Pediatric Teaching Session

1. Pediatric Teaching Session 1/10/07 Dan Imler

2. Case Presentation • 4 yo M with 3 day h/o URI sx since last night has comes to your office with trouble breathing. • SpO2: 88% • Sub-costal and Sub-sternal Retractions • No wheezing on exam

3. Acute Asthma Exacerbation • What do you do? • ABC • Oxygen • Rescue Medication (Bronchodialator) • Anti-Inflammatory Agent (Steroids, PO vs. IH) • Admit (What do you do there?) • Continuous Albuterol, Trebutiline, Theophylline, Intubation

4. Case Presentation • 2 yo F comes to clinic with 2 days of respiratory distress. • Allergic sx • Pt coughs every night, keeps mom up • SpO2: 95% • Bilateral wheezing • Mild retractions

6. Asthma - Types • Asthma, or hyperreactive airway disease, is one of the most common chronic diseases worldwide and is the most common cause of hospitalization for children in the United States. • Types • Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role, in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophils, and epithelial cells. In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation also causes an associated increase in the existing bronchial responsiveness to a variety of stimuli. • Exercise-induced asthma (EIA), or exercise-induced bronchospasm, is an asthma variant defined as a condition in which exercise or vigorous physical activity triggers acute bronchospasm in persons with heightened airway reactivity. It is observed primarily in persons who are asthmatic but can also be found in patients with atopy, allergic rhinitis, or cystic fibrosis and even in healthy persons. EIA is often a neglected diagnosis, and the underlying asthma may be silent in as many as 50% of patients, except with exercise.

7. Asthma - Pathophysiology • The pathophysiology of asthma is complex and involves the following components: (1) airway inflammation, (2) intermittent airflow obstruction, and (3) bronchial hyperresponsiveness. The mechanism of inflammation in asthma may be acute, subacute, or chronic, and the presence of airway edema and mucus secretion also contributes to airflow obstruction and bronchial reactivity. Varying degrees of mononuclear cell and eosinophil infiltration, mucus hypersecretion, desquamation of the epithelium, smooth muscle hyperplasia, and airway remodeling are present. • The pathogenesis of EIA is controversial. The disease may be mediated by water loss from the airway, heat loss from the airway, or a combination of both. The upper airway is designed to keep inspired air at 100% humidity and body temperature at 37°C (98.6°F). The nose is unable to condition the increased amount of air required for exercise, particularly in athletes who breathe through their mouths. The abnormal heat and water fluxes in the bronchial tree result in bronchoconstriction, occurring within minutes of completing exercise. Results from bronchoalveolar lavage studies have not demonstrated an increase in inflammatory mediators. These patients generally develop a refractory period, during which a second exercise challenge does not cause a significant degree of bronchoconstriction.

9. Asthma - Epidemiology • Asthma affects 5-10% of the population or an estimated 14-15 million persons, including 5 million children. The prevalence rate of EIA is 3-10% of the general population if persons who do not have asthma or allergy are excluded, but the rate increases to 12-15% of the general population if patients with asthma are included. The rate of exercise-induced symptoms in persons with asthma has been reported to vary from 40-90%. • More than 1.8 million emergency department evaluations occur annually. The figures from the 1997 National Institutes of Health report indicate an estimated 500,000 hospitalizations and 5000 deaths annuallyEIA has not been reported to cause death. Morbidity is associated with exercise limitation. This is observed most dramatically in elite athletes with high levels of exercise who may be limited by airway hyperreactivity.

10. Asthma - Epidemiology • Asthma predominantly occurs in boys in childhood, with a male-to-female ratio of 2:1 until puberty, when the male-to-female ratio becomes 1:1. • Boys are more likely than girls to experience a decrease in symptoms by late adolescence. • Two thirds of all asthma cases are diagnosed before the patient is aged 18 years. Approximately half of all children diagnosed with asthma have a decrease or disappearance of symptoms by early adulthood.

11. Asthma - Diagnosis • Pulmonary function testing (spirometry) • Spirometry measures the forced vital capacity, the maximal amount of air expired from the point of maximal inhalation, and the FEV1. A reduced ratio of FEV1 to forced vital capacity, when compared with predicted values, demonstrates the presence of airway obstruction. Reversibility is demonstrated by an increase of 12% or 200 mL after administration of a short-acting bronchodilator. • Methacholine- or histamine-challenge testing • Exercise testing • Eucapnic hyperventilation • Peak-flow monitoring • Exhaled NO

12. Common examples of abnormal flow-volume loops. A, Mild obstructive airway disease characterized by decreased flow at low lung volume when elastic support is reduced. B, Significant obstructive airway disease characterized by decreased overall flows with a further decrease at low lung volumes. C, Variable intrathoracic large airway obstruction in which peak flow is decreased at higher lung volumes with preservation of normal flow-volume relationship at lower lung volumes. D, Restrictive pulmonary disease with decreased VC and flows, but preservation of normal flow-volume relationships. (Reproduced with permission from Light RW. Clinical pulmonary function testing, exercise testing, and disability evaluation. In: George RB, Light RW, Matthay MA, Matthay RA, eds. Chest Medicine. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2000:93.)

