A 72-year-old woman with a history of chronic obstructive pulmonary disease (COPD) and cor pulmonale is found unresponsive at home. Emergency Medical Services (EMS) initiates CPR. Upon arrival at the emergency department, the patient has been receiving CPR for 18 minutes. The cardiac monitor shows asystole. After confirmation of asystole in two leads and proper electrode placement, epinephrine 1 mg IV/IO is administered. CPR is continued for another 2 minutes, and the rhythm remains asystole. What is the most appropriate next action?