Acute Appendicitis

General Anatomy:

  • It’s a blind end structure bound to the cecum -> follow tenia coli for identification
  • Blood supply: SMA -> ileocecal branch -> appendicular A
    • Appendix is supplied by an end artery (i.e. no anastomoses = poor blood supply), so if it gets blocked -> easily leading to ischemia and perforation



  • Related to luminal obstruction of the appendix:
    • Fecalith (elderly) -> bacterial overgrowth and fermentation -> gas -> luminal distension -> increased wall tension -> venous and arterial compromise -> ischemia and perforation
    • Hypertrophic lymphoid tissue (young)
    • Inspissated contrast material
    • Enterobius vermicularis


Clinical Presentation:

1. Periumbilical abdominal pain shifting to RLQ

  • Appendicitis present as migratory pain; meaning the pain has disappeared from one place and appeared in another location. Unlike radiating pain (e.g.: biliary pain radiating to scapula), where there is pain in both places at the same time
  • The patient should be able to point to the pain w\ one finger
  • The base of the appendix is constant (McBurney’s point), but the length and position of the tip is variable -> which is why we also get pain\tenderness elsewhere in the abdomen

Appendicitis 2

  • Usually the patient will present w\ such pain for the first time, however; previous recurrent attacks doesn’t rule appendicitis out
  • There is no such thing as ‘’chronic appendicitis”, instead; repeated attacks of acute\subacute appendicitis
  • This usually means the cause isn’t necessarily a fecalith, instead; lymphatic hyperplasia which might have resolved spontaneously
  • Microscopically, there are no changes in the appendix between the attacks, so you can’t tell if this was first-time presentation or recurrent appendicitis

2. Vomiting:

  • Why? Reflex pyloric spasm (probably protective to the GIT)
  • While in renal colic they vomit b\c of the pain itself
  • In appendicitis, GI symptoms start after pain onset
    • If before = gastroenteritis
    • If together = exacerbation of PUD

3. Fever:

  • Not high grade, no shivering; unless perforation, abscess, or wrong dx

4. Bowel habit:

  • Mostly normal
  • Some with constipation -> but if present, then it’s a risk factor of SBO
  • Some with diarrhea: typically starts early (day 1), which can mean 2 things:
    • Location of the appendix tip is pelvic (close to the sigmoid) -> causing rectal irritation (tenesmus and diarrhea)
    • Another dx: e.g. gastroenteritis
  • If presenting w\ late diarrhea (e.g. day 4) -> means perforation (usually associated w\ high temperature and WBC)

5. Urinary symptoms:

  • Usually no urinary symptoms
  • Some can have dysuria or dark urine b\c of dehydration
  • If the tip of the appendix is subceccal or pelvic -> might increase urination frequency and suprapubic pain
  • In U\A, you might find some WBC (due to irritation of the ureters), but not in the range of UTI

6. Other imp points in the history:

  • Ask about prior Hx of URTI or congested throat esp. in children -> mesenteric lymphadenitis (caused by Yersinia enterocolitica), which mimics appendicitis
  • Hx of appendectomy doesn’t rule out the dx of appendicitis due to residual appendix


Physical Examination:

  • Nothing impressive in vital signs (some tachycardia)
  • The patient is not too sick-looking
  • Lying flat, maybe flexing right hip to relieve the pain (which relaxes the psoas muscle)
  • Rebound tenderness: why? Inflamed appendix’s visceral peritoneum touches parietal peritoneum
  • Afflicting this pain can cause great distress to the patient, so refrain from doing it over and over. It can be elicited through other means:
  1. Dunphy sign: increased pain w\ coughing or moving
  2. Rovsing sign: palpation of the left side (which moves gas over) -> causes pain in RLQ
  3. Obturator sign: RLQ pain when flexing the knee and internally rotating the hip [pelvic appendix]
  4. Iliopsoas sign: RLQ pain when extending the hip [retrocecal appendix]
  • Retroceccal appendix presents as an atypical picture of appendicitis
  • Testicular, groin orifice, and rectal exam are integral in presumed appendicitis
  • During rectal exam, you might feel a tender budge in the right wall -> pelvic abscess

Appendicitis 1



1. Non-complicated 

  • Conservative Rx: hydration, analgesia, antipyretics
  • But definitive Rx is appendectomy: either open or laparoscopic; they are both accepted, unless in certain groups where laparoscopic is preferred:
    • Uncertain dx -> “diagnostic laparoscopy” (mainly females of child-bearing age group)
    • Obesity: usually in open appendectomy, the wound is small, but due to thick abdominal wall in an obese pt, this leads to the extension of the wound anyways. So, reaching the abdomen directly through a small laparoscopic wound makes more sense
    • Perforated appendix: better drainage
  • Advantages of laparoscopic over open? Faster recovery and lower chance of wound infection
  • If the pt is unwilling to go under surgery or where surgery is not preferred (e.g.: cardiac pts) -> give antibiotics
    • Antibiotics for acute appendicitis is an established practice, but it’s not the standard of care. Most pts improve, but the problem is 30% will recur w\in the first year


2. Complicated:

  • By perforation, which can lead to either:
    • Abscess: don’t operate! give broad spectrum abx, GI rest, good hydration and drain by interventional radiology
    • Appendicular mass (where the body will try to contain it): don’t operate! (it will create more damage than good, b\c everything is jammed). So, give abx and bring the pt for interval appendectomy 6 wks later
  • However, interval appendectomy is an old practice, why? Since the appendix has already perforated and shattered, the likelihood of going in and finding a decent-size appendix to remove is low -> which makes the likelihood of recurrence ‘if left alone’ also low!
  • Unless older than 50 (which might be a tumor) -> bring them back for CT and colonoscopy after 6 wks
  • If you’re in doubt if this is an abscess or appendicular mass -> order a CT to differentiate


Random notes:

  • If the clinical picture of the pt is not convincing of appendicitis, trust your clinical judgment and avoid doing CT (treat the pt and not the CT), and discharge the pt w\ instructions
  • It’s better to do a negative appendectomy than leaving the pt to perforate
  • In children and females in childbearing age, rates of negative appendectomies can reach up to 23%
  • Most common late complication of appendectomy? SBO due to adhesions
  • Most common organism in appendix? E. coli
  • Be more careful w\ females w\ presumed appendicitis -> investigate more and image
  • Don’t expect perforation w\in 24 hrs, unless immunocompromised, or taking abx (which mask Sx)




Download the PDF version: here


  • Dr Alabeidi’s and Dr Ayaz’s clinical notes

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