ASTHMA/BRONCHIOLITIS
Allan S. Lieberthal, MD, Clinical Professor of Pediatrics, Keck School of Medicine, University of Southern California,
Los Angeles
Educational Objectives
| The goal of this program is to improve the medical care of patients with asthma and patients with bronchiolitis. After hearing
and assimilating this program, the clinician will be better able to:
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 | 1. Describe current guidelines from the National Heart, Lung, and Blood Institute for managing asthma in children.
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| 2. Identify common triggers for episodes or exacerbations of asthma.
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| 3. Educate patients about self-management techniques for controlling asthma.
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| 4. Describe current guidelines from the American Academy of Pediatrics for managing bronchiolitis in children.
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| 5. Implement effective strategies for preventing bronchiolitis.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning
committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest.
Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary
business or commercial interest. For this program, Dr. Lieberthal and planning committee reported nothing to disclose.
Acknowledgments
Dr. Lieberthal was recorded at the 49th Annual Pediatric Symposium, presented October 12-13, 2007, in Anaheim,
CA, by Kaiser Permanente of Southern California, and at Clinical Pediatrics, presented February 14-17, 2008, in Palm
Springs, CA, by the American Academy of Pediatrics, California Chapter 2. The Audio-Digest Foundation thanks Dr.
Lieberthal and the sponsors for their cooperation in the production of this program.
| PEDIATRIC ASTHMA: A PRACTICAL APPROACH
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| Asthma defined (National Heart, Lung, and Blood Institute [NHLBI] guidelines, 2007): 3 components;
pathophysiologic—chronic inflammatory disorder of airways in which many cells and cellular elements play role (in
particular, mast cells, eosinophils, and neutrophils; especially common in sudden-onset fatal exacerbations, occupational
asthma, and patients who smoke); includes T-lymphocytes, macrophages, and epithelial cells; clinical—in susceptible
individuals, inflammation causes recurrent episodes of coughing (particularly at night or early in morning), wheezing,
breathlessness, and chest tightness; cough may be present without wheeze; pulmonary—episodes usually associated
with widespread but variable airflow obstruction; often reversible
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| Ethnic variability: prevalence in blacks same as in whites, but mortality rate much higher in blacks; role of socioeconomic
factors and access to health care unclear
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| Presentation: cough without wheezing (cough-variant asthma) most common expression in children; cough usually dry,
worse at night, and increases with exercise; chest tightness and difficulty breathing out due to expiratory obstruction
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| Triggers: in children <5 yr of age, viral illness most common trigger; viral-induced wheezing may be different entity from
classic atopic asthma; exercise (not necessarily cough and wheeze while exercising; patients tire, and symptoms develop
≈5 min after exercise); inhalant allergens; inhaled irritants (tobacco smoke, Mentholatum [menthol, camphor, eucalyptus
oil]); changes in weather; emotional triggers
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| Pulmonary function tests: spirometry and/or bronchial provocation testing recommended to confirm diagnosis; history
key (normal spirometry does not rule out asthma); physicians tend to underestimate severity of asthma (vs severity
determined by pulmonary function testing)
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| Differential diagnosis: wheeze and/or cough not necessarily asthma; specific diagnoses—viral-induced cough or
wheeze; gastroesophageal reflux disease, with or without aspiration; (stomach acid entering esophagus causes reflex
bronchospasm); swallowing incoordination, chronic aspiration, and foreign bodies; vascular rings can cause stridor and/
or wheezing (laryngeal web more often causes stridor); recurrent wheezing and cough may be clue to cystic fibrosis;
masses, lymph nodes, hemangiomas, tumors, and congenital laryngotracheal or bronchial malacia; congenital heart disease
(especially with left heart failure; weight of heart compresses airways, causing wheezing and pulmonary edema);
chronic lung disease of prematurity; habit cough
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| Determining whether asthma under control
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| Questions: do you use quick-relief inhaler >2 times/wk? do you awaken at night with asthma >2 times/mo? do you refill
your prescription for short-acting β-agonist >2 times/yr? if answer “yes” to any question, patient has persistent asthma
(asthma not under control)
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| Asthma-control test: included children 4 to 11 yr of age; patient may not realize that cough symptomatic of asthma
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| Assessing asthma severity: intermittent—symptoms ≤2 days/wk; mild persistent—symptoms >2 days/wk; moderate
persistent—daily symptoms; severe persistent—symptoms always present; nighttime awakening—child <4 yr of age
