Appendicitis

Question 1

What is appendicitis?

Answer 1

Appendicitis = inflammation of the appendix, a small out-pouching from the caecum

Commonly retrocaecal
Can be pelvic, retroileal or retrocolic
Small mesentery with sole blood supply from appendicular artery

Question 2

What is the aetiology of appendicitis?

Answer 2

Main cause of acute appendicitis is obstruction of the lumen. Causes of obstruction:
Faecolith (hard faecal mass)/stool
More common in elderly
Faecolith causes 40% of simple appendicitis, and 90% of perforated appendicitis

Lymphoid hyperplasia
Secondary to IBD

Parasite
Eastern countries
Microbiological organisms infect the appendix wall, leading to oedema, ischaemic necrosis and perforation

Hygiene hypothesis = impaired ability to prevent invasion due to less previous exposure

3 types
Mucosal - Mildest form, diagnosed by pathology report

Phlegmonous (diffuse spreading of inflammation) - Slow onset/progression

Necrotic - Acute bacterial infection with ischaemic necrosis leading to perforation

Question 3

What are the risk factors of appendicitis?

Answer 3

Less than 6 months of breast feeding
Low fibre intake
Smoking – active and passing

Question 4

What is the epidemiology of appendicitis?

Answer 4

Most common cause of urgent abdominal surgery
Can affect any age
Most common from early teens to early twenties
Uncommon under age of 4 and over 80

Increased incidence in Western world – due to dietary fibre
Very slight male predominance (1.3:1)
7% lifetime risk

Question 5

What are the symptoms of appendicitis?

Answer 5

RLQ pain - Begins peri-umbilically (early), and then localises to RIF (late)

Nausea and vomiting

Pain precedes vomiting ~3-4 hours

Anorexia

Constipation

Question 6

What are the signs of appendicitis?

Answer 6

Abdominal tenderness
Guarding, rebound and percussion tenderness
Fever
Tachycardia
Diminished bowel sounds
Furred tongue
Lying still 

Rovsing’s sign (Pain elicited on RIF by pressing on LIF)

Psoas sign (Pain elicited by extending R thigh when lying on left lateral side = retrocaecal appendix)

Cope’s (obturator) sign (Pain elicited by internal rotation of flexed R thigh = appendix near obturator internus)

Aaron’s sign (Referred pain in epigastric region when McBurney’s point pressed)

Question 7

What are the investigations for appendicitis?

Answer 7

Bloods
FBC
Mild leucocytosis, neutrophilia
Raised CRP

Abdo and pelvic CT
Abnormal appendix (>6mm)
Identified/calcified appendicolith

Urinary pregnancy test

Other investigations:
Abdo US
Aperistaltic structure with outer diameter >6mm
Urinanalysis
Abdo and pelvic MRI (if pregnant)

Question 8

What is the management of appendicitis?

Answer 8

Emergency medical resuscitation:
IV access
Catheterise – if hypotensive/septic

Uncomplicated:
Appendectomy
Laparoscopic has better outcomes
Muscle splitting gridiron incision centred at McBurney’s point (1/3 distance between ASIS and umbilicus)

Supportive care
NBM with Ringer’s lactate
IV ABs
24hrs cefoxitin

Perforation/abscess:
IV ABs

Supportive care
Appendectomy
Drainage
For abscess, thus may not need appendectomy

Therapy should be given until afebrile and no leucocytosis

Question 9

What are the possible complications of appendicitis?

Answer 9

Perforation – localised or generalised
Severe pain, high fever (>38.3), localised tenderness

Generalised peritonitis

Wound infection

Bowel obstruction

RIF appendix mass

RIF abscess

Pelvic abscess

Question 10

What is the prognosis of appendicitis?

Answer 10

Good prognosis
0.2-0.8% mortality rate (mostly due to disease complication)

Increased mortality in elderly patients over 70 (20%)
Due to diagnostic and therapeutic delay
Rate of perforation is up to 40%
Complications occur in 1-5%
Postoperative wound infections account for 1/3 of morbidity