Differential Diagnosis

The patient's presentation suggests a severe abdominal condition. Here's a categorized differential diagnosis:

• Single most likely diagnosis

  • Acute Pancreatitis: The patient's symptoms of sudden onset epigastric pain, intractable nausea, vomiting, and fever, along with elevated amylase and lipase levels, are highly suggestive of acute pancreatitis. The physical examination findings of marked tenderness, guarding, and systemic signs such as hypotension, tachycardia, and fever further support this diagnosis.

• Other Likely diagnoses

  • Peptic Ulcer Disease: Although the laboratory results point towards pancreatitis, peptic ulcer disease could present with similar symptoms, including epigastric pain and vomiting. However, the significant elevation in lipase is more indicative of pancreatitis.
  • Cholecystitis: Inflammation of the gallbladder could cause similar symptoms, especially if a gallstone is obstructing the common bile duct, leading to pancreatitis. The diagnosis would depend on the findings of the pending CT scan.
  • Gastrointestinal Perforation: This condition could present with severe abdominal pain, vomiting, and fever. However, the absence of free air under the diaphragm on an upright chest X-ray (not mentioned) and the specific laboratory findings make this less likely.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • Mesenteric Ischemia: Although less likely given the laboratory findings, mesenteric ischemia is a life-threatening condition that requires prompt diagnosis and treatment. It can present with severe abdominal pain out of proportion to physical findings, vomiting, and signs of shock.
  • Ruptured Abdominal Aortic Aneurysm: This is a medical emergency that can present with severe abdominal pain, hypotension, and signs of shock. The patient's history of hyperlipidemia increases the risk of vascular diseases.
  • Sepsis of Abdominal Origin: The patient's presentation with fever, hypotension, and tachycardia could indicate sepsis, which is a life-threatening condition requiring immediate attention.

• Rare diagnoses

  • Diabetic Ketoacidosis with Abdominal Crisis: Although the patient has diabetes, the primary symptoms and laboratory findings do not strongly suggest diabetic ketoacidosis as the primary diagnosis. However, it could be a contributing factor or a complication.
  • Porphyria: This is a group of rare disorders that can cause severe abdominal pain, nausea, and vomiting. However, the patient's presentation and laboratory findings do not specifically suggest porphyria.