should not awaken at night from cough or wheezing (child >5 yr of age may awaken twice/mo)
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| Short-acting beta-agonist: eg, albuterol (use as needed, but not frequently); short-acting β-agonist should be used <2
days/wk (exception, exercise-induced asthma); investigate activity tolerance (if physical education class causes coughing
and wheezing, solution treatment rather than avoidance
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| Step-wise approach to therapy
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| Short-acting β-agonist: eg, albuterol, levalbuterol (Xopenex); at doses that produce equivalent bronchial dilatation, levalbuterol
and albuterol have same side effects; use as needed (never prescribe administration multiple times per day)
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| Inhaled corticosteroids: best controller medications; intermittent asthma—does not require preventive medication; mild
persistent asthma—start with low-dose corticosteroids; consider adding long-acting β-agonist; moderate severe
asthma—medium dose of long-acting β-agonist; moderate persistent asthma—consider leukotriene inhibitor (eg,
montelukast [Singulair]; drug not effective as single-agent asthma controller, but may give boost to inhaled corticosteroids);
severe disease—high-dose long-acting β-agonist and leukotriene inhibitor
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| Patient education: patients need written instructions and understandable goals
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| More about triggers: if atopy suspected, consider serum IgE test (panels available targeted to community, not as comprehensive
skin testing for specific antigens); alternatively, consider traditional prick or intradermal tests; educate patients
about avoidance of allergens
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| Methods for self-evaluation of asthma control: symptom-based, peak expiratory flow, or forced expiratory volume
in first second of expiration (FEV1 ) monitoring
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| Drug dosage and delivery: teach correct technique for administering inhaled medications (do not assume that pharmacist
will do it); for some medications, correct timing important (administer montelukast at night; oral steroids better given
in morning); patient-initiated oral corticosteroids—systemic steroids have systemic side effects (even 4 or 5 short
courses of steroids can affect adrenal-hypothalamic axis)
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| Written action plans for asthma in children (Bhogal et al, 2006): children using symptom-based written action
plans had lower risk for exacerbations requiring acute care visit; effectiveness of self-management using written action
plan based on peak flow equivalent to self-management using symptoms-based written action plan
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| PiKo-1 monitor: combines peak flow and FEV1 monitoring; peak flow gross measure of airway obstruction (FEV1 finer
measure); peak flow readings vary by product (for comparison in office, use device used by patient); if peak flow used,
speaker recommends monitoring 3 times/day
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| More about drug delivery: inhaler with valved holding chamber (Aerochamber) stores medication in chamber, permitting
slow deep inhalation; metered dose inhaler (MDI) used without Aerochamber delivers rapid burst of medication (90%
deposited on palate); studies show no difference in outcome between MDI with valved holding chamber and nebulizer (however,
carefully controlled conditions in studies do not necessarily reflect patient behavior at home); MDI less expensive and
takes less time to administer than nebulizer; problem that most inhalers do not have dose counter (now in development); dry
powder inhalants—breath-activated (patient must be able to generate enough inspiratory pressure to activate inhaler); lack
of propellant avoids potential harm to environment; requires less coordination in cooperative child; most dry powder inhalants
have dose counters; when is device depleted of active ingredient?—patients may be puffing for months on empty inhaler;
shaking inhaler, watching for visible propellant, or floating device in water not effective; with first use, put date on
inhaler; know maximum number of doses in inhaler; when limit reached, inhaler should be discarded; dose counters make
monitoring easier
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| Nebulizers: easier to use correctly than inhaler with valved holding chamber; most nebulizer chambers designed for single
use (after few days, device clogs easily); patient may be using nebulizer and getting no medication (proper cleaning
essential); Pari LC Plus jet nebulizer— breath controlled (relatively little medication lost when breathing out or not
breathing); Sidestream nebulizer (Respironics)—good particle size; washable; not breath-controlled (if patient stops to
cough or talk, much medication lost); common disposable nebulizer chamber—effective for use in office but not at home
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| Prognosis: >95% of patients can achieve complete control of their asthma (compliance biggest obstacle); many patients
require controller medication only during active season
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| DIAGNOSIS AND MANAGEMENT OF BRONCHIOLITIS: CURRENT AAP GUIDELINES
