A 33-year-old asthmatic patient presents to the emergency department with dyspnea, sternal retractions, intercostal retractions, tachypnea, and forced expiration. The patient is not responsive to traditional asthma rescue therapies. Continuous albuterol is initiated in addition to corticosteroids and oxygen therapy. The patient develops pulse discrepancies with a decreased pulse on inspiration and increased pulse on expiration. Which is the priority nursing action?