Asthma

Question 1

Asthma

Answer 1

A chronic inflammatory disorder of the airways characterized by:
- recurring symptoms
- airway obstruction (reversible spontaneously or with treatment)
- bronchial hyper-responsiveness to stimuli
Most common chronic childhood illness
Major cause of school absenteeism, visits to emergency, and hospital admissions

Question 2

Incidence

Answer 2

1-2 kids in 10 children
More common in boys (until adolescence), then trend reverses
80-90% have symptoms before 4-5 years
2 main types
- recurrent wheezing in early childhood; usually precipitated by viral infections (RSV)
- chronic asthma associated with allergy persisting into later childhood & often adulthood

Question 3

Classification of Asthma, ages 5-11 years: Step 1

Answer 3

Intermittent Asthma:
- symptoms < 2 days/week

Question 4

Classification of Asthma, ages 5-11 years: Step 2

Answer 4

Mild Persistent Asthma
- symptoms > 2 times/week, but < once/day

Question 5

Classification of Asthma, ages 5-11 years: Step 3 or 4

Answer 5

Moderate Persistent Asthma
- daily symptoms

Question 6

Classification of Asthma, ages 5-11 years: Step 5 or 6

Answer 6

Severe persistent Asthma
- symptoms several times a day

Question 7

Purpose of Step Classification for Asthma

Answer 7

provides stepwise approach to pharmacologic management, environmental control & educational interventions needed at each step

Question 8

Etiology

Answer 8

Multifactorial - biochemical, genetic, immunologic, environmental, infectious, endocrine, & psychological factors
Allergy influences persistence& severity of disease -> atopy (IgE - mediated respones to common aeroallergens) is strongest identifiable predisposing factor for developing asthma
BUT: 20-40% have no evidence of any allergic disease and still acquire asthma

Question 9

Risk Factors (8)

Answer 9

atopy (including hx of allergies or atopic dermatitis)
heredity (e.g., parent/sibling)
Gender (boys > girls until adolescence then girls > boys)
Smoking or exposure to second-hand smoke
Maternal smoking during pregnancy
Ethnicity (african-american at greatest risk)
Low birthweight
Being overweight

Question 10

Examples of Triggers

Answer 10

Allergens - trees, shrubs, grasses, pollens, air pollution, dust mites, dust, pollens, mould, smoke, sprays
Occupational chemicals
Physical exercise
Cold air
Weather or temperature changes
Environmental change
Cold & infections - viral or bacterial
Animals - cats, dogs, rodents, horses
Medications - aspirin, NSAIDS, antibiotics
Strong emotion - fear, anger, laughing, crying
Foods - nuts, milk, diary
Conditions - GER, TEF
Endocrine factors - menses, pregnancy, thyroid disease

Question 11

Pathophysiology

Answer 11

Initial release of inflammatory mediators from bronchial mast cells, macrophages, & epithelial cells
Migration & activation of other inflammatory cells
Alterations in epithelial integrity & autonomic neural control of airway tone
Increase in airway smooth muscle responsiveness -> wheezing, dyspnea, & eventual obstruction
Mast cells release histamine which leaks into the airway and then the more severe reaction starts -> brochospasm, airway is getting close and mucus is being produced

Question 12

Pathophysiology - Obstructive Symptoms

Answer 12

Inflammation & edema of mucous membranes
Accumulation of tenacious secretions from mucous glands
Spasm of smooth muscle of bronchi & bronchioles -> decreases caliber of bronchioles
Could be mucus plugging the alveoli
Two mainstays of treatment: first one deals with diameter of the airway - something to relax the bronchospasm (beta 2 agonist - salbutamol or ventolin)
second one: anticholinergic to clear the mucus (atrovent or ipratropium)

Question 13

What causes an asthmatic episode?

Answer 13

some asthma triggers are exercise, infection, and allergies. Asthma obstructions airflow through bronchoconstriction and inflammatory changes, narrowing the airway and thus increasing production of mucus. Alveoli may become hyperinflated or collapse because of obstruction, leading to impaired gas exchange.

Question 14

Pathophysiology: immunologic factors

Answer 14

Allergy is strongest epidemiologic risk factor for chronic asthma morbidity & mortality -> IgE is most active antibody in allergic reactions. Mediates hypersensitive reaction in bronchial mucosa -> specific tissue binding

Question 15

Immunologic Factors: Release of chemical mediators

Answer 15

Histamine, leukotrienes, platelet-activating factor, prostaglandins, serotonin
Major effect:
- increased permeability of blood vessels
- contraction of smooth muscle
- stimulation of mucous secretion

Question 16

Pathophysiology: Vagal Stimulation

Answer 16

Balance of vagal & sympathetic nerve influences maintenance of tone of bronchial smooth muscle -> irritant receptors react to triggers & stimulate reflex bronchospasm -> normal response but in asthma this is abnormally severe

