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    Patent Pending

    Pediatric Appendicitis Risk Calculator (pARC)

    Quantifies appendicitis risk in pediatric patients with abdominal pain, possibly better than the Pediatric Appendicitis Score.


    Use in children ≥5 years old presenting to the emergency department or outpatient setting with acute abdominal pain (duration <96 hours).

    When to Use
    Why Use

    • Children ≥5 years old presenting to the emergency department or outpatient setting with acute abdominal pain (duration <96 hours).

    • Patients with the following conditions were excluded from the study:
      • Pregnancy.
      • Previous abdominal surgery.
      • Inflammatory bowel disease.
      • Chronic pancreatitis.
      • Sickle cell anemia.
      • Cystic fibrosis.
      • Any medical condition affecting the ability to obtain an accurate history.
      • History of abdominal trauma within the previous 7 days.

    • The age range of patients included in the study was 5-18 years. Appendicitis is relatively rare in children <5 years old, and is more likely to present with atypical features not captured by this calculator.

    • Cases of appendicitis among the lowest risk groups (<5% or 5-14% risk as determined by the calculator) were missed only 0.4% of the time in each. The sensitivity of this calculator in children with <5% risk was 100%; the sensitivity was 97.2% in children determined to have a 5-14% risk of acute appendicitis.

    • May help determine need for advanced imaging such as formal ultrasound or CT.

    • Can identify low risk patients who can be observed in or discharged from the ED with follow up or return precautions.

    • In the validation study, Kharbanda et al found that the formula performed better than the Pediatric Appendicitis Score (sorts fewer patients into equivocal risk categories), making it more useful in aiding clinical decisionmaking.

    Pediatric ED
    24 to <48
    48 to 96
    Unknown (defaults to <24 hrs)
    × 10³ cells/µL


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    Next Steps
    Creator Insights
    Dr. Anupam B. Kharbanda

    About the Creator

    Anupam Kharbanda, MD, is a pediatric emergency medicine physician and Chief of Critical Care Services at Children's Minnesota. He has published numerous articles and several textbook chapters in the field of pediatric emergency medicine and he is nationally recognized for his work on developing clinical pathways for the management of pediatric appendicitis. Dr. Kharbanda currently co-leads a federally-funded multi-center study to implement appendicitis care pathways into the HealthPartners and Kaiser Northern California health systems, and additional current research areas include developing and implementing evidenced-based care pathways in order to enhance patient experience, improve quality of care, and minimize health care expenditures.

    To view Dr. Anupam B. Kharbanda's publications, visit PubMed

    Content Contributors
    Reviewed By
    • Hector Vazquez, MD
    About the Creator
    Dr. Anupam B. Kharbanda
    Partner Content
    Content Contributors
    Reviewed By
    • Hector Vazquez, MD