Back to Basics: Pediatric Status Asthmaticus Treatment
Treatment of Status Asthmaticus in Children
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Asthma = a result of airway EDEMA + HYPERRESPONSIVE + CONSTRICTED
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Status asthmaticus = prolonged severe asthma attack that does not respond to standard treatment
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Most common chronic disease in childhood
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Males >females
TREATMENT OF ACUTE ASTHMA EXACERBATION = BIOMES
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Beta agonists → increase cAMP therefore bronchodilation; administer continuous neb if severe exacerbation (defined as PEF <50%)
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Ipratropium → decrease bronchoconstriction
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Oxygen → maintain SpO2 >90%
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Mag sulfate, 25-75 mg/kg over 20 minutes (max single dose 2g)→ use if child presents with severe exacerbation not responding to initial therapies; it’s a smooth muscle relaxant, thus promoting bronchodilation; also can decrease BP, so closely monitor
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Epi, 1:1000 0.01mg/kg q10-20 min x 3 doses, max 0.3-0.5 mg/dose subQ or IM, which is 0.3-0.5 mL of 1 mg/mL solution (or terbutaline)
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Steroids (prednisone, methylprednisolone, or dexamethasone) → require hours to take effect but give EARLY; they decrease inflammation
**Fluid loading is also important because these patients are predisposed to dehydration and intravascular volume depletion from respiratory losses and as a side effect of beta agonists and other treatment agents
Non-invasive positive pressure ventilation (NIPPV) is a choice to treat severely ill children with asthma who are responding poorly to other interventions and you want to avoid intubation
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Objective: to maximize expiratory time, prevent airway collapse, and decrease work of breathing
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Settings: low RR, high IFR; maintain plateau pressure <30 cm H2O to maintain patent airways
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Permissive hypercapnia to avoid breath stacking
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NIPPV should be discontinued if there is clinical deterioration
BONUS: What causes an asthmatic’s pulse ox to drop after administering albuterol alone (without O2)?
V/Q mismatch → beta agonists cause pulmonary vasodilation, thus increasing perfusion (Q) to poorly ventilated lung units, therefore worsening hypoxemia initially
Sources:
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Chung C: Asthma, in Fleisher & Ludwig’s 5-Minute Pediatric Emergency Medicine Consult, Wolters Kluwer, 2012.
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Zorc J et al: Chapter 84 - Asthma, in Fleisher & Ludwig’s Textbook of Pediatric Emergency Medicine, 7th Ed., Wolters Kluwer, 2016.