Small Bowel Flashcards

Question

Pancreatic polypeptide

Answer 1

From: Pancreas Action: Clinical usefulness of pancreatic polypeptide is limited to being a marker for other endocrine tumors of the pancreas Stimulated by: Cephalic - vagus. Gastric - reflexes. Intestinal - food in small bowel

Answer 2

From: SI, Colon Action: Pancreatic secretion, vasodilation, inhibits gastric acid secretion Stim by: Fat

Answer 3

From: SI, Colon Action: Inhibits gastric acid secretion, pancreatic exocrine secretion, and migrating myoelectric complexes

Answer 4

From: SI, Colon Action: Increases glycogenolysis, lipolysis, gluconeogenesis Stim by: Lowe serum glucose Inhib by: Somatostatin

Answer 5

Action: Inhibits MMCs, increases gastric emptying, increases pepsin secretion alkaline enviornment Stim by: Vagus, fat, intraduodenal Inhib by: Pancreatic polypeptide

Answer 6

Jejunum has larger diameter, thicker wall, more prominent plicae circulares Jejunum has few arcades (1-2) with long vasa recta Ileum has many arcades with short vasa recta Ileum has fatty mesentery

Answer 7

Since > 93% of ingested fat is usually absorbed, >6g of fecal fat over 24h with 100g lipid per day diet is steatorrhea

Answer 8

Large bowel Can be used as alternative energy source for people who suffer from carb malabsorption

Answer 9

In SBO, neoplasm is rarely the cause. If it is, it is likely secondary to extrinsic compression as opposed to intraluminal obstruction

Answer 10

``` Pervious abdominal surgery Hernia IBD (Crohn's secondary to stricture formation) Diverticular disease Cholelithiasis Ingested foreign body ```

Answer 11

``` Colicky abdominal pain Distention N/v Obstipation Hyperactive BS Signs of low volume (hemoconcentration, lyte issues) bc of low PO intake, vomiting, and accumulation of fluid in bowel lumen and wall (third spacing) ``` (+) flatus and BM initially then later on obstipation early on borborygmi matching up with colicky pain. Later on no BS

