Asthma (EPR3: Guidelines for Diagnosis and Management of Asthma, NIH 2007)
• Chronic disorder of recurring symptoms resulting from airway inflammation,
hyperresponsiveness, and obstruction
• Important information to obtain in history
• Description of sx: Wheeze, nighttime cough, chest tightness, difficulty breathing
• Pattern of symptoms: Continual/episodic, onset, duration, frequency
• Precipitating/aggravating factors: Viral infection, environmental allergens (dust mites, cat/dog dander, cockroach, pollution), smoke exposure, exercise, emotion, meds (such as aspirin β-blockers), changes in environment, comorbid conditions (obesity, GERD, sinusitis, rhinitis)
• Hx: # of hospitalizations, ICU admits, or intubations; age of dx; h/o prior airway injury (BPD, parental smoking, early PNA/RSV infection); meds used and compliance; need for oral corticosteroids and frequency of use; number of flares in last yr
• Family history of atopy: Asthma, eczema, allergy, sinusitis, rhinitis, nasal polyps
• Social history: Day care, social factors that may interfere w/ adherence, social supports, smoke exposure
• Impact of asthma: Number of school days missed, limitations of activity
• Assessment of patient’s and family’s perception of disease
• Knowledge of asthma and Rx plan, ability to recognize severity of exacerbation
• Examination
• Overall patient comfort, hyperinflated chest, accessory muscle use, wheeze or
prolonged expiratory phase, nasal secretions or polyps, eczema
• Respiratory rate & trend of respiratory rate is important; slowing can be sign of fatigue
• Classification of asthma
ICS, inhaled corticosteroids; LABA, long-acting β-agonist.
• Outpatient management of asthma
• Method of delivery, age of child, and ability to execute proper technique are important treatment considerations
• Short-acting β-agonist: Albuterol (Proair, Proventil), levalbuterol (Xopenex). Mechanism: Bronchodilator. Side effects: Tachycardia, hypertension, tremor, nervousness, paradoxical bronchospasm, tachyphylaxis (with long-term use)
• Inhaled corticosteroids (ICS) Budesonide (Pulmicort), fluticasone (Flovent),
beclomethasone (Qvar), flunisolide, ciclesonide. Mechanism: Acts locally in the lungs to inhibit the inflammatory process. Side effects: Thrush (use spacer or valved holding chamber and rinse mouth with water to reduce the incidence), dysphonia/hoarseness (use spacer or valved holding chamber), reflex cough/bronchospasm (use spacer or valved holding chamber and slower rates of inspiration to reduce incidence), behavioral disturbances
• Regular use of nebulized budesonide more effective than budesonide used only as needed (Arch Dis Child 2008;93:654–659)
• Daily use of budesonide not superior to intermittent use in preschool children with wheezing (N Engl J Med 2011;365:1990)
• Beclomethasone may be used as rescue plus albuterol as a step-down for children with mild asthma (Lancet 2011;377:650)
• Doubling dose of ICS w/ URI not effective (J Allergy Clin Immunol 2011;128:278)
• Leukotriene inhibitors: Montelukast (Singulair), zafirlukast (Accolate), & zileuton (Zyflo). Mechanism: Leukotriene receptor antagonists (LTRA) prevent leukotriene binding (montelukast/zafirlukast) or leukotriene receptor inhibitors (zileuton). Side effects: Elevated liver transaminases
• LTRAs provide modest improvement in lung fxn when used as monoRx in children as young as 5 & in asthma control outcomes (other than lung fxn) in pts as young as 2 (EPR3: Guidelines for Diagnosis and Management of Asthma, NIH 2007)
• Fluticasone vs. montelukast: Fluticasone more effective in improving pulmonary fxn, asthma symptoms, and rescue albuterol use (J Pediatr 2005;147:213–220)
• Montelukast can offer protection from exercise-induced bronchospasm (Treat Respir Med 2004;3:9; Ann Allergy Asthma Immunol 2001;86:655)
• Long-acting β-agonist (LABA) combined with ICS: Fluticasone/salmeterol (Advair), budesonide/formoterol (Symbicort). Mechanism: Long-acting bronchodilation. Side effects: Tachycardia, tremor
• In adolescents & adults (not children), LABAs combined w/ low/med dose ICS may be beneficial for poorly controlled asthma (Cochrane Rev 2010;CD005533)
• Black-box warning: Increased risk of death when LABA used alone, esp in African-American population (SMART, Chest 2006;129:15)
• Tiotropium (Spiriva): Mechanism: Anticholinergic, reduces smooth muscle
contraction. Side effects: Hypersensitivity reaction, anticholinergic effects (dry mouth, urinary retention, blurred vision, mental status changes), constipation, thrush
• Equivalent to fluticasone/salmeterol for step-up therapy in asthma (N Engl J Med 2010;363:1715)
• Theophylline: Mechanism: Methylxanthine, relaxes bronchial smooth muscle and anti-inflammatory. Side effects: Narrow therapeutic window, cardiac arrhythmias, seizures, tremors, agitation, nausea/vomiting, electrolyte abnormalities (hypokalemia and metabolic acidosis)
• Oral xanthines as maintenance for pediatric asthma suitable in the absence of ICS or in conjunction w/ other therapies in severe asthma (Cochrane Rev 2006;CD002885)
• Oral steroids (Prednisolone, Prednisone): Mechanism: Anti-inflammatory. Side effects: Weight gain, hyperglycemia, mood changes, osteoporosis, adrenal
insufficiency, immunosuppression, gastritis or ulcers, sodium/fluid retention & HTN
• Used in acute setting in short bursts typically from 5 to 7 d–2 wk. More effective than inhaled steroids in severe acute asthma (N Engl J Med 2000;343:689)
