eMedicine Specialties > Emergency Medicine > Pediatric

Pediatrics, Reactive Airway Disease

Eric S Chin, MD, Consulting Staff, Department of Emergency Medicine, Kaiser Permanente Hospital, South San Francisco

Updated: Jun 30, 2009

Introduction

Background

Not all children who wheeze have asthma. Most children younger than 3 years who wheeze are not predisposed to asthma. Only 30% of infants who wheeze go on to develop asthma. Reactive airway disease has a large differential diagnosis and must not be confused with asthma.

Clinical factors suggestive of childhood asthma include recurrent wheezing, symptomatic improvement with a bronchodilator, recurrent cough, exclusion of alternative diagnoses, and suggestive peak flow findings.

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Pathophysiology

Numerous environmental stimuli induce an allergen-antibody interaction, causing a release of mediators that create airway inflammation. Airway inflammation is the primary factor responsible for smooth muscle hyperresponsiveness, edema, and increased mucous production, resulting in increased work of breathing. A complex interaction occurs between inflammatory cells and airway epithelium. Mediators released from mast cells induce edema, mucous secretion, and bronchospasm. These mediators include histamine, tryptase, heparin, leukotrienes, platelet-activating factor, cytokines, interleukins, and tumor necrosis factor. The other inflammatory cells (ie, eosinophils, lymphocytes) also release mediators and create a toxic environment to respiratory epithelial cells.

In infants and children younger than 3 years, the intrapulmonary airways are so small that any lower airway infection results in diminished airway function. Other anatomical factors, such as poor collateral ventilation, decreased elastic recoil pressure, and a partially developed diaphragm, may predispose the very young child to respiratory compromise.

Speculation exists that all infants are born with highly responsive airways. Increased immunoglobulin E (IgE) levels have been found in those younger than 2 years. A decrease in airway responsiveness may be associated with environmental allergens, viral respiratory diseases, and hereditary factors. 

Rhinovirus infections are an important contributor to asthma exacerbations in children. Hence, therapies against rhinovirus might reduce the risk of severe exacerbations.²
 
Breastfeeding might protect children younger than 24 months of age against recurrent wheezing. The cytokine, TGF-B1, in human milk may have both suppression and enhancement functions in the immune reaction.

Exposure to maternal environmental tobacco smoke during pregnancy or the first year appears to predispose children to reactive airway disease.

Current research on the genetic basis for the pathogenesis of asthma may lead to new diagnostic and preventive treatments. The ADAM33 gene on the short arm of chromosome 20 is hypothesized as being important in the development and pathogenesis of asthma.

Frequency

United States

Risk of developing asthma is 7% if neither parent has asthma, 20% if one parent has asthma, and 64% if both parents have asthma. In the United States, approximately one half of all ED and clinic visits for asthma are children younger than 18 years. Pediatric asthma is a chronic, multifactorial, lower airway disease that affects 5-15% of children (2.7 million children in the United States alone). ED visits peak in the fall. School holidays disrupt the spread of infections with a subsequent decrease in hospitalization. Asthma prevalence appears to be increasing worldwide. Air pollutants may play a role in the prevalence increase. Higher prevalence occurs in poverty stricken urban areas where children are less likely to have routine doctor visits and access to the availability of medications.

A correlation may exist between high levels of exposure to cockroach allergen and the frequency of asthma-related health problems in inner-city children.³ Homes in poverty areas were more likely to have high cockroach allergen levels. Asthma may develop in children from early exposure to cockroach allergen.⁴

Status asthmaticus appears to be on the rise; several retrospective studies reflect an increase in hospital admissions, particularly in those younger than 4 years. Fewer hospital and ED visits occur in children using inhaled corticosteroid therapy.

An algorithm has been developed to determine the risk factors for developing persistent asthma symptoms among children younger than 3 years of age who had 4 or more episodes of wheezing during the previous year.⁵  The Asthma Predictive Index included either (1) one of the following: parental history of asthma, a physician diagnosis of atopic dermatitis, or evidence of sensitization to aeroallergens; or (2) two of the following: evidence of sensitization to foods, ≥4% peripheral blood eosinophilia, or wheezing apart from colds. 

An association may exist between obesity and childhood asthma. Increased resistin, an adipokine produced by adipose tissue, may play a negative predictive role in asthma.⁶

International

Worldwide, the prevalence of asthma is increasing. Asthma is found to be more common in Western countries than in developing countries. Asthma is more prevalent in English-speaking countries. Prevalence increases as a developing country becomes more Westernized and urbanized.

Mortality/Morbidity

• One third of all children younger than 18 years are significantly affected.
• Reactive airway disease accounts for 13 million health care visits annually in the United States and 200,000 hospitalizations for which approximately $1.8 billion is spent annually.
• Mortality rates are increasing despite new pharmacologist advances.

Race

Reactive airway disease is more common in black and Hispanic children; hospitalization rates in African Americans are 4 times greater than in the white population.

No correlation exists with income or education level from a retrospective review.

Sex

The male-to-female ratio is 1.5:1

Age

The peak prevalence of asthma is in those aged 6-11 years.

Clinical

History

• The following information should be elicited:
  • Initiation of symptoms (More than a few days decreases the chance of quick reversal in the ED because of prolonged inflammation and mucous plug formation)
  • Upper respiratory infection (URI) symptoms, fever, and production of phlegm
  • Precipitating factors
  • Use of an bronchodilator inhaler; how often it was used in the past 24-48 hours prior to the ED visit; how often it was used over the past week or month
  • How many inhalers were used in the past month
  • How many puffs are being administered with each use and if the inhaler is being used with a spacer
  • Compliance with use of corticosteroid inhaler (Ask if it was used daily despite any symptoms of wheezing)
  • Date of last ED visit; how severe the current episode is compared with previous episodes⁷
  • Date of the last hospital admission
  • Number of admissions in the past year; number of intensive care unit admissions
  • History of intubation and how long ago it was
  • Recent use of oral steroids
  • Factors that usually initiate symptoms
  • Whether this is a typical episode
  • Presence of any underlying cardiac, GI, or immunologic diseases
  • Other current medications
  • Exposure to tobacco smoke and allergens (ie, cat dander)
  • Ability to tolerate fluids
  • Recent mental status changes
  • Baseline peak expiratory flow rate (PEFR)
  • History of atopic dermatitis or other allergic skin conditions⁸
  • Dry cough or wheezing  that is often worse at night
  • History of recurrent wheezing and dyspnea
  • Wheeze or cough after active playing
  • Relationship to emotional expressions
  • Relationship to menses

Physical

• Fever
• Tachycardia
• Tachypnea, dyspnea
• Wheezing
• Coughing
• Flushing, cyanosis
• Flaring of nasal alae
• Presence of nasal polyps and nasal secretions
• Intercostal retractions
• Poor feeding
• Diaphoresis
• Distant breath sounds, hyperresonance (Beware of "silent chest," too little air movement to hear wheezing.)
• Pulsus paradoxus (mild asthma pulsus paradoxus = 10, moderate = 10-20, severe >20)
• Altered mental status
• Decreased peak expiratory flow rate
• Inspiratory-to-expiratory ratio (An increased inspiratory-to-expiratory ratio is a bad sign.)
• Allergic shiner (ie, dark semicircles of skin under the eyes)
• Transverse nasal skin fold from repeatedly rubbing the nose
• Increased anteroposterior diameter or pectus carinatum
• Murmur
• Clubbing
• Subcutaneous emphysema
• Mild asthma: the child can speak in sentences and is not short or breath at rest, slight increase in respiratory rate but no accessory muscle usage
• Moderate asthma: the child is short of breath while talking and speaks in short phrases, respiratory and heart rate increased, loud wheezes throughout expiratory phase
• Severe asthma: the child is short of breath at rest, very agitated, sitting upright and not speaking or using only one single word, wheezes throughout inspiration and expiration
• Respiratory arrest imminent if child is drowsy and wheezes are absent

