioprine or mycophenolate are used alongside corticosteroids.
  • Oxygen Therapy: Prescribed for patients with hypoxemia, especially during exertion or sleep.
  • Lung Transplantation: In advanced cases of ILD, particularly IPF, lung transplantation may be the only option to significantly improve survival and quality of life.

Complications

  • Pulmonary Hypertension: Scarring of the lung tissue increases resistance to blood flow, leading to elevated pressure in the pulmonary arteries.
  • Right-Sided Heart Failure (Cor Pulmonale): Chronic lung disease can lead to failure of the right side of the heart due to increased pressure in the lungs.

Pulmonary Hypertension (PH)

Pulmonary Hypertension is a condition characterized by elevated pressure in the pulmonary arteries, leading to right heart strain and eventual heart failure. It can be primary (idiopathic) or secondary to other lung diseases (e.g., COPD, ILD), heart conditions, or thromboembolic diseases.

Causes and Classifications

Group Type of Pulmonary Hypertension (PH)Description
Group 1Pulmonary Arterial Hypertension (PAH)Idiopathic or associated with connective tissue diseases, HIV, or exposure to drugs/toxins.
Group 2PH Due to Left Heart DiseaseElevated pulmonary pressure secondary to left heart failure or mitral valve disease.
Group 3PH Due to Lung Disease or HypoxiaAssociated with lung conditions like COPD, interstitial lung disease (ILD), or sleep apnea.
Group 4Chronic Thromboembolic PH (CTEPH)Caused by chronic blood clots in the pulmonary arteries.
Group 5PH with Unclear or Multifactorial MechanismsLinked to conditions such as sarcoidosis or chronic kidney disease.

Clinical Manifestations

  • Dyspnea on Exertion: One of the earliest signs, progressing to dyspnea at rest.
  • Fatigue and Weakness: Common as the disease progresses.
  • Chest Pain or Pressure: Often exertional, due to strain on the heart.
  • Syncope: Fainting due to decreased cardiac output.
  • Edema: Swelling of the ankles or abdomen, indicating right heart failure.

Diagnosis

  • Echocardiogram: The initial screening test, showing elevated pulmonary artery pressures and right heart strain.
  • Right Heart Catheterization: The gold standard for measuring pulmonary artery pressure and diagnosing PH.
  • Chest CT or V/Q Scan: Used to rule out chronic thromboembolic disease.

Treatment

  • Vasodilators: Prostacyclins (e.g., epoprostenol), endothelin receptor antagonists (e.g., bosentan), or phosphodiesterase inhibitors (e.g., sildenafil) are used to lower pulmonary pressures in PAH.
  • Anticoagulation: Recommended in patients with CTEPH to prevent further clot formation.
  • Oxygen Therapy: Essential in patients with hypoxia, particularly in Group 3 PH.
  • Diuretics: To manage fluid overload and right-sided heart failure.
  • Lung Transplantation: Considered in severe, refractory cases of PAH.

Complications

  • Right Ventricular Hypertrophy and Failure: Chronic elevation of pulmonary pressures leads to right heart failure.
  • Arrhythmias: Both atrial and ventricular arrhythmias can occur in advanced PH, increasing the risk of sudden cardiac death.

Cystic Fibrosis (CF)


Cystic Fibrosis is a genetic disorder caused by mutations in the CFTR gene, leading to abnormal chloride and sodium transport across epithelial cells. This results in thick, sticky mucus that clogs the airways and ducts in various organs, particularly the lungs and pancreas. It is the most common lethal genetic disease among Caucasians.

Causes and Pathophysiology

  • CFTR Gene Mutation: Defective CFTR protein impairs chloride and sodium transport, resulting in the production of thick mucus that obstructs airways and ducts.
  • Multisystem Impact: CF affects the lungs, pancreas, liver, intestines, and reproductive system, but respiratory complications are the primary cause of morbidity and mortality.

Clinical Manifestations

  • Chronic Cough: Often productive with thick, purulent sputum.
  • Recurrent Respiratory Infections: Particularly with Pseudomonas aeruginosa or Staphylococcus aureus.
  • Wheezing and Shortness of Breath: Due to airway obstruction and bronchiectasis.
  • Failure to Thrive: Poor weight gain and growth in children, often related to pancreatic insufficiency.
  • Clubbing of Fingers: Common in advanced disease, indicating chronic hypoxia.
  • Salty Sweat: A hallmark of CF, due to abnormal sodium chloride handling.

Diagnosis

  • Sweat Chloride Test: The gold standard diagnostic test, showing elevated chloride levels in the sweat (>60 mEq/L).
  • Genetic Testing: Confirms the presence of CFTR mutations.
  • Pulmonary Function Tests (PFTs): Show obstructive patterns with reduced FEV1.

Treatment

  • Airway Clearance Techniques: Chest physiotherapy, postural drainage, and devices like oscillating positive expiratory pressure (PEP) help clear mucus.
  • Inhaled Medications:
    1. Bronchodilators: Alleviate airway constriction.
    2. Mucolytics: Inhaled dornase alfa (Pulmozyme) breaks down mucus, making it easier to expectorate.
    3. Inhaled Antibiotics: Target chronic infections with Pseudomonas aeruginosa.
  • Pancreatic Enzyme Replacement Therapy (PERT): Essential for digestion in patients with pancreatic insufficiency.
  • CFTR Modulators: Newer treatments like ivacaftor and lumacaftor improve the function of the defective CFTR protein in patients with specific mutations.
  • Lung Transplantation: For patients with advanced CF who develop respiratory failure.

Complications

  • Bronchiectasis: Permanent enlargement of parts of the airways due to chronic infection and inflammation.
  • Respiratory Failure: The leading cause of death in CF patients, due to progressive lung damage.
  • Diabetes: CF-related diabetes (CFRD) is common due to pancreatic damage.
  • Liver Disease: Biliary cirrhosis can develop due to blocked bile ducts.