Asthma causes treatment and oxygen theraphy

Asthma

1. Asthma

2. Asthma
Definition
Reactive airway disease
Chronic inflammatory lung disease
Inflammation causes varying degrees of
obstruction in the airways
Asthma is reversible in early stages

3. Triggers of Asthma
Allergens
Exercise
Respiratory Infections
Nose and Sinus problems
Drugs and Food Additives
GERD
Emotional Stress

4. Early and Late Phases of Responses of
Asthma
Fig. 28-1

5. Asthma
Pathophysiology
Bronchospasm
Airway inflammation

6. Asthma
Pathophysiology
Early-Phase Response
Peaks 30-60 minutes post exposure, subsides 30-
90 minutes later
Characterized primarily by bronchospasm
Increased mucous secretion, edema formation,
and increased amounts of sputum.
Patient experiences wheezing, cough, chest
tightness, and dyspnea

7. Asthma
Pathophysiology
Late-Phase Response
Characterized primarily by inflammation
Histamine and other mediators set up a self-
sustaining 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

8. Factors Causing Airway Obstruction in
Asthma
Fig. 28-3

9. Summary of Pathophysiologic
Features
Reduction in airway diameter
Increase in airway resistance r/t
Mucosal inflammation
Constriction of smooth muscle
Excess mucus production

10. Asthma
Clinical Manifestations
Unpredictable and variable
Recurrent episodes of wheezing,
breathlessness, cough, and tight chest

11. 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

12. 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

13. Asthma
Clinical Manifestations
Difficulty with air movement can create a
feeling of suffocation
Patient may feel increasingly anxious
Mobilizing secretions may become difficult

14. 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)

15. Asthma
Complications
Status asthmaticus
Severe, life-threatening attack refractory
to usual treatment where patient poses
risk for respiratory failure

16. Asthma
Diagnostic Studies
Detailed history and physical exam
Pulmonary function tests
Peak flow monitoring
Chest x-ray
ABGs

17. Asthma
Diagnostic Studies
Oximetry
Allergy testing
Blood levels of eosinophils
Sputum culture and sensitivity

18. Asthma
Collaborative Care
Education
Start at time of diagnosis
Integrated into every step of clinical care
Self-management
Emphasis on evaluating outcome in terms of
patient’s perceptions of improvement

19. Asthma
Collaborative Care
Acute Asthma Episode
O
2 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

20. 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

21. 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

22. Asthma
Collaborative Care
Status asthmaticus
IV corticosteroids
Continuous monitoring
Supplemental O
2to 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

23. Asthma
Drug Therapy
Long-term control medications
Achieve and maintain control of persistent
asthma
Quick-relief medications
Treat symptoms of exacerbations

24. 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

25. 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

26. Asthma
Drug Therapy
Bronchodilators (longer acting)
8 –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

27. 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

28. 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

29. 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

30. 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

31. 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

32. 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

33. Thank You