Transcript Asthma - University of Windsor

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
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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
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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
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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
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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
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Start at time of diagnosis
Integrated into every step of clinical care
 Self-management
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Tailored to needs of patient
Emphasis on evaluating outcome in terms of
patient’s perceptions of improvement
Asthma
Collaborative Care
Acute Asthma Episode
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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
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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
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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
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Achieve and maintain control of persistent
asthma
 Quick-relief medications
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Treat symptoms of exacerbations
Asthma
Drug Therapy
 Bronchodilators
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-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
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Asthma
Drug Therapy
Antiinflammatory drugs
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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
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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
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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)
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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
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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
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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
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Teach patient to identify and avoid
known triggers
 Use
dust covers
 Use of scarves or masks for cold air
 Avoid aspirin or NSAIDs
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Desensitization can decrease sensitivity
to allergens
Nursing Management
Health Promotion
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Prompt diagnosis and treatment of upper
respiratory infections and sinusitis may
prevent exacerbation
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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
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Nursing Management
Nursing Implementation
Acute Intervention
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Monitor respiratory and cardiovascular
systems
 Lung sounds
 Respiratory rate
 Pulse
 BP
Nursing Management
Nursing Implementation
 ABGs
 Pulse
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oximetry
 FEV and PEFR
 Work of breathing
Response to therapy
Nursing Management
Nursing Implementation
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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
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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:
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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.):
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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
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Usually 80-100% of personal best
Remain on medications
Nursing Management
Nursing Implementation
Peak Flow Results
 Yellow zone
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Usually 50-80% of personal best
Indicates caution
Something is triggering asthma
Nursing Management
Nursing Implementation
Peak Flow Results
 Red zone
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50% or less of personal best
Indicates serious problem
Definitive action must be taken with health care
provider