What is the initial workup for a patient?

Initial Workup for a Patient

The initial workup for a patient should include a thorough medical history, physical examination with assessment of volume status and orthostatic blood pressure changes, complete blood count, comprehensive metabolic panel, urinalysis, chest X-ray, and ECG. 1

Core Laboratory Tests

Essential Blood Tests

• Complete blood count with differential and platelets 1
• Comprehensive metabolic panel including:
  • Electrolytes (sodium, potassium, calcium, magnesium) 1
  • Blood urea nitrogen and serum creatinine 1
  • Liver function tests (AST, ALT, alkaline phosphatase, bilirubin) 1, 2
  • Fasting blood glucose or glycohemoglobin 1
  • Lipid profile 1
• Thyroid-stimulating hormone 1
• Lactate dehydrogenase 1
• Beta-2 microglobulin (particularly for suspected hematologic malignancies) 1, 3
• Coagulation studies (PT, PTT, fibrinogen) if bleeding concerns 3

Urine Studies

• Urinalysis 1
• 24-hour urine protein collection (if protein abnormalities suspected) 1

Imaging Studies

First-line Imaging

• Chest X-ray (PA and lateral) 1, 3
• Additional imaging based on clinical suspicion:
  • Abdominal ultrasound (first-line for hepatomegaly/splenomegaly) 3
  • CT scan with contrast of chest/abdomen/pelvis (for detailed evaluation) 3
  • Echocardiography (for suspected cardiac issues) 1

Specialized Testing Based on Clinical Presentation

For Suspected Cardiac Issues

• 12-lead ECG 1
• Echocardiography to assess LVEF, LV size, wall thickness, and valve function 1
• Coronary arteriography if angina or significant ischemia present 1

For Suspected Hematologic Malignancies

• Peripheral blood flow cytometry 3
• Serum protein electrophoresis and immunofixation 1
• Bone marrow aspiration and biopsy if indicated 3
• PET/CT scan for suspected lymphoma 1, 3

For Suspected Gastrointestinal Issues

• Liver function panel (AST, ALT, alkaline phosphatase, GGT, bilirubin, albumin) 2, 4
• Hepatitis serology if liver dysfunction present 4
• Endoscopy with biopsies if GI symptoms present 1

Special Considerations for Immunocompromised Patients

Immunocompromised patients require particular attention as they may not present with typical signs and symptoms:

• Contrast-enhanced CT scan is the most reliable exam for diagnosing intra-abdominal disease 1
• Test for Clostridioides difficile and its toxin if diarrhea present 1
• Consider specific tests for HIV-associated conditions if HIV positive 1

Important Caveats

• Clinical signs may not be reliable in immunocompromised patients; the more severe the immunocompromise, the less reliable the clinical presentation 1
• Laboratory tests may not accurately reflect the severity of the clinical condition in immunocompromised patients 1
• Plain radiographs and ultrasound are often not sufficiently sensitive in immunocompromised patients 1
• Dynamic liver function tests (such as indocyanine green plasma disappearance rate) may be superior to static tests for assessing liver function in critically ill patients 5

The initial workup should be tailored based on the patient's presenting symptoms, but these core elements provide a foundation for comprehensive evaluation. Additional specialized testing should be guided by the initial findings and clinical suspicion.