A 52-year-old male from Mumbai with 15 years of heavy alcohol use presents with fever (38.5°C), right upper quadrant pain, and jaundice. Laboratory findings: WBC 14,000/μL, AST 280 U/L, ALT 120 U/L, bilirubin 4.8 mg/dL, ALP 320 U/L. Ultrasound shows hepatomegaly, fatty infiltration, and dilated intrahepatic bile ducts without gallstones. Blood cultures are pending. What is the most appropriate next step in management?