7. Appendicitis and Diverticulitis Flashcards
What is the appendix?
Diverticulum of caecum
Can be retro-caecal, pelvic, sub-caecal or para-ileal
What is the blood supply to the appendix?
Ileocolic branch of superior mesenteric artery, coming up through mesoappendix
What are the types of appendicitis?
Acute (mucosal oedema)
Gangrenous (transmural inflammation and necrosis)
Perforated
What are the causes of appendicitis?
Blockage of appendiceal lumen creates a higher pressure in the appendix (lymphoid hyperplasia)
Causes venous pressure to rise (causing oedema in walls), harder for arterial blood to supply appendix, ischaemia in walls, bacterial invasion follows
What is an alternative explanation to appendicitis?
Viral or bacterial infections causes mucosal changes that allow bacterial invasion of appendiceal walls
What is the classic presentation of appendicitis?
Poorly localised peri-umbilical pain Reduced appetite Nausea/vomiting Low grade fever After 12-24 hrs, pain is felt more intensely in right iliac fossa
What happens if appendix is retro-caecal or pelvic in its position?
May not get right iliac fossa pain
Parietal peritoneum in right iliac fossa does not come into contact with inflamed appendix
Supra-pubic pain, right sided rectal or vaginal pain
Why does the pain present the way it does in appendicitis?
Appendix is retroperitoneal
Visceral afferent stimulated
Pain referred to T9,10
Following enlargement, touches wall of abdomen (parietal peritoneum), giving pain in right iliac fossa
What are the signs of appendicitis?
Patients appear slightly ill
Sleight fever/tachycardia
Generally lie quite still as peritoneum is inflamed
Localised right quadrant tenderness
Rebound tenderness in right iliac fossa appears to be relatively specific
What is the diagnosis of appendicitis?
Blood tests - raised WBC
History and physical examination
Pregnancy test/urine dip to rule out pregnancy or UTI
What is the treatment for appendicitis?
Open appendicectomy
Laparoscopic appendicectomy
What is diverticulosis?
Outpouchings of mucosa and submucosa herniate through muscularis layers
Usually in sigmoid colon
Occurs where nutrient vessels penetrate bowel wall
What is diverticulosis caused by?
Increased intra-luminal pressure (low fibre diet)
What is diverticular disease?
When patient experiences pain but there is no inflammation/infection
What is acute diverticulitis?
When diverticula become inflamed or perforate
What is the pathophysiology of acute diverticulitis?
Entrance of diverticula is blocked by faeces
Inflammation eventually allows bacterial invasion of wall of diverticula
Can lead to perforation
What is uncomplicated diverticulitis?
Inflammation and small abscesses confined to colonic wall
What is complicated diverticulitis?
Larger abscesses
Fistula
Perforation
What are the symptoms d acute diverticulitis?
Abdominal pain at site of inflammation (usually left lower quadrant) Fever Bloating Constipation Haematochezia
What are the signs of acute diverticulitis?
Localised abdominal tenderness
Distension
Reduced bowel sounds
Signs of peritonitis (following perforation)
How do you diagnose acute diverticulitis?
Blood tests - raised WBC Ultrasound CT Colonoscopy if large haematochezia Elective colonoscopy after symptoms have settles to determine causes of symptoms if unclear
What is the treatment of acute diverticulitis?
Antibiotics, fluid resuscitation, analgesia
Surgery if perforation or large abscess need to be drained
