Snapshot A 5-year-old is brought to the ED by her parents because "her breathing is labored." On physical exam you see a young girl in distress taking deep slow breaths to try and catch her breath. On physical exam you note diminished breath sounds in all lung fields without wheezing. Introduction Reversible airway obstruction secondary to bronchial hyperactivity acute or chronic inflammation mucous plugging smooth muscle hypertrophy Triggers can include allergens house dust mites are the most common trigger upper respiratory infections cold air exposure exertion stress Be fearful of a child who is sleepy and becoming less responsive because they are likely tiring and retaining CO2 Historical risk factors (thought increasingly less so) include male gender older age Can be a constellation known as aspirin exacerbated respiratory disease (AERD) caused by shift of arachidonic acid to produce leukotrienes instead of prostaglandins asthma chonic rhinositis nasal polyps aspirin- or NSAID-induced bronchospasm Presentation Symptoms often worse in early morning and at night and may include productive cough dyspnea episodic wheezing chest tightness excess mucous production Physical exam tachycardia tachypnia use of accessory muscles prolonged expiratory wheezes high-pitched sibilant rhonchi dyspnea persitant cough hyperinflation of the lungs (hyperresonance) decreased SaO2 (late sign) pulsus paradoxus Evaluation ABG mild hypoxia early respiratory alkalosis respiratory acidosis in more severe cases indicative of CO2 retention normalizing PCO2 in acute exacerbation may indicate fatigue and impending respiratory failure, hence clinical picture is important PFTs acutely diminished peak expiratory flow rate (PEFR) PEFR < 40% of personal best or < 200 L/min indicates severe obstruction decreased FEV1 / FVC ratio increased residual volume and TLC normal DLCO CXR shows hyperinflation CBC possible eosinophilia depending on trigger Methacholine challenge used for definitive diagnosis tests for bronchial hyperactivity in a well patient Differential Anaphylaxis, choking on foreign object, cystic fibrosis, brochiectasis Treatment of Acute Exacerbations Medical O2 and β2-agonists indications first line of treatment in acute asthma attack technique O2 by mask (humidified) methylprednisone indications as second line of treatment if O2 and β2-agonists fail will lead to significant and immediate improvement intubation indications if patient continues to have a compromised airway despite acute treatment or normalization/increase of CO2 value (they should be hyperventilating) Treatment of Chronic Asthma Asthma severity categories Intermittent patients have symptoms <3 days/week, nighttimes awakenings less than 3 times per month, uses a SABA <3 days/week, has no interference with normal activity, and has normal FEV1 function between exacerbations treat with SABA as needed Mild Persistent patients have symptoms >2 days/week (but not daily), nighttime awakenings 3-4 times/month, use a SABA >2 days/week (but not daily), has minor interference with normal activity, and has FEV1 >80% add a low-dose inhaled corticosteroid Moderate Persistent patients have symptoms daily, nighttime awakenings more more than 1 night/week (but not every night), use SABA daily, and have an FEV1 60-80% predicted preferred treatment is low-dose inhaled corticosteroid with a long acting beta agonist or medium-dose inhaled corticosteroid Severe Persistent patients have symptoms throughout the day, nighttimes awakenings every night, use a SABA multiple times per day, have extreme interference with normal activity, and have FEV1 <60% Medical lifestyle modifications O2, bronchodilators, ipratropium, IV steroids, Mg2+, anticholingerics indicated for treatment of acute exacerbations O2 by mask (humidified) short-acting β2-agonists (albuterol) methylprednisone for sympathomimetic bronchodilator resistant never use ipratropium alone long-acting bronchodilators, steriods, cromolyn, lukasts, ipratropium indicated for treatment of chronic asthma degree of lung function often guides management inhaled steroids predisposes to oral candidiasis ("thrush") cromolyn preferred treatment for exercise-induced asthma theophyline is no longer used zafirlukast or montelukast oral adjuncts to inhaled therapies in cases resistant to treatment particularly beneficial in patients with aspirin-induced asthma ipratropium bromide anticholinergic inhibits contraction of smooth muscle used in elderly with an asthmatic Prognosis, Prevention, and Complications Prognosis excellent when asthma responsive to low level medical management can be poor to fatal if not treated appropriately or if recognized too late Prevention reduce environmental exposure to pollution and allergens take medication appropriately to avoid flares educate family members on recognizing signs of impending "attack" respond quickly to "attacks" with inhaler or other agents to prevent respiratory arrest Complications use of non-specific β-blockers (i.e., blocking β2) can close airways leading to death