What is the appropriate workup and imaging for a 21-year-old female, 3 weeks post-cesarean section (C-section), presenting with severe upper abdominal pain?

Workup and Imaging for Severe Upper Abdominal Pain in a 21-Year-Old Female 3 Weeks Post-Cesarean Section

Computed tomography (CT) scan of the abdomen and pelvis with intravenous and oral contrast is the most appropriate initial imaging study for a 21-year-old female presenting with severe upper abdominal pain 3 weeks after cesarean section. 1

Initial Assessment

• Obtain vital signs to assess for fever, tachycardia, hypotension, or tachypnea which may indicate infection, bleeding, or other post-surgical complications 1
• Complete blood count to evaluate for leukocytosis, which may suggest infection or inflammation 1
• C-reactive protein and procalcitonin levels to assess for inflammatory response 1
• Serum electrolytes, liver function tests, and renal function tests to evaluate for organ dysfunction 1
• Serum lactate and blood gas analysis to assess for tissue hypoperfusion 1
• Beta-hCG testing to rule out pregnancy-related complications 1

Differential Diagnosis

The differential diagnosis for severe upper abdominal pain in a post-cesarean patient includes:

• Post-cesarean complications:
  • Uterine rupture or dehiscence 2
  • Intra-abdominal abscess 2
  • Wound infection with extension to deeper tissues 1
• Non-obstetric causes:
  • Acute cholecystitis 1
  • Acute pancreatitis 1
  • Small bowel obstruction 1
  • Mesenteric ischemia 1

Imaging Recommendations

First-line Imaging

• CT scan of abdomen and pelvis with IV and oral contrast is the study of choice for post-surgical patients with acute abdomen 1
  • Provides detailed evaluation of post-surgical anatomy
  • Can identify collections, abscesses, anastomotic leaks, and other post-surgical complications
  • Allows assessment of solid organs and bowel

Alternative Imaging Options

• Ultrasonography of the abdomen if:

  • Right upper quadrant pain is the predominant symptom (to evaluate for cholecystitis) 1
  • CT is unavailable 1
  • Point-of-care ultrasound can be used to rule out cholecystitis, biliary disease, and detect free intraperitoneal fluid 1

• MRI of the abdomen if:

  • Patient has contraindications to CT (such as severe contrast allergy) 1
  • Radiation exposure is a significant concern 1

Management Considerations

• If clinical suspicion for surgical pathology is high despite negative imaging, diagnostic laparoscopy should be considered 1
• Do not delay surgical exploration if there are alarming clinical signs/symptoms, even with negative radiological assessment 1
• Consider endoscopic evaluation if CT suggests leak or fistula and the patient is hemodynamically stable 1

Important Caveats

• Plain abdominal X-rays have limited diagnostic value in this setting and should only be considered when CT is unavailable 1
• The absence of oral and intravenous contrast can significantly decrease the sensitivity and specificity of CT imaging 1
• Uterine rupture, while rare, is a potentially life-threatening complication that should be considered in any postpartum patient with acute abdominal pain, especially with risk factors such as previous cesarean sections 2
• Post-cesarean patients may present with atypical symptoms or pain patterns, making diagnosis more challenging 2

Follow-up Recommendations

• If initial imaging is negative but symptoms persist, consider:
  • Repeat imaging in 24-48 hours 1
  • Diagnostic laparoscopy, which has higher sensitivity and specificity than any radiological assessment 1
  • Consultation with specialists (general surgery, obstetrics/gynecology) based on clinical suspicion 1