Acute Bronchiolitis.pptx

Paediatric acute bronchiolitis

1. Acute Bronchiolitis AIMIEN Efosa (MBBS , Zaria)

2. Outline Introduction Epidemiology Etiology Pathophysiology Risk factors Clinical manifestations Management Complications Prognosis Prevention Conclusion

3. Introduction Acute bronchiolitis is a diagnostic term used to describe the clinical picture produced by several different viral lower respiratory tract infections in infants and very young children. It is as a result of an acute inflammatory injury to the bronchioles that as caused by a viral infection. It is the commonest lower respiratory tract infection in children less than 1 year of age.

4. Epidemiology According to the WHO bulletin, an estimated 150 million new cases occur annually. Over 100,000 young children are hospitalized annually in the United States with the diagnosis of bronchiolitis, About 75% of cases occur in children younger than 1 year, and 95% in children younger than 2 years. Incidence peaks in those aged 2-8 months (3-6months crescendo). Male to female ratio – 1.25-2 : 1 Death is 1.5 times more likely in males.

5. Etiology Respiratory syncytial virus: >50% cases Human metapneumovirus : 9 – 30% Rhinovirus: (16%) Parainfluenza Influenza (6%) Bocavirus Adenovirus

6. Pathophysiology Bronchiolar injury and the consequent interplay between inflammatory and mesenchymal cells can lead to diverse pathologic and clinical features: Day 0 – 2 (upper respiratory tract): Virus damages the upper respiratory tract epithelial cells which are sloughed to the lower respiratory tract, thus constituting cellular debris. Day 3 – 10 (lower respiratory tract): Further epilethial cell invasion. Increased mucus production. Mucosal edema. Ciliary function impairment. Proliferation and infiltration of polymorphonuclear cells and lymphocytes. Air trapping. Atelectasis and ventilation-perfusion mismatch. The above lead to significant narrowing of the bronchioles. Day 11 – 22 (upper and lower respiratory tracts): Epithelial regeneration.

7. Risk Factors Low birthweight Age less than 3 months. Low socioeconomic group Chronic lung diseases e.g BPD Congenital heart or neurological diseases Exposure to second-hand tobacco smoke. Those who have not been breastfed crowded living conditions, daycare centers. Risk is also higher for infants with mothers who smoked during pregnancy. Older family members, including older siblings with respiratory tract infection.

8. Clinical Manifestations Day 0 – 2 Rhinorrhea Nasal congestion Low grade fever Mild cough

9. Clinical Manifestations Day 3 – 10 Wheezing Subcostal and intercostal retractions Cough Impaired feeding Cyanosis, apnea Rhonchi, crackles

10. Management Management of a child presenting with features suggestive of acute bronchiolitis entails detailed history, physical examination, diagnostic evaluation, treatment and follow-up.

11. Management History usually preceded by exposure to contacts with a minor respiratory illness within the previous week The infant first develops signs of upper respiratory tract infection with sneezing and clear rhinorrhea. This may be accompanied by diminished appetite and fever. Gradually, respiratory distress ensues, with paroxysmal cough, dyspnea, and irritability. The infant is often tachypneic , which can interfere with feeding. Apnea may precede lower respiratory signs early in the disease, particularly with very young infants.

12. Management History Birth history includes weeks of gestation, neonatal complications including history of intubation or oxygen requirement, maternal complications, and prenatal smoke exposure. Past medical history includes any comorbid conditions. Family history of cystic fibrosis, immunodeficiencies , asthma in a first-degree relative, or any other recurrent respiratory conditions in children should be obtained.

13. Management History Social history should include any second-hand tobacco or other smoke exposure, daycare exposure, number of siblings, pets, and concerns regarding home environment (e.g., dust mites, construction dust, heating and cooling techniques, mold, cockroaches). The patient's growth chart should be reviewed for signs of failure to thrive

14. Management Physical examination Respiratory rate and oxygen saturation is an important initial step. Wheezing and crackles. Expiratory time may be prolonged. Work of breathing may be markedly increased, with nasal flaring and retractions. Complete obstruction to airflow can eliminate the turbulence that causes wheezing; thus the lack of audible wheezing is not reassuring if the infant shows other signs of respiratory distress. Poorly audible breath sounds suggest severe disease with nearly complete bronchiolar obstruction

