CURRENT Essentials of Critical Care.pdf

110 Current Essentials of Critical Care■■■Status AsthmaticusEssentials of Diagnosis• Severe asthma (severely reduced peak flow, FEV 1 , VC) poorlyor nonresponsive to therapy• Hypoxemia; may have hypercapnia with acute respiratory acidosis• Poor air movement, severe wheezing but wheezing absent whenvery severe, hyperinflation, use of accessory muscles of respiration,pulsus paradoxus• Associated with worsening asthma and increasing bronchodilatoruse over days, but may develop suddenly without warningDifferential Diagnosis• Acute upper airway obstruction (larnygeal edema, angioedema,tumor, foreign body, trauma, epiglottis)• Vocal cord dysfunction syndrome• COPD exacerbation• Cardiogenic pulmonary edema, pneumothorax, pulmonary embolism,pneumoniaTreatment• Oxygen, 2–4 L/min nasal cannula or 40–60% by mask, toachieve PaO 2 60–70 mm Hg• Inhaled bronchodilators: albuterol every 20–30 minutes; thenhourly; ipratropium bromide every 2–4 hours• Systemic corticosteroids: prednisone, 40–60 mg, 1–4 times perday; or IV methylprednisolone, 20–40 mg every 6 hours• If needed, noninvasive positive pressure ventilation; endotrachealintubation and mechanical ventilation• Antibiotics not usually indicated; but consider if purulent sputum,fever, pneumonia• Other therapy: IV magnesium sulfate (2–8 g IV every 4 hours)may benefit very severe asthma; no clear role for leukotrienemodifiers, inhaled corticosteroids■ PearlBecause airway inflammation, not bronchospasm, is the cause of statusasthmaticus, be patient; several days might be needed before obstructionreverses.ReferenceMcFadden ER Jr: Acute severe asthma. Am J Respir Crit Care Med2003;168:740 [PMID: 14522812]