Appendicitis

Question 1

Definition of appendicitis

Answer 1

-inflammation of the vermiform appendix, most likely due to obstruction of the lumen of the appendix (by faecolith, normal stool, infective agents, lymphoid hyperplasia)

Question 2

Symptoms of appendicitis

Answer 2

• sudden
• abdominal pain starting in the mid-abdomen and later localising in the right lower quadrant
• associated fever, anorexia, nausea, vomiting
• pain aggravated by cough, steady pain

Different appendix positions:

• retrocaecal appendix can cause flank or back pain
• retroileal appendix can cause testicular pain due to irritation of the spermatic artery or ureter
• pelvic appendix can cause suprapubic pain
• paracolic long appendix with tip inflammation in the right upper quadrant may cause pain in this region

Question 3

Diagnosis of appendicitis

Answer 3

• acute severe right iliac fossa pain
• poorly localised central abdominal pain that becomes localised to the right lower quadrant
• anorexia, nausea, vomiting
• perforated appendix = signs of shock/sepsis, guarding, palpable mass

-psoas sign - flexred right hip

Question 4

Risk factors for appendicitis

Answer 4

• low dietary fibre
• improved personal hygiene (frequent use of antibiotics, hygienic conditions = imbalance of GI microbiota flora= modified response to viral infection = trigger appendicitis
• smoking

Question 5

Aetiology of appendicitis

Answer 5

• obstruction of the lumen of the appendix; faecolith (hard mass of faecal matter), normal stool, or lymphoid metaplasia
• neuroimmune aetiology in some cases

Question 6

Pathophysiology of appendicitis

Answer 6

• lumen distal to the obstruction starts to fill with mucus and acts as a closed-loop obstruction = distension, increased intraluminal pressure
• overtime, resident bacteria in the appendix rapidly multuply- Bacteriodes fragilis, Escherichia coli
• distension of the lumen of the appendix causes reflex anorexia, nausea, vomiting, visceral pain
• as pressure of the lumen > venous pressure, small venules/capilaries become thrombosed but arterioles remain open = appendix engorged and congested
• once the small arterioles are thrombosed, the anti-mesenteric border become ischaemic, infarction and perforation
• bacteria leaks from dying walls, pus forms around appendix

Question 7

Management of appendicitis

Answer 7

• emergency appendicectomy
• if sepsis= critical care
• preoperative resus
• maintain high level of suspicion of appendicitis in pregnant women, after 1st trimester, RUQ or right flank pain can occur

Question 8

Scoring system for appendicitis

Answer 8

AIR = Appendicitis Inflammatory Response

AAS = Adult Appendicitis Score

Question 9

Investigations for appendicitis

Answer 9

-use of initial blood tests, history, examination and scoring system to determine whether imaging required

Imaging- abdominal US or CT, MRI in pregnant if US inconclusive

• high risk patients <40 may go straight to surgery without imaging
• if >40, should have imaging
• low-risk discharged

-urinalysis to rule out UTI (NOT to diagnose)

-raised WBCs, neutrophils
-raised CRP (seen >12hrs)
-

-leukocytosis shift