Review Question - QID 210962

A 42-year-old woman presents to the emergency department for evaluation of abdominal pain. The pain started last night during dinner and has persisted. This morning, the patient felt very ill and her husband called emergency medical services. She has a medical history of obesity, diabetes, and depression. Her temperature is 104°F (40°C), blood pressure is 90/65 mmHg, pulse is 160/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam is notable for a very ill-appearing woman. Her skin is jaundiced, and there is scleral icterus. She is in an antalgic position on the stretcher. There is tenderness to palpation over the right upper quadrant. Laboratory values are ordered as seen below. Right upper quadrant ultrasound demonstrates a thickened, distended common bile duct.

Hemoglobin: 13 g/dL
Hematocrit: 38%
Leukocyte count: 22,500 cells/mm^3 with normal differential
Platelet count: 257,000/mm^3

Alkaline phosphatase: 355 U/L
Bilirubin, total: 11.3 mg/dL
Bilirubin, direct: 9.8 mg/dL
AST: 42 U/L
ALT: 31 U/L

The patient is started on antibiotics and IV fluids. Which of the following is the most appropriate next step in management?