3.04 General Surgery - Large Bowel Disease Flashcards
What is the pathophysiology of appendicitis?
Luminal obstruction (e.g. faecolith, lymphoid hyperplasia, impacted stool, appendiceal tumour) causes commensal bacteria to multiple, resulting in acute inflammation.
Reduced venous drainage and localised inflammation results in increased pressure within the appendix, in turn resulting in ischaemia.
Untreated, ischaemia within the appendiceal wall results in necrosis and subsequent perforation.
Give the risk factors for acute appendicitis.
- family history
- ethnicity (Caucasian)
- environmental (seasonal presentation in summer)
What are the clinical features of acute appendicitis?
- peri-umbilical abdominal pain (visceral peritoneum inflammation), classically dull and poorly localised
- right iliac fossa abdominal pain (parietal peritoneum inflammation), classically localised and sharp
- vomiting
- anorexia
- nausea
- diarrhoea
- constipation
OE rebound tenderness and percussion pain over McBurney’s point; guarding; Rovsing’s sign +ve; Psoas sign +ve
Describe what constitutes a positive test result for
a) Rovsing’s sign
b) Psoas sign
a) RIF pain upon palpation of LIF
b) RIF pain with extension of right hip (suggests retrocecal position)
What are the differential diagnoses to acute appendicitis?
Gynaecological: ovarian cyst rupture; ectopic pregnancy; PID
Renal: ureteric stones; urinary tract infection; pyelonephritis
Gastrointestinal: IBD; Meckel’s diverticulum; diverticular disease
Urological: testicular torsion; epididymo-orchitis
How should suspected appendicitis be investigated?
- urinalysis (exclude renal / urological cause)
- pregnancy test if F of reproductive age
- FBC & CRP
- US / CT for imaging
How is acute appendicitis managed?
Laparascopic appendectomy is gold standard with appendix sent to histopathology to look for malignancy.
What are the complications of acute appendicitis?
- perforation
- surgical site infection
- appendix mass
- pelvic abscess
Which age group most commonly develops acute appendicitis?
20-30 years old
What is a diverticulum?
An outpouching of the bowel wall, most commonly found in the sigmoid colon.
Describe what is meant by:
a) diverticulosis
b) diverticular disease
c) diverticulitis
d) diverticular bleed
a) asymptomatic presence of diverticula
b) symptoms arising from the diverticula
c) inflammation of the diverticula
d) diverticula erodes into a vessel and causes a large volume, painless bleed
What is the pathophysiology of diverticular disease?
Aging bowel naturally weakens over time, resulting in outpouching of mucosa through weak areas.
Bacteria can overgrow, leading to inflammation of the diverticulum, which can sometimes perforate. Perforation can lead to peritonitis sepsis and death.
In chronic cases, fistulae can form, commonly colovesical or colovaginal.
Describe how diverticulitis is classified.
a) simple
b) complicated
a) no abscess or perforation
b) abscess +/- perforation
What are the risk factors for diverticular disease?
- increasing age
- low dietary fibre intake
- obesity
- smoking
- family history
- NSAID use
What are the clinical features of diverticulosis?
Asymptomatic and found incidentally during routine colonoscopy or CT imaging. Often no clinical significance.
What are the clinical features of diverticular disease?
- intermittent lower abdominal pain
- colicky
- relieved by defecation
- altered bowel habit
- nausea
- flatulence
What are the clinical features of acute diverticulitis?
- acute LIF pain
- sharp
- worsened by movement
OE localised tenderness, anorexia, pyrexia, nausea.
If the diverticulum perforates, there will be signs of localised peritonism or generalised peritonitis.
What are the differential diagnoses for a patient presenting with lower abdominal pain and bowel symptoms?
- inflammatory bowel disease
- bowel cancer
- mesenteric ischaemia
- renal stones
What investigations are used to diagnose diverticulitis?
- FBC, CRP and U&Es
- Group & Save, VBG
- urine dipstick to exclude urological causes
- CT abdomen-pelvis
If uncomplicated diverticular disease, flexible sigmoidoscopy can be used to investigate.
How is diverticular disease managed?
- simple analgesia
- encourage oral fluid intake
- regular colonoscopy to exclude masked malignancies
In cases of bleeds, blood products may be needed to resuscitate the patient.
How is acute diverticulitis managed?
- antibiotics
- intravenous fluids
- analgesia
Surgical intervention if perforation with faecal peritonitis or overwhelming sepsis. Hartmann’s procedure (sigmoid colectomy with formation of end colostomy).
What are the complications of diverticular disease?
- recurrence of diverticulitis
- stricture formation
- fistulae formation
What is a volvulus?
Twisting of a loop of intestine around its mesenteric attachment, compromising blood supply and leading to bowel necrosis and perforation.
Most commonly occurs at sigmoid colon.
Explain why sigmoid volvulus is the most common type.
Sigmoid colon has a long mesentery, which means that this segment bowel is more prone to twisting on its mesenteric base.
What are the risk factors for volvulus?
- increasing age
- chronic constipation
- male gender
- previous abdominal operations
What are the clinical features of volvulus?
- bowel obstruction
- colicky pain
- abdominal distention
- absolute constipation
OE tympanic to percussion