Appendicitis (GI)

Question 1

Define acute appendicitis.

Answer 1

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

Question 2

Describe the aetiology of acute appendicitis.

Answer 2

• obstruction of the lumen of the appendix caused normally by faecolith (hard mass of faecal matter), normal stool, infective agents or lymphoid hyperplasia
• lumen distal to obstruction starts to fill with mucus –> distension and increase in intraluminal and intramural Pa
• resident bacteria in appendix (Bacteroides fragilis and Escherichia coli) rapidly multiply
• Pa of lumen>venous Pa = small venules and capillaries become thrombosed but arterioles remain open –> engorgement and congestion of appendix
• inflammation progresses to involve outer serosa layer = parietal peritoneum
• anti-mesenteric border becomes ischaemic –> infarction and perforation
• bacteria leak out of infarcted wall = pus collects within and around appendix

Question 3

Describe the epidemiology of acute appendicitis. (2)

Answer 3

• M>F
• 10-19 years old

Question 4

How does appendicitis typically present?

Answer 4

Acute abdominal pain starting in mid-abdomen and later localising to RLQ, associated with fever, anorexia, N&V and neutrophilia

Question 5

What are the signs and symptoms of acute appendicitis? (8)

Answer 5

• abdominal pain (starts peri-umbilical then moves to RLQ + worse on moving or coughing)
• anorexia
• nausea and vomiting
• mild pyrexia (37.5-38.5C)
• RLQ tenderness (McBurney point)
• diarrhoea / constipation
• tense, rigid abdomen (peritonitis - could indicate perforated appendix)
• hypotension and tachycardia

Question 6

What might you see on examination in acute appendicitis? (8)

Answer 6

• palpable mass (peri-appendiceal abscess caused by perforated appendix)
• low-grade pyrexia
• flushed face and a fetor (strong, foul smell)
• reduced bowel sounds (sign of perforated appendix)
• Rovsing’s sign
• psoas sign
• obturator sign
• Blumberg sign

Question 7

Where is McBurney’s point?

Answer 7

1/3 of the distance laterally from umbilicus towards right ASIS

Question 8

What is Rovsing’s sign?

Answer 8

Palpation in LIF causing pain in RIF

Question 9

What is the psoas sign?

Answer 9

• RIF pain on extending hip if retrocaecal appendix (so hip appears flexed)
• could also be a sign of psoas abscess = CT abdomen should be done

Question 10

What is the obturator sign?

Answer 10

Pain on internal rotation of a flexed thigh

Question 11

What is the Blumberg sign?

Answer 11

Rebound tenderness in RLQ

Question 12

What could a high fever indicate instead of acute appendicitis?

Answer 12

Mesenteric adenitis

Question 13

What type of pain can a retrocaecal appendix cause?

Answer 13

Flank or back pain

Question 14

What type of pain can a retroileal appendix cause?

Answer 14

Testicular pain due to irritation of the spermatic artery or ureter

Question 15

What type of pain can a pelvic appendix cause?

Answer 15

Suprapubic pain (possibly flexed right hip and loose mucus stool)

Question 16

What are some risk factors for acute appendicitis? (4)

Answer 16

• M > F
• age 10-30 years
• Fx
• white

Question 17

What are the first-line investigations for acute appendicitis? (4)

Answer 17

• FBC
• CRP
• abdominal ultrasound
• contrast-enhanced abdominal CT

Question 18

What test is done to all women of childbearing age presenting with acute appendicitis?

Answer 18

Bedside pregnancy test to exclude pregnancy/ectopic pregnancy before any other investigations in women with LIF/RIF pain

Question 19

What is the key FBC finding in acute appendicitis? (In adults vs children)

Answer 19

• leukocytosis (10-18 x 10^9/L) with neutrophilia is present in 80-90% of adults with appendicitis
• leukocytosis (>16 x 10^9/L) and elevated CRP level (>10mg/L) are strong predictive factors for appendicitis in children

Question 20

What is CRP like in acute appendicitis?

Answer 20

Elevated

Question 21

When is urine analysis useful for acute appendicitis?

Answer 21

• useful to exclude pregnancy in women, renal colic and UTI
• may show mild leukocytosis but no nitrites in appendicitis patient

Question 22

What forms of imaging do we do for acute appendicitis?