Answer 12

``` Tenderness Tachy Fever Markedly elevated WBC Acidosis with high lactate ``` These are NOT present in 5-15%, esp the elderly

Answer 13

Colicky abd pain with borborygmy and/or obstipation - get KUB then CT with barium KUB - look for Air fluid levels CT - if barium can enter rectum it is not completed obstructed - if it pools somewhere we know it's total and know it's location If complete - surgery If strangulated - IVF then surgery If partial/stable patient - medical management with NPO, IVF, NGT suction, Foley, monitor lytes for hypoK, metabolic acidosis (sign of ischemia) If they get worse or signs of peritoneal signs develop take to OR. If there is no change in 24h then surgery.

Answer 14

IBD characterized by transmural inflammation involving ANY part of the GI tract from mouth to anus Inflammation is discontinuous (Skip lesions) Often leads to fibrosis and ultimately obstruction as well as fistulae

Answer 15

80% have involvement of SI, usually distal ileum (33% of these patients just have ileitis) 50% of patients have involvement of ileum AND colon 20% have involvement of colon only - diff from UC bc Crohn's patients tend to have rectal sparing 33% have perianal disease Diagnosis most common btw ages 15 and 40, second peak btw 50-80.

Answer 16

Jewish FHx Urban dwelling Smoking

Answer 17

Crampy abdominal pain (RLQ usually), diarrhea, weight loss Fever, fatigue Bleeding (hemoccult + stools common, but gross lower GI bleed less common than in UC) Perianal disease including skin tags, anal fissures, perirectal abscesses, and anorectal fistulae Signs/symptoms of intestinal perf and/or fistula formation (combo of localized peritonitis, fever, ab pain, tenderness, palpable mass)

Answer 18

Oral involvement (aphthous ulcers) Joints (arthritis) Ocular involvement Derm involvement (erythema nodosum, pyoderma gangrenosum) Hepatobiliary (sclerosing cholangitis)

Answer 19

History of prolonged diarrhea with abdominal pain, weight loss, and fever with or without gross bleeding PE can be nonspecific or be suggestive with perianal skin tags, sinus tracts, or palpable abdominal mass Colonoscopy with bx, visualization of terminal ileum may reveal focal ulcerations adjacent to areas of normal mucosa along with cobblestone appearance of mucosa EGD for proximal disease Imaging (small bowel contrast studies) helpful in characterizing length of involvement and areas of stricture, especially in parts of small bowel that can't be reached via colonoscopy Rads: mucosal nodularity, narrowed lumen, ulceration, string sign, presence of abscesses or fistulae

Answer 20

1) Medical - Corticosteroids, aminosalicylates (sulfasalazine, 5-ASA), immune modulators (azathrioprine, 6MP, cyclosporine), infliximab (anti-TNFa), metronidazole - Many patients require surgery to relieve symptoms that do not respond to drugs or to treat complications such as obstruction, abscesses, fistulae, perf, perianal disease or cancer Surg should be avoided if possible since Crohn's is not curable by surgery like UC is About 80% will eventually require some intervention Increased risk of colon cancer with long-standing crohn's colitis

Answer 21

Adenomas > leiomyomas > lipomas Leiomyomas most likely to cause symptoms tho Most SI benign neoplasms are found in duodenum #1 cause of adult intussusception Most patients in 5th or 6th decade of life

Answer 22

Hereditary syndromes - Peutz-Jeghers (hamartomatous polyps) - Gardner (adenoma) - FAP (adenoma) Consumption of red meat and salt-cured foods

Answer 23

Most asymptomatic until they are large (#1 symptom) Intermittent obstruction - crampy ab pain, distention, nausea, vomiting Occult or overt bleeding Palpable abdominal mass Obstructive jaundice (periampullary lesion)

Answer 24

1) EGD - can see prox duodenum. Most duodenal neoplasms are found by accident - Endo US. Can tell us depth of invasion too 2) Rads - small bowel series (low sensitivity) - CT - Enteroclysis** can detect tumors in distal small bowel 3) Majority of patients: Small bowel series with follow-through followed by enteroclysis 4) High risk patients: Enteroclysis

Answer 25

double contrast study involving passing a tube into prox small bowel and injecting barium and methylcellulose. Can detect tumors missed on conventional small bowel follow-through

Answer 26

All symptomatic lesions = resection (surg or endo) Tumors in prox duodenum, even asymptomatic ones should be removed endo (2) Tumors in second portion of duodenum, near ampulla, may require Whipple (pancreaticoduodenectomy)

Answer 27

Rare Adenocarcinoma > Carcinoid > GI stromal tumor > lymphoma Adeno risks: Crohn's, Celiac, FAP, P-J Syndrome Lymphoma: Celiac, immunodeficiency, autoimmune

Answer 28

1) Wide resection of involved intestine 2) For adeno - wide local excision with its accompany mesentery along with regional nodes 3) GISTS usually treated with segmental resection of affected intestine and Gleevec (tyrosine kinase inhib) 4) Duodenal lesions may need Whipple 5) Bypass may be required for palliation 6) Localized lymphoma is treated with segmental resection of intestine and mesentery 7) Diffuse lymphoma is only situation where chemo (not surg) should be primary

