MSFinals-6601

A 67-year-old man presents to the emergency department with sudden onset epigastric pain described as burning and radiating into his back. He reports vomiting and ongoing nausea. The patient has a history of recurrent gallstones and is awaiting a semi-elective cholecystectomy. He is not taking any regular medications. On examination, the patient has jaundiced sclera and diffuse abdominal tenderness with guarding. There is also periumbilical superficial oedema and bruising, and decreased bowel sounds on auscultation.

What is a crucial aspect of the immediate management of this patient, given the likely diagnosis?