15. Management Diagnostic evaluation Acute bronchiolitis is a clinical diagnosis and thus investigations to confirm the diagnosis are seldom needed. CBC: white blood cell and differential counts are usually normal and are not predictive of bacterial superinfection , However, may show lymphocytosis ABG: hypoxia and hypercapnia Chest X-ray: might show findings misconstrued for bronchopneumonia thus encouraging the unnecessary use of antibiotics. Rapid antigen detection for RSV, parainfluenza , influenza and adenovirus (sensitivity 80=90%) Immunofluorescence, viral culture and PCR

16. Management Differential diagnosis Bronchopneumonia Asthma Foreign body aspiration GERD

17. Management Admission Criteria SPO2 below 92% in room air Markedly elevated respiratory rate (>70cpm) Respiratory distress Chronic lung disease Congenital heart disease Prematurity Age <3 months Inability or difficulty with feeding Parental anxiety

18. Management Treatment Among the many medications and interventions used in the management of bronchiolitis, only oxygen appreciably improves the condition of the ailing child. Healthy children with bronchiolitis usually have limited disease and do well with supportive care only. Therapy is directed towards symptomatic relief and maintenance of hydration and oxygenation.

19. Management Treatment Supportive care includes: Supplemental humidified oxygen Maintenance of hydration Nasal and oral suctioning Apnea and cardiorespiratory monitoring Thermoregulation Mechanical ventilation.

20. Management Guidelines for treatment In 2006, the American Association of Paediatricians in conjunction with the America College of Chest Physicians, American Thoracic Society and American Academy of Family Physicians published the following recommendations as guideline for the treatment of acute bronchiolitis.

21. Management Treatment guidelines Diagnosis and severity should be based on history and physical findings. Bronchodilators should not be routinely used. Corticosteroids should not be routinely used. Ribavirin should not be routinely used. Antibiotics should be used only upon proven bacterial co-infection, Hydration and the ability to take oral fluids should be assessed.

22. Management Treatment guidelines Supplemental oxygen should be supplied for saturations below 90% on pulse oximetry . Palivizumab prophylaxis should be administered to selected children. Hand decontamination is indicated to prevent nosocomial spread. Infants should not be exposed to secondary smoking, and breastfeeding is recommended. Clinicians should inquire about use of complementary and alternative medicine therapies.

23. Complications Otitis media Pneumonia Pneumothorax Dehydration Respiratory acidosis Respiratory failure Heart failure Prolonged apneic spells leading to death

24. Prognosis Infants with acute bronchiolitis are at highest risk for further respiratory compromise in the first 72 hours after onset of cough and dyspnea. The case fatality rate is <1% in developed countries, with death attributable to respiratory arrest and/or failure or severe dehydration and electrolyte disturbances. A majority of deaths due to bronchiolitis occur in children with complex medical conditions or comorbidities such as bronchopulmonary dysplasia, congenital heart disease, or immunodeficiency. The median duration of symptoms in ambulatory patients is approximately 14 days; 10% may be symptomatic for 3 weeks.

25. Prevention Meticulous hand hygiene is the best measure to prevent transmission of the viruses responsible for bronchiolitis. For high-risk populations, palivizumab , an intramuscular monoclonal antibody to the RSV F protein, may be given as a prophylactic agent. Palivizumab has been demonstrated to reduce risk of hospitalization due to RSV bronchiolitis in certain populations. It has not been shown to decrease mortality and does not protect against bronchiolitis caused by other viruses and is also quite costly. As a result, there is some controversy surrounding which populations should receive palivizumab .

26. Prevention U.S. guidelines suggest use for children born at <29 weeks completed gestation, those with significant heart disease or chronic lung disease of prematurity, through the 1 st or 2 nd (for those with persistent chronic lung disease of prematurity) year of life. Prophylaxis may be considered in infants with neuromuscular disease and immunocompromised states.

27. Conclusion Acute bronchiolitis is a viral lower respiratory tract infection commonest in under-2s which frequently presents with cough, wheezing, respiratory distress, fever and impaired feeding. It is usually preceded by rhinorrhea. RSV is implicated in more than 50% of cases of acute bronchiolitis. Hydration, oxygen optimization and other supportive care targeted towards symptomatic relief are the main stay of management. Meticulous hand hygiene remains the best measure to prevent transmission of the viruses responsible for bronchiolitis.

28. References Kliegman , R. (2020). Nelson textbook of pediatrics (Edition 21.). Philadelphia, PA: Elsevier. Kumar, V., Abbass , A. K., & Aster, J. C. (2015). Robbins and Cotran pathologic basis of disease (9 th Edition.). Philadelphia, PA: Elsevier/Saunders. Medscape