What is the appropriate emergency department workup for a 7-year-old patient with Down syndrome (Trisomy 21) presenting with abdominal pain?

Emergency Department Workup for a 7-Year-Old with Down Syndrome Presenting with Abdominal Pain

Ultrasound should be the first-line imaging modality for evaluating abdominal pain in a 7-year-old child with Down syndrome, followed by MRI or low-dose CT if ultrasound is inconclusive or unavailable. 1

Initial Assessment

• Obtain vital signs including temperature, heart rate, respiratory rate, blood pressure, and oxygen saturation to assess for signs of sepsis or shock 1
• Perform rapid cardiopulmonary assessment to ensure hemodynamic stability before proceeding with detailed evaluation 2
• Administer IV fluids if signs of dehydration or shock are present (20 mL/kg normal saline) 2
• Provide appropriate analgesia early in the evaluation process 1

History and Physical Examination Considerations

• Down syndrome patients may have atypical presentations of common conditions and may not reliably communicate pain 1
• Assess for specific comorbidities common in Down syndrome that can cause abdominal pain:
  • Constipation (very common in Down syndrome)
  • Celiac disease (higher prevalence in Down syndrome)
  • Atlantoaxial instability (may present with referred abdominal pain)
  • Congenital heart defects (may present with abdominal symptoms) 1
• Physical examination should be thorough but gentle, with special attention to:
  • Abdominal distension
  • Localized tenderness
  • Presence of masses
  • Signs of peritoneal irritation 3

Laboratory Studies

• Complete blood count with differential to assess for leukocytosis 1
• C-reactive protein (CRP) - elevated levels are a significant predictor of serious pathology requiring admission 4
• Basic metabolic panel to assess electrolyte abnormalities and renal function 1
• Liver function tests 1
• Urinalysis to rule out urinary tract infection 5

Imaging Studies

First-Line Imaging:

• Ultrasound of the abdomen should be the initial imaging modality 1
  • Benefits: No radiation exposure, no need for sedation, can identify common causes of abdominal pain including appendicitis, intussusception, and gallbladder disease 1
  • Limitations: Operator-dependent, may be limited by patient body habitus or bowel gas 1
  • Sensitivity for appendicitis in children with definitive results: 99% (range 84-100%) 1
  • Specificity for appendicitis in children with definitive results: 96% (range 71-98%) 1

Second-Line Imaging (if ultrasound is inconclusive or unavailable):

• MRI without contrast if available and patient can cooperate 1

  • Benefits: No radiation exposure, high sensitivity (98%) and specificity (97%) for appendicitis 1
  • Limitations: Requires patient cooperation, longer scan time, may require sedation in younger children 1

• Low-dose CT with IV contrast if MRI is unavailable or patient cannot cooperate 1

  • Benefits: Quick acquisition, high sensitivity (96-98%) and specificity (96-98%) for appendicitis 1
  • Limitations: Radiation exposure, though pediatric-specific protocols should adhere to ALARA (as low as reasonably achievable) principle 1

Special Considerations for Down Syndrome

• Higher incidence of gastrointestinal anomalies including duodenal atresia, Hirschsprung disease, and imperforate anus may complicate the clinical picture 3
• Consider atlantoaxial instability which may present with referred abdominal pain 3
• Patients may have difficulty communicating pain, making physical examination findings less reliable 1
• Increased risk of celiac disease may present with abdominal pain 3

Decision Algorithm

1. If patient is unstable (signs of shock, peritonitis):

   • Immediate surgical consultation
   • Fluid resuscitation
   • Consider CT abdomen/pelvis with IV contrast if surgical intervention likely 1

2. If patient is stable:

   • Perform ultrasound as first-line imaging 1
   • If ultrasound is conclusive → Treat based on findings
   • If ultrasound is inconclusive or appendix not visualized:
     • Consider observation with serial exams if low clinical suspicion 1
     • Consider MRI if available and patient can cooperate 1
     • Consider CT with IV contrast if MRI unavailable or impractical 1

3. If transfer to a pediatric specialty center is being considered:

   • If patient will be transferred regardless of imaging findings → Defer imaging to receiving institution 1
   • If imaging will determine need for transfer → Perform appropriate imaging 1

Common Pitfalls to Avoid

• Relying solely on physical examination findings, as children with Down syndrome may have atypical presentations 1
• Underestimating the significance of tachycardia, which may be the only early sign of serious intra-abdominal pathology 1
• Performing unnecessary radiation-exposing studies when alternatives are available 1
• Failing to consider the higher prevalence of certain conditions in Down syndrome patients (celiac disease, Hirschsprung's disease, duodenal atresia) 3
• Delaying surgical consultation when peritoneal signs are present 1