Respiratory objectives study guide

1. Upper Airway Disorders

Etiology

  • Viral infections most common (rhinitis, sinusitis, pharyngitis, laryngitis).
  • Bacterial causes less frequent (e.g., peritonsillar abscess).

Pathophysiology

  • Inflammation of mucosal lining → edema, mucus production, epithelial shedding.
  • Sinusitis: obstruction of sinus drainage → mucus stasis → infection.
  • Laryngitis: inflammation of vocal cords from overuse, infection, or irritants.

Risk Factors

  • Viral exposure, allergies, smoking, GERD, voice strain, poor hygiene.

Signs/Symptoms

  • Rhinitis/Sinusitis: congestion, facial pressure, thick mucus, fever, tooth pain.
  • Pharyngitis: sore throat, difficulty swallowing, uvular deviation if abscess.
  • Laryngitis: hoarse or lost voice, dry cough, throat pain.

Complications

  • Periorbital/orbital cellulitis (sinusitis).
  • Peritonsillar abscess (pharyngitis).

Treatment

  • Symptomatic relief (hydration, rest, saline rinses).
  • Antibiotics only if bacterial.
  • Avoid irritants (smoke, yelling).

2. Aspiration Risks

Concept

  • Aspiration = entry of foreign material (food, fluid, vomitus) into lower airway.
  • Can lead to aspiration pneumonia or airway obstruction.

Risk Factors

  • Impaired swallowing (stroke, neuromuscular disease).
  • Depressed consciousness (anesthesia, intoxication).
  • GERD, feeding tubes, elderly.

Complications

  • Pneumonia, lung abscess, ARDS.

3. Bronchitis

Etiology

  • Viral most common (influenza, RSV).
  • Bacterial: Mycoplasma pneumoniae, Chlamydia pneumoniae, Bordetella pertussis.
  • Secondary bacterial infection common in COPD.

Pathophysiology

  • Inflammation of tracheobronchial tree → edema, exudate, narrowed airways.
  • Irritation of bronchial lining → mucus production.

Risk Factors

  • Smoking, COPD, viral exposure, poor immunity.

Signs/Symptoms

  • Cough (productive or dry), wheezing, chest discomfort, fatigue.

Treatment

  • Supportive: rest, fluids, bronchodilators if wheezing.
  • Antibiotics only if bacterial.

4. Atelectasis

Etiology

  • Incomplete alveolar expansion or collapse.
  • Causes: obstruction, surfactant deficiency, compression, fibrosis.

Pathophysiology

  • Collapsed alveoli → ↓gas exchange → hypoxemia.
  • Blood flow continues to unventilated areas → shunting.

Risk Factors

  • Post‑operative immobility, mucus plugs, lung disease.

Signs/Symptoms

  • Dyspnea, cough, anxiety, restlessness.

Treatment

  • Incentive spirometry, ambulation, bronchodilators, treat underlying cause.

Outcomes

  • Reversible if re‑expanded early; prolonged collapse → fibrosis.

5. Shunting

Concept

  • Blood passes through lungs without gas exchange.
  • Occurs when alveoli are perfused but not ventilated (e.g., pneumonia, atelectasis).
  • Leads to hypoxemia resistant to oxygen therapy.

6. Restrictive Disorders

Etiology

  • Conditions limiting lung expansion: atelectasis, pleural effusion, pneumothorax, fibrosis.

Pathophysiology

  • ↓lung compliance → ↓tidal volume → hypoventilation → hypoxemia.

Signs/Symptoms

  • Dyspnea, tachypnea, decreased breath sounds.

Diagnostics

  • FEV1/FVC ratio normal or increased (small volumes, but air exits normally).

Treatment

  • Treat underlying cause (drain effusion, re‑expand lung).

7. Obstructive Disorders

Etiology

  • Airflow limitation due to airway narrowing or obstruction.
  • Includes asthma, COPD (chronic bronchitis, emphysema).

Pathophysiology

  • Air trapping → ↑residual volume → ↓expiratory flow.
  • FEV1/FVC ratio <0.8.

8. Asthma

Etiology

  • Allergens, irritants, exercise, cold air, stress.

