• Maintain a broad differential diagnosis – including ectopic pregnancy, ovarian/testicular torsion, bowel ischemia, ruptured AAA.
• Sick or not sick? Ensure patient is hemodynamically stable, manage with IV crystalloid or vasopressors if necessary, analgesia, may consider IV antibiotics empirically if appearing septic.
• Make patient NPO.

• One of the most common causes of the acute abdomen.
• Cause is usually an obstruction of the appendiceal lumen causing inflammation of the appendiceal wall, which may be followed by localized ischemia, perforation, and the development of a contained abscess or generalized peritonitis.
• Most common abdominal surgical emergency globally, with a lifetime risk of 8.6% in males and 6.9% in females.
• Most common in patients aged 10-19 years, the most frequent cause of atraumatic abdominal pain in children >1 year old, most common non-obstetric surgical emergency in pregnancy.

• Clinical Stratification Scoring: Alvarado Score for Acute Appendicitis, Samuel’s Pediatric Appendicitis Score (PAS) can help exclude acute appendicitis and identify intermediate-risk patients needing imaging.
• Presentation
  • Symptoms: constant right lower quadrant abdominal pain, anorexia, nausea and vomiting.
  • “Classic” presentation: periumbilical in nature with subsequent migration to the RLQ as inflammation progresses (migratory pain occurs only in 50-60%.)
  • May have non-specific features, including indigestion, flatulence, bowel irregularity, diarrhea, generalized malaise.
• Physical examination
  • Low-grade fever may be present (can be higher.)
  • Tenderness in the right lower quadrant (RLQ.)
  • McBurney’s point tenderness maximal tenderness at 1.5 to 2 inches from the anterior superior iliac spine (ASIS) on a straight line from the ASIS to the umbilicus.
  • Rovsing’s sign pain in the right lower quadrant with palpation of the left lower quadrant.
  • Psoas sign is associated with a retrocecal appendix. RLQ pain with passive right hip extension.
  • Sensitivity is low (0.16-0.27) and specificity moderate (0.86-0.89) for these signs.

• Investigations
  • WBC >10 often present but normal WBC and/or CRP does not rule out appendicitis.
  • ~80% of patients have leukocytosis and a left shift.

• Imaging
  • CT Abdomen/Pelvis is the preferred imaging evaluation in adults – with ultrasound and MRI reserved for pregnant women and children.
  • CT scanning with contrast findings: enlarged appendiceal diameter >6 mm with an occluded lumen, appendiceal wall thickening (>2 mm), peri-appendiceal fat stranding, appendiceal wall enhancement, or appendicolith (~25% of patients.)
  • The most accurate ultrasound finding is an appendiceal diameter of >6 mm.

• Non-perforated appendicitis (simple or uncomplicated appendicitis) – 80% of cases.
• Usually surgical treatment but stable patients with can be treated with immediate appendectomy or initial nonoperative management based on local surgical preference.

Comparison of antibiotics vs. appendectomy for non-perforated appendicitis.

• All patients should initially be admitted hospital regardless of operative or non-operative management.
• In non-operative management, typically admit for 1-3 days of close observation.

• Consider transfer to another facility if there is no general surgery service/appropriate imaging available.

• Consult General Surgery for early operative consult.

• If non-operative management, may be appropriate to discharge home in 1-3 days after close observation and treatment with step down to oral antibiotics from intravenous.
• After appendectomy for simple – observe for diet tolerance.
• Most patients are discharged within 24 to 48 hours of surgery.

1. Di Saverio S, Podda M, De Simone B. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World Journal of Emergency Surgery. 2020;15(1).

   
   

2. Martin RF, Kang SKKK. Acute Appendicitis in Adults: Diagnostic Evaluation [Internet]. UpToDate. 2021 [cited 2022Nov22]. Available from: https://www.uptodate.com/contents/acute-appendicitis-in-adults-diagnostic-evaluation?sectionName=IMAGING&search=appendicitis&topicRef=1386&anchor=H612714599&source=see_link#H612714599

   
   

3. Smink D, Soybel DISI. Management of Acute Appendicitis in Adults [Internet]. UpToDate. [cited 2022Nov22]. Available from: https://www.uptodate.com/contents/management-of-acute-appendicitis-in-adults#H9259945

   
   

4. Ward M, Visser R, Gillman LM. Dynamic practice guidelines for emergency general Surgery: Acute Appendicitis [Internet]. Acute Appendicitis: Dynamic practice guidelines for emergency general surgery. Committee on Acute Care Surgery, Canadian Association of General Surgeons; 2018 [cited 2022Nov22]. Available from: https://cags-accg.ca/wp-content/uploads/2019/07/ACS-Handbook-CPG-Ch-21-Abdominal-Wall-Reconstruction.pdf