A client arrives at the emergency department reporting crush…

A client arrives at the emergency department reporting crushing substernal chest pain radiating to the left arm and jaw for the past 45 minutes. The client appears anxious and diaphoretic.Assessment findings:BP: 88/54 mm HgHR: 118/minRR: 26/minSpO₂: 90% on room air12-lead ECG shows ST-segment elevation in leads II, III, and aVFWhich action should the nurse take first?