upper respiratory tract

Lower Respiratory Tract Disorders

• Atelectasis: collapse/closure of alveoli leading to loss of lung volume
  • Acute vs chronic
  • Commonly seen on CXR
  • Types:
    • Absorptive Atelectasis: worst scenario in respiratory assessment, occurs by surfactant ration or decreased levels of inhaled nitrogen
    • Compressive Atelectasis: external forces compress on pleural lung tissue (e.g., pleural effusion, lung tumor, pneumothorax, hemothorax, abdominal distension)
    • Obstructive Atelectasis: blockage that impedes passage of air to and from alveoli (e.g., secretions, mucus plugs, airway tumors, foreign body)
• 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

Pneumonia

• Pneumonia in immunocompromised patient:
  • Patients receiving immunosuppressive drugs, corticosteroids, broad-spectrum antibiotics, AIDS, genetic immune disorders, etc.
  • Types: Pneumocystis Pneumonia (PCP), Fungal, TB
• Clinical manifestations: fever, cough, dyspnea, leukocytosis
• Treatment: antibiotics based on type of pneumonia

Pulmonary Tuberculosis

• Caused by Mycobacterium tuberculosis
• Airborne transmission
• Patho: initial infection 2-10 weeks after exposure
  • Granulomas form, become necrotic and dormant
  • Primary TB: clinically silent
  • Miliary TB: spread of TB via lymph and blood to other parts of the body
• Clinical manifestations: low-grade fever, fatigue, night sweats, cough, stiff neck
• Risks: born/lived in country with high TB rate, comorbidities, low-income, homeless, overcrowded housing, healthcare workers, immunocompromised
• Diagnostic test: Mantoux test (tubercle bacillus extract injected into forearm to form a bleb)

Aspiration

• Inhalation of foreign body material into lungs
• Can lead to PNA, hypoxia, or death
• Caused by acute inflammatory response in lung parenchyma, blockage of airway, or secondary infection
• Risk factors: altered LOC, neurological disorders, dysphagia, recumbent positioning, NG tubes, advanced age, mechanical ventilation
• Prevention: high-risk patients - high Fowler's position, 30-45 degree HOB, early mobilization, deep breathing and coughing, no straws, thickened liquids, assess NG tube with CXR

Pulmonary Edema

• Abnormal accumulation of fluid in lung tissue/alveolar space
• Acute pulmonary edema or "Flash Edema" = life-threatening
• Non-cardiogenic: ARDs, neurogenic, re-expansion, negative pressure
• Cardiogenic: L-sided heart failure
• Clinical manifestations: severe respiratory distress, foamy/frothy blood-tinged sputum, wheezing and crackling in the lungs (may be audible), confusion, tachycardia
• Treatment: O2 therapy, intubation or mechanical ventilation, vasodilators, ACE inhibitors, diuretics, digoxin, opioids

Pleural Effusion

• Abnormal collection of fluid into pleural space
• Normal amount: 20-25 mL
• Usually secondary to other conditions (e.g., HF, PNA, Cancer, Ascites)
• Transudate fluid: imbalance of oncotic pressures, non-diseased pleura
• Exudate fluid: inflammatory bacterial products or tumors; empyemas
• Clinical manifestations: dyspnea, tachypnea, sharp pleuritic chest pain, decreased/absent breath sounds
• Primary: no underlying lung disease
• Secondary: underlying lung disease

Acute Respiratory Distress Syndrome (ARDS)

• Severe form of acute lung injury with absence of L-sided heart failure
• Needs mechanical ventilation with higher than normal airway pressures
• Diffuse alveolar injury and pulmonary capillary injury
• B/L infiltrates
• Sudden progressive pulmonary edema
• Severe hypoxia refractory to supplemental oxygen
• Risk factors: sepsis, GERD, high fatty or spicy fluids, nasal polyps, stress, weather changes, menstrual cycle, and strong emotions

Asthma

• Patho: predisposing factors (atopy, genetic predisposition), causal factors (indoor/outdoor allergens, occupational), contributing factors (respiratory infection, air pollution, smoking, diet, premature birth)
• Clinical manifestations: worse at night, can occur suddenly or over several hours, cough, dyspnea, wheezing, chest tightness, tachycardia
• Management: patient education, know triggers and early sx, bronchodilators, inhaled corticosteroids/oral steroids, leukotriene receptor antagonists