Question 17

Pathophysiology: Ventilation

Answer 17

Increased airway resistance -> forced expiration -> air trapping -> increased WOB: fatigue, decreased respiratory effectiveness, increased O2 consumption, decreased effectiveness of cough, dyspnea, cyanosis, tachypnea

Question 18

Pathophysiology: Gas exchange

Answer 18

Depends on ratio of poorly ventilated & hyperextended alveoli to well-ventilated alveoli
-> as severity of obstruction increases -> reduced alveolar ventilation: CO2 retention, hypoxemia, respiratory acidosis, respiratory failure

Question 19

Pathophysiology - Exacerbations

Answer 19

Episodes of progressively worsening SOB, cough, wheezing, chest tightness
Decreases in expiratory airflow: airways narrow because of bronchospasm, mucosal edema, & mucous plugging -> air trapped behind narrowed airways
Hyperventilation -> keeps airways open & permits gas exchange
Hypoxemia -> ventilation/perfusion mismatch

Question 20

Clinical Manifestations: Classic

Answer 20

Dyspnea
Wheezing
Coughing

Question 21

Clinical Manifestations other

Answer 21

prodromal itching (frontal neck or upper part of back)
breathing changes -> wheezing
mood changes -> feeling uncomfortable or irritable & increasingly restless
headache, feeling tired or chest feels “tight”
Hacking, paroxysmal, irritative & non-productive cough which becomes productive as secretions accumulate
coughing in absence of resp infection esp at night (interferes with sleep)

Question 22

Getting worse (8)

Answer 22

SOB, prolonged expiratory phase, audible wheezing, increased RR & HR, shallow breathing
Pale -> cyanosis
Restless & apprehensive -> anxious facial expression; irritability
listlessness
Sweating
position
Voice changes - short, panting, broken phrases
Retractions

Question 23

Pediatric Respiratory Assessment Measure (PRAM)

Answer 23

puts the assessment into the objective data category
done on patient with asthma symptoms and done before they get treatment and after they get treatment
want low scores

Question 24

PRAM Criterions (WOSSA)

Answer 24

O2 sat
Suprasternal retractions
Scalene muscle contraction
Air entry
Wheezing

Question 25

Inpatient Asthma Management pathway

Answer 25

want to know if it is working. do PRAM score after administration
Asthma diagnosed after 3 wheezing episodes

Question 26

Complications

Answer 26

Increased susceptibility to infections
Atelectasis
Emphysema
Pneumothorax
Status asthmaticus

Question 27

Diagnostic Evaluation

Answer 27

Clinical manifestations, history, physical examination, & lab tests
Pulmonary function tests
Peak expiratory flow rate
- green, yellow, or red zone based on personal best value (do it three times and record highest number)
Skin testing -> allergies
CBC, CXR

Question 28

Detailed History

Answer 28

Current symptoms - medications, triggers
History of attacks - seasonal, with colds (hospitalizations, intubated)
Family History - asthma or allergies
Paint the picture (compare attacks, look at differences)

Question 29

Chest Assessment

Answer 29

Observation: colour, tachypnea, rhythm, cough, wheezing, difficulty, accessory muscles, indrawing, irritable, tachycardia, posture, fever, cold s/s
Auscultation: air entry, breath sounds, crackles, wheezes, movement of air. changes with coughing, medications
Tests: CXR, PEFR, ABGs, O2 sats

Question 30

Therapeutic Management

Answer 30

Allergen control: house dust mites, cockroach
Drug therapy
Breathing exercises & physical training
Hypo-sensitization
Exercise

Question 31

Supportive Care

Answer 31

Maintain patent airway - humidified O2; positioning (raise HOB)
Rest & stress reduction - group care; quiet environment
Fluids - warm, may need IV
Medications
Avoidance of triggers
Reassurance - child and family
Discharge planning & teaching

Question 32

Medications: Corticosteroids - anti-inflammatories

Answer 32

inhaled - preventors: fluticasone (flovent), budesnide (pulmicort), beclomethasone (beclovent)
Oral: prednisone, prednisolone, dexamethasone
IV: Methylprednisolone
Discharged home on and take regularly. 1 puff twice a day

Question 33

Medications: Beta2 agonists - “rescuers” or “relievers”

Answer 33

Salbutamol (ventolin), salmeterol (serevent), terbutaline (bricanyl)
have this during asthma attacks or exacerbations

Question 34

Medications: Anticholinergics

Answer 34

Ipratropium (atrovent)

Question 35

Medications: magnesium sulphate

Answer 35

Rescuer - bronchodilator: used for severe or life-threatening exacerbations
- given IV. monitor for hypotension, arrhythmias, do cardiorespiratory monitoring and BP monitoring every 5 min

Question 36

Methylxanthines

Answer 36

Rescuers
Aminophylline
used primarily in emergency department when unresponsive to other therapy

Question 37

Mast Cell Inhibitors

Answer 37

Preventors
Cromolyn sodium, nedocromil sodium

Question 38

Leukotriene receptor antagonists

Answer 38

Preventors
Zafirlukast, Montelukast sodium