Lower Respiratory Tract Disorders

Lower Respiratory Tract Disorders

• Atelectasis:
  • Collapse or closure of alveoli leading to loss of lung volume
  • Types:
    • Absorptive atelectasis: worst scenario in respiratory assessment, occurs due to surfactant ratio imbalance or decreased levels of inhaled nitrogen
    • Compressive atelectasis: external forces compressing on pleural lung tissue
    • Obstructive atelectasis: blockage of air passage to and from alveoli
• Clinical manifestations:
  • Increasing dyspnea, sputum production, cough, fever, egophony
• Risk factors:
  • Surgery, opioid use, abdominal distension, NG tube
• Diagnostic studies:
  • O2 sat, CXR, CT chest, ABGs, Bronchoscopy
• Prevention:
  • Move and ambulate, deep breathing, coughing, incentive spirometer, chest physiotherapy, nebulizer

Pneumonia

• Inflammation of lung parenchyma caused by microorganisms
• Classification:
  • Community-acquired pneumonia (CAP): Streptococcus pneumoniae, risk factors include previous PNA, smoking, household >10 people, contact with children
  • Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP): Enterobacter species, risk factors include prolonged intubation, exposure to antibiotics
  • Healthcare-associated pneumonia (HCAP): nonhospitalized patients with extensive healthcare contact
• Risk factors:
  • Altered LOC, neurological disorders, dysphagia, recumbent positioning, NG tubes, advanced age, mechanical ventilation
• Prevention:
  • High-risk patients: high Fowler's position, early mobilization, deep breathing, coughing, NO straws, thickened liquids, assessing NG tube with CXR

Pulmonary Edema

• Abnormal accumulation of fluid in lung tissue/alveolar space
• Types:
  • Acute pulmonary edema or "Flash Edema": life-threatening
  • Noncardiogenic: ARDS, neurogenic, reexpansion, negative pressure
  • Cardiogenic: left-sided heart failure
• Clinical manifestations:
  • Severe respiratory distress, foamy/frothy blood-tinged sputum, wheezing and crackling in the lungs
• Treatment:
  • O2 therapy, intubation or mechanical ventilation, vasodilators, ACE inhibitors, diuretics, digoxin, opioids

Pleural Effusion

• Abnormal collection of fluid in the pleural space
• Types:
  • Transudate fluid: imbalance of oncotic pressures, nondiseased pleura
  • Exudate fluid: inflammatory bacterial products or tumors; empyemas
• Clinical manifestations:
  • Dyspnea, tachypnea, sharp pleuritic chest pain, decreased/absent breath sounds
• Diagnostic:
  • CXR/CT: similar to cardiogenic pulmonary edema, bilateral patchy infiltrates, and increased alveolar dead space

Chronic Obstructive Pulmonary Disease (COPD)

• Chronic and progressive expiratory airflow limitations
• Pathophysiology:
  • Airflow restriction due to emphysema and chronic bronchitis
• Risk factors:
  • Tobacco, exposure to particles, genetic factors, cooking in poorly ventilated areas
• Clinical manifestations:
  • Dyspnea, chronic cough > 3 months, sputum production, barrel chest, wheezing, pursed lip breathing, digital clubbing
• Management:
  • Stop smoking, exercise, nutrition, PNA/Influenza vaccinations, bronchodilators, inhaled corticosteroids, diuretics, phosphodiesterase-4 inhibitors, alpha-1 replacement therapy, antibiotics, oxygen therapy

Asthma

• Common, obstruction of small airways
• Pathophysiology:
  • Predisposing factors: atopy, female sex
  • Causal factors: indoor/outdoor allergens, occupational
• Clinical manifestations:
  • Worse at night, cough, dyspnea, wheezing, chest tightness, tachycardia
• Management:
  • Patient education, bronchodilators, inhaled corticosteroids, oral steroids, leukotriene receptor antagonists