Causes

• Precipitants of asthma exacerbation
  • Infection -Respiratory syncytial virus (RSV) most commonly isolated from infants and preschool-aged children; Mycoplasma pneumoniae most commonly isolated from school-aged children
  • Tobacco smoke
  • Pet dander, cockroach and dust mite allergen
  • Molds
  • Pollen
  • Exercise
  • Weather changes
  • Stress
  • Drugs
• A precipitant of bronchiolitis is respiratory infection, usually due to RSV.
• Gastroesophageal fistula
• Mediastinal mass (external compression of the airway)
• Cystic fibrosis

Differential Diagnoses

Other Problems to Be Considered

Cystic fibrosis
Enlarged mediastinal mass
Gastroesophageal reflux (GER)
Laryngeal webs
Roundworms
Tracheoesophageal fistula
Vascular rings
Ventricular septal defect (VSD)

Workup

Laboratory Studies

• A complete blood count (CBC) may be indicated for a suspected viral infection (lymphocytosis, leukopenia), parasitic infection (eosinophilia), or hemosiderosis.
• An arterial blood gas (ABG) determination should be performed for any patient in status asthmaticus to check for hypoxia, hypercarbia, or acidosis; alternatively, a venous blood gas measurement can be used to assess for hypercarbia and acidosis and combined with pulse oximetry monitoring.
• An assessment of electrolyte levels may reveal hypokalemia in patients who are using albuterol.
• Although theophylline is prescribed less frequently, a theophylline level is useful for those on the drug.

Imaging Studies

• Routine radiography does not need to be part of the initial routine workup of asthma.⁹  
• Consider chest radiography if increased temperature, absence of family history of asthma, and the presence of localized wheezes or rales.
  • Hyperinflation
  • Peribronchial thickening
  • Atelectasis
  • Radiographs may provide evidence of foreign body, associated vascular anomalies, cardiac enlargement, pulmonary hypertension, infiltrates, or masses. 

Other Tests

• All chronically wheezing infants and children with chronic asthma should have a sweat chloride test for cystic fibrosis at a subsequent primary care provider (PCP) visit or during inpatient evaluation.
• A tuberculosis skin test may be indicated if significant risk factors exist.
• Allergy testing
• Exercise tolerance testing

Procedures

• Spirometry (decreased forced expiratory volume in one second [FEV₁])
  • Bedside spirometry is the primary procedure for children with RAD who are older than 5 years.
  • Patients with decreased FEV₁ require further evaluation and treatment.
• A barium swallow may be indicated to determine any esophageal, pulmonary, or vascular pathology, particularly a tracheoesophageal fistula.
• Bronchoscopy (rarely indicated) Table 1. Peak Flow Rates in Liters per Minute¹⁰

  Height in Inches	Average Rate	Range*	Height in Inches	Average Rate	Range*
  40	150	110-190	56	330	240-420
  41	160	115-205	57	340	240-420
  42	170	120-220	58	360	260-460
  43	180	130-220	59	375	270-480
  44	190	135-245	60	390	280-500
  45	200	145-255	61	400	290-510
  46	210	150-270	62	415	300-530
  47	220	160-280	63	430	310-550
  48	230	165-295	64	445	320-570
  49	240	175-305	65	460	330-590
  50	250	180-320	66	480	345-615
  51	260	190-330	67	500	360-640
  52	270	195-345	68	515	370-660
  53	280	200-360	69	530	380-680
  54	300	215-385	70	550	395-705
  55	315	225-405	71	570	410-730

  
  *Includes 95% of white males aged 7-20 years.Derived and adapted from J Pediatr 1979;95:192-6.
• Peak expiratory flow (PEF) is the most common form of pulmonary function test monitoring. Record the best of 3 attempts. Possible life-threatening asthma exacerbation with PEF predicted of less than 30%; severe exacerbation, with less than 50%; and moderate exacerbation, with less than 80%.

Treatment

Prehospital Care

Provide oxygen during transport, cardiorespiratory monitoring and pulse oximetry, beta-agonist nebulization, and intravenous access if the patient is in moderate-to-severe respiratory distress. Subcutaneous terbutaline or epinephrine may be considered if severe distress and very poor air movement are present.

Emergency Department Care

Mild-to-moderate exacerbations (PEF >50% and/or oxygen saturation >92% on room air)

Albuterol is recommended for the initial treatment of mild-to-moderate acute exacerbations of asthma, administered either by a metered-dose inhaler with spacer (with or without mask) or by a hand-held nebulizer.

Two to six puffs of albuterol via metered-dose inhaler with spacer or 0.15 mg/kg (2.5 mg minimum dose, 5 mg maximum dose) via hand-held nebulizer every 20 minutes for up to 3 doses is recommended.

Oral dexamethasone 0.6 mg/kg/dose (first-line treatment) or oral prednisolone 2 mg/kg/dose (second-line treatment).

Severe exacerbations (PEF <50% and/or oxygen saturation <92% on room air) or exacerbations refractory to first-line treatment

Nebulized ipratropium bromide and short-acting beta-agonists, every 20 minutes for up to 3 treatments, are recommended for the treatment of children (250 mcg/dose) and adolescents (500 mcg/dose) with severe exacerbations. 

Supplemental oxygen (by nasal cannula or mask, whichever is better tolerated) to maintain an oxygen saturation >92% is recommended during the delivery of short-acting beta-agonists and anticholinergics in patients with severe exacerbations.
  
Oral dexamethasone 0.6 mg/kg/dose (first-line treatment) or oral prednisolone 2 mg/kg/dose (second-line treatment) may be administered if early response to bronchodilators, otherwise parenteral steroids (dexamethasone or methylprednisolone) should be given.

Management of status asthmaticus

Management of status asthmaticus includes continuous inhaled beta-agonist of 0.5 mg/kg/h, nebulized ipratropium, IV dexamethasone 0.6 mg/kg, and intravenous magnesium 25-40 mg/kg (given over 20 min as a single dose up to a maximum of 2 g) concurrently for the child in severe respiratory distress. Consideration for IM or SC epinephrine or terbutaline. IV hydration is recommended in severe asthmatic requiring admission. Patient should be kept NPO in case of respiratory failure and need for intubation.

Frequent evaluation of the patient's cardiorespiratory status is imperative. Pulse oximetry and noninvasive end-tidal CO ₂ monitoring are ideal. Serial blood gas measurements may be necessary if the patient remains critically ill. If a child fails to improve with these interventions, admission to an ED observation area, inpatient unit, or pediatric critical care unit should be initiated. Continued failure to respond with mental status changes is an ominous finding and suggests rising pCO₂. Consider noninvasive positive pressure ventilation (PPV) (eg, continuous positive airway pressure [CPAP] 3-5 cm H₂ O, intermittent positive airway pressure [IPAP] 10-18 cm H₂ O) prior to rapid sequence intubation. Consider the increased risk of pneumothorax if intubated. Optimize ventilator settings.

