Consider the following treatments for your severe asthma exacerbation:

• ED mantra - ABCs, IV, O2, monitor
• Oxygen - HFNC, NRB
• Goal SpO2 >92%
• Inhaled Beta-2 agonists - bronchodilation
• Nebulized vs MDI albuterol every 20 mins x 3
• Inhaled anticholinergic - blocks bronchoconstriction; w/ beta-2 agonist promotes bronchodilation
• Nebulized ipratropium every 20 mins x 3
• Systemic Corticosteroids - reduce inflammation and increase responsiveness of Beta receptors
• Prednisone PO 40-60mg/d
• Methylprednisolone IV 1mg/kg q6h
• Magnesium - relax smooth muscle
• 2g IV over 15-30 mins
• Epinephrine - beta agonist - bronchodilation; vasoconstriction; reduce airway edema
• 0.3-0.5mg IM/SQ every 20mins (1mg/ml)
• Ketamine - bronchodilation
• Note risk of laryngospasm, increase airway secretions
• 0.2mg/kg bolus followed by infusion 0.5mg/kg/hr
• 1-2mg/kg for RSI
• IVF - replace insensible losses
• 30cc/kg
• NIPPV - decrease work of breathing
• BIPAP, 10/5, titrate IPAP
• Mechanical ventilation - last resort if decreased mental status, confusion, exhaustion, progressive hypercarbia
• Note: does NOT fix underlying bronchodilation
• Permissive hypercarbia, avoid hyperinflation/breath stacking
• Reduced respiratory rate, 6-8 breaths/min
• Decrease I/E ratio
• Tidal volume 6ml/kg IBW
• PEEP 0-5 Titrate to lowest FiO2

References:

Cydukla R.. "Acute Asthma" Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e Eds. Judith E. Tintinalli, et al. New York, NY: McGraw-Hill, 2016

Holley et al. Management of acute severe and near-fatal asthma. Emerg Med Australas (2009) PMID 19682010