Pathophysiology

  • Chronic airway inflammation → bronchoconstriction, edema, mucus.
  • Immune cascade (IgE, mast cells, eosinophils).

Signs/Symptoms

  • Wheezing, dyspnea, chest tightness, cough.

Diagnostics

  • Peak flow meter, pulmonary function tests (↓FEV1/FVC).

Treatment

  • Bronchodilators (albuterol).
  • Corticosteroids.
  • Avoid triggers.

Outcomes

  • Reversible with treatment; chronic inflammation may cause remodeling.

9. COPD (Chronic Bronchitis & Emphysema)

Etiology

  • Smoking, air pollution, alpha‑1 antitrypsin deficiency.

Pathophysiology

  • Emphysema: alveolar wall destruction → air trapping, hyperinflation.
  • Chronic Bronchitis: mucus hypersecretion, airway inflammation.

Signs/Symptoms

  • Emphysema (“Pink Puffer”): dyspnea, barrel chest, clubbing.
  • Chronic Bronchitis (“Blue Bloater”): cyanosis, productive cough, edema.

Diagnostics

  • ↓FEV1/FVC ratio, hyperinflated lungs on imaging.

Treatment

  • Bronchodilators, corticosteroids, oxygen (target SpO₂ 88–92%).
  • Smoking cessation.

Outcomes

  • Progressive, irreversible; may lead to cor pulmonale.

10. Pulmonary Hypertension & Cor Pulmonale

Etiology

  • Chronic hypoxia (COPD, sleep apnea, fibrosis).
  • Left heart disease, pulmonary embolism.

Pathophysiology

  • Hypoxia → vasoconstriction → ↑pulmonary pressure → RV hypertrophy → right‑sided heart failure.

Signs/Symptoms

  • Dyspnea, fatigue, peripheral edema, JVD.

Treatment

  • Manage underlying lung disease, oxygen therapy, diuretics.

11. Obstructive Sleep Apnea (OSA)

Etiology

  • Upper airway collapse during sleep.
  • Central apnea: decreased ventilatory drive.
  • Obesity hypoventilation syndrome: BMI ≥30 + daytime hypercapnia.

Pathophysiology

  • Recurrent obstruction → hypoxia, hypercapnia, arousal → sleep fragmentation.

Signs/Symptoms

  • Loud snoring, gasping, daytime fatigue, morning headaches.

Complications

  • Pulmonary hypertension, systemic HTN, stroke, right‑sided heart failure.

Treatment

  • CPAP, weight loss, avoid sedatives.

12. V/Q Mismatch

Concept

  • V = ventilation, Q = perfusion.
  • Normal ratio = 0.8 (4 L air/min ÷ 5 L blood/min).
  • >0.8: ventilation exceeds perfusion (e.g., pulmonary embolism).
  • <0.8: perfusion exceeds ventilation (e.g., asthma, pneumonia).

Examples

  • Obstructive: asthma, CF, ARDS.
  • Restrictive: atelectasis, pleural effusion, pneumothorax.
  • Perfusion: pulmonary embolism.

13. Tuberculosis (TB)

Etiology

  • Mycobacterium tuberculosis; airborne transmission.

Pathophysiology

  • Bacteria inhaled → alveoli → macrophage phagocytosis → granuloma formation.
  • Latent TB: contained infection, not contagious.
  • Active TB: caseous necrosis, lung destruction, contagious.

Signs/Symptoms

  • Chronic cough, hemoptysis, fever, night sweats, weight loss.

Diagnostics

  • PPD skin test, IGRA blood test, chest X‑ray, sputum culture.

Treatment

  • Multi‑drug therapy (isoniazid, rifampin, ethambutol, pyrazinamide).
  • Isolation until noninfectious.

Outcomes

  • Preventable with early detection and adherence to therapy.

14. Lung Cancer

Etiology

  • Smoking (primary risk factor).
  • Carcinogens → DNA mutations → loss of tumor suppressor function.

Types

  • Small Cell: neuroendocrine tumor, heavy smokers, poor prognosis.
  • Non‑Small Cell (85%): squamous