• Avoid intubation if possible.
  • Consider all other measures first (eg, bilevel positive airway pressure, continuous beta-agonist, helium-oxygen mixture [heliox]).
  • For rapid sequence intubation, use ketamine for sedation/dissociative state, 1 mg/kg IV (provides 15 min anesthesia and may provide further bronchodilation for up to 30 min) then paralysis with succinylcholine, 2 mg/kg IV preceded by atropine 0.02 mg/kg in the pediatric patient (older adolescent: 1-1.5 mg/kg IV without atropine) may be used. For more information, see Tracheal Intubation, Medications.
  • Tube size = (age/4) + 4
  • Avoid nasal intubation. Oral intubation allows for a larger tube size and easier access for suctioning and bronchoscopy.
• Albuterol
  • Aerosolized albuterol, a beta2-agonist, relieves bronchospasm.
  • Although studies suggest that delivery of albuterol by metered dose inhaler (MDI) with spacer is equally as effective as nebulization in children as young as 2 years, nebulization is recommended for those younger than 6 years or those with severe asthma or poor air movement. Infants and small children need doses of MDI equivalent to those used by adults because of decreased retention time of the drug in the lung, because of their inability to hold their breath, and because the size of the airway limits delivery of medication.
  • The use of chlorofluorocarbon (CFC) inhalers is being phased out to protect the ozone layer. A decreased ozone layer may lead to health and environmental problems. No difference exists in efficacy between CFC and non-CFC inhalers.
  • Continuous albuterol nebulization may reduce the need for endotracheal intubation in status asthmaticus.
  • Levalbuterol, the single isomer, may result in higher patient discharge rates from the ED or hospital and hence may be more cost-effective than the traditional, racemic albuterol given.
• Ipratropium: The combination of a beta-adrenergic agonist and ipratropium improves FEV₁ more effectively than either agent used alone. Other anticholinergics, such as glycopyrrolate, also may be nebulized.
• Corticosteroids
  • Oral steroids given early during ED treatment reduces hospital admission rates.
  • Dexamethasone (given as an oral dose or parenteral dose) is the preferred steroid because of longer duration of action and the need for only one additional dose (0.6 mg/kg) to be given 1 or 2 days later. 
  • The dosages for prednisone and prednisolone both are 2 mg/kg/dose. Prednisone, in tablet form, is given to older children or adolescents. Prednisolone can be given orally (Prelone), or methylprednisolone (Solu-Medrol) may be given parenterally. 
  • Nebulized corticosteroids could prove useful in the ED setting. Further studies are pending.
  • Long-term use of inhaled steroids may have a deleterious effect on lung and organ development during the first 3 years of life.
• Oral beta2-agonists have no role in the acute setting. Oral beta-agonists may be beneficial in preschool children for outpatient therapy.
• Theophylline has no role in the acute setting. It may be considered for outpatient treatment in patients with poor compliance with inhaled beta-agonist and for patients with nocturnal asthma exacerbation.
• Magnesium at 40 mg/kg IV may provide a "therapeutic bridge." Studies remain in conflict regarding magnesium's effectiveness.
• 
  

  

  Stepwise approach for managing asthma in children 0 to 4 years of age. National Institutes of Health. National Heart, Lung, and Blood Institute. National Asthma Education and Prevention Program. Expert Panel Report 3: Guidelines for the diagnosis and management of asthma. August 2007. NIH publication no. 07-4051. Available at: http://www.nhlbi.nih.gov/guidelines/asthma/index.htm. 3 Accessed December 30, 2007. PRN, As necessary.

  
  

Consultations

• Pediatric emergency medicine specialist
• Pediatric critical care specialist
• Pediatric pulmonary specialist

Medication

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Beta2-adrenergic agonist agents, inhaled

These agents relieve reversible bronchospasm by relaxing smooth muscles of the bronchi. Systemic beta-agonists allow systemic delivery of medication to the pulmonary system in medical conditions where bronchoconstriction may inhibit delivery of medication to desired site because of little to no air movement. Oral administration is less effective than inhaled beta-adrenergic agonists, and has therefore fallen into disfavor. Does not appear to alter admission.

Salmeterol is a highly selective, long-acting beta2-adrenergic agonist with bronchodilatory activity. Salmeterol's benzene moiety resembles the structure of catecholamines, and occupies the active site of beta2-adrenergic receptor, while the long, lipophilic side chain of salmeterol, binds to the so-called exosite near the beta2-receptors. The binding at the exosite allows the active portion of the molecule to remain at the receptor site and continually engage and disengage with the receptor, therefore providing a long duration of action. This agent stimulates intracellular adenyl cyclase to catalyze the conversion of adenosine triphosphate to cyclic-3',5'-adenosine monophosphate (cAMP). Increased cAMP levels result in relaxation of bronchiolar smooth muscle, bronchodilation, and increased bronchial airflow.

Salmeterol (Serevent Diskus)

Long-acting beta2-agonist. Not for emergent use since onset is 30 min or more. By relaxing the smooth muscles of the bronchioles in conditions associated with bronchitis, emphysema, asthma, or bronchiectasis, can relieve bronchospasms. Effect may also facilitate expectoration.
Adverse effects are more likely to occur when administered at high or more frequent doses than recommended. Available as a dry powder for inhalation in 50 mcg blister packs.

Dosing

Adult

Prevention: 50 mcg inhaled bid approximately 12 h apart

Pediatric

Prevention:
<4 years: Not established
>4 years: Administer as in adults

Interactions

Concomitant use of beta-blockers may decrease bronchodilating, and vasodilating effects of beta agonists such as salmeterol; concurrent administration with methyldopa may increase pressor response; coadministration with oxytocic drugs may result in severe hypotension; ECG changes and hypokalemia resulting from diuretics may worsen when coadministered with salmeterol

Contraindications

Documented hypersensitivity; angina, tachycardia, and cardiac arrhythmias associated with tachycardia

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Not indicated to treat acute asthmatic symptoms; black box FDA warning describes that chronic use may result in increased asthma morbidity and mortality, use only as additional therapy for patients not adequately controlled on other asthma-controller medications (eg, low- to medium-dose inhaled corticosteroids) or patients whose disease severity clearly warrants initiation of treatment with 2 maintenance therapies, including salmeterol

Albuterol (Ventolin HFA, Proventil HFA)

Beta-agonist for bronchospasm refractory to epinephrine. Relaxes bronchial smooth muscle by action on beta2-receptors with little effect on cardiac muscle contractility. May decrease mediator release from mast cells and basophils and inhibit airway microvascular leakage. MDI delivers 90 mcg/actuation.
Continuous therapy may reduce need for mechanical ventilation.

Dosing

Adult

Quick relief:
MDI: 2-4 actuations (180-360 mcg) q4h prn

Pediatric

Asthma exacerbation:
MDI:
>20 kg: 6 actuations (540 mcg) inhaled PO q20min initially
Nebulizer: 0.15 mg/kg/dose in 2 mL in 0.9% NaCl administered q20min; not to exceed 5 mg/dose; alternatively, 0.5 mg/kg/h continuous nebulization; not to exceed 15 mg/h

Interactions

Beta-adrenergic blockers antagonize effects; inhaled ipratropium may increase duration of bronchodilatation by albuterol; cardiovascular effects may increase with MAOIs, inhaled anesthetics, TCAs, and sympathomimetic agents

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in hyperthyroidism, diabetes mellitus, hypokalemia, muscle tremors, and cardiovascular disorders

Levalbuterol (Xopenex)

Used for treatment or prevention of bronchospasm. A selective beta2-agonist agent. Albuterol is a racemic mixture, while levalbuterol contains only the active R-enantiomer of albuterol. The S-enantiomer does not bind to beta2-receptors but may be responsible for some adverse effects of racemic albuterol, including bronchial hyperreactivity and reduced pulmonary function during prolonged use.

Dosing

Adult

Asthma exacerbation: 1.25-2.5 mg via nebulizer q20min for 3 doses, then 1.25-5 mg q1-4h prn

Pediatric

Asthma exacerbation: 0.075 mg/kg (minimum dose 1.25 mg) inhaled via nebulizer q20 min for 3 doses, then 0.075-0.15 mg/kg (not to exceed 5 mg/dose) q1-4h prn

Interactions

Decreased efficacy with beta-blockers; digoxin levels may be decreased; may potentiate the kaliuretic effects of drugs such as loop or thiazide diuretics

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Doses higher than 0.63 mg tid may cause tachycardia; immediate hypersensitivity reactions reported; caution in patients with hypokalemia; may cause paradoxical bronchospasm and increased pulse rate or blood pressure

Anticholinergic agents

These agents decrease muscle tone in the small and large pulmonary airways.

Ipratropium (Atrovent)

A quaternary ammonium anticholinergic bronchodilator acting at muscarinic receptors of the parasympathetic nervous system. Chemically related to atropine. Has antisecretory properties and, when applied locally, inhibits secretions from serous and seromucous glands lining the nasal mucosa.
Synergistic with beta2-agonists. Each actuation delivers 17 mcg. Solution for nebulization available as 0.02% (500 mcg/vial).

