A 72-year-old man with a history of chronic obstructive pulmonary disease and poorly controlled type 2 diabetes mellitus is found unresponsive by nursing staff in his long-term care facility. He is apneic and pulseless. The cardiac monitor displays asystole. His skin is cool to touch, and pupils are fixed and dilated. Given this clinical presentation and the cardiac rhythm, which of the following represents the most appropriate initial management strategy and what critical monitoring parameter should be immediately prioritized?

A 72-year-old woman, recently discharged three days prior after a total knee arthroplasty, presents to her primary care clinic reporting increasing dyspnea and lightheadedness over the last 24 hours. She has a history of severe interstitial lung disease. Her initial vital signs are: temperature 37.10C, pulse 115 beats/min, blood pressure 90/50 mmHg, respirations 32 breaths/min, and oxygen saturation 86% on room air. On examination, she appears distressed with cool and mottled extremities, and is drowsy but arousable. Lung auscultation reveals diminished breath sounds at the bases. As the nurse attempts to obtain intravenous access, the patient suddenly becomes unresponsive and pulseless. Cardiopulmonary resuscitation (CPR) is immediately initiated. The cardiac monitor shows an organized electrical activity, similar to her prior sinus rhythm, but without any palpable pulses. Considering her presentation and the observed cardiac rhythm, what is the most likely underlying rhythm and the immediate critical pharmacologic intervention?