Acute appendicitis — Alvarado, imaging and antibiotics-first

Alvarado (MANTRELS). Migration 1, Anorexia 1, Nausea/vomiting 1, Tenderness RLQ 2, Rebound 1, Elevated temperature 1, Leukocytosis 2, Shift left 1 (total 10). Ohle bands low 1–4, intermediate 5–6, high 7–10: cut point 5 rules out (99% sensitivity overall), cut point 7 rules in poorly (81% specificity overall).^[1][11]

Imaging.

• Child / pregnant / young woman: USS first (Doria: USS sensitivity 88% children, 83% adults); MRI second-line in pregnancy if USS inconclusive, first-line where available.^[6][7]
• Adult male / atypical: CT first-line or problem-solving after equivocal USS (Doria: CT 94% sensitive and specific in adults; low-dose not inferior to standard).^[6][7]
• Peritonitic high-risk patient: surgical review before prolonged imaging delay.

Antibiotics-first. APPAC: ~73% avoided surgery at 1 year but non-inferiority to appendicectomy not met on the primary margin; recurrence common.^[4] CODA: antibiotics non-inferior on 30-day health status; ~29% appendectomy by 90 days; appendicolith higher risk.^[5] Offer only for selected uncomplicated cases with informed consent — surgery remains first-line default for most fit patients.

Perioperative antibiotics. Ceftriaxone 2 g 24-hourly + metronidazole 500 mg 6-hourly when operating or treating complicated disease (WSES-advised empiric cover).^[7]