Dosing

Adult

Asthma exacerbation:
Nebulizer: 500 mcg q20min for 3 doses, then as needed
MDI: 8 actuations inhaled PO q20min prn up to 3 h

Pediatric

Asthma exacerbation:
Nebulizer: 500 mcg q20min for 3 doses, then q2-4h prn
MDI: 4-8 actuations inhaled PO q20min prn up to 3 h

Interactions

Drugs with anticholinergic properties, such as dronabinol, may increase toxicity; albuterol increases effects of ipratropium

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Not indicated for acute episodes of bronchospasm; caution in narrow-angle glaucoma, prostatic hypertrophy, and bladder neck obstruction

Beta2-adrenergic agonist agents, injection

These agents act to decrease the muscle tone in the small and large pulmonary airways.

Epinephrine (Adrenalin)

Elicits alpha-agonist effects that include increased peripheral vascular resistance, reversed peripheral vasodilatation, systemic hypotension, and vascular permeability. Beta2-agonist effects include bronchodilatation, chronotropic cardiac activity, and positive inotropic effects.

Dosing

Adult

Asthma exacerbation: 1:1000 solution (1 mg/mL) 0.1-0.5 mg SC q20min for 3 doses

Pediatric

Asthma exacerbation: 1:1000 solution (1 mg/mL) 0.01 mg/kg up to 0.3 mg/dose SC q20min for 3 doses
<30 kg: EpiPen Jr (1:2000) SC delivers 0.15 mg/dose
>30 kg: EpiPen (1:1000) SC delivers 0.3 mg/dose

Interactions

Increases toxicity of beta- and alpha-blocking agents and of halogenated inhalational anesthetics

Contraindications

Documented hypersensitivity; cardiac arrhythmias or angle-closure glaucoma; local anesthesia in areas such as fingers or toes because vasoconstriction may produce sloughing of tissue; not to use during labor (may delay second stage of labor)

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in elderly patients, prostatic hypertrophy, hypertension, cardiovascular disease, diabetes mellitus, hyperthyroidism, and cerebrovascular insufficiency; rapid IV infusions may cause death from cerebrovascular hemorrhage or cardiac arrhythmias

Terbutaline (Brethine)

Acts directly on beta2-receptors to relax bronchial smooth muscle, relieving bronchospasm and reducing airway resistance.

Dosing

Adult

Asthma exacerbation: 0.25 mg/dose SC repeated q20min once; not to exceed total dose of 0.5 mg in a 4-h period

Pediatric

Asthma exacerbation: 0.01 mg/kg SC up to 0.3 mg q20min up to 3 doses; alternatively, 2-10 mcg/kg IV loading dose over 10 min, then continuous IV infusion of 0.08-0.4 mcg/kg/min

Interactions

Concomitant use with beta-blockers may inhibit bronchodilating, cardiac, and vasodilating effects of beta-agonists; concomitant administration of MAOIs may result in hypertensive crisis; concurrent administration of oxytocic drugs such as ergonovine with terbutaline may result in severe hypotension

Contraindications

Documented hypersensitivity; tachycardia resulting from cardiac arrhythmias

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Paradoxical bronchoconstriction may occur with excessive use; through intracellular shunting, terbutaline may decrease serum potassium levels, which can produce adverse cardiovascular effects; decrease is usually transient and may not require supplementation

Methylxanthines

These agents provide bronchodilation at the cellular level. The exact mechanism is unknown (eg, alteration of intracellular calcium, inhibition of phosphodiesterase, and/or antagonism of prostaglandins). Routine addition to beta-agonist provides benefit in ED management. May be of benefit in impending respiratory failure.

Theophylline, 85% (Aminophylline)

Potentiates exogenous catecholamines, stimulates endogenous catecholamine release and diaphragmatic muscular relaxation, which, in turn, stimulates bronchodilation.
For bronchodilation, near toxic (>20 mg/dL) levels are usually required.
No role in acute asthma exacerbation.
Considered in children who are responding poorly on maximal therapy.

Dosing

Adult

Loading dose: 6 mg/kg IV
Maintenance dose: 0.7 mg/kg/h IV infusion

Pediatric

Loading dose: 6 mg/kg IV infused over 20-30 min
Maintenance dose:
6 weeks to 6 months: 0.5 mg/kg/h IV infusion
6 months to 1 year: 0.6-0.7 mg/kg/h IV infusion
1-9 years: 1-1.2 mg/kg/h IV infusion
9-12 years: 0.9 mg/kg/h IV infusion
>12 years: Administer as in adults

Interactions

Aminoglutethimide, barbiturates, carbamazepine, ketoconazole, loop diuretics, charcoal, hydantoins, phenobarbital, phenytoin, rifampin, isoniazid, and sympathomimetics may decrease effects of theophylline; theophylline effects may increase with allopurinol, beta-blockers, ciprofloxacin, corticosteroids, disulfiram, quinolones, thyroid hormones, ephedrine, carbamazepine, cimetidine, erythromycin, macrolides, propranolol, and interferon

Contraindications

Documented hypersensitivity; uncontrolled arrhythmias; peptic ulcers; hyperthyroidism; uncontrolled seizure disorders

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in peptic ulcer, hypertension, tachyarrhythmias, hyperthyroidism, and compromised cardiac function; do not inject IV solution >25 mg/min; patients with pulmonary edema or liver dysfunction are at greater risk of toxicity because of reduced drug clearance

Magnesium salt

These agents decrease acetylcholine release at the neuromuscular junction and may decrease resting tone of smooth muscle.

Magnesium sulfate

Thought to produce bronchodilation through counteraction of calcium-mediated smooth muscle constriction.

Dosing

Adult

2 g IV infused over 20-30 min

Pediatric

25-40 mg/kg IV not to exceed 2 g/dose, infuse over 20-30 min

Interactions

Concurrent use with nifedipine may cause hypotension and neuromuscular blockade; may increase neuromuscular blockade observed with aminoglycosides and potentiate neuromuscular blockade produced by tubocurarine, vecuronium, and succinylcholine; may increase CNS effects and toxicity of CNS depressants, betamethasone, and cardiotoxicity of ritodrine

Contraindications

Documented hypersensitivity; heart block; Addison disease; myocardial damage; severe hepatitis

Precautions

Pregnancy

A - Fetal risk not revealed in controlled studies in humans

Precautions

Magnesium may alter cardiac conduction leading to heart block in digitalized patients; respiratory rate, deep tendon reflex, and renal function should be monitored when electrolyte is administered parenterally; caution when administering magnesium dose because it may produce significant hypertension or asystole; in overdose, calcium gluconate, 10-20 mL IV of 10% solution, can be given as antidote for clinically significant hypermagnesemia

Gas mixture

This agent is a blend of oxygen and helium that is less dense than air.

Helium and oxygen (Heliox)

Reduces airway resistance in bronchi with turbulent flow because of low density. Decreases the work of breathing, hence, delaying the onset of respiratory muscle fatigue, allowing other therapies to work.
Available in mixtures of 80:20 (helium:oxygen), 70:30, and 60:40.

Dosing

Adult

80:20 mixture at 10 L/min by nonrebreather mask; may increase to 15 L/min

Pediatric

80:20 mixture at 10 L/min by nonrebreather mask

Interactions

None reported

Contraindications

None reported

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

None reported

General anesthetic

Nonbarbiturate anesthetic/analgesic agent. An induction agent for airway management in patients with status asthmaticus and has a brief bronchodilatory effect.

Ketamine (Ketalar)

Acts on the cortex and limbic system, decreasing bronchospasm.

Dosing

Adult

Intubation: 0.1 mg/kg IV followed by 0.5 mg/kg/h IV infusion for 3 h

Pediatric

Administer as in adults

Interactions

Increases CNS effects of narcotics, barbiturates, and hydroxyzine; thyroid hormones and muscle relaxants increase toxicity of ketamine

Contraindications

Documented hypersensitivity; angina; thyrotoxicosis; aneurysms; hypertension; congestive heart failure

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Resuscitative equipment should be immediately available during administration of medication

Mast cell stabilizers

These agents inhibit degranulation of sensitized mast cells following exposure to specific antigens.

Cromolyn (Intal)

Inhibits histamine release and slow-reacting substance of anaphylaxis from mast cell. MDI delivers 800 mcg/actuation. Solution for nebulization available as 20 mg/2 mL

Dosing

Adult

Prevention:
MDI: 2-4 actuations inhaled qid

Pediatric

Prevention:
MDI: 2 actuations tid/qid
Nebulizer: 20 mg (2 mL) inhaled via nebulization bid/qid

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Caution in severe renal or hepatic impairment; symptoms may reoccur when withdrawing drug

Leukotriene inhibitors

These agents inhibit the synthesis of leukotriene.