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| Bronchiolitis defined (American Academy of Pediatrics [AAP], 2006): viral infection of lower respiratory
tract, characterized by acute inflammation, edema, and necrosis of epithelial cells lining small airways; increased mucus
production and bronchospasm
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| Epidemiology: respiratory syncytial virus (RSV) causes ≈70% of bronchiolitis (metapneumovirus, 10%-20%; parainfluenza,
influenza, and adenovirus, 10%-20%); by 2 yr of age, at least 90% of children have had RSV infection (20% develop
lower respiratory tract infection; 3% hospitalized); mortality rate close to 0%; peak age at presentation 2 to 5 mo;
rate in first month of life low, due to maternal antibodies
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| Clinical course: incubation period 2 to 8 days; upper respiratory tract infection (URTI; 1-3 days; most children develop
only URTI); worsening lower airway disease (3-5 days); full recovery (2-8 wk)
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| Diagnosis of bronchiolitis
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| AAP recommendations: diagnose bronchiolitis and assess severity of disease, based on history and physical examination;
clinicians should not order laboratory and radiologic studies routinely for diagnosis; assess risk factors for severe disease
when making decisions about evaluation and management of children with bronchiolitis; risk factors for severe
disease—age <12 wk; history of prematurity; underlying pulmonary disease; immunodeficiency
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| Clinical diagnosis: most children—upper respiratory prodrome, rhinorrhea, cough; other signs and symptoms—wheezing;
tachypnea; progressive respiratory effort (grunting, nasal flaring, retractions)
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| Chest radiography (Schuh et al, 2007)
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| Study design: “typical bronchiolitis” defined as nontoxic appearance, coryza, cough, first wheeze, and no other risk factors;
265 affected infants 2 to 23 mo of age received chest x-rays; simple bronchiolitis—prominent bronchial markings
and peribronchial infiltrates (airway disease only); complex bronchiolitis—airway disease and adjacent airspace disease,
but lacking lobar consolidation (more alveolar infiltrate); findings inconsistent with classic bronchiolitis—lobar
consolidation, cardiomegaly
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| Results (x-ray findings): incidence of simple bronchiolitis, 93% (246 of 265 cases); complex bronchiolitis, 6.9%; inconsistent
findings, 2 of 265 cases; admission decision changed based on radiography in 7 of 265 patients; antibiotic decision
changed in 29 of 39 (74.3%)
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| Laboratory screening for RSV (enzyme immunoassay [EIA] test): sensitivity, 40% to 93% (during peak season,
sensitivity and specificity 80% to 90%); sensitivity decreases as prevalence falls
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| Risk factors predictive of severe disease (Shaw, 1991): ill or toxic appearance (risk ratio 4.6; patients 4.5 times
more likely to be admitted to intensive care unit [ICU]); oxygen saturation <95% (risk ratio 3.3); atelectasis on chest x-
ray; prematurity; respiratory rate >70 bpm; age <3 mo
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| Prediction of need for intensive care (Pediatric Investigators Collaborative Network on Infections in
Canada [PICNIC], 1995): 25% of patients requiring ventilation had chronic lung disease (5% died; current mortality
lower); other risk factors—cardiac disease; prematurity; immunocompromise; age <6 wk; if no risk factors—risk of
requiring ventilation 3% (mortality rate 0%)
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| RSV therapies utilized in 36 hospitals (Christakis et al, 2005): >50% of hospitals used bronchodilators; need
for oxygen major indication for hospital admission; in some hospitals, 40% of patients received intravenous (IV) antibiotics
(as many as 40% received corticosteroids); other interventions —IV fluids; ICU admission; ventilation
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| AAP recommendation: bronchodilators should not be used routinely in management of bronchiolitis; option—perform
carefully monitored trial of α- or β-adrenergic medication (epinephrine or albuterol); inhaled bronchodilators should be
continued only if there is positive clinical response to trial
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| Evidence for modest short-term improvement: 57% of children improved with administration of bronchodilator (43%
with placebo); more management tips—mild side effects common (tachycardia, hypoxemia); no impact on overall
course of disease in inpatients; studies comparing epinephrine to albuterol mixed
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| Cochrane reviews: Gadomski and Bhasale (2006)—clinical score for inpatients (≈30 min, slight improvement from
bronchodilators); for outpatients, tendency for improvement (some patients respond, some do not); however, no clinical
difference in improvement in overall disease; bronchodilators do not prevent hospital admission; Hartling et al
(2004)—epinephrine vs albuterol (at 30-90 min, no difference in efficacy)
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| AAP recommendation: corticosteroid medications should not be used routinely in management of bronchiolitis
