30th April 2024

A 48-year-old woman presents to the emergency department with a 6-hour history of intense, constant epigastric pain radiating to the back.

A 48-year-old woman presents to the emergency department with a 6-hour history of intense, constant epigastric pain radiating to the back. She reports nausea but no vomiting. Her medical history is unremarkable, and she denies alcohol use. On examination, her abdomen is tender in the epigastric area, and she appears in distress due to pain. Her vital signs are normal, except for a mild tachycardia.

Which of the following is the most appropriate initial test to confirm the diagnosis?