Zileuton (Zyflo)

Effective in aspirin-induced, cold air, and exercise-induced asthma. Not for use in acute episodes of asthma. Prophylactic use only.
Hepatic transaminase levels should be evaluated before initiation. Contraindicated in patients with active liver disease.

Dosing

Adult

Prevention: 600 mg PO qid

Pediatric

Prevention:
<12 years: Not recommended
>12 years: Administer as in adults

Interactions

Theophylline should be reduced by 50% for those taking both agents; coadministration with propranolol results in increased beta-blocker activity; coadministration with warfarin results in increased PT (monitor closely)

Contraindications

Documented hypersensitivity; active liver disease

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in hepatic impairment, may increase LFTs; neuropsychiatric events have been reported, and following further FDA evaluation, the prescribing information has been updated to include case reports during postmarketing surveillance that include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor

Zafirlukast (Accolate)

Cysteinyl leukotriene-receptor antagonist. Inhibits aspirin-induced, cold air, and exercise-induced asthma.
Not for use in acute episodes of asthma.

Dosing

Adult

Prevention: 20 mg PO bid between meals

Pediatric

Prevention:
<5 years: Not established
5-11 years: 10 mg PO bid
>12 years: Administer as in adults

Interactions

Erythromycin and theophylline reduce plasma concentrations; coadministration with warfarin results in increase in PT (monitor closely); coadministration with aspirin increases zafirlukast effects

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Not a bronchodilator; have appropriate rescue medication available; caution in hepatic impairment; neuropsychiatric events have been reported, and following further FDA evaluation, the prescribing information has been updated to include case reports during postmarketing surveillance that include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor

Montelukast (Singulair)

Cysteinyl leukotriene-receptor antagonist. Inhibits aspirin-induced, cold air, and exercise-induced asthma. Not for use in acute episodes of asthma.

Dosing

Adult

Prevention: 10 mg PO every evening

Pediatric

Prevention:
<1 year: Not established
12-23 months: 1 packet of 4 mg oral granules PO every evening
2-5 years: 4 mg-chew tab or granules every evening
6-14 years: 5 mg PO every evening
>14 years: Administer as in adults

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Not a bronchodilator; have appropriate rescue medication available; neuropsychiatric events have been reported, and following further FDA evaluation, the prescribing information has been updated to include case reports during postmarketing surveillance that include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor

Corticosteroid

These agents have anti-inflammatory properties and cause profound and varied metabolic effects. They modify the body's immune response to diverse stimuli. Oral prednisone should never be substituted for an inhaled corticosteroid in children with a severe acute asthma exacerbation.

Frequent use of inhaled corticosteroid therapy is associated with less ED visits and less hospitalizations. Current research has not proven any long-term adverse effects with children receiving long-term inhaled corticosteroid.

Dexamethasone (Decadron)

Has many pharmacologic benefits but significant adverse effects. Stabilizes cell and lysosomal membranes, increases surfactant synthesis, increases serum vitamin A concentration, inhibits prostaglandin and proinflammatory cytokines (eg, TNF-alpha, IL-6, IL-2, and IFN-gamma). The inhibition of chemotactic factors and factors that increase capillary permeability inhibits recruitment of inflammatory cells into affected areas. Suppresses lymphocyte proliferation through direct cytolysis and inhibits mitosis. Breaks down granulocyte aggregates, and improves pulmonary microcirculation. Has multiple glucocorticoid and mineralocorticoid effects.
Readily absorbed via the GI tract and metabolized in the liver. Inactive metabolites are excreted via the kidneys. Lacks salt-retaining property of hydrocortisone.
Patients can be switched from an IV to PO regimen in a 1:1 ratio.

Dosing

Adult

Asthma exacerbation: 16 mg PO/IM/IV for 2 d

Pediatric

Asthma exacerbation: 0.6 mg/kg PO/IM/IV; not to exceed 16 mg to be given in 2 separate doses (ie, initial dose, then 2nd dose administered 24-48 h afterward)

Interactions

Effects decrease with coadministration of barbiturates, phenytoin and rifampin; dexamethasone decreases effect of salicylates and vaccines used for immunization

Contraindications

Documented hypersensitivity; active bacterial or fungal infection

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Increases risk of multiple complications, including severe infections; monitor adrenal insufficiency when tapering drug; abrupt discontinuation of glucocorticoids may cause adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections are possible complications of glucocorticoid use

Prednisolone (Orapred, Prelone, Pediapred)

Glucocorticosteroid that occurs naturally and synthetically. Used for both acute and chronic asthma. May decrease inflammation by reversing increased capillary permeability and suppressing PMN activity.
Loading or initial dose should be taken all at once in the am; may suppress natural cortisone production; hence, requires tapering the dose upon discontinuation.
As soon as the dose for relief is found, a maintenance dose may be established until the nonsteroidal drugs are effective; must always use a decreasing dose to avoid serious renal suppression.
In seasonal allergy a "booster" of prednisone may speed resolution of symptoms. Quite effective in "exhaustion" stage of seasonal allergy.

Dosing

Adult

Tapered dose for asthma exacerbation: 30 mg PO on day 1, 25 mg PO in am on day 2, continue decreasing dose by 5 mg/d each day until 5 mg is administered on day 6, then discontinue
Other regimens: Up to 60 mg PO qd, or every other day to control symptoms, or 40-60 mg/d for 3-10 d

Pediatric

Asthma exacerbation: 0.25-2 mg/kg PO qd or q2d

Interactions

Decreases effects of salicylates and toxoids (for immunizations); phenytoin, carbamazepine, barbiturates, and rifampin decrease effects of corticosteroids

Contraindications

Documented hypersensitivity; viral, fungal, or tubercular skin lesions

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in hyperthyroidism, osteoporosis, cirrhosis, nonspecific ulcerative colitis, peptic ulcer, diabetes, and myasthenia gravis

Prednisone (Sterapred)

May decrease inflammation by reversing increased capillary permeability and suppressing PMN activity.

Dosing

Adult

Asthma exacerbation: 5-60 mg/d PO qd or divided bid/qid; taper over 2 wk as symptoms resolve
Alternatively, administer 5-60 mg/d for 7 d without taper

Pediatric

Asthma exacerbation: 1-2 mg/kg PO qd or divided bid/qid; taper over 2 wk as symptoms resolve
Alternatively, administer above dose 7 d without taper

Interactions

Coadministration with estrogens may decrease clearance; concurrent use with digoxin may cause digitalis toxicity secondary to hypokalemia; phenobarbital, phenytoin, and rifampin may increase metabolism of glucocorticoids (consider increasing maintenance dose); monitor for hypokalemia with coadministration of diuretics

Contraindications

Documented hypersensitivity; viral infection, peptic ulcer disease, hepatic dysfunction, connective tissue infections, and fungal or tubercular skin infections; GI bleeding or ulceration

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Abrupt discontinuation of glucocorticoids may cause adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections may occur with glucocorticoid use

Methylprednisolone (Medrol, Solu-Medrol)

For treatment of inflammatory and allergic reactions. By reversing increased capillary permeability and suppressing PMN activity, may decrease inflammation. Allows reduction of ongoing airway inflammation. May increase responsiveness to beta2-agonists by increasing the number of beta2-adrenergic receptors. Prophylactic inhaled steroids in those diagnosed with asthma may impede airway remodeling, bronchial hyperreactivity, and future airway damage.
Systemic adverse effects rarely occur with inhaled corticosteroids. Systemic response time is the same in IV and PO.
Steroid use is recommended if minimal improvement occurs after first beta2-agonist treatment, the patient was recently discontinued from steroids, the patient reports a history of asthma symptoms for a few days before presentation, or URI-associated symptoms are present.

