Asthma - University of Windsor
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Asthma
Asthma
Definition
Reactive airway disease
Chronic inflammatory lung disease
Inflammation causes varying degrees of
obstruction in the airways
Asthma is reversible in early stages
Triggers of Asthma
Allergens
Exercise
Respiratory Infections
Nose and Sinus problems
Drugs and Food Additives
GERD
Emotional Stress
Early and Late Phases of Responses of
Asthma
Fig. 28-1
Asthma
Pathophysiology
Bronchospasm
Airway inflammation
Asthma
Pathophysiology
Early-Phase Response
Peaks 30-60 minutes post exposure, subsides 3090 minutes later
Characterized primarily by bronchospasm
Increased mucous secretion, edema formation,
and increased amounts of tenacious sputum
Patient experiences wheezing, cough, chest
tightness, and dyspnea
Asthma
Pathophysiology
Late-Phase Response
Characterized primarily by inflammation
Histamine and other mediators set up a selfsustaining cycle increasing airway reactivity
causing hyperresponsiveness to allergens and
other stimuli
Increased airway resistance leads to air trapping
in alveoli and hyperinflation of the lungs
If airway inflammation is not treated or does not
resolve, may lead to irreversible lung damage
Factors Causing Airway Obstruction in
Asthma
Fig. 28-3
Summary of Pathophysiologic
Features
Reduction in airway diameter
Increase in airway resistance r/t
Mucosal inflammation
Constriction of smooth muscle
Excess mucus production
Asthma
Clinical Manifestations
Unpredictable and variable
Recurrent episodes of wheezing,
breathlessness, cough, and tight chest
Asthma
Clinical Manifestations
Expiration may be prolonged from a
inspiration-expiration ratio of 1:2 to 1:3 or
1:4
Between attacks may be asymptomatic
with normal or near-normal lung function
Asthma
Clinical Manifestations
Wheezing is an unreliable sign to gauge
severity of attack
Severe attacks can have no audible
wheezing due to reduction in airflow
“Silent chest” is ominous sign of
impending respiratory failure
Asthma
Clinical Manifestations
Difficulty with air movement can create a
feeling of suffocation
Patient may feel increasingly anxious
Mobilizing secretions may become difficult
Asthma
Clinical Manifestations
Examination of the patient during an acute
attack usually reveals signs of hypoxemia
Restlessness
Increased anxiety
Inappropriate behavior
Increased pulse and blood pressure
Pulsus paradoxus (drop in systolic BP during
inspiratory cycle >10)
Asthma
Complications
Status asthmaticus
Severe, life-threatening attack refractory
to usual treatment where patient poses
risk for respiratory failure
Asthma
Diagnostic Studies
Detailed history and physical exam
Pulmonary function tests
Peak flow monitoring
Chest x-ray
ABGs
Asthma
Diagnostic Studies
Oximetry
Allergy testing
Blood levels of eosinophils
Sputum culture and sensitivity
Asthma
Collaborative Care
Education
Start at time of diagnosis
Integrated into every step of clinical care
Self-management
Tailored to needs of patient
Emphasis on evaluating outcome in terms of
patient’s perceptions of improvement
Asthma
Collaborative Care
Acute Asthma Episode
O2 therapy should be started and monitored
with pulse oximetry or ABGs in severe cases
Inhaled -adrenergic agonists by metered
dose using a spacer or nebulizer
Corticosteroids indicated if initial response is
insufficient
Asthma
Collaborative Care
Acute Asthma Episode
Therapy should continue until patient
• is breathing comfortably
• wheezing has disappeared
• pulmonary function study results are
near baseline values
Asthma
Collaborative Care
Status asthmaticus
Most therapeutic measures are the same as
for acute
Increased frequency & dose of
bronchodilators
Continuous -adrenergic agonist nebulizer
therapy may be given
Asthma
Collaborative Care
Status asthmaticus
IV corticosteroids
Continuous monitoring
Supplemental O2 to achieve values of 90%
IV fluids are given due to insensible loss of
fluids
Mechanical ventilation is required if there is
no response to treatment
Asthma
Drug Therapy
Long-term control medications
Achieve and maintain control of persistent
asthma
Quick-relief medications
Treat symptoms of exacerbations
Asthma
Drug Therapy
Bronchodilators
-adrenergic agonists
(e.g., albuterol, salbutamol[Ventolin])
Acts in minutes, lasts 4 to 8 hours
Short-term relief of bronchoconstriction
Treatment of choice in acute exacerbations
Asthma
Drug Therapy
Bronchodilators
Useful
in preventing bronchospasm
precipitated by exercise and other stimuli
Overuse may cause rebound bronchospasm
Too frequent use indicates poor asthma
control and may mask severity
