Next Step in Management
The next step is to obtain a contrast-enhanced CT scan of the abdomen to evaluate for acute pancreatitis and assess disease severity, since the patient presents with classic symptoms but has normal amylase and lipase levels. 1, 2
Diagnostic Considerations
This patient presents with a diagnostic dilemma that requires immediate clarification:
The clinical presentation is highly suggestive of acute pancreatitis (sudden severe epigastric pain, nausea, vomiting, tachycardia, and epigastric tenderness), but the normal amylase and lipase levels create diagnostic uncertainty. 3, 4
Acute pancreatitis is diagnosed when two of three criteria are met: characteristic abdominal pain, serum amylase/lipase ≥3 times the upper limit of normal, and/or imaging findings consistent with pancreatitis. 2, 4, 5
In this case, only one criterion (abdominal pain) is clearly present, making imaging essential to establish or exclude the diagnosis. 1, 2
Why CT Imaging is the Next Step
Dynamic contrast-enhanced CT should be obtained when there is diagnostic uncertainty, as in this patient with classic symptoms but normal enzymes. 6, 1
Normal amylase and lipase do not exclude acute pancreatitis—approximately 10-20% of patients with acute pancreatitis may have normal or minimally elevated enzyme levels, particularly if they present very early or late in the disease course. 5
CT imaging will either confirm pancreatitis with characteristic findings (pancreatic edema, inflammation, peripancreatic fat stranding) or reveal an alternative diagnosis requiring different management. 1, 4
Alternative Diagnoses to Consider
The differential diagnosis with this presentation includes:
- Perforated peptic ulcer (though the absence of free air signs and normal vital signs except tachycardia make this less likely) 6
- Acute cholecystitis or biliary colic (though liver enzymes are normal) 2
- Mesenteric ischemia (the tachycardia and severe pain warrant consideration, especially in older patients) 6
- Acute coronary syndrome (though EKG is normal, atypical presentations occur) 3
Immediate Management While Awaiting Imaging
While arranging CT imaging, initiate supportive care:
Begin intravenous fluid resuscitation with Lactated Ringer's solution, targeting urine output >0.5 ml/kg/hour, as aggressive early fluid therapy is critical if this proves to be pancreatitis. 1, 2, 7
Provide adequate analgesia—opioids are safe and appropriate for severe pain control. 1, 2
Keep the patient NPO (nothing by mouth) until the diagnosis is clarified. 1
Monitor vital signs closely, including oxygen saturation, and provide supplemental oxygen if needed to maintain saturation >95%. 2
Common Pitfalls to Avoid
Do not dismiss acute pancreatitis based solely on normal enzyme levels—imaging is required when clinical suspicion is high. 5
Do not delay CT imaging in a patient with severe, unexplained epigastric pain and an unclear diagnosis. 6, 1
Avoid ordering plain abdominal radiographs as the primary diagnostic test—they have limited utility in acute pancreatitis except to detect complications like free air. 6