Intestinal Obstruction and Tumours Flashcards
What are the 3 main causes of intestinal obstruction?
1) Contraction
2) Increased pressure
3) Blockage
What are 3 causes of blockage?
1) Tumour
2) Diaphragm disease (NSAIDs)
3) Gallstones in bladder (rare)
What are 3 causes of contraction?
1) Hirschsprung’s disease
2) Inflammation
3) Intramural Tumours
How is intestinal obstruction caused by Crohn’s disease?
1) Crohn’s disease –> Inflammation –> Fibrosis –> Contraction –> Obstruction
How does Diverticulitis cause the intestinal obstruction?
Outpouching of the mucosa, leads to faecal matter being trapped, inflammation in bowel wall, contraction leads to obstruction
What is Hirschsprung’s disease?
Congenital condition of lack of motility in the Bowel from lack of nerves, causing obstruction and gross dilation
What are 3 causes of pressure?
1) Volvulus
2) Adhesions
3) Peritoneal Tumour
What is a Volvulus and where will it most likely be seen?
Closed loop obstruction from twist/rotation in the Bowel, presenting a risk of necrosis
- Free floating sections of the bowel, e.g. mesentery –> Sigmoid colonic is long so can twist in on itself
Define and describe the causes of Adhesions
Def: Stuck together loops of bowel which distort and pull the bowel (Sec to surgery)
Desc: Secondary effect after abdominal surgery
What are 4 common adult causes of small bowel obstruction?
- Adhesions.
- Hernias.
- Crohn’s disease.
- Malignancy.
What are 3 common child causes of small bowel obstruction?
- Appendicitis.
- Volvulus.
- Intussusception.
Which type of Bowel obstruction is more common?
Small Bowel (Makes up 75%)
What is intussusception?
Part of the intestine invaginates into another section of the intestine -> telescoping. It is caused by force in-balances.
What is a Hernia?
Protrusion of part of the viscera into cavity into an area where doesn’t belong
What is the main risk of an untreated Hernia? What are the main symptoms?
Irreducible: Can’t return them to correct body cavity as can become strangulated
1) Palpable Lump 2) Abdominal pain
Would dilatation, distension and increased secretions be seen proximal or distal to an intestinal obstruction?
Proximal
What are main 5 symptoms of small bowel obstruction?
- Vomiting.
- Pain.
- Constipation.
- Distension.
- Tenderness.
What are main signs of small bowel obstruction?
1) Increased vital signs
2) Resonance
3) Tenderness and Swelling
4) Bowel sounds
What investigations would be done for small bowel obstruction?
1) Good Patient History
2) X-Ray
3) MRI, CT scan Ultrasound
4) FBC, U&E, and Lactate
What is the main management and treatment for SBO?
- Fluid resuscitation.
- Bowel decompression.
- Analgesia and anti-emetics.
- Antibiotics.
- Surgery e.g. laparotomy, bypass segment, resection.
What are the main causes and symptoms of LBO?
C: Volvulus, Colorectal Cancer
S: Tenesmus, Constipation, Bloating, Vomit, Weight Loss, Abdominal Discomfort
What are the investigations and treatments for LBO?
I: DRE, Sigmoidoscopy, Plain X-Ray, CT
T: Fast patient, supplementary O2, IV fluids to replace losses and correct electrolyte, urinary catheterisation to monitor urinary output
What are the 3 main causes of untreated intestinal obstructions?
1) Ischaemia
2) Necrosis
3) Perforation
How does normal epithelium progress to colorectal cancer?
1) Normal epithelium
2) Adenoma
3) Colorectal adenocarcinoma
4) Metastatic adenocarcinoma
What is an adenocarcinoma?
Malignant tumour of glandular epithelium
What is familial adenomatous polyposis?
What is its PP?
C: Genetic condition causing development of thousands of polyps during teen years
PP: Mutation in APC protein, so apc/GSK complex isn’t formed and beta catenin levels increase, causing up-regulation of adenomatous gene transcription
How can adenoma formation be prevented?
NSAIDs
What is HNPCC and the treatment for it?
HNPCC: Inherited higher tendency to develop colorectal cancer
T: No DNA repair proteins so risk of colonic and EM cancers
What is the treatment for colorectal adenocarcinoma?
Surgical resection can be done when there is no spread. Remember to balance risks v benefits. The patient has a pre-op assessment.
If metastatic: Chemotherapy & Palliative Care
Why has Bowel Cancer survival increased and what are the main risk factors?
Increased: Colonoscopic Technique, Screening Programme, Treatment Options better
RF: Alcohol, Smoking, Diet: Low fibre or High red meat, PMH of adenoma/ulcerative colitis, family history of CC
(Presentation affected by proximity to rectum)
What are main signs of rectal cancer?
- PR bleeding.
- Mucus.
- Thin stools.
- Tenesmus.
What are the signs of Left and Right side sigmoid cancer?
L: PR Bleeding, Change of Bowel Habit
R: Anaemia, Mass and non-settling Diarrhoea
What investigations might you do in someone who you suspect might have colorectal cancer?
Colonoscopy = gold standard!
It permits biopsy and removal of small polyps.
- Tumour markers are good for monitoring progress.
- Faecal occult blood is used in screening but not diagnosis.
What are the emergency presentations of each type of cancer?
LHS: Narrow and most likely to show signs of obstruction
RHS: Signs of perforation as RHS is wide
