Intestines Flashcards
Define intestinal failure
Definition - IF results from an inability to maintain adequate nutrition or fluid status via the intestines. Intestinal failure results from obstruction, dysmotility, surgical resection, congenital defect, or disease associated loss of absorption and is characterised by the inability to maintain protein-energy, fluid, electrolyte, or micronutrient balance.
I.e. where gut is no longer able to supply the hydration and nutritional needs of the body.
Briefly describe the three types of intestinal failure
- Self limiting short term postoperative paralytic ileus - cared for in HDU, ITU
- Prolonged, associated with sepsis and metabolic complications. Often related to abdominal surgery with complications - cared for in HDU, ITU
- Long term but stable, home parenteral nutrition often indicated - cared for either in wards or home
Type I intestinal failure
Time period?
Treatment?
Complications?
Common
Short term - days, weeks
Replace fluid, correct electrolytes, PPI, allow some diet
Complications - sepsis, SVC thrombosis, line fracture
Type II intestinal failure
Who gets it?
How long does it take to treat?
Septic patients, abdominal fistulae, perioperative who may develop a complication of feeding
Weeks/months of care (ICU/HDU)
Type III intestinal failure (chronic)
Treatment?
Home parenteral nutrition, or intestinal transplantation
Short bowel syndrome
What is it?
Normal bowel length is 250-850 cm; >200 cm = short bowel.
This is insufficient length to meet nutritional needs without artificial nutritional support
What are some causes of small bowel ischaemia?
Mesenteric arterial occlusion - Mesenteric artery atherosclerosis - Thromboembolism from heart Non occlusive perfusion insufficiency - Shock - Strangulation obstructing venous return e.g. hernia - Drugs e.g. cocaine - Hyperviscosity Bowel ischaemia is usually acute but can be chronic
What is the pathogenesis of bowel ischaemia?
The mucosa is the most metabolically active part of the bowel wall and therefore the most sensitive to the effects of hypoxia.
The longer the period of hypoxia the greater the depth of the damage to the bowel wall and the greater the likelihood of complications.
In non-occlusive ischaemia much of the tissue damage occurs after reperfusion.
Acute ischaemia outcome is determined by the length of time of ischaemia
Mucosal infarction –> mural infarction –> transmural infarction
Meckel’s Diverticulum
What is it?
Presentation?
A tubular structure, 2 inches long, usually 2 ft above IC valve - cause by incomplete regrettion of vitello-intestinal duct
May cause bleeding, perforation or diverticulitis which mimicks appendicitis.
Commonly assymptomatic, incidental finding.
Classical presentation is a young person presents with what seems like appendicitis, and then look up the s mall bowel for about two feet and find a Meckel’s Diverticulum
Carcinoma of the small bowel
Associated with?
Appearance?
Metastases?
Crohn’s & coeliac disease
Identical to colorectal carcinoma in appearance
Metastases to the lymph nodes and liver
What are the common origins of secondary cancers of the small bowel?
Ovary
Colon
Stomach
What pathology is seen in appendicitis?
Acute inflammation (neutrophils)
Mucosal ulceration
Serosal congestion, exudates
Pus in lumen
What pathology is seen in coeliac disease?
There is increasing loss of enterocytes due to IEL mediated damage.
This leads to loss of villous structure, loss of surface area, a reduction in absorption and a flat duodenal mucosa.
There is increased inflammation in the lamina propria and increased intraepithelial lymphocytes
What is the typical management for small intestine obstruction?
“Drip and Suck”
- ABG
- Analgesia
- Fluids with potassium
- Cathaterise
- NG tube
Mesenteric ischaemia
What is it typically associated with?
Embolus from AF
What are the three types of mesenteric ischaemia?
- Acute mesenteric ischaemia
- Chronic mesenteric ischaemia
- Chronic colonic ischaemia (ischaemic colitis)
Acute appendicitis
Pathogenesis?
Symptoms?
Rosving’s sing?
Got organisms invade the appendix wall after lymphoid obstruction by lymphoid hyperplasia; faecolith; or filarial worms. This leads to oedema, ischaemic necrosis and perforation
Classically periumbilical pain that moves to the RIF; anorexia; constipation; diarrhoea
Rosving’s sign = pain in the RIF when the LIF is pressed on
Appendicectomy and antibiotics - metronidiazole and cefuroxim
Mesenteric adenitis
This is just abdo pain that comes and goes in children
IBS
What is it?
Rome III criteria?
What are symptoms exacerbated by?
A mixed group of abdominal symptoms for which no organic cause can be found. Most are probably due to disorders of intestinal motility or VISCERAL HYPERSENSITIVITY
Recurret abdo pain/ discomfort for at least 3 days per month for 3 months
AND there are >2 of:
- Improvement with defaecation
- Onset associated with change in stool frequency
- Onset associated with change in stool form
Stress, menstruation, gastroenteritis
IBS
Signs?
What foods should be avoided in IBS?
Examination is often normal, but general discomfort is sometimes found
Fibre, lactose, fructose, wheat, starch, caffeine, alcohol, fizzy drinks
Pro-biotics may be of use
What are some additional symptoms of IBS aside from the Rome III criteria?
Bloating
Urgency
Tenesmus
PR mucous
What is the most common cause of small bowel obstruction?
What causes this?
Prevention?
What four things show on CXR?
Adhesions
Handling of the serosal surface of the bowel causes inflammation, which over weeks to years can lead to the formation of fibrous bands that tether the bowel to itself or adjacent structures
They can also form secondary to infection, Crohn’s, and other inflammatory processes
The best prevention is to avoid abdo surgery
- Multiple loops of dilated small bowel
- Loops located within the center of the abdomen
- Paucity of gas in the distal large bowel
- Valvulae conniventes - markings across the whole width of bowel
