One-page cheat sheet
Acute appendicitis
The commonest surgical emergency
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Key facts
- Peak age 10–30; lifetime risk about 7–8%
- Obstruction of the lumen (faecolith, lymphoid hyperplasia) → distension, ischaemia, perforation
- Perforation is more likely in children, the elderly and with delay beyond 36–48 hours
Story and signs
- Central (T10) pain that migrates to the right iliac fossa
- Anorexia, nausea or vomiting, low-grade fever
- RIF tenderness over McBurney’s point, guarding, percussion or rebound tenderness
- Rovsing’s: LIF pressure → RIF pain. Psoas: retrocaecal. Obturator: pelvic
Investigations
- FBC, CRP, U&E, urinalysis
- Pregnancy test in every woman of child-bearing age
- Scores: Alvarado, AIR, Adult Appendicitis Score (best at ruling out)
- Ultrasound first in children, young women and pregnancy; low-dose CT in most adults when unclear; MRI in pregnancy if ultrasound is not diagnostic
Management
- Analgesia early (it does not mask signs), IV fluids, nil by mouth
- Antibiotics once the diagnosis is made
- Laparoscopic appendicectomy is the standard
- Uncomplicated, selected adults: antibiotics first is an option, but about 1 in 3 recur within 5 years
- Appendix mass or abscess: antibiotics ± percutaneous drainage; check for a tumour (CT or colonoscopy) in patients over 40
Don’t miss
- Ectopic pregnancy, ovarian torsion or cyst, PID
- Right ureteric stone, pyelonephritis
- Mesenteric adenitis, Meckel’s diverticulitis, Crohn’s
- Right lower lobe pneumonia and DKA in children
Exam pearls
- Elderly and pregnant patients present atypically: the appendix rises with the uterus
- Day 5–7 swinging fever after surgery with diarrhoea or rectal tenderness = pelvic abscess
- A normal-looking appendix at laparoscopy is usually removed, after checking for other causes