• Refractory asthma may require daily low-dose or alternate-day dose oral steroids
• IgE mediators: Omalizumab (Xolair) effective maintenance therapy for patients with severe, persistent asthma, which cannot be controlled even with high doses of corticosteroids. Mechanism: Recombinant DNA-derived humanized IgG1k monoclonal antibody that selectively binds to IgE. Side effect: Anaphylaxis, expensive (J Allergy Clin Immunol 2009;124:1210)
• Cromolyn sodium (Intal): Mechanism: Anti-inflammatory, mast cell stabilizer. Side effects: Non-specific
• Inhaled corticosteroids more effective than cromolyn sodium for asthma control in adults and children (Cochrane Rev 2006;CD003558)
• When to refer to pulmonologist
• Patient has had a life-threatening asthma exacerbation
• Patient is not meeting the goals of asthma therapy after 3–6 mo of treatment
• Atypical signs and symptoms
• Complicating conditions (e.g., sinusitis, nasal polyps, aspergillosis, severe rhinitis, VCD, GERD, COPD)
• Need for additional diagnostic testing (e.g., allergy skin testing, rhinoscopy,
complete pulmonary function studies, provocative challenge, bronchoscopy)
• Patient requires additional education and guidance on complications of therapy, problems with adherence, or allergen avoidance
• Patient is being considered for immunotherapy
• Patient has required more than two bursts of oral corticosteroids in 1 yr or has an exacerbation requiring hospitalization
• Patient has a history suggesting an occupational/environmental inhalant or ingested substance is provoking or contributing to asthma
• Risk factors for status asthmaticus
• Asthma history: Prior severe exacerbation: Intubation/PICU stay
• 2 or more hospitalizations for asthma or 3 or more ED visits for asthma in past yr, or hospitalization/ED visit for asthma in past mo
• Using >2 canisters/mo of inhaler
• Poor compliance/understanding
• Social history: Low SES, illicit drug use, psychosocial problems
• Comorbidities: Cardiovascular dz, other chronic lung dz, psychiatric dz
• Management of status asthmaticus
• ABCs, medications (see below)
• Consider NPPV or intubation (ketamine is the induction drug of choice) for persistent hypoxia/hypercarbia/WOB, altered mental status, FiO2 >60%
• Ventilation strategy: Treat obstruction/atelectasis, limit hyperinflation and barotrauma
• Volume control preferred (ensures consistent min ventilation despite changing airway resistance)
• Limit TV (8–10 cc/kg) & RR (8–12) w/ “permissive hypercapnia” (goal pH > 7.2)
• Limit I-time (I:E 1.3–1.5) to allow complete exhalation and minimize auto-PEEP
• Avoid paralysis
• For refractory cases, consider inhalational anesthetics (e.g., isoflurane, halothane [bronchodilators of unknown mechanism] or ECMO)
• Medications for status asthmaticus
• Complications
• Dynamic hyperinflation (auto-PEEP)
• Progressive airtrapping → hyperinflation → alveolar rupture/hemodynamic compromise
• To assess for auto-PEEP: Check plateau pressure (end-expiratory pressure =
airway pressure; goal < 30), expiratory pause maneuver
• Mechanical ventilation complications (PTX, HoTN, myopathy, VAP, GIB)
• Prognosis: 2–3% mortality w/ mech ventilation (Crit Care Med 2002;30:581)
Bronchiolitis (Pediatrics 2006;118:1774)
• AAP Guidelines established for 1 mo–2 yo; excludes pt w/ immunodeficiencies or underlying lung or heart dz
• Swelling and mucus buildup in the smallest air passages in the lungs (bronchioles), usually due to viral infection
• Pathophysiology
• Lower respiratory tract infection with acute inflammation, edema, and necrosis of epithelial cells lining small airways, inc mucus production, and bronchospasm
• 2/2 viruses: RSV, human metapneumovirus, influenza, adenovirus, and parainfluenza, rhinovirus
• History
• Assess for risk factors for severe disease: Age <12 wk, history of prematurity, underlying cardiopulmonary disease, or immunodeficiency
• Viral URI prodromal symptoms, cough, wheeze, apnea
• Ability to feed/remain hydrated, and ability of the family to care for the child
• Response to any treatments
• Prior episode of wheeze
• Clinical manifestations
• Exam variable over time – need serial observations to assess
• Rhinitis, tachypnea, use of accessory muscles, nasal flaring, grunting, apnea
• Auscultation: Cough, crackles, wheezing
• May have concomitant/secondary bacterial infxn: Pneumonia, acute otitis media, UTI
• Diagnostic studies
• Pulse oximetry both awake and while sleeping
• RSV viral test for cohorting patients
• CXR, blood tests, urinalysis not typically recommended unless toxic or febrile
• Treatment/course
• O2 supplementation to keep O2 >90%, IVF if dehydrated
• Bulb suctioning of nares may provide some temporary relief
• Hand washing/contact precautions, cohorting patients
• Additional treatments
• Saline or hypertonic (3%) nebs: May cause bronchospasm; closely monitor response
• Bronchodilators: 1 in 4 children treated with bronchodilators may have a transient improvement in clinical score, particularly if reactive component
• Epi nebs: No effect on hospital stay/course of illness. (N Engl J Med 2003;349:27)
• Corticosteroids: Not generally recommended, no difference in clinical scores or outcomes (Cochrane Rev 2008:CD004878)
• Antibiotics: Not recommended unless secondary bacterial infection
• Chest PT: Generally not recommended