Treatment of Bronchial Asthma

1. Treatment of Bronchial Asthma

2. Bronchial Asthma • Epidemiology. • Pathophysiology. • Diagnosis & assessment. • Treatment of Acute exacerbations of Asthma. • General guidelines for asthma treatment. • What`s New?

3. Epidemiology • Childhood Asthma is the most common cause of childhood emergency department visits, hospitalizations & missed school days. • Worldwide,Childhood asthma is increasing in prevalence. • Childhood Asthma is common in modern locales & is strongly linked to allergies in contrast to children of rural areas.

4. Increasing prevalence,WHY? • Multifactorial. • The first 3 years of life are the most critical in environmental influence on development of asthma. • General life style changes:maternal smoking, housing , dietary, prematurity,LBW. • The relevance of atopy & pattern of T-lymphocyte response.

5. “The Hygiene Hypothesis” • The increase in Asthma is due to a decrease in exposure to infections in early life. • Frequent infections generate Th1 cytokines ( IL12, IL 18 INF Gamma). • It explains the inverse relation ship between economic status & asthma & why first born children have higher prevalence of Asthma .

6. Asthma is generally an undediagnosed , under treated condition. • Even Children with Mild Asthma are at risk of death ( Among 51 asthma death reports 17 { 33%} occurred in patients classified with mild asthma) • Before puberty : M:F = 3:1 , by adolescence they are equal , Adult onset asthma is more common in women. • 80% of asthmatics report disease onset before the age of 6years. • 70% of asthma occurs before the age of 3 , onset starts before 1 yr in 1/3 of these

7. Early childhood Risk factors for Persistent Asthma • Parental Asthma • Allergy: • Atopic dermatitis. • Allergic rhinitis. • Food allergy • Severe lower RTI: • Pneumonia • Bronchiolitis requiring hospitalization. • Male Gender . • Wheezing apart from Colds. • Low birth weight. • Environmental Tobacco exposure.

8. Pathogenesis • Asthma is a chronic inflammatory condition of the lung airways resulting in episodic airflow obstruction. • Chronic inflammation increases airway hyper-responsiveness to provocative exposures.

11. Assessment & diagnosis • Diagnosis is challenging. • Lack of objective measure( spirometry). • American Thoracic Society : 4 out of 5 • Wheezing with colds • Wheezing apart from colds. • Dyspnea associated with wheeze. • Wheeze after exertion • Persistent cough

12. Asthma exacerbation management • Progressively worsening symptoms , associated with expiratory airflow obstruction. • Apreciate severity based on frequency/severity of previous exacerbations • Identify asthmatics with increased risk for life threatening exacerbations.

13. The number of emergency department visits, hospitalizations,systemic glucocorticode courses. • Best predictors of fatal asthmatic episode or future life threatening episodes: • A previous exacerbation resulting in respiratory distress, hypoxia or respiratory failure. • Biologic, environmental, economic & psychological risk factors .

14. High Risk Patients • Past history of sudden severe exacerbations. • History of prior intubation for asthma or ICU admission. • Two or more hospitalizations for asthma in the past year. • Three or more ER visits in the past year. • Hospitalization or ER visit within the last month. • Use of 2 or more canisters of inhaled short acting beta-2 agonists / month. • Current use of systemic steroids or recent withdrawal from systemic steroids.

15. Home management of Asthma exacerbations • All asthmatics should have a written action plan. • Intensifying treatment as soon as symptoms are recognized , may abbort the exacerbation. • A study showed that having a written home action plan reduced the risk of death by 70%.

16. Immediate treatment with rescue medications ( Inhaled B2 agonists : 3 in 1 hr). • Good response: • Resolution of symptoms within 1 hr. • No further symptoms over the next 4 hours. • 80% improvement in PEF of predicted or personal best. • Contact the Child`s physician for follow up , if repetition of treatment required within 24-48 hrs.

