Asthma Flashcards
What are the 10 factors that contribute to hyper-responsiveness of the airways in an asthmatic episode?
- Inflammatory cell infiltration (eosinophils, neutrophils, and lymphocytes)
- goblet cell hypertrophy
- mucus hypersecretion
- loss of ciliated epithelium
- mucus hypersecretion
- squamous metaplasia
- destruction of alveolar walls
- peribronchial fibrosis
- airway edema
- mast cell activation
What is the pathophysiology of airflow obstruction? (3)
Airway narrowing –> decreased resistance
Loss of elastic recoil of the lungs
Inflammation of airways
Which cells are involved in the inflammation responsible for asthma?
mast cells, macrophages, eosinophils, T-cells, epithelial cells
What is the mast cell’s involvement in asthma?
They initiate arousal condition in IgE receptors
What is the eosinophil’s involvement in asthma?
releases granular protein that damages bronchial epithelium and promotes airway hyperresponsiveness
What are the lymphocytes’ involvement in asthma?
produce cytokines, leukotriene B4, C4, prostaglandin and histamine
Describe how leukotrienes are involved in the inflammation of asthma
Leukotrienes are potent inflammatory mediators.
They increase vascular permeability (edema), increase mucus production, decrease mucociliary transport, and recruit other inflammatory cells. One leukotriene, LTD4 is a potent bronchoconstrictor.
Is the primary problem in asthma inflammation or bronchospasm?
Inflammation. Bronchspasm occurs secondary to inflammation.
Which class of medications work by relaxing the smooth muscle of the bronchioles?
beta 2 agonists, for example albuterol
The four characteristics of asthma
reversible airflow obstruction
variable and recurring symptoms
bronchial hyper-responsiveness
underlying inflammation
List some nonspecific asthma triggers
exercise, URI’s, rhinosinusitis, postnasal drip, aspiration, GE reflux, changes in weather, stress, tobacco smoke, ozone, Tartrazine dye, aspirin, non-steroidal anti-inflammatory drugs
What are the four main symptoms of asthma?
coughing
wheezing
SOB
possible seasonal or diurnal variations
note: symptoms typically occur with exposure to a trigger and resolve in its absence
What are 5 associated symptoms of asthma
tachypnea/tachycardia/systolic hypertension
audible harsh respirations/prolonged expiration/wheezing
sputum production
chest pain or tightness
could have diminished breath sounds during an acute attack
What time of day is asthma typically worst?
3-4am. Cortisol is lowest between 3-4 in the morning. Eosinophils are most active and highest. Pollen counts also highest at that time.
What are some possible findings on the physical exam?
nasal mucosal swelling nasal polyps increased nasal secretions eczema atopic dermatitis wheezing or prolonged expiration changes in body posture (tripod) accessory muscle use fragmented speech pattern
What are the four “pillars” of asthma diagnosis?
- history (intermittent symptoms and family history of asthma, allergies, or atopy)
- signs and symptoms suggestive of asthma
- confirmation of variable expiratory airflow limitation, preferably by spirometry
- exclusion of alternative diagnosis
Name three category types of diagnostic testing for asthma
- pulmonary function testing
- chest x-ray
- skin testing
name three types of pulmonary function testing for asthma
spirometry, peak flow, and bronchial provocation testing
How do we use spirometry in asthma diagnosis?
We order it before and after use of a bronchodilator.
The test must demonstrate reversibility of symptoms.Reversibility demonstrated by increase in FEV1 ≥ 12% and 200 mL OR ≥ 15% or 200 mL in FVC
What is bronchial provocation testing?
Methacoline, an irritant is used to try to induce an asthmatic episode for diagnostic purposes. Here, we want to see if the FEV 1 falls by 20% or more. That would be a positive test, and a positive diagnosis for asthma.
Alternatively, one could try to provoke asthma by exercise on a treadmill in the office.
Describe a peak flow meter.
It is not used to diagnose asthma. It is used to track asthma symptoms. it is an inexpensive and portable device. It measures how fast air comes out of the lungs with forceful exhalation after inhaling fully. This measures the peak expiratory flow.
How is a peak flow meter helpful in managing asthma?
- Determines degree of airflow limitation
- learning asthma triggers
- determines if the asthma action plan is working
- adjusting medications
- knowing when to seek emergency care
- Having an objective measurement of the pts. pulmonary status at the time. (some patients have less awareness of their degree of impairment.
What are some questions to ask an asthmatic patient to assess degree of control or severity of symptoms
- in the past year have you taken oral glucocorticoids for your asthma?
- have you been hospitalized for your asthma? intubated? How many hospitalizations in the past year?
- How many ED visits for asthma have you had in the last year?
- Do you smoke?
- Any increase in asthma symptoms after taking aspirin or NSAIDS?
- What is your normal peak flow?
- Does your asthma wake you up at night or early in the morning?
- Have you needed your quick acting relief medication more than usual?
- Have you needed any unscheduled care for your asthma, including calling in, an office visit, or going to the emergency room?
- Have you been able to participate in school/work and recreational activities as desired?
- If you are measuring your peak flow, has it been lower than your personal best?
What are the four components of asthma management?
- Routine monitoring of symptoms and lung function
- patient education
- control of triggers and comorbid conditions
- pharmacologic therapy