Answer 29

Overal 5yr

Answer 30

Malignant tumor of enterochromaffin cell origin, part of amine precursor uptake and decarboxylation (APUD) system Most common in appendix

Answer 31

29-40% of primary small bowel malignancies Peak incidence btw 50-70yrs More than 90% diagnosed in GI system Appendix is most common GI carcinoid site followed by small bowel followed by rectum

Answer 32

Slow growing; therefore frequently asymptomatic and found incidentally In symptomatic patients, vague abdominal pain is #1 symptom Intermittent obstruction in 25% of patients Rectal bleeding (from rectal carcinoid), pain, weight loss Carcinoid syndrome - 10% of cases - Due to production of serotonin, bradykinin, tryptophan by tumor and exposure of these products to systemic circulation prior to breakdown by liver - cutaneous flushing, sweating, watery diarrhea, wheezing, dyspnea, valvular lesions (R>L)

Answer 33

Most found incidentally during rads studies, appendectomy, or surgery for intestinal obsruction If patient has the syndrome: - 5HIAA in 24h urine collection - plasma chromogranin A - independent predictor of prognosis - Pentagastrin provocation test (pentagastrin induces flushing) - Otherwise diagnosed as any other small bowel neoplasm

Answer 34

Typically, appendiceal and SI carcnoids cause the syndrome only after they have metastasized to liver Thus, not surgical candidates due to extensive mets Wheezing = endobronchial lesion maybe

Answer 35

Medical: Serotonin antagonists (cyproheptadine) or somatostatin analogues for sumptoms Surg: - Appendiceal 2cm = R hemicolectomy - Small intestinal = resect tumor with mesenteric lymph nodes as well as inspect entire small bowel for synchronous lesions Otherwise, resect tumor and any solitary liver mets

Answer 36

Overall 5 year = 54% 5 year after palliative resection = 25% After curative resection = 70%

Answer 37

Communication btw 2 epithelialized surfaces. It can form btw 2 parts of the GI or GU tract, an internal fistuala (choledocho-duodenal or colo-vescical) OR btw an internal organ and an outer epithelialized surface (enterocutaneous) - external fistual

Answer 38

Previous abdominal surgery (80%) Diverticular disease Crohn's Colorectal cancer

Answer 39

Iatrogenic fistulae usually appear 5-10 days postop If associated with an abscess, can be with fever and leukocytosis Drainage of succus entericus (bowel contents) from skin (enterocutaneous fistula) Diarrhea, usually secondary to malabsorption (entero-enteric; esp btw prox and distal small bowel or colon since a large portion of small bowel absorptive surface is bypassed) Pneumaturia and symptoms of urinary tract infection (colovesicular fistula)

Answer 40

Proximal causes more issues bc the draining contents are more acidic, more fluid/lytes are lost, and more absorptive area is lost

Answer 41

CT with enteral contrast shows leakage of contrast from intestinal lumen Small bowel series Enteroclysis Fistulogram: contrast is injected directly into fistula tract

Answer 42

1) Stabilize - manage lytes, fluid losses, and nutritional status 2) Drainage of abscesses if present 3) Allow time for spontaneous closure - bowel rest - provide nutrition (TPN) - Consider octreotide for high output and pancreatic fistulas 4) If 6-8w pass without improvement, then surgery should be performed to resect the fistula tract, together with the segment of small bowel from which it originates

Answer 43

High: Drains > 500 ml/24h and are proximal (stomach, duodenum, prox small bowel) Low:

Answer 44

Enterocutaneous fistulas have 15-20% mortality related to complications of sepsis and underlying disease Surgery is associated with considerable morbidity and a high recurrence rate

Answer 45

Reduction in blood flow to small bowel secondary to variety of things Can result in 2 distinct conditions: Acute and chronic MI

Answer 46

Rapid onset of intestinal hypoperfusion Can be caused by arterial occlusion (usually a single artery) - SMA embolism = 50% - SMA thrombosis = 15-25% - Vasospasm (nonocclusive AMI) = 20-30% - Venous obstruction (thrombosis or strangulation usually of SMV) = 5% Regardless of cause, AMI can lead to mucosal sloughing within 3hrs of onset and to intestinal infarction within 6hrs of onset SMA is most common vessel involved. Most emboli that cause AMI come from heart (LA or LV). 95% of patients with AMI have history of cardio disease (AFib or MI)

Answer 47

FRIENDS ``` Foreign body Radiation Inflammation/Infx Epithelialization Neoplasm Distal obstruction Short segment fistula ( ```

Answer 48

1) Cardiac - low CO states, cardiac arrhythmias, severe cardiac valvular disease, recent MI 2) Age 3) Atherosclerosis 4) Hypercoagulable states

Answer 49

Abdominal pain out of proportion to exam Pain is colicky and diffuse, typically in mid abdomen Can be associated with nausea and vomiting and diarrhea Following infarction, peritonitis (rebound and rigidity), abdominal distention and passage of bloody stools occurs

