definition * populaton
Etiology & Onset
Work of Breathing
Complications, Prognosis








  • I.    Definition:  A severe airway disorder characterized by hyperactive airways that result in severe airway obstruction due too
    • A)    Constricting and bronchospactic airways
    • B)    Swelling airways
    • C)    The pouring of secretions into the lumen of airways
  • II    Population:
    • A)    Children
      • 1)    5-10% effected in the United States
      • 2)    Most frequent cause of hospitalization in the United States among children
      • 3)    Effects 1 in 12 school children
    • B)    Adults
      • 1)    3-5% effected in the United States
      • 2)    Half of the adult asthma patients effected before the age of 10
  • III  Etiology:  The exact etiology of the disease is unknown, but several participating factors have been identified.
    • A)    Allergens
      • 1)    Molds
      • 2)    Pollens
    • B)    Outdoor irritants
      • 1)    Smoke
      • 2)    Air pollution
    • C)    Indoor irritants
      • 1)    Animal dander
      • 2)    Dusts
    • D)    Exercise
    • E)    Viral infections
    • F)    Foods
    • G)    Emotions
    • H)    Aspirin
  • IV Onset
    • A)    Sudden onset
      • 1)    Higher amounts of neutrophils and less eosinophils in airway mucosa
    • B)    Slow onset
      • 1)    More common
      • 2)    Possible different mechanism of action for sudden onset
  • Pathophysiology:  
    • A)Can be broken down into two phases
      • 1)    Allergic
        • a)    Triggering stimuli (Listed above) of airways rupture or degranulate mast cells
        • b)    Mast cells release chemical mediators including histamine, leukotrienes, eosinophilic chemotactic factor of anaphylaxis, and prostaglandins.
        • c)    These mediators promote bronchospasm, vasodilatation, edema, increased secretions, and accumulation of eosinophils.
      • 2)    Inflammatory  phase
        • a)    Mediators are released by eosinophils, neutrophils, macrophages, and lymphocytes.
        • b)    These mediators initiate the inflammatory response of the airways.
    • B Work of Breathing
      •     1) Inhalation
        • a)  Resistance increases
        • b)  Ventilation and perfusion mismatches increase
        • c)  Arterial blood gasses diminish
        • d)  Patient status deteriorates
      •     2)  Exhalation
        • a)  Narrowing of airways causes air trapping and an increased FRC
        • b)  The patient must exert an increasing amount of intraplural pressure to maintain normal tidal volume, increasing patient fatigue.
      •     3)    V/Q mismatching leads to hypoxemia
        • a)    Hypoxemia causes the patient to hyperventilation and become hypocarbic
        • b)    Hypocarbia limits conservation of bicarbonate by the kidney which leads to metabolic acidosis
      •     4)    Derangement of both cardiovascular and metabolic function
        • a)    Patient becomes dehydrated due to
          • i)    A decreased ability to take fluids
          • ii)    A increased metabolis rate from tachypnea and possible fever
        • b)    The patient experiences lactic acidosis due to
          • i)    Hypoxemia
          • ii)    Dehydration
          • iii)    Increased metabolism due to tachypnea
      •    5)    Respiratory failure
        • a)    As the patient becomes exhausted maintaining ventilation, PaCo2 begins to rise causing the patient to enter acute respiratory failure
  • VI. Diagnosis
        • Family history of allergy and asthma
        • Child’s symptoms
          •     Coughing wheezing  shortness of breath or rapid breathing  chest tightness
          • Frequency and severity of the child’s symptoms
        • Medications the child is using
      • 2. PHYSICAL EXAM
        • Wheezing (may or may not be present)
        • Hyperexpansion of the thorax, use of accessory muscles, tachypnea
        • Presence of other allergic diseases
        •     atopic dermatitis/eczema                            
        • swelling of and/or pale nasal mucosa                                
        • clear nasal discharge
        • Spirometry for children > 4 years of age
          •     FEV1, FVC, FEV1/FVC
        • Presence of ANY indicators from the history and physical examination
      • 1    Initial diagnosis and determination of severity
      • 2    Ongoing monitoring and management
      • 3    Components of assessment
        • a    Medical history
        • b   Physical assessment
        • c   Objective measures of pulmonary function
      • 1    Physician usually will be the primary historian
      • 2    Therapist history
        • a.    less “formal”
          • i.    “What do you think made you have to be admitted to the hospital?”
      • 3    use information to assess educational needs
      • 4    Family history of asthma and allergy
        • a    Patient’s symptoms
          • i.    When do symptoms occur?
          • ii.    What causes symptoms (triggers)?
          • iii.    What makes symptoms worse?
          • iv.    Frequency and severity of symptoms
          • v.    Do symptoms limit physical activity?
          • vi    Do symptoms interfere with sleep?
          • vii    Do symptoms interfere with school performance or activities
          • viii    ER visits or hospital admissions needed?
          • ix    Medication usage
          • x    What and how much?
      • 1    Indicators of respiratory distress and severity
        • a    Respiratory Rate
        • b   Use of accessory muscles
        • c    Breath sounds
        • d Respiratory rate
        • e    Increased respiratory rate is a reliable indicator of respiratory distress
        • f    “Norms” and acceptable ranges are age dependent
        • g Accessory Muscle Use
        • h    None with no distress
        • i    Intercostal and tracheosternal retractions with moderate distress
