Diagnostic Approach to Acute Abdominal Pain

Diagnostic Considerations

The American College of Gastroenterology suggests that 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
In cases of diagnostic uncertainty, such as a patient with classic symptoms of acute pancreatitis but normal amylase and lipase levels, imaging is essential to establish or exclude the diagnosis 1, 2

The European Society of Gastrointestinal and Abdominal Radiology recommends dynamic contrast-enhanced CT when there is diagnostic uncertainty, as in patients with classic symptoms but normal enzymes 3, 1
CT imaging will either confirm pancreatitis with characteristic findings or reveal an alternative diagnosis requiring different management 1

Perforated peptic ulcer, although less likely in the absence of free air signs and normal vital signs except tachycardia, should be considered in the differential diagnosis 4
Acute cholecystitis or biliary colic, despite normal liver enzymes, are alternative diagnoses to consider 2
Mesenteric ischemia, especially in older patients, and acute coronary syndrome, despite a normal EKG, should also be considered 4

The American College of Surgeons recommends beginning intravenous fluid resuscitation with Lactated Ringer's solution, targeting urine output >0.5 ml/kg/hour, as aggressive early fluid therapy is critical if the diagnosis is pancreatitis 1, 2
Providing adequate analgesia with opioids is safe and appropriate for severe pain control 1, 2
Keeping the patient NPO until the diagnosis is clarified is recommended 1
Monitoring vital signs closely, including oxygen saturation, and providing supplemental oxygen if needed to maintain saturation >95% is crucial 2