A 67-year-old patient with a history of COPD presents to the emergency department with increased shortness of breath, wheezing, and a productive cough with green sputum. The patient has a respiratory rate of 26 breaths/min, oxygen saturation of 88% on room air, and is using accessory muscles to breathe. After administering supplemental oxygen, what is the next best step in the management of this patient?
Prescribe antibiotic therapy for suspected bacterial infection.
Order an immediate chest x-ray.
Administer a short-acting bronchodilator via nebulizer.
Initiate systemic corticosteroid therapy.