What is the initial workup and management for a patient presenting with abdominal pain?

Initial Workup and Management for Abdominal Pain

The initial workup for abdominal pain should follow a step-up approach beginning with clinical and laboratory examination, progressing to appropriate imaging based on the location of pain and suspected diagnosis. 1

Initial Assessment

History

• Pain characteristics:
  • Location (quadrant-specific)
  • Onset (sudden vs. gradual)
  • Duration
  • Quality (sharp, dull, cramping)
  • Radiation
  • Aggravating/alleviating factors
• Associated symptoms:
  • Nausea/vomiting
  • Changes in bowel habits
  • Fever
  • Urinary symptoms
  • Vaginal bleeding/discharge

Physical Examination

• Vital signs (tachycardia, hypotension, fever)
• Abdominal examination:
  • Inspection for distension
  • Auscultation for bowel sounds
  • Palpation for tenderness, guarding, rigidity
  • Percussion for tympany or dullness
  • Assessment for peritoneal signs (rebound tenderness)
• Specific maneuvers:
  • Murphy's sign for cholecystitis
  • Psoas sign for appendicitis
  • Carnett's test to differentiate abdominal wall from visceral pain

Laboratory Tests

• Complete blood count (CBC)
• Comprehensive metabolic panel (CMP)
• Urinalysis
• Pregnancy test in women of reproductive age 1
• C-reactive protein (CRP)
• Lipase for suspected pancreatitis
• Stool studies if diarrhea present (culture, C. difficile, ova and parasites) 1

Imaging Based on Pain Location

Right Upper Quadrant Pain

• Ultrasonography is the initial imaging test of choice 1
• Consider CT if ultrasonography is inconclusive
• Cholescintigraphy may be considered for suspected cholecystitis with negative ultrasound

Right Lower Quadrant Pain

• CT with contrast media is the recommended initial imaging study 1
• Ultrasonography may be considered as initial study in young patients, pregnant women, or when radiation exposure is a concern

Left Lower Quadrant Pain

• CT with contrast media is the recommended initial imaging study 1
• Particularly useful for suspected diverticulitis with sensitivity >95% 1

Nonlocalized/Diffuse Abdominal Pain

• CT is typically the imaging modality of choice if serious pathology is suspected 1
• A prospective study found CT altered the diagnosis in 49% of patients and changed management in 42% of patients 1

Special Considerations

Bowel Obstruction

• Accounts for approximately 15% of hospital admissions for acute abdominal pain 1
• Initial evaluation should include:
  • Assessment for previous abdominal surgery (85% sensitivity, 78% specificity for adhesive small bowel obstruction) 1
  • Plain radiography may be appropriate for suspected bowel obstruction 1
  • CT for confirmation and to determine the cause and level of obstruction

Pregnant Patients

• Ultrasonography is first-line imaging
• If inconclusive, MRI is preferred over CT 1

Elderly Patients

• May present with atypical symptoms
• Lower threshold for advanced imaging
• Higher risk for serious pathology (mesenteric ischemia, perforation)

Management Principles

1. Resuscitation first for hemodynamically unstable patients

   • IV fluids
   • Correction of electrolyte abnormalities
   • Pain control

2. Pain management

   • Do not withhold analgesia while awaiting diagnosis
   • Opioid analgesia if severe pain

3. Specific treatment based on diagnosis

   • Surgical consultation for suspected surgical abdomen
   • Antibiotics for infectious causes
   • Supportive care for self-limiting conditions

4. Disposition

   • Admission criteria:
     • Hemodynamic instability
     • Severe pain uncontrolled with oral medications
     • Inability to tolerate oral intake
     • Need for surgical intervention
     • Significant comorbidities

Common Pitfalls to Avoid

1. Overreliance on conventional radiography - Limited diagnostic value in most cases of abdominal pain 1

2. Failure to consider extra-abdominal causes - Pneumonia, myocardial infarction, or abdominal wall pain can present as abdominal pain

3. Delayed surgical consultation - Early involvement of surgeons is crucial for potentially surgical conditions

4. Neglecting pregnancy testing - Should be performed in all women of reproductive age before imaging 1

5. Inappropriate use of CT - Consider radiation exposure risks, especially in young patients and those requiring repeated imaging

By following this structured approach to the workup and management of abdominal pain, clinicians can efficiently diagnose and treat patients while minimizing unnecessary testing and potential complications.