2. Sepsis and Metabolic Surgery Flashcards
Metabolic syndrome has a 34% adult prevalence in the USA. What does it comprise?
Explain how someone with MS may come to need administered insulin (100’s IU).
What is metabolic surgery? List the 3 types.
At least 3 from the following 5:
Central obesity, hypertension, hyperglycaemia, hypertriglyceridaemia, low HDL cholesterol.
Insulin resistance -> tissues increasingly deaf to circulating insulin -> increasing levels of circulating insulin to counteract deafness -> eventual exhaustion of pancreatic endocrine function -> requirement of administered insulin.
Manipulation of hormones postulated as primary mechanism of action: ghrelin, GLP/GIP, peptide YY.
Types: restrictive, malabsorptive, combination.
What is restrictive metabolic surgery? Give examples.
What are some caveats of this type of surgery?
Reduces volume eaten at each sitting. Doesn’t influence absorption of food. Effects modest (30-50% EWL). Types: gastric balloon, gastric band, sleeve gastectomy. [Pic]
- Unsuitable for “sweet eaters”
- Tolerance of proceedure can be poor
- Balloon devices temporary
- Nausea and vomiting common SEs
- Intensive support required
- Higher failure rates
What is malabsorptive metabolic surgery? Give examples.
What is combination metabolic surgery? What are the 2 main types?
JI (jejunoileal) bypass - removed all but 30-45cm of small bowel. Proximal jejunum anastamosed to terminal ileum. Good weight loss but long term complications incl. bacterial overgrowth and cirrhosis. Largely redundant now - massive complications including death from loss of vitamins, minerals and proteins. [Pic]
Moderate malabsorption combined with restriction of intake.
Gastric bypass: RNY (Roux en-y) or MGB (mini gastric bypass)
What are the 4 RNY gastric bypass techniques available?
How do these techniques work?
- Small gastric pouch (50ml)
- Gastrojejunostomy (1m distal to DJ flexure)
- Jejunojejunostomy (50cm distal)
- Common channel (2.5m)
Reduction in ghrelin production: when the stomach is empty, ghrelin is secreted. When the stomach is stretched, secretion stops. Small stomach = lower baseline levels which decrease after small meal.
Describe the actions of ghrelin.
Describe the foregut hypothesis.
Describe the hindgut hypothesis.
[Pic]
Foregut: suggests exclusion of the duodenum and proximal jejunum from the transit of nutrients may interrupt signals that lead to insulin resistance and T2DM. This is the primary mediator of T2D resolution. (85% immediate resolution of hyperglycaemia - suggests weightloss alone can’t account for resolution of T2DM)
Hindgut: suggests enhanced delivery of nutrients to distal ileum alters secretion of hormones and improves glucose metabolism.
GLP-1 may be a major mediator of this effect.
What do GLP-1 (glucagon-like peptide) and GIP (glucose-dependent insulinotropic peptide) do (foregut theory)?
List 4 specific things that GLP-1 does.
Account for 50-60% of nutrient-related insulin secretion. In addition to insulin stimulation, GLP-1 suppresses glucagon and slows gastric emptying, which delays digestion and reduces postprandial glycaemia. It also acts on the hypothalamus to induce satiety. No effect when glucose administered IV.
- Increases insulin production by pancreas
- Reduces glucagon production
- Reduces appetite
- Stimulates B cell production in pancreas
What does peptide YY do (hindgut theory)?
What is the best surgical method for T2DM resolution (ability to discontinue all diabetes-related meds, maintain normal fasting glycemia, normalisation of glycosylated Hb etc.)?
What is the POSE proceedure?
Peptide YY, like GLP-1, is secreted by L cells of the distal small intestine and is responsible for increasing satiety and delaying gastric emptying after meals. Increases in postprandial peptide YY and GLP-1 levels after gastric bypass.
- *BPD** (biliopancreatic diversion) or duodenal switch (98.9%). Then RYGB (roux en-y) (83.7%), VBG (vertical banded gastroplasty) (71.6%), LAGB (laproscopic adjustable gastric band) (47.9%).
- BPD and RYGB effect immediate; LAGB slow*.
Primary obesity surgery endoluminal - non-invasive (performed through mouth), folds are created in stomach wall and reducing overall capacity so feel fuller on less. [Pic]
What is laproscopic plication?
Minimally invasive investigational weight-loss surgery. Folds stomach wall inwards and sutures it over a sizing tube. After stomach is freed from attachments in the abdomen it’s folded and stitched, and the sizing tube removed. [Pic]
What is an endo barrier?
Medical device for T2DM treatment. Thin plastic sleeve lines first 60cm of small intestine causing food to be absorbed further down. Non surgical technique of duodenal exclusion. Inserted endoscopically under sedation. Similar diabetic resolution as RNY bypass. Temporary - 1 year. Gradual return of T2D after removal.