Asthma
Drug Therapy
Bronchodilators (longer acting)
– 12 or 24 hr; useful for nocturnal asthma
Avoid contact with tongue to decrease side
effects
Can be used in combination therapy with
inhaled corticosteroid
8
Asthma
Drug Therapy
Antiinflammatory drugs
Corticosteroids (e.g., beclomethasone,
budesonide)
Suppress inflammatory response
Inhaled form is used in long-term control
Systemic form to control exacerbations and
manage persistent asthma
Asthma
Drug Therapy
Antiinflammatory drugs
Corticosteroids
Do
not block immediate response to
allergens, irritants, or exercise
Do block late-phase response to subsequent
bronchial hyperresponsiveness
Inhibit release of mediators from
macrophages and eosinophils
Asthma
Drug Therapy
Anti-inflammatory drugs
Mast cell stabilizers (e.g., cromolyn, nedocromil)
Inhibit release of histamine
Inhibit late-phase response
Long-term administration can prevent and reduce
bronchial hyper-reactivity
Effective in exercise-induced asthma when used 10
to 20 minutes before exercise
Asthma
Drug Therapy
Leukotriene modifiers (e.g. Singulair)
Leukotriene – potent bronchco-constrictors
and may cause airway edema and
inflammation
Have broncho-dilator and anti-inflammatory
effects
Asthma
Patient Teaching Related to Drug
Therapy
Correct administration of drugs is a major
factor in determining success in asthma
management
Some persons may have difficulty using an MDI
and therefore should use a spacer or nebulizer
DPI (dry powder inhaler) requires less manual
dexterity and coordination
Asthma
Patient Teaching Related to Drug
Therapy
Inhalers should be cleaned by removing dust
cap and rinsing with warm water
-adrenergic agonists should be taken first if
taking in conjunction with corticosteroids
Nursing Management
Nursing Diagnoses
Ineffective airway clearance
Anxiety
Ineffective therapeutic regimen
management
Nursing Management
Planning
Normal or near-normal pulmonary function
Normal activity levels
No recurrent exacerbations of asthma or
decreased incidence of asthma attacks
Adequate knowledge to participate in and
carry out management
Nursing Management
Health Promotion
Teach patient to identify and avoid
known triggers
Use
dust covers
Use of scarves or masks for cold air
Avoid aspirin or NSAIDs
Desensitization can decrease sensitivity
to allergens
Nursing Management
Health Promotion
Prompt diagnosis and treatment of upper
respiratory infections and sinusitis may
prevent exacerbation
Fluid intake of 2 to 3L every day
Nursing Management
Health Promotion
Adequate nutrition
Adequate sleep
Take -adrenergic agonist 10 to 20
minutes prior to exercising
Nursing Management
Nursing Implementation
Acute Intervention
Monitor respiratory and cardiovascular
systems
Lung sounds
Respiratory rate
Pulse
BP
Nursing Management
Nursing Implementation
ABGs
Pulse
oximetry
FEV and PEFR
Work of breathing
Response to therapy
Nursing Management
Nursing Implementation
Nursing Interventions
Administer
O2
Bronchodilators
Chest physiotherapy
Medications (as ordered)
Ongoing patient monitoring
Nursing Management
Nursing Implementation
An important goal of nursing is to decrease
the patient’s sense of panic
Stay with patient
Encourage slow breathing using pursed lips for
prolonged expiration
Position comfortably
Nursing Management
Nursing Implementation
The
patient must learn about medications
and develop self-management strategies
Patient
and health care professional must
monitor responsiveness to medication
Patient
must understand importance of
continuing medication when symptoms are
not present
Nursing Management
Nursing Implementation
Important patient teaching:
Seek medical attention for bronchospasm or
when severe side effects occur
Maintain good nutrition
Exercise within limits of tolerance
Nursing Management
Nursing Implementation
Important patient teaching (cont.):
Patient must learn to measure their peak flow
at least daily
Asthmatics frequently do not perceive changes
in their breathing
Nursing Management
Nursing Implementation
Counseling may be indicated to resolve
problems
Relaxation therapies may help relax
respiratory muscles and decrease
respiratory rate
Nursing Management
Nursing Implementation
Peak Flow Results
Green zone
Usually 80-100% of personal best
Remain on medications
Nursing Management
Nursing Implementation
Peak Flow Results
Yellow zone
Usually 50-80% of personal best
Indicates caution
Something is triggering asthma
Nursing Management
Nursing Implementation
Peak Flow Results
Red zone
50% or less of personal best
Indicates serious problem
Definitive action must be taken with health care
provider