Asthma

• Facts:
  Reversible airway destruction secondary to bronchial hypersensitivity, airway inflammation, mucous plugging, and smooth muscle hypertrophy
• History / PE:
  Mild hypoxia and respiratory alkalosis (ABG)
  Decreased FEV1/FVC
  Increase in RV and total lung capacity (TLC)
  Eosiniophilia
• Diagnosis:
  Metacholine challenge tests for bronchial hyperresponsiveness
• Complications:
  Severe asthma attack presents with normal to increased PCO2 values (should be low from tachypnea), speech difficulty, diaphoresis, AMS, cyanosis, and 'silent lungs'
• Notes:
  Intermittent
  
  < 2 days/week < 2 nights/month
  FEV1 > 80 %
  No daily medications
  PRN short acting bronchodilator
  
  Mild persistent
  
  > 2 days/week but < 1/day, > 2 nights/month
  FEV1 > 80 %
  Daily low dose inhaled steroids
  PRN short acting bronchodilator
  
  Moderate persistent
  
  Daily symptoms
  > 1 night/week
  60-80 % FEV1
  Low to medium dose steroids
  Long acting inhaled β2 agonists
  
  Severe persistent
  Continual, frequent symptoms
  < 60% FEV1
  High dose steroids
  Long acting inhaled β2 agonists
  Possible PO steroids
  PRN short acting bronchodilator
• See Also:
  Obstructive lung disease
• Associated With:
  Gastroesophageal reflux disease (GERD)