Dosing

Adult

Asthma exacerbation: 125 mg IV qid

Pediatric

Asthma exacerbation: 1-2 mg/kg/d PO qd or divided bid; alternatively, 0.5-2 mg/kg/dose IV q6h

Interactions

Coadministration with digoxin may increase digitalis toxicity secondary to hypokalemia; estrogens may increase levels of methylprednisolone; phenobarbital, phenytoin, and rifampin may decrease levels of methylprednisolone (adjust dose); monitor patients for hypokalemia when taking medication concurrently with diuretics

Contraindications

Documented hypersensitivity; viral, fungal, or tubercular skin infections

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Hyperglycemia, edema, osteonecrosis, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, growth suppression, myopathy, and infections are possible complications of glucocorticoid use

Budesonide (Pulmicort Flexhaler, Pulmicort Respules)

Inhibits bronchoconstriction mechanisms, produces direct smooth muscle relaxation, may decrease number and activity of inflammatory cells, in turn decreasing airway hyperresponsiveness. Has extremely potent vasoconstrictive and anti-inflammatory activity. Alters level of inflammation in airways by inhibiting multiple types of inflammatory cells and decreasing production of cytokines and other mediators. Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing capillary permeability.
Available as powder for inhalation in 90 mcg/actuation (actuation delivers ~80 mcg) or 180 mcg/actuation (actuation delivers ~160 mcg). Also available as suspension for nebulized inhalation in 0.25-mg/2 mL, 0.5-mg/2 mL, and 1-mg/2 mL. Indicated for maintenance treatment of asthma and prophylactic therapy.

Dosing

Adult

Dry powder oral inhalant (Flexhaler): 180-360 mcg inhaled PO bid initially; may increase if needed, not to exceed 720 mcg bid

Pediatric

Dry powder oral inhalant (Flexhaler):
<6 years: Not established
≥6 years: 180 mcg inhaled PO bid initially; for some patients a starting dose of 360 mcg bid may be required; not to exceed 360 mcg bid
Nebulization (Respules):
<1 year: Not established
1-8 years: 0.5-1 mg inhaled via nebulization qd or divided bid; not to exceed 1 mg/d

Interactions

None reported

Contraindications

Documented hypersensitivity; viral, fungal, and bacterial infections

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Prolonged use may cause Cushing syndrome, reversible HPA axis suppression, hyperglycemia, and glycosuria; adverse effects include oral thrush, hoarseness, adrenal suppression, glaucoma, skin bruising, and alteration in bone metabolism; not for acute asthma

H2 receptor antagonists

The combination of H1 and H2 antagonists may be useful in anaphylaxis not responding to H1 antagonists alone.

Cimetidine (Tagamet)

If no response to H1 antagonist alone, coadministration with this H2 antagonist treats itching and flushing in anaphylaxis, pruritus, urticaria, and contact dermatitis.

Dosing

Adult

300-800 mg PO q6-8h; not to exceed 2400 mg/d
300 mg q6-8h IV/IM; not to exceed 2400 mg/d

Pediatric

20-40 mg/kg/d (300 mg/5 mL syr) PO divided bid/qid

Interactions

Can increase blood levels of theophylline, warfarin, tricyclic antidepressants, triamterene, phenytoin, quinidine, propranolol, metronidazole, procainamide, and lidocaine

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Elderly persons may experience confusional states; may cause impotence and gynecomastia in young males; may increase levels of many drugs; adjust dose or discontinue treatment if changes in renal function occur

Monoclonal antibody

May be considered in patients with severe asthma caused by allergens and unresponsive to other treatments.

Omalizumab (Xolair)

Recombinant, DNA-derived, humanized IgG monoclonal antibody that binds selectively to human IgE on surface of mast cells and basophils. Reduces mediator release, which promotes allergic response. Indicated for moderate-to-severe persistent asthma in patients who react to perennial allergens in whom symptoms are not controlled by inhaled corticosteroids.

Dosing

Adult

Prevention: 150-375 mg SC q2-4wk; inject slowly over 5-10 sec due to viscosity; not to exceed 150 mg/injection site
Precise dose and frequency established by serum total IgE level (IU/mL)

Pediatric

<12 years: Not established
>12 years: Administer as in adults

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Not effective to treat acute asthma; do not abruptly discontinue inhaled corticosteroids when initiating omalizumab; anaphylaxis may occur following any dose, even if no reaction occurred to the first dose (observe patient for at least 2 h after administration in setting able to manage life-threatening anaphylaxis); patients should carry an epinephrine syringe (EpiPen) and know how to initiate emergency self-treatment; malignancy incidence among omalizumab-treated patients (0.5%) was numerically higher than among patients in control groups (0.2%); malignancies were of various types, and further long-term observation is needed to fully assess risk; may cause injection-site reaction

Follow-up

Further Inpatient Care

• Consider admission if the initial peak expiratory flow rate (PEFR) is less than 20-25% of predicted and posttreatment is less than 70% of predicted or if no improvement occurs after 4 hours.
• If a child fails to improve within the first 2-3 hours of ED management, admission to an ED observation area, inpatient unit, or pediatric critical care unit is warranted.
• If the patient is able to ambulate and tolerate fluids in the ED without distress, discharge may be considered.
• Arrange for follow-up with the primary care provider within 24 hours.

Further Outpatient Care

Monitoring

Follow-up of pediatric asthma patients may be conducted by phone or in person; may include physical examination and/or spirometry; and may be performed by a case manager, registered nurse, nurse practitioner, or physician. Follow-up is recommended:

• Within 1 week of an asthma exacerbation
• Within 4 weeks after initiation of therapy or any significant change in therapy, and every 2-4 weeks thereafter until control is obtained
• Every 4-6 months to assess control for patients with persistent asthma

Inpatient & Outpatient Medications

• The child should be started on an inhaler corticosteroid for mild cases and addition of an oral steroid, prednisone or prednisolone (Prelone) (1-2 mg/kg/d) for 3-7 days, or dexamethasone for one additional day, for more severe cases.
• Leukotriene receptor antagonists are an option for the preventive treatment of recurrent asthma exacerbations secondary to viral respiratory tract infections in children aged 5 years or younger who do not have evidence of persistent asthma.

Deterrence/Prevention

• Parents of asthmatic children should have at least 2 sets of inhalers (eg, one for school and one for home).
• After an asthma exacerbation, the child may return to school when asymptomatic and the PEFR is within 20% of normal.
• Reduction in allergen exposure results in reduction of asthma and rhinitis symptoms and medications needed.
• Avoid outdoor exposure and/or physical activity during periods of high smog alerts in community.
• Change home furnace filters, remove dust, change linen, and vacuum regularly to reduce potential triggers.
• In humid climates, keep humidity below 50% by using a dehumidifier to keep mold from growing
• Avoid second-hand tobacco smoke, a well-known trigger of asthma attacks in infants and children.
• Pediatric Asthma Controller Trial (PACT)¹¹ compared the effectiveness of 3 regimens in achieving asthma control:
  • Fluticasone 100 mg twice daily (fluticasone monotherapy), fluticasone 100 mg/salmeterol 50 mg in the morning and salmeterol 50 mg in the evening (PACT combination), and montelukast 5 mg in the evening
  • The conclusions of the study were in favor of fluticasone monotherapy in treating children (>6 y) with mild-to-moderate persistent asthma.

