Small bowel disease Flashcards
What are the causes of small bowel ischaemia?
- Mesenteric arterial occlusion- mesenteric artery atherosclerosis or thromboembolism from heart
- Non occlusive perfusion insufficiency- shock, strangulation that is obstructing venous return (hernia or adhesion), drugs or hyperviscosity
What is the pathogenesis of small bowel ischaemia?
- mucosa is sensitive to hypoxia
- the longer the period of hypoxia the greater the depth of damage to the bowel and the greater the likelihood of complications
- longer periods of hypoxia lead to stricture and then gangrene
What are the complications of small bowel ischaemia?
- resolution
- fibrosis, stricture, chronic ischemia, mesenteric angina and obstruction
- gangrene, perforation, peritonitis, sepsis and death
What is Meckel’s diverticulum?
- Congenital abnormality which is incomplete regression of vitello-intestinal duct
- May cause bleeding, perforation or diverticulitis
- Mimics appendicitis
What are the tumours of the small bowel?
Primary are rare: lymphomas, carcinoid and carcinomas
Secondary metastases from ovary, colon and stomach are much more common
What are the primary tumours of the small bowel?
- Lymphomas: treated with surgery and chemotherapy
- Carcinoid tumours: can cause obstruction and present with flushing and diarrhoea if there are metastases in the liver
- Carcinoma: associated with Crohn’s and Coeliac
What does appendicitis present with?
umbilical pain then RIF, one vomit, increased white cell count, slight fever, Rosving’s, Psoas, Obturator and tenderness
What are the causes of appendicitis?
unknown, bacteria, viruses, faecolith in the lumen, dehydration, lymphoid hyperplasia, parasites and rarely tumours
What is the pathology of appendicitis?
acute inflammation, mucosal ulceration, exudate and pus in lumen
What are the complications of appendicitis?
peritonitis, rupture, abscess, fistula and sepsis
What is Coeliac disease?
- lifelong sensitivity to gluten
- autoimmune disorder that leads to the disruption of the structure and function of the small intestine mucosa
How common is Coeliac disease?
- 1 in 100
- runs in families
- more women get it
- strong association to type 1 diabetes in children
What is the cause of Coeliac disease?
- Gliadin in gluten is modified by tTG
- T cells recognise this modifies Gliadin and secrete lymphokines for inflammation so damage to the villi
What is the most useful marker for Coeliac disease and why?
Anti-tTG from B cells is produced which can be used as a diagnostic marker
How does Coeliac disease present?
- asymptomatic
- fatigue
- wide range of GI symptoms
- weight loss
- nutrient deficiencies
- failure to thrive
- dermatitis herpetiformis
What does Coeliac disease cause?
- malabsorption of sugars, fats, amino acids, water and electrolytes
- reduced intestinal hormones so less pancreatic secretion and bile flow so gallstones
What are the investigations for Coeliac disease?
Bloods for anti-tTG
Upper GI endoscopy
Biopsy
What is the treatment for Coeliac disease?
Gluten-free diet
Supplements for deficiencies
What are the complications of Coeliac disease?
- Malabsorption
- Osteoporosis and osteomalacia
- Lactose intolerance due to villi destruction
- Hyposplenism
- Reduced fertility
- Neurological conditions
- T cell lymphomas in GI tract
- Gallstones
What is malabsorption?
Malabsorption is the failure of absorption of one or more nutrients from the GI tract by defective luminal digestion, mucosal disease or structural disorders
What are the causes of malabsorption?
- caused by disease processes that disrupt digestion, mucosal function and motility
- Coeliac disease
- Crohn’s disease
- cirrhosis
- biliary obstruction
- lactase deficiency
What are the components that can be malabsorbed?
Protein Fat Carbohydrate Vitamins Minerals
How does malabsorption present?
- Mild disease is asymptomatic
- Severe disease presents with diarrhoea and weight loss with abdominal discomfort and bloating
- Steatorrhoea (pale, bad smelling stools that you can’t flush) is for malabsorption of fat
What are the tests for malabsorption?
