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