Complications

• Respiratory failure/mechanical ventilation
• Atelectasis
• Flaccid paralysis (self-limited)
• Death
• Pneumothorax
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
• Altered theophylline metabolism

Prognosis

• The prognosis is excellent with attention to general health and appropriate use of medications.
• Fewer than 50% of patients "out grow" asthma.
• Predictors of mortality risk
  • More than 3 ED visits per year
  • More than 2 hospitalizations per year
  • Hospitalization or ED visit in the last month
  • History of ICU admission
  • Mechanical ventilation
  • Use of 2 or more albuterol canisters in a month
  • Current use or recent discontinuation of systemic steroids
  • History of an acute onset of severe asthma exacerbation
  • Nocturnal symptoms
  • History of syncope
  • Comorbid cardiac disease
  • Illicit drug use
  • Serious psychosocial or psychiatric problems
  • Low socioeconomic situation
  • Limited access to health care

Patient Education

• Monitoring PEFR is an easily performed test that can be mastered for those as young as 3-4 years. PEFR monitoring is an important tool in asthma management that uses a zone system to optimize effectiveness of asthma control.
  • Green zone (80-100% predicted or child's best) - Good control
  • Yellow zone (50-80%) - Necessitates increased awareness and treatment
  • Red zone (<50%) - Poor control, requires immediate intervention
• Educate children and their families about asthma.
  • Avoidance of potential triggers.
  • Emphasis on the use of anti-inflammatory inhalation
  • Instruct on peak expiratory flow and symptom monitoring
• Spacer devices should be used in all children with asthma. They improve the deposition of drug into the lower airway, hence improving efficacy of medication.
• Long-acting bronchodilators do not replace the need for routine preventers. Their slow onset means the short-acting dilators may still be required. 
• There is little evidence to support or refute the use of alternative medicine such as acupuncture, osteopathic, chiropractic, physiotherapy or respiratory therapeutic maneuvers.
• There is no evidence that air ionizers improve asthma symptoms.¹²
• For excellent patient education resources, see eMedicine's Asthma Center. Also, visit eMedicine's patient education article, Asthma.

Miscellaneous

Medicolegal Pitfalls

• Failure to initiate steroid therapy
• Discharging a patient with abnormal vital signs without an explanation
• Discharging a patient with a high respiratory rate or with oxygen saturation less than 94%
• Early intubation
• Barotrauma after intubation due to inappropriate volumes

Special Concerns

• Gastroesophageal reflux (GER) is common in asthmatic children. Proton-pump inhibitor therapy may help. In those with abnormal esophageal pH monitoring, severe persistent asthma and recurrent pneumonia, surgical therapy for GER may be an option. Infants may improve with alterations in feeding strategy.

Multimedia

Media file 1: Patient peak flow record.

Media file 2: This nomogram results from tests carried out by S. Godfrey, MD, and his colleagues on a sample of 382 healthy boys and girls aged 5-18 years. Each child blew 5 times into a standard Wright Peak Flow Meter, and the highest reading was accepted in each case. All measurements were completed within a 6-week period. The outer lines of the graph indicated that the results of 95% of the children fell within these boundaries.

Media file 3: Stepwise approach for managing asthma in children 0 to 4 years of age. National Institutes of Health. National Heart, Lung, and Blood Institute. National Asthma Education and Prevention Program. Expert Panel Report 3: Guidelines for the diagnosis and management of asthma. August 2007. NIH publication no. 07-4051. Available at: http://www.nhlbi.nih.gov/guidelines/asthma/index.htm. 3 Accessed December 30, 2007. PRN, As necessary.

References

1. [Guideline] Reddel HK, Taylor DR, Bateman ED, et al. An official American Thoracic Society/european Respiratory Society statement: asthma control and exacerbations: standardizing endpoints for clinical asthma trials and clinical practice. Am J Respir Crit Care Med. Jul 1 2009;180(1):59-99. [Medline].

2. Szefler SJ. Advances in pediatric asthma in 2007. J Allergy Clin Immunol. Mar 2008;121(3):614-9. [Medline].

3. Rosenstreich DL, Eggleston P, Kattan M, et al. The role of cockroach allergy and exposure to cockroach allergen in causing morbidity among inner-city children with asthma. N Engl J Med. May 8 1997;336(19):1356-63. [Medline].

4. Litonjua AA, Carey VJ, Burge HA, et al. Exposure to cockroach allergen in the home is associated with incident doctor-diagnosed asthma and recurrent wheezing. J Allergy Clin Immunol. Jan 2001;107(1):41-7. [Medline].

5. Castro-Rodríguez JA, Holberg CJ, Wright AL, Martinez FD. A clinical index to define risk of asthma in young children with recurrent wheezing. Am J Respir Crit Care Med. Oct 2000;162(4 Pt 1):1403-6. [Medline]. [Full Text].

6. Kim KW, Shin YH, Lee KE, Kim ES, Sohn MH, Kim KE. Relationship between adipokines and manifestations of childhood asthma. Pediatr Allergy Immunol. Sep 2008;19(6):535-40. [Medline].

7. Federico MJ, Wamboldt FS, Carter R, Mansell A, Wamboldt MZ. History of serious asthma exacerbations should be included in guidelines of asthma severity. J Allergy Clin Immunol. Jan 2007;119(1):50-6. [Medline].

8. Stewart LJ. Pediatric asthma. Prim Care. Mar 2008;35(1):25-40, vi. [Medline].

9. Hederos CA, Janson S, Andersson H, Hedlin G. Chest X-ray investigation in newly discovered asthma. Pediatr Allergy Immunol. Apr 2004;15(2):163-5. [Medline].

10. Hsu KH, Jenkins DE, Hsi BP, et al. Ventilatory functions of normal children and young adults--Mexican- American, white, and black. II. Wright peak flowmeter. J Pediatr. Aug 1979;95(2):192-6. [Medline].

11. [Best Evidence] Sorkness CA, Lemanske RF Jr, Mauger DT, Boehmer SJ, Chinchilli VM, Martinez FD, et al. Long-term comparison of 3 controller regimens for mild-moderate persistent childhood asthma: the Pediatric Asthma Controller Trial. J Allergy Clin Immunol. Jan 2007;119(1):64-72. [Medline].

12. Blackhall K, Appleton S, Cates CJ. Ionisers for chronic asthma. Cochrane Database Syst Rev. 2003;CD002986. [Medline]. [Full Text].

13. Amirav I, Newhouse MT. Metered-dose inhaler accessory devices in acute asthma: efficacy and comparison with nebulizers: a literature review. Arch Pediatr Adolesc Med. Sep 1997;151(9):876-82. [Medline].

14. Apter AJ, Szefler SJ. Advances in adult and pediatric asthma. J Allergy Clin Immunol. Mar 2004;113(3):407-14. [Medline].

15. Baren JM, Zorc JJ. Contemporary approach to the emergency department management of pediatric asthma. Emerg Med Clin North Am. Feb 2002;20(1):115-38. [Medline].

16. Beasley R, Crane J, Lai CK, Pearce N. Prevalence and etiology of asthma. J Allergy Clin Immunol. Feb 2000;105(2 Pt 2):S466-72. [Medline].

17. Becker A, Watson W, Ferguson A, et al. The Canadian asthma primary prevention study: outcomes at 2 years of age. J Allergy Clin Immunol. Apr 2004;113(4):650-6. [Medline].

18. Clainche LL, Timsit S, Rigourd V, et al. Asthma and the child below 5 years of age: diagnosis and treatment [in French]. Rev Mal Respir. Feb 2000;17(1 Pt 2):213-23. [Medline].

19. Craig VL, Bigos D, Brilli RJ. Efficacy and safety of continuous albuterol nebulization in children with severe status asthmaticus. Pediatr Emerg Care. Feb 1996;12(1):1-5. [Medline].

20. Crain EF, Mortimer KM, Bauman LJ, et al. Pediatric asthma care in the emergency department: measuring the quality of history-taking and discharge planning. J Asthma. 1999;36(1):129-38. [Medline].

21. Csonka P, Mertsola J, Klaukka T, et al. Corticosteroid therapy and need for hospital care in wheezing preschool children. Eur J Clin Pharmacol. Nov 2000;56(8):591-6. [Medline].

22. Darr CD. Asthma and bronchiolitis. In: Emergency Medicine: Concepts and Clinical Practice. 4^th ed. 1998:1137-45.

23. Eggleston PA, Wood RA, Rand C, et al. Removal of cockroach allergen from inner-city homes. J Allergy Clin Immunol. Oct 1999;104(4 Pt 1):842-6. [Medline].

24. [Guideline] Expert panel commissioned by the National Asthma Education and Prevention Program (NAEPP) Coordinating Committee(CC), coordinated by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. The Expert Panel Report 3 (EPR–3) Full Report 2007: Guidelines for the Diagnosis and Management of Asthma. August 28, 2007;[Full Text].

25. Farber HJ, Johnson C, Beckerman RC. Young inner-city children visiting the emergency room (ER) for asthma: risk factors and chronic care behaviors. J Asthma. 1998;35(7):547-52. [Medline].

