1. Pathophysiology
   1. Bronchoconstriction in the trachea, bronchi, and bronchioles.
      1. Airway walls dilate and leak secretions, oedema, adding to the overall narrowing and hyper-responsiveness of the airway.
         1. The epithelium becomes damaged and starts to shed creating a hyper-sensitive airway exposing of sensory nerves, allowing the penetration of allergens, and breaking down inflammatory mediators.
            1. Unmyelinated afferent fibers in combination with peptide neurotransmitters can induce smooth muscle or bronchospasm.
            2. Mast cell degranulation leads to vasoactive mediators increasing vasodilation and capillary permeability while chemotactic mediators increase cellular infiltration with the over-production of neutrophils, eosinophils, and lymphocytes.
            3. An abnormal narrowing and hypersensitive, congested airway.
            4. Bronchospasms create a quick and sharp contraction of the bronchial smooth muscle adding to the overall narrowing of the airway.
            5. As asthma progresses and is left untreated or not properly managed, the structure of the airway can be remodeled leading to permanent fibrotic damage changing the structural cells and tissues in the lower respiratory tract.
            6. The chronic remodeling of the airway is what characterizes chronic asthma.
   2. Around 100 different identified genes have been show to play a role in the susceptibility and pathogenesis of asthma.
      1. Frequent factors that can increase a genes expression of asthma that include exposures to air pollution, smoke or tobacco products, recurrence of upper respiratory infections, gastroesophageal reflux disease, and obesity.
      2. These genes show expression in asthma patients can often be based off age and irritant exposure.
      3. Influence the production of interleukin-4, interleukin-5, immunoglobulin E, eosinophils, B-adrenergic receptors, and mast cells.
2. Epidemiology
   1. United States has a 4-8% prevalence rate with more boys affected than girls.
   2. Genetics or familiar history can play a significant role in diagnosis.
   3. 7 million Children in America.
   4. Asthma effects as many as one third adolescents in some countries.
   5. Boys are more frequently effected that girls.
   6. Around 10% of children in the U.S. between the ages of 5 -17.
3. Reference
   1. American Lung Association, (2016). Asthma Action Plan. Lung Health & Diseases. Retrieved from http://www.lung.org/assets/documents/asthma/asthma-action-plan.pdf.
   2. American Lung Association, (2016). How is Asthma Diagnosed? Lung Health & Diseases. Retrieved from http://www.lung.org/lung-health-and-diseases/lung-disease lookup/asthma/diagnosing-treating-asthma/how-is-asthma-diagnosed.html
   3. American Lung Association, (2016). Learn about Asthma. Lung Health & Diseases. Retrieved from http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/asthma/learn-about-asthma/
   4. Gierer, S. (2014). An Update in Asthma Diagnosis and Management. The University of Kansas Hospital. Retrieved from http://www.kansasdo.org/download/springconf2014/Presentations/Gierer-Asthma.pdf.
   5. Huether, S.E. & McCance, K. L. (2012). Understanding pathophysiology (Laureate custom ed.). St. Louis, MO: Mosby.
   6. McPhee, S. J., & Hammer, G. D. (2010). Pathophysiology of disease: An introduction to clinical medicine (Laureate Education, Inc., custom ed.). New York, NY: McGraw-Hill Medical.
   7. Pollart, S. (2011). Management of Acute Asthma Exacerbations. American Family Physician. 84(1):40-47. Retrieved from http://www.aafp.org/afp/2011/0701/p40.html
   8. Zimbron, J. (2008). Mind maps—Dementia, endocarditis, and gastro-oesophageal reflux disease (GERD) [PDF]. Retrieved from http://MedMaps.co.uk
4. Risk Factors
   1. Environmental
      1. Dust Mites
      2. Pollen and Spores
      3. Cockroach
      4. Cats
      5. Air pollution
   2. Genetic
      1. More common in ethnic minority populations
      2. African American
      3. Hispanic
   3. Infections
      1. Respiratory syncytial virus (more common in children less than 2)
      2. Rhinovirus
   4. Dietary - Vitamin D deficiency
5. Clinical Presentation
   1. Infants
      1. Head bobbing
      2. Wheezing
      3. High pitched sounds
      4. Increase heart rate and respiratory rate
      5. Retractions
         1. Substernal
         2. Subcostal
         3. Intercostal
         4. Suprasternal
         5. Sternocleidomastoid
      6. Quiet lung sounds - late sign
      7. Blue lips/ fingernails - late sign
      8. Hyperinflation - late sign
   2. Asthma has a considerable spectrum in severity of symptoms based off of symptoms and frequency of exacerbation (Chronic vs. Acute)
      1. Intermittent
      2. Mild Persistent
      3. Moderate Persistent
      4. Severe Persistent
   3. Children
      1. Air movement
         1. High pitched/ Musical sounds
         2. Soft/ Quiet (late signs)
      2. Pulsus paradoxus
      3. Anxiety
         1. Diaphoretis
         2. Short sentences
      4. Wheezing
         1. Tightness in chest
         2. Shortness of breath
      5. Blue lips/ fingernails
      6. Hyperinflation - Barrel chest
      7. Prolongation of the expiratory phase
      8. Increase heart rate and respiratory rate
      9. Waking at night with symptoms
6. Diagnosis
   1. Most episodes of wheezing are proceeded by a viral respiratory infection (about 70-80%)
   2. Identification of underlying triggers or infection
   3. Comprehensive Assessment
      1. It is essential to assess the severity of the symptoms by establishing how often they occur.
      2. Whether signs and symptoms are cause nocturnal waking or exercise limitation.
   4. Clinical Manifestations
      1. Confirmed by a worsening of symptoms.
         1. Wheezing
         2. Shortness of Breath
         3. Chest tightness
         4. Frequent cough
   5. Pulmonary function tests
      1. Pulse Oxygen Level test
      2. Spirometery
      3. Low Expiratory Flow Rates (i.e. Peak Flow)
      4. Test Exhaled Nitric Oxide
      5. Consider chest X-ray
   6. Labs
      1. Respiratory alkalosis
      2. Hypoxemia
      3. Hypercapnia
   7. Other
      1. Sensitivity to Allergens
      2. Parental recall of symptoms
      3. Atopic Dermatitis
7. Treatments
   1. Medications
      1. Anti-inflammatory medications
      2. Inhaled corticosteroids
      3. Short- acting, beta-agonist
      4. Use Albuterol/Levalbuterol
      5. Steroids
   2. Other
      1. Asthma Control Test - allows a clinician to monitor how well current treatments are working.
      2. Peak Flow meters
      3. Chronic asthma cases tends to have persistent and prolonged effects that is not responsive to medications.
      4. Education
         1. Knowledge of Asthma Action Plan
         2. Knowledge on when and what medications to take
         3. Knowledge on medication administration techniques
         4. Knowledge and avoidance of irritants
   3. Avoidance of irritants
      1. Environmental
      2. Infections
      3. Dietary / Maintain Vitamin D Levels