A 32-year-old woman is evaluated in the emergency department for the acute onset of dyspnea, wheezing, and progressive respiratory distress. She has a history of severe persistent asthma with 4 four previous admissions to the ICU, 2 of which required intubation. Her preadmission medications are high-dose inhaled corticosteroid, salmeterol, and 4-times-daily albuterol via nebulizer. She does not respond to aggressive bronchodilator therapy or IV corticosteroids. On physical examination, she is in distress and anxious. Temperature is 37 °C (98.6 °F), blood pressure 156/110 mm Hg, heart rate 136 beats/min, and respiratory rate 45 breaths/min. Bilateral breath sounds reveal very faint wheezing. Arterial blood gas analysis on room air shows Pco2 95 mm Hg, Po2 50 mm Hg, and pH 7.10. Chest radiograph shows hyperinflation but no infiltrates. She undergoes rapid sequence intubation and is started on mechanical ventilation. What is the most important consideration in improving this patients overall ventilatory status?