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| Meta-analysis: clinical scores—treatment vs no treatment (on day 3, no significant difference in clinical score); patients
with previous history of wheezing (no difference in clinical score); benefit seen in patients with atopic asthma (not
bronchiolitis); studies by Schuh and others—even at higher doses, corticosteroids do not affect length of hospital stay
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| Dexamethasone for bronchiolitis (Corneli et al; Pediatric Emergency Care Applied Research Network
[PECARN], 2007): study design—600 infants with first episode of wheezing diagnosed as moderate to severe
bronchiolitis in emergency department (ED); trial compared dexamethasone (1 mg/kg) to placebo; primary outcome hospital
admission; results—41% of those in placebo group admitted to hospital (vs 39.7% in dexamethasone group; difference
1.3%)
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| O2 therapy: supplemental O2 indicated if oxyhemoglobin saturation falls persistently below 90% in previously healthy infants;
if saturation of peripheral O2 (SpO2 ) persistently falls below 90%, adequate supplemental O2 should be used to
maintain SpO2 ≥90%; corollary—O2 may be discontinued if SpO2 ≥90%, infant feeding well, and has minimal respiratory
distress; continuous pulse oximetry not needed routinely; once patient stable, measure O2 saturation as part of q4h vital
signs
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| Antibacterial medications: use only in children with bronchiolitis who have specific indication of coexistence of bacterial
infection; when present, bacterial infection should be treated in same manner as in absence of bronchiolitis; incidence
of severe bacterial infection low
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| Supportive measures: assess hydration and ability to take fluids orally; chest physiotherapy should not be used routinely
in management of bronchiolitis (studies show no benefit); nasal suctioning may provide temporary relief of nasal
congestion
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| Preventing nosocomial spread of RSV: hand decontamination most important step; hands should be decontaminated
before and after direct contact with patients, after contact with inanimate objects in direct vicinity of patients, and
after removing gloves; alcohol-based rubs preferred, but hand washing with antimicrobial soap adequate; educate personnel
and family members on hand sanitation; some evidence that gowns and gloves (but not masks) useful in decreasing
nosocomial spread to patients
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| Decreasing risk for bronchiolitis: 4 mo of breast-feeding decreases risk for viral infection; passive smoking alters
airway defenses and makes child more susceptible to illness; smaller day care center preferable
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| Conclusion: bronchiolitis clinical diagnosis; bronchiolitis self-limited disease; observation active intervention
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Internet Resources
Guidelines for the diagnosis and management of asthma (National Heart, Lung, and Blood Institute [NHLBI], 2007):
www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm
Clinical practice guideline; diagnosis and management of bronchiolitis (American Academy of Pediatrics [AAP], 2006):
http://aappolicy.aappublications.org/practice_guidelines/index.dtl
Suggested Reading
American Academy of Pediatrics Subcommittee on Diagnosis and Management of Bronchiolitis: Diagnosis
and management of bronchiolitis. Pediatrics 118:1774, 2006; Bass JL, Gozal D: Oxygen therapy for bronchiolitis.
Pediatrics 119:611, 2007; Bhogal S et al: Written action plans for asthma in children. Cochrane Database Syst
Rev 3:CD005306, 2006; Christakis DA et al: Variation in inpatient diagnostic testing and management of bronchiolitis.
Pediatrics 115:878, 2005; Corneli HM et al; Bronchiolitis Study Group of the Pediatric Emergency Care
Applied Research Network (PECARN): A multicenter, randomized, controlled trial of dexamethasone for bronchiolitis.
N Engl J Med 357:331, 2007; Gadomski AM, Bhasale AL: Bronchodilators for bronchiolitis. Cochrane Database
Syst Rev 3:CD001266, 2006; Hall CG, Lieberthal AS: Viral testing and isolation of patients with bronchiolitis.
Pediatrics 120:893, 2007; Hartling L et al: Epinephrine for bronchiolitis. Cochrane Database Syst Rev 1:CD003123,
2004; Levine DA et al: Risk of serious bacterial infection in young febrile infants with respiratory syncytial virus. Pediatrics
113:1728, 2004; Lieberthal AS: Oxygen therapy for bronchiolitis. Pediatrics 120:686, 2007; Pelletier AJ et
al: Direct medical costs of bronchiolitis hospitalizations in the United States. Pediatrics 118:2418, 2006; Purcell K,
Fergie J: Concurrent serious bacterial infections in 2396 infants and children hospitalized with respiratory syncytial virus
lowers respiratory tract infections. Arch Pediatr Adolesc Med 156:322, 2002; Schuh S et al: Evaluation of the utility of
radiography in acute bronchiolitis. J Pediatr 150:429, 2007; Shaw KN et al: Outpatient assessment of infants with bronchiolitis.
Am J Dis Child 145:151, 1991; Wang EE et al: Pediatric Investigators Collaborative Network on Infections in
Canada (PICNIC) prospective study of risk factors and outcomes in patients hospitalized with respiratory syncytial viral
lower respiratory tract infection. J Pediatr 126:212, 1995.
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