Answer 50

1) High clinical suspicion especially if history of cardiac disease or hypercoagulopathy 2) No lab test is sensitive for diagnosis. Findings may include leukocytosis, acidosis, hemoconcentration, occult blood in stool 3) If there are peritoneal signs, then patient should undergo emergent laparotomy 4) Otherwise pursue diagnostic tests - Mesenteric angiography: most sensitive and specific but it's invasive - CT scan: good initial test. Can rule out other causes of abdominal pain. Can reveal evidence of ischemia. Can reveal occlusion/stenosis of vasculature - if high suspicion get MA after a negative CT bc CT can't see an arterial AMI. Great sensitivity for venous thrombosis tho

Answer 51

Stabilize patient - hemodynamic monitoring and fluids. Correct lytes. Broad spectum Abx. Place NGT for decompression Patient with peritoneal signs - surgery - embolic causes = intraoperative embolectomy - For CA/SMA thrombosis - bypass site of obstruction using saphenous graft Therapy via angiography includes vasodilators (papaverine) or thrombolytic agents (streptokinase, urokinase, tPA), angioplasty, placement of a stent, embolectomy Venous thrombosis requires heparin

Answer 52

Acute arterial mortality = 59-93% Acute mesenteric venous thrombosis mortality = 20-50% (30% recurrence if not anticoagulated)

Answer 53

Insidious, episodic, or constant state of intestinal hypoperfusion Rarely leads to infarction of small bowel due to development of collateral circulation Can be caused by: 1) Arterial ischemia (#1) - associated with atherosclerosis of more than one mesenteric and splanchnic vessels 2) Venous thrombosis - portal or splenic veins leading to portal HTN with subsequent varices and splenomegaly 3) Vasculitis

Answer 54

Atherosclerotic valvular disease (half of patients have history of peripheral vascular disease or CAD) Smoking

Answer 55

Intestinal angina - dull, crampy, postprandial ab pain leading to food aversion and weight loss Patients with chronic venous thrombosis may be asymptomatic due to collateral formation or may present with variceal bleeding

Answer 56

High clinical suspicion Must rule out other causes of chronic ab pain, weight loss, and food aversion (malignancy) Diagnosis is supported by demonstration of high-grade stenoses in multiple mesenteric vessels Diagnostic tests: - Angiography = Gold standard - CT and MRA - good initial tests since they can ID a stenosis and serve as guide for angiography - mesenteric duplex US - can be used for screening to detect stenosis of celiac and SMA

Answer 57

Hereditary or acquired thrombophilias

Answer 58

Arterial CMI: 1) surgical revasculatization - aortoesenteric bypass graft - mesenteric endarterectomy 2) Percutaneous transluminal angioplasty (PTA) with or without placement of a stent - less relief of symptoms and less durability than surgery - serves as alternative to surgery for those patients who are not optimal surgical candidates due to comorbidiites Chronic venous mesenteric thromboses: 1) Anticoagulation with heparin

Answer 59

"Celiac artery compression syndrome" CMI due to compression of celiac artery by diaphragm Tx = release of arcuate ligament and bypass of persistent stricture

Answer 60

Catheter sepsis Liver/kidney failure Venous thrombosis

Answer 61

Periop mortality 0-16% Initial relief of symptoms with surgery 90% Recurrence following surgery

Answer 62

Presence of

Answer 63

Adults - AMI, Crohn's, Malignancy Peds - Volvulus, intestinal atresia, necrotizing enterocolitis

Answer 64

Malabsorption occurs following resection of 50-80% of small bowel presence of intact colon, as well as an ileocecal valve lowers severity of malabsorption Resection of ileum is associated with higher malabsorption secondary to inability to absorb bile salts and vitamin B12 Small bowel adaptation period is about 1-2 years following surgery

Answer 65

Medical: 1) Repletion of fluid and lytes. Initially, most patients require TPN 2) PPI/H2 blockers to lower gastric acid secretion 3) Antimotility agents to lower transit time through small bowel 4) Octreotide to lower intestinal secretions Surgical: 1) Restoration of intestinal continuity in patients with stomas in order to increase absorptive capacity Surgeries aimed at slowing transit through small bowel: 1) Segmental reversal of the small bowel 2) Placement of a segment of colon between 2 segments of small bowel 3) Creation of artificial small bowel valves Surgeries aimed at lengthening the small bowel: 1) Longitudinal intestinal lengthening and tailoring (LILT) 2) Serial transverse enteroplasty procedure (STEP) 3) Small bowel transplant - indicated for patients with life-threatening intestinal failure or complications from TPN - Risk = rejection and CMV infection - Good results with no need for TPN

Answer 66

50-70% who initially require TPN can be completely weaned Peds patients are more likely than adults to gain independence from TPN