Acute Appendicitis

Key considerations: Perforated appendicitis with sepsis, Appendiceal abscess, Appendiceal neoplasm (especially in elderly)

Cannot miss

history: Classic migration: periumbilical pain → RLQ (12-24hr); Anorexia, nausea, vomiting (typically after pain onset); Duration of symptoms; exam: RLQ tenderness, McBurney point tenderness; Rebound tenderness, guarding; Rovsing, psoas, obturator signs; Rectal exam if pelvic appendicitis suspected; labs: CBC with differential (WBC >10k in 80%); CRP (elevated in 96%); Urinalysis (rule out UTI; mild pyuria can occur with pelvic appendicitis); HCG in women of reproductive age; imaging: CT abdomen/pelvis with IV contrast (sensitivity 98%); US if pregnant or pediatric (right lower quadrant target); MRI if pregnant and US nondiagnostic; bedside: POCUS for free fluid, appendix visualization if experienced

immediate: NPO; IV fluids; IV antibiotics (cefoxitin or pip-tazo) before surgery; Pain management; general: Surgical consultation; Appendectomy (laparoscopic preferred); specific: diagnosis: Simple Appendicitis; steps: Laparoscopic appendectomy within 24 hours; Single dose preoperative antibiotics; Antibiotics-only approach may be considered in select uncomplicated cases (CODA trial); diagnosis: Perforated with Abscess; steps: If well-contained abscess >4cm: IR percutaneous drainage + IV antibiotics; Interval appendectomy in 6-8 weeks; If diffuse peritonitis: urgent appendectomy

admit: All confirmed appendicitis; Observation if equivocal and Alvarado intermediate; discharge: Negative imaging with alternative diagnosis; Low Alvarado with serial exam plan and 12-24hr recheck; consults: General surgery; IR if percutaneous drainage needed

Alvarado score ≤4: low risk, consider discharge with follow-up; ≥7: high risk, surgical consult
CT sensitivity ~98% but consider US first in children and pregnant patients
CODA trial: antibiotics alone is reasonable for uncomplicated appendicitis but ~30% eventually need appendectomy within 90 days