Answer 22

• abdominal US - useful in females with suspected appendicitis to rule out ovarian pathology
  
  • presence of free fluid should raise suspicion - first line in pregnant women
  • in pregnant women if US inconclusive –> MRI
• if US inconclusive or malignancy suspected –> contrast-enhanced abdominal CT
• imaging not needed for thin, male patients with high likelihood of appendicitis - may be diagnosed clinically

Question 23

What might you see on imaging for acute appendicitis?

Answer 23

• aperistaltic or non-compressible structure with outer diameter >6mm
• abnormal appendix (diameter >6mm) identified or calcified appendicolith seen in association with peri-appendiceal inflammation

Question 24

When do we do erect CXR for acute appendicitis?

Answer 24

If perforation suspected

Question 25

What diagnostic criteria is used for acute appendicitis?

Answer 25

- Appendicitis Inflammatory Response (AIR) or Adult Appendicitis Score (AAS) to determine risk - Alvarado score - used to rule out appendicitis but do not use to positively confirm a diagnosis (not specific enough)

Question 26

What is the Alvarado score diagnostic criteria for acute appendicitis?

Answer 26

MANTRELS - migration of pain to RLQ (1) - anorexia (1) - nausea and/or vomiting (1) - tenderness in RLQ (2) - rebound pain (1) - elevated temperature >37.3C (1) - leukocytosis (2) - shift left of neutrophils (1) Likelihood: - /=7 high

Question 27

What are some differential diagnoses for acute appendicitis?

Answer 27

- acute mesenteric adenitis (children, Hx URTI, lymphadenopathy) - viral gastroenteritis - Meckel's diverticulitis - intussusception (sudden colicky pain) - Crohn's disease - peptic ulcer disease - right-sided ureteric stone (colicky severe pain from loin to groin) - cholecystitis (RUQ) - UTI (suprapubic pain) - primary peritonitis (abrupt pain, distension, rebound tenderness) - pelvic inflammatory disease (bilateral LQ tenderness, purulent discharge from cervical os) - ruptured Graafian follicle - ectopic pregnancy - ovarian torsion (female RLQ pain)

Question 28

What is the standard first choice treatment for uncomplicated appendicitis?

Answer 28

Laparoscopic appendicectomy within 24 hours of diagnosis

Question 29

What is 1st line treatment for uncomplicated appendicitis (fit for surgery or with appendicolith)?

Answer 29

- supportive treatment: - NBM (IV maintenance fluids) if surgery considered - analgesia e.g. paracetamol, morphine - prophylactic Abx before surgery - cefuroxime and metronidazole - PLUS appendicectomy (laparoscopic > open surgery)

Question 30

What is 1st line treatment for uncomplicated appendicitis (unfit for surgery and without appendicolith)?

Answer 30

- supportive treatment (paracetamol/morphine) - antibiotics (ceftriaxone/cefotaxime + metronidazole OR amoxicillin+clavulanate) - (in children, if conservative management fails do appendicectomy)

Question 31

What is 1st line treatment for complicated appendicitis (with free perforation)?

Answer 31

- supportive treatment - suspected perforation + signs of shock/sepsis: fluid challenge to correct hypotension and tachycardia - NBM + IV fluids - analgesia - prophylactic Abx - emergency appendicectomy - postoperative Abx (amoxicillin + metronidazole)

Question 32

What is 1st and 2nd line treatment for complicated appendicitis (stable with abscess or phlegmon)?

Answer 32

1st line: - supportive treatment (NBM, IV fluids, analgesia, prophylactic Abx) - laparoscopic appendicectomy - postoperative Abx (amoxicillin + metronidazole) 2nd line: - supportive treatment (analgesia) - Abx and percutaneous image-guided drainage (amoxicillin + metronidazole) - consider interval appendicectomy (delayed)

Question 33

What are some complications of appendicitis? (8)

Answer 33

- perforation - signs of shock/sepsis - generalised peritonitis - tense, distended abdomen with guarding/rigidity and absent bowel sounds - appendicular mass - appendicular abscess - tender LQ mass, swinging fever leukocytosis - surgical wound infection - appendiceal malignancy - stump appendicitis - pelvic abscess post-appendicectomy

Question 34

What can an appendicitis perforation lead to?

Answer 34

Peritonitis

Question 35

What are the symptoms of a pelvic abscess post-appendicectomy, and how do we manage this? (4 + 1)

Answer 35

- pain - fever - sweats - mucus diarrhoea - management: drainage

Question 36

Describe the prognosis of acute appendicitis.

Answer 36

Good if patients are treated in a timely fashion - laparoscopic appendicectomy decreases incidence of overall complications