13. Asthma - Allergies • A very common cause of Asthma exacerbations are allergies. • Dust: Cats, Dogs, Mold & Fungus Spores, Food particles, Bacteria, small parts of insects and plants.

14. Dust Mites: microscopic insects that live in bedding, upholstered furniture, and carpets, thrive in summer (high humidity, temp >70) and die in winter. Their waste products contain proteins which are allergenic. • As many as 10 percent of the general population and 90 percent of people with allergic asthma are sensitive to dust mites. Recent studies in the United States suggest that at least 45 percent of young people with asthma are allergic to dust mites • There may be many as 19,000 dust mites in one gram of dust, but usually between 100 to 500 mites live in each gram. • Cockroaches – Also a common allergen for asthma suffers • In one study of inner- city children, 37 percent were allergic to cockroaches, 35 percent to dust mites, and 23 percent to cats.

18. Case Presentation • 15 mo F with 2 wk h/o new onset wheezing. • SpO2: 98% • Right side decrease breath sounds • Left side diffuse wheezing • Coughing up green mucus • No family history, no history of atopy

19. Foreign Body Aspiration • Since the angles made by the mainstem bronchi with the trachea are identical until the age of 15 years, foreign bodies are found on either side with equal frequency in this age group. With normal growth and development, the adult right and left mainstem bronchi diverge from the trachea with very different angles, with the right mainstem bronchus being more acute and therefore making a relatively straight path from larynx to bronchus. Objects that descend beyond the trachea are more often found in the right endobronchial tree than in the left. • In the series reported by Debeljak et al, 42 foreign bodies were in the right endobronchial tree, 20 were in the left, and 1 was in the trachea.

20. Foreign Body Aspiration • Vegetable material may swell over hours or days, worsening the obstruction. Cough, wheeze, stridor, dyspnea, cyanosis, and even asphyxia might ensue. Organic foreign bodies, such as oily nuts (commonly peanuts), induce inflammation and edema • The incidence rate was 2 per 100,000 population younger than 1 year, and 0.6 per 100,000 population aged 1-4 years. • Male-to-female ratio is 2:1, depending on the study. • Most foreign bodies are radiolucent. Fewer than 20% of aspirated foreign bodies are radiopaque.

21. Foreign Body Aspiration • Perform standard posteroanterior (PA) inspiratory chest radiographs to look for unilateral hyperinflation, lobar or segmental atelectasis, mediastinal shift, or pneumomediastinum. • Expiratory chest radiographs are more sensitive for air trapping than inspiratory chest radiographs. Signs are enhanced lucency and relatively low diaphragm position. If the patient cannot cooperate, lateral decubitus views may demonstrate air trapping in the dependent lung.

22. Peanut

23. Case Presentation • 6 wk old M infant presents with expiratory stridor for his entire life • SpO2: 98% • Stridor worse in supine position and when crying • Patient not gaining wt well and poor feeder

24. Tracheomalacia • Tracheomalacia is a process characterized by flaccidity of the supporting tracheal cartilage, widening of the posterior membranous wall, and reduced anterior-posterior airway caliber. These factors cause tracheal collapse, especially during times of increased airflow such as coughing, crying, or feeding. • Tracheomalacia is a structural abnormality of the tracheal cartilage allowing collapse of its walls and airway obstruction. A deficiency and/or malformation of the supporting cartilage exists, with a decrease in the cartilage-to-muscle ratio.

25. The incidence of primary airway malacia was estimated to be at least 1 in 2,100 • Commonly there are co-morbidities such as TEF • Most commonly affects the distal third of the trachea. • Almost all children out grow symptoms by age 18-24 months. Surgery usually only in patients with significant symptoms or with co-morbidities.

26. Case Presentation • 30 min old M with respiratory distress • FT, no prenatal complications other than gestational diabetes • LGA • SpO2: 91% • Grunting, Retractions, Flaring

27. Case Presentation • 1 mo M with pneumonia • SpO2: 90% • Wt: <3%, poor feeder • PSHx: Mom says he had some sort of surgery when he was born for constipation.