26. Garde Garde Jf, Haro E, Sanchez-Lucas C, Garde Noguera J. Antileukotrienes. Their use in pediatrics [in Spanish]. Allergol Immunopathol (Madr). May-Jun 2000;28(3):136-43. [Medline].

27. Gibbs MA, Camargo CA, Rowe BH, Silverman RA. State of the art: therapeutic controversies in severe acute asthma. Acad Emerg Med. Jul 2000;7(7):800-15. [Medline].

28. [Best Evidence] Guilbert TW, Morgan WJ, Zeiger RS, Mauger DT, Boehmer SJ, Szefler SJ, et al. Long-term inhaled corticosteroids in preschool children at high risk for asthma. N Engl J Med. May 11 2006;354(19):1985-97. [Medline]. [Full Text].

29. [Best Evidence] Hondras MA, Linde K, Jones AP. Manual therapy for asthma. Cochrane Database Syst Rev. Apr 18 2005;CD001002. [Medline]. [Full Text].

30. Kellner JD, Ohlsson A, Gadomski AM, Wang EE. Efficacy of bronchodilator therapy in bronchiolitis. A meta-analysis. Arch Pediatr Adolesc Med. Nov 1996;150(11):1166-72. [Medline].

31. Kemp JP, Dockhorn RJ, Shapiro GG, et al. Montelukast once daily inhibits exercise-induced bronchoconstriction in 6- to 14-year-old children with asthma. J Pediatr. Sep 1998;133(3):424-8. [Medline].

32. Kitch BT, Chew G, Burge HA, et al. Socioeconomic predictors of high allergen levels in homes in the greater Boston area. Environ Health Perspect. Apr 2000;108(4):301-7. [Medline].

33. Le Clainche L, Timsit S, Rigourd V, et al. Asthma in children below 5 years of age: diagnosis and treatment. Rev Mal Respir. Feb 1999;16(1):17-27. [Medline].

34. Newson T, McKenzie S. Cough and asthma in children. Pediatr Ann. Mar 1996;25(3):156-8, 161. [Medline].

35. Qureshi F, Zaritsky A, Lakkis H. Efficacy of nebulized ipratropium in severely asthmatic children. Ann Emerg Med. Feb 1997;29(2):205-11. [Medline].

36. Roback MG, Dreitlein DA. Chest radiograph in the evaluation of first time wheezing episodes: review of current clinical practice and efficacy. Pediatr Emerg Care. Jun 1998;14(3):181-4. [Medline].

37. Rubin BK, Albers GM. Use of anticholinergic bronchodilation in children. Am J Med. Jan 29 1996;100(1A):49S-53S. [Medline].

38. Rudolph CD. Supraesophageal complications of gastroesophageal reflux in children: challenges in diagnosis and treatment. Am J Med. Aug 18 2003;115 Suppl 3A:150S-156S. [Medline].

39. Schreck DM, Babin S. Comparison of racemic albuterol and levalbuterol in the treatment of acute asthma in the ED. Am J Emerg Med. Nov 2005;23(7):842-7. [Medline].

40. Schuh S, Reisman J, Alshehri M, et al. A comparison of inhaled fluticasone and oral prednisone for children with severe acute asthma. N Engl J Med. Sep 7 2000;343(10):689-94. [Medline].

41. Spahn JD. Pharmacologic management of pediatric asthma. 1998;18 (1):165-81.

42. Stempel DA, Meyer JW, Stanford RH, Yancey SW. One-year claims analysis comparing inhaled fluticasone propionate with zafirlukast for the treatment of asthma. J Allergy Clin Immunol. Jan 2001;107(1):94-8. [Medline].

43. Steyer TE, Mallin R, Blair M. Pediatric asthma. Clinics in Family Practice. Jun 2003;5.

44. Suissa S, Ernst P, Benayoun S, et al. Low-dose inhaled corticosteroids and the prevention of death from asthma. N Engl J Med. Aug 3 2000;343(5):332-6. [Medline].

45. Sun HL, Chou MC, Lue KH, et al. The relationship of air pollution to ED visits for asthma differ between children and adults. Am J Emerg Med. Oct 2006;24(6):709-13. [Medline].

46. Walsh-Kelly CM, Kim MK, Hennes HM. Chest radiography in the initial episode of bronchospasm in children: can clinical variables predict pathologic findings?. Ann Emerg Med. Oct 1996;28(4):391-5. [Medline].

47. Welliver RC. Immunologic mechanisms of virus-induced wheezing and asthma. J Pediatr. Aug 1999;135(2 Pt 2):14-20. [Medline].

48. Werk LN, Steinbach S, Adams WG, Bauchner H. Beliefs about diagnosing asthma in young children. Pediatrics. Mar 2000;105(3 Pt 1):585-90. [Medline].

49. Williams JR, Bothner JP, Swanton RD. Delivery of albuterol in a pediatric emergency department. Pediatr Emerg Care. Aug 1996;12(4):263-7. [Medline].

50. Wohl ME, Majzoub JA. Asthma, steroids, and growth. N Engl J Med. Oct 12 2000;343(15):1113-4. [Medline]. [Full Text].

51. Wolfram RW. Asthma. In: The Clinical Practice of Emergency Medicine. 2^nd ed. 1997:1093-96.

52. Zeffren BS, Windom HH, Bahna SL. Modern Treatment of Asthma in Children. Vol 43. Mosby Year Book; 1996:423-68.

Keywords

reactive airway disease in children, asthma, pediatric asthma, exercise induced asthma, exercise-induced asthma, asthma treatment, asthma assessment, asthma symptoms, asthma triggers, asthma causes, bronchospasm, obstructive airway disease, childhood asthma, hypersensitivity reaction, wheeze, wheezing, RAD, airway inflammation, upper respiratory infection, tachypnea, dyspnea, cyanosis, intercostal retractions, nasalpolyps, nasal secretions, diaphoresis, hyperresonance, pulsus paradoxus, decreased peak expiratory flow rate, pectus carinatum, clubbing, subcutaneous emphysema, respiratory syncytial virus infection, RSV infection, Mycoplasma pneumoniae, pet dander, cockroach allergen, dust mite allergen, molds, pollen, weather changes, bronchiolitis, gastroesophageal fistula, cystic fibrosis

Contributor Information and Disclosures

Author

Eric S Chin, MD, Consulting Staff, Department of Emergency Medicine, Kaiser Permanente Hospital, South San Francisco
Disclosure: Nothing to disclose.

Medical Editor

Debra Slapper, MD, Consulting Staff, Department of Emergency Medicine, St Anthony's Hospital
Debra Slapper, MD is a member of the following medical societies: American Academy of Emergency Medicine
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Grace M Young, MD, Associate Professor, Department of Pediatrics, University of Maryland Medical Center
Grace M Young, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Emergency Physicians
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Richard G Bachur, MD, Associate Professor of Pediatrics, Harvard Medical School; Associate Chief and Fellowship Director, Attending Physician, Division of Emergency Medicine, Children's Hospital of Boston
Richard G Bachur, MD is a member of the following medical societies: American Academy of Pediatrics, Society for Academic Emergency Medicine, and Society for Pediatric Research
Disclosure: Nothing to disclose.

Clinical guidelines

Managing asthma long term in children 0-4 years of age and 5-11 years of age. In: National Asthma Education and Prevention Program (NAEPP). Expert panel report 3: guidelines for the diagnosis and management of asthma. Bethesda (MD): National Heart, Lung, and Blood Institute; 2007 Aug. p. 281-325.

Global Initiative for Asthma (GINA), National Heart, Lung and Blood Institute (NHLBI). Global strategy for asthma management and prevention. Bethesda (MD): Global Initiative for Asthma (GINA), National Heart, Lung and Blood Institute (NHLBI); 2007. 92 p.

Managing exacerbations of asthma. In: National Asthma Education and Prevention Program (NAEPP). Expert panel report 3: guidelines for the diagnosis and management of asthma. Bethesda (MD): National Heart, Lung, and Blood Institute; 2007 Aug. p. 373-417.

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