What lab tests are recommended for a patient presenting with abdominal pain to check kidney and liver function?

Laboratory Testing for Abdominal Pain: Kidney and Liver Function Assessment

Yes, obtain a comprehensive metabolic panel (CMP) and lipid panel is NOT typically indicated—instead, order a CMP which includes both kidney and liver function tests, along with additional essential labs based on clinical presentation. 1, 2

Initial Laboratory Workup

The American College of Emergency Physicians recommends a comprehensive laboratory evaluation for patients presenting with abdominal pain that includes: 1, 2

• Complete blood count (CBC) to assess for leukocytosis (>11,000/μL) indicating infection or inflammation 1
• Comprehensive metabolic panel (CMP) which includes:
  • Electrolytes 1, 2
  • Liver function tests (ALT, AST, alkaline phosphatase, bilirubin) 1, 2
  • Renal function tests (creatinine, BUN) 1, 2
• Urinalysis to evaluate for urinary tract infection or nephrolithiasis 1, 2
• Serum lipase for suspected pancreatitis (>3 times upper limit of normal is diagnostic) 1, 2
• Beta-hCG testing in all women of reproductive age—this is mandatory before proceeding with imaging 1, 2

Important Clarification on "Lipid Panel"

A lipid panel (cholesterol, triglycerides, HDL, LDL) is not part of the standard workup for acute abdominal pain. The CMP already includes the liver and kidney function tests you need. 1, 2

Location-Specific Laboratory Testing

Right Upper Quadrant Pain

• Emphasize liver function tests (ALT, AST, alkaline phosphatase, bilirubin) and hepatobiliary markers for suspected cholecystitis or hepatobiliary pathology 1, 2
• Ultrasonography is the initial imaging test of choice 3

Lower Quadrant Pain (Right or Left)

• CBC with differential to assess for appendicitis or diverticulitis 1, 2
• C-reactive protein (CRP) as an inflammatory marker 1
• CT with contrast is the preferred imaging modality 3

Diffuse Abdominal Pain

• Lactate and D-dimer if mesenteric ischemia is suspected 1, 2
• Blood cultures if sepsis is suspected 1, 2

Critical Pitfalls to Avoid

Failing to obtain pregnancy testing in women of reproductive age before imaging can lead to delayed diagnosis of ectopic pregnancy or unnecessary radiation exposure. 1, 2 This is a common and potentially dangerous oversight.

Do not rely on laboratory tests alone for diagnosis—findings early in disease may be of limited value, and clinical correlation is essential. 1 If initial workup is inconclusive but clinical suspicion remains high for serious pathology, proceed with appropriate imaging based on pain location. 1, 2

When Laboratory Results Are Equivocal

If the CMP and other initial labs are normal but symptoms suggest acute pancreatitis, maintain a low threshold for admission and treatment, as approximately 25% of acute pancreatitis cases may have normal initial enzyme levels. 4 Similarly, about 1 in 10 patients without acute pancreatitis may have falsely elevated pancreatic enzymes. 4

For suspected mesenteric ischemia, lactate and D-dimer lack specificity, so proceed with CT angiography if clinical suspicion is high despite normal or equivocal laboratory results. 1, 2