A 45-year-old man with a history of alcohol excess presents with severe epigastric pain radiating to the back, associated with nausea and vomiting for the past 12 hours. On examination, he is tender in the epigastrium with guarding. His amylase level is 1500 U/L (Normal range <100 U/L). According to guidelines, what are the two most important initial management priorities besides analgesia?