        • j    Retractions and ­ accessory muscle use (particularly sternocleidomastoids) with severe distress
        • k Breath Sounds
        • l    Expiratory wheezes with mild exacerbation
        • m    Inspiratory / expiratory wheezes             with more severe exacerbation
        • n    “Silent chest” is ominous sign
        • o    Aeration may be decreased locally or throughout
        • p    Absence of wheezing does not rule out asthma (cough may be the only symptom) 
      • 1 Spirometry
        • a    Airflow obstruction indicated by ¯ FEV1 and FEV1/FVC relative to predicted values
        • b    Significant reversibility is indicated by an increase of at least 12% and 200 ml in FEV1 post short-acting bronchodilator. 
        • c. Indications for Spirometry
        • d    Initial diagnosis
        • e    Periodic assessment  (every 1 - 2 years)
        • f Peak Expiratory Flow (PEF)-long term monitoring
        • g    To evaluate response to changes in therapeutic regime
        • h    Primarily a measure of large airway function
        • i    Published reference values vary widely and according to brand of meter
        • j    Valuable as a serial measurement related to patient’s PERSONAL BEST (PB) or predicted
        • k    PB is the highest peak flow number a patient can achieve over a 2 - 3 week period with his/her asthma under good control
        • l    PEF variability (%) is a factor in asthma severity
        • m. Peak Flow Monitoring
        • n    PEF may be useful for any child (generally over 5 years of age)
        • o    Particularly recommended for patients with
        • p    poor symptom perception
        • q    moderate to severe asthma
        • r    history of severe exacerbation
        • s    Part of daily routine
        • t    Every morning , before taking medications, or
        • u    In the morning and late afternoon or evening; > 20% difference between measurements suggests inadequate control
        • v    When having symptoms of an attack (and after taking medications for the attack)
  • VIII Asthma Treatment:
    • A. Avoid Triggers (see prevention)
    • B. Oxygen
    • C. Heliox (80/20 mix of helium/oxygen)
    • D. Drugs:
      • 1. Sympathomimetics (Beta 2 Adrenergic Agonists)
        • Method of action: cause bronchodilation, inhibit mast cell degranulation, reduce permeability of pulmonary vasculature, and improve mucociliary transport of secretions.
        • Examples: epinephrine, isoproterenol, isoetharine (these have been show to cause tremors, palpitations, and anxiety), bitolterol, metaproterenol, terbutaline, fenoterol, albuterol, pirbuterol, carbuterol, procaterol, salmeterol xinafoate and formoterol.
        • Action mainly in the small innervated peripheral bronchioles and therefore should be given second.
        • b. Beta 2-adrenergic sites
        • Bronchodilation
        • Inhibit mast cell degranulation
        • Reduce permeability of pulmonary vasculature
        • Improve mucociliary transport of secretions
      • 2. Parasympatholytics (Anticholenergics)
        • Method of action: actively bind to muscarinic receptors (antagonist of nerve impulses) and block transmission of nerve impulses.
        • Examples: atropine, glycopyrrolate, ipratopium bromide, and oxitropium bromide.
        • Action mainly in the large airways and therefore should be given first.
      • 3. Corticosteroids
        • Method of action: suppress the release of inflammatory mediators and reversal of airway hyperactivity.
        • Examples: beclomethasone dipropionate, fluticosone, trimcinolone acetonide, funisolide, and budenoside.
      • 4.    Xanthine
      • 5.    Antibiotics
      • 6.    Cromolyn sodium and Nedacromil Stabilize mast cells and prevent degranulation
    • E. Fluid administration
    • F. Humidification
  •   IX Prevention
    • A. Avoid the following precipitating factors that lead to an asthma attack:
      • 1. Allergens
      • 2. Molds
      • 3. Pollens
    • B. Outdoor Irritants
      • 1. Smoke
        • a. especially prenatally
      • 2. Air pollution
      • 3. Molds and Fungi
    • C. Indoor Irritants
      • 1.    Animal danders
        • a. If you must have a pet in the house:
          • i.  wash them often
          • ii.  keep them out of the asthmatics room
      • 2. Dusts
        •     a. dust mites
          • i.  found in mattresses, pillows, sheets and stuffed animals
          • ii. to prevent dust mites wash the above items with hot water often
      •       3. Cockroaches
        •   a. to prevent cockroaches:
          • i.   keep a clean house
          • ii.  do not leave food out
          • iii. place traps
      •       4. Molds and Fungi
        • a. to prevent molds from growing:
          • i.  fix leaky pipes
          • ii. clean areas with bleach
    • D. Exercise
      •      1. take meds prior to exercising
    • F. Cold Air
      •     1. wear a scarf around nose and mouth
    • E. Viral Infections
      •       1. RSV
    • F. Foods
    • G. Emotions/Stress
    • H. Aspirin and related drugs
    •  I* Other methods important in preventing asthma attacks: patient compliance to medications, use of preventative medications, use of spacer with MDI’s, use of proper technique when taking MDI’s and nebs, and patient education.
Links to Asthma Related Resources On-Line    
Professional Parent's Children's

National Institute for Health Information
National Institute for Health Guide
AAAAI Inflamation
CDC/NCHS statistics
Merck Asthma Guide
NLM/NIH Medline Guide
American Academy Pediatrics ASTHMA

ASTHMA for Palm Pilot

Virtual Hospital ASTHMA

WebMD asthma in children
WebMD asthma in pregnancy
Parent Guide No-Attacks
American Lung Guide
Alergy Buyers Guide
Pediatric on-call ASTHMA in Children

Merck Asthma Guide

CDC Health topics for kids
U Virginia Asthma Guide
bronchus gif animation

ASTHMA tube image
American Lung Sesame St

Merck Asthma Guide