(usual) Blood tests for anaemia and other deficiency Stool microscopy Faecal elastase Upper GI endoscopy Imaging Breath scan
How do you treat malabsorption?
Treat underlying cause
Correct deficiency
What is intestinal failure?
arises from a lack of working gut due to intestinal resection or associated with diseased such as small bowel Crohn’s
What is intestinal failure characterised by?
by inability to maintain protein-energy, fluid balance so weight loss, undernutrition and dehydration
What can intestinal failure be due to?
obstruction, dysmotility, surgical resection, congenital defect or disease associated loss of absorption
What are the three types of intestinal failure?
Type 1: short term- surgical ileus, critical problems, GI problems, normal or slightly malnourished
Type 2: medium term- post surgery awaiting reconstruction after admission, septic patients, treat with parenteral nutrition
Type 3: long term- short bowel syndrome, Crohns, radiation, dysmotility, malabsorption
What is short bowel syndrome?
less than 200cm so there is insufficient length to meet nutritional needs without artificial feeding
(less than 50cm is critical)
How can parenteral nutrition be given?
centrally or peripherally
What is malnutrition?
a state of nutrition in which a deficiency so an excess or imbalance of energy, protein or other nutrient causes measurable adverse effects on clinical outcome
What can cause malnutrition?
- decreased intake
- impaired digestion and/or absorption
- increased nutritional requirements
- increased nutrient loss
What is nasogastric tube feeding?
a tube down into the stomach for patients who can’t swallow or are at risk of aspiration
What is percutaneous endoscopic gastrostomy?
the tube is straight into the stomach
What is parenteral feeding?
- providing nutrition intravenously
- short-term can be provided peripherally but causes inflammation
- centrally which is into subclavian or jugular vein
When is parenteral feeding required?
- after surgery
- in Crohn’s
- ischaemia
- after radiotherapy
What are contraindications of parenteral?
functioning GI tract, treatment for only a few days or if QOL is not improved by the nutrition
What are complications of parenteral feeding?
pneumothorax, line sepsis, venous thrombosis or electrolyte disturbances
What is the screening tool for malnutrition?
MUST score
What are the contraindications for enteral tube feeding?
- Lower GI obstruction
- Prolonged intestinal ileus
- Severe D or V
- High enterocutaneous fistula
- Intestinal ischaemia
What are the consequences of malnutrition?
- Impaired immune function
- Delayed healing
- Pressure sores
- Immobility
- Muscle weakness
- Cardio-respiratory weakness
When is small bowel haemorrhage found?
when no bleeding is found on the upper GI endoscopy
What is small bowel obstruction caused by?
adhesions or herniation, radiation and Crohn’s
What does small bowel obstruction present with?
distension or vomiting depending on the location of the obstruction
What are the investigations for small bowel obstruction?
urinalysis, bloods and gases and AXR and contrast CT for diagnosis
What is the treatment for small bowel obstruction?
- drip and suck so analgesia, fluids with potassium, catheter and NG tube (Ryles drain to decompress)
- 72 hours or if there is strangulation, perforation or ischaemia then intervene early
- lap op
What is chronic mesenteric ischaemia?
typically pain after eating and is angina of the gut
What is acute mesenteric ischaemia?
- infarction of the small bowel
- little old lady with a sore tummy which will kill her within 12 hours
- acidosis is ischaemic gut until proven otherwise
hat is the presentation of acute mesenteric ischaemia?
- pain that is out of proportion to the clinical signs
- lactate elevated
- acidosis on gases
Why does the small bowel become ischaemic and not the large bowel?
no marginal artery like in the colon so no collateral
What are the immediate complications of any surgery?
- local- haemorrhage and enterotomy
- systemic- anaphylaxis
What are the early complications of any surgery?
- local- wound infections or pelvic abscess
- systemic- atelectasis, ileus and portal pyaemia
What are the late complications of any surgery?
- local- adhesive obstruction, faecal fistula, inguinal hernia or incisional hernia
- systemic- DVT or PE
