Asthma


  • The lungs are made up of progressively smaller airway branches.  Bronchi (airway passages) branch into smaller-diameter passages, called bronchioles.  These in turn branch into even smaller bronchioles.  Oxygen from the air is transported to the blood through the small, thin terminal sacs (alveoli) at the end of the smallest final branches of the airways.
  • Waste products (carbon dioxide) from the blood are also transported outside the body via the alveoli. 
  • Asthma is the result of narrowing, inflammation or mucus plugging of the bronchioles and bronchi.
  • Small muscle bundles, surrounding the bronchioles, can constrict, further narrowing the bronchioles.  When deprived of circulating air, the alveoli can collapse (atelectasis), but this is secondary to the plugging of the bronchioles.
  • If enough airway passges are narrowed or plugged, the asthmatic feels short of breath and cannot move air in and out fast enough to meet the needs of the body. 
  • Many agents (see below) may trigger asthma.  The mechanism of how this specifically occurs is still not clearly understood.  Multiple factors are known to contribute.
  • Agents that treat/improve asthma usually affect a single factor that is interfering with the patency of the bronchioles.  For example:
    1. Beta agonists affect beta receptors on the bronchi and bronchioles, causing the air passages to open.
    2. Corticosteroids decrease inflammation around the air passages.
    3. Anti-leukotrienes prevent local hormones from causing inflammation.

  • Shortness of breath
  • Wheezing
  • Cough
  • Chest tightness
  • Heart racing
  • Rapid breathing
  • Sweating
  • Bluish skin color (cyanosis)

  • Allergy induced (pollens, dust, mites, molds, cigarette smoke, etc.)
  • Exercise induced
  • Bronchitis
  • Gastroesophageal Reflux
  • Congestive Heart Failure (fluid backs up into lungs)
  • Stress
  • Cold air
  • Odors
  • Post-nasal drip
  • Sinus infections
  • Weather changes
  • Beta-blocker medications (e.g., propranolol)
  • Aspirin
  • Nasal polyps & aspirin together
  • Nonsteroidal anti-inflammatories (e.g., ibuprofen)
  • Aerolized pentamadine
  • Other medications
  • Sulfites (additive to food and wine)

  • Examination may show:
    1. Wheezing in lungs
    2. Prolonged time to exhale air
    3. Poor air movement in lungs
    4. Flow meter shows decreased peak airway flow
  • Pulmonary function testing:
    1. Limited airflow especially on exhaling
    2. Worse airflow when given methacholine
    3. Improved airflow with medications to open up bronchi and bronchioles.
  • Laboratory findings (possible occurrences)
    1. Increased eosinophil count
    2. Abnormal arterial blood gas
  • Chest X-Ray usually normal

  • Acute attack:
    1. Short-acting beta agonist inhalers, e.g., albuterol (Proventil, Ventolin)
    2. Corticosteroids, e.g., prednisone
    3. Anticholinergics, e.g., Atrovent
    4. Aminophylline
    5. Oxygen if necessary
    6. Terbutaline
    7. Epinephrine
    8. Isoproterenol (now rarely used)
  • Chronic (preventive) treatment:
    1. Corticosteroid inhalers (e.g., Flovent)
    2. Cromolyn Sodium inhaler
    3. Nedocromil Sodium (Tilade) inhaler
    4. Chronic (preventive) asthma medications usually do not help during an asthma attack.  Do not use them for this!  Contact your physician or get immediate emergency medical care.
    5. Asthma can lead to death.  Seek emergency medical help/advise quickly.

  • Avoid known triggers at work or home.
  • Treatment of underlying causes such as infections, GE Reflux, Congestive Heart Failure, etc.
  • Sinus infections, allergies, and GE Reflux commonly interfere with the treatment of asthma.  Treat these in order to treat the asthma properly.