17. Incomplete response: • Persistent symptoms &/or PEF of 60-80% of predicted or personal best. • short course of glucocorticoid therapy ( pred. 1-2 mg/kg/24 hrs for 4 days)+inhaled B2 agonist . • Contact physician for further instructions. • Immediate Medical Care: • Persistent signs of respiratory distress. • Lack of expected response or sustained improvement after initial treatment. • Further deterioration. • Risk factors for asthma morbidity & mortality • Severe exacerbations

18. Emergency department management of Acute asthma • Aims: • correction of hypoxia. • Improving airflow obstruction . • Prevention of progression & recurrence. • Assess severity. • Risk Factors associated with death. • Closely monitor clinical status.

19. High Flow oxygen via non-rebreathing mask to maintain O2 sat> 92%. • Inhaled B2 agonist every 20 min. for 1hour. • If no significant improvement , inhaled ipratropium may be added. • Systemic glucocorticoids IV or orally at 2mg/kg /d . • Epinephrine , other B agonist SQ injection may be considered in severe cases.

20. Discharge home: • Sustained improvement in symptoms • Normal physical findings. • PEF > 70% • O2 sat >92% in room air for 4 hrs. • Discharge medications: • Inhaled B agonist Q 3-4 hrs. • Oral glucocorticoids for 3-7 days.

21. Admit patients with moderate to severe asthma if: • No significant improvement in initial symptoms after 1-2 hrs of treatment. • PEF < 70% • O2 sat < 90-92%. • Prolonged symptoms before the ER visit. • Inadequate access to medical care & medications. • Difficult psychosocial conditions.

22. Hospital management • Supplemental Oxygen. • Short acting B agonists : frequently or continuously: • Continuous cardiac monitoring. • Pulse oxymetry • Ipratropium Q 6 hrs. • IV hydration.

23. Intravenous theophylline • If a child responds poorly to nebulized albuterol, ipratropium & parenteral steroids: IV theophylline. • Recent Study : • Acute severe asthma( FEV1< 37%): Theophylline IV resulted in rapid & sustained improvement in O2 sat & lung function , fewer patients required IV albuterol & it decreased the duration. • All those who required mechanical ventilation: placebo group.

24. Propper dosage for age & weight should be used. • Serum level monitoring. • Contraindications: • Documented hypersensitivity • Uncontrolled arrythmias. • Peptic ulcer • Hyperthyroidism. • Uncontrolled seizure disorders

25. Heliox • Inhaled Helium : Oxygen= 70: 30 • Acute severe Asthma, early on. • Heliox : 1/3 density of room air. • Decreases airway resistance & causes improvement in 20 even with other medications. • Limits prolonged use of O2.

26. Magnesium Sulfate • Controversial Issue. • Smooth muscle relaxant effect. • A small study: • Acute ER management:25mg/kg max. 2gm • Decreased hospitalization & improved lung function. • Monitor Blood pressure 10—15 min during infusion till 90 min after infusion. • Mg level before & 30 min after infusion.

27. Mechanical Ventilation • It requires careful balance between enough pressure to overcome obstruction , while reducing hyperinflation , airtrapping & barotrauma: pneumothorax, pneumomediastinum. • Anticipate respiratory failure:ICU setting • Elective intubation with sedation & paralytic agent is safer than emergency intubation

28. Adequate oxygenation , mild to moderate hypercapnia ( 40-60 mmhg) is acceptable. • Chest percussion & airway lavage are not recommended: induce further bronchspasm. • Rapid onset exacerbations resolve quickly: hours—2 days. • Gradual progression: days to weeks for extubation, usually complicated by muscle atrophy.

29. Management in medical centers is usually successful. • Most deaths occur at home or in community settings. • Medical / Legal pitfalls: • Failure to recognize the severity of an acute severe episode & to initiate aggressive management. • Failure to diagnose pneumothorax. • Identification of associated or complicating conditions : allergic rhinitis / Sinusitis. • Underdiagnosis of asthma.

30. Coming Soon: • Treatment of chronic Asthma. • New strategies in management. • Steroids ? What about them ?? • Prevention & Education. • Devices & drug delivery methods in children. • A QUIZZ ?? MAYBE ??

31. References for everybody !

32. THANK YOU !