GI 4 Flashcards

1
Q

Anatomy difference between colon and small bowel

A

Small bowel is attached to mesentery and aorta; free moving

Colon is attached to the abdominal wall and cannot move

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2
Q

Patho SBO

A
  • occurs when the normal flow of intestinal contents is interrupted
  • focal point of narrowing–> obstruction of flow
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3
Q

Causes of SBO

A
  • Postoperative adhesions
  • Hernias
  • Intus susception
  • Volvulus
  • Crohn’s disease
  • Gallstones
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4
Q

Clinical SBO

A
  • crampy abdominal pain
  • nausea
  • vomit a lot and feel better afterwards
  • no passage of flatus/ stool
  • more belching/hiccups
  • abdominal distention
  • abdominal tenderness
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5
Q

Labs SBO

A

CBC with diff

Chem 7 because vomiting so much and metabolic alkalosis is common

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6
Q

Imaging SBO

A

Abdominal X-ray: dilated bowel loops and air-fluid levels in step ladder pattern; point of transition
CT- contrast given has osmotic properties that may alleviate/treat the adhesive SBO

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7
Q

Tx SBO

A

NPO
IVF
NG tube- decompress intestine
Surgery- done for all the other causes except adhesions and Crohn’s; if adhesion/Crohn give the patient 4 days on other tx before surgery

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8
Q

Patho Ileus

A
  • postoperative paralytic ileus

- non-mechanical insult disrupts the normal coordinated propulsive motor activity of the GI tract

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9
Q

Clinical Ileus

A
  • vomit
  • abdomen distended
  • not passing gas
  • Xray/CT show the whole bowel is dilated without a transition pt
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10
Q

Appendix anatomy

A
  • located where the tenia joins at cecum
  • intraperitoneal organ
  • true diverticulum
  • supplied by superior mesenteric artery
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11
Q

Who gets appendicitis?

A

young people

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12
Q

Patho appendicitis

A

Obstruction at lumen of appendix –> Stasis/stoppage of flow in GI–> bacteria stopped and replicate–> inflamation/swollen appendix–> artery unable to supply blood to appendix due to inflammation–> ischemia–> necrosis–> falls apart–> perforation–> bacteria leaks into stomach–> abscess risk and peritonitis–> RLQ pain

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13
Q

MC organism in appendicitis

A

E. coli

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14
Q

What can cause obstruction at the lumen of appendix?

A
  • Fecaliths
  • calculi
  • lymphoid hyperplasia
  • infection
  • tumors
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15
Q

Clinical appendicitis

A
  • Crampy abdominal pain
  • N/V
  • low grade fever
  • anorexia
  • malaise
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16
Q

Different physical tests for appendicitis

A

McBurney Point
Rovsing Sign
Psoas Sign
Obturator Sign

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17
Q

Labs appendicitis

A

CBC with diff- leukocytosis
Low electrolytes (not eating/ drinking)
LFT
Urinalysis

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18
Q

Imaging appendicitis

A

US- can ID appendix

CT- highest sensitivity/ specificity; not always necessary

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19
Q

Tx appendicitis

A

NPO
IVF
IV ABX- broad spectrum
Surgery- appendectomy

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20
Q

Def Toxic Megacolon

A

total or segmental non-obstructive colonic dilation plus systemic toxicity

21
Q

Causes Toxic Megacolon

A

IBD
Bacterial- c. diff, salmonella, shigela, campylobacter, yersinia
Parasitic- E. histolytica, Cryptosporidium
Viral- CMV

22
Q

Patho Toxic Megacolon

A
  • Mucosal inflammation–> release of inflammatory mediators and bacterial products–> increased NO synthesis , antimotility agents–> colonic dilation
  • severe inflammation –> paralysis of the colonic smooth muscle–> dilation
23
Q

Possible precipitating agents of toxic megacolon

A

hypokalemia, antimotility agents, opiates, anticholinergics, antidepressants, barium enema, colonoscopy

24
Q

Dx Essentials Toxic Megacolon

A
  • abdominal distention and acute/chronic diarrhea
  • radiographic evidence of colonic distention
  • 3 of the following: fever over 38C, HR over 120, WBC over 10,500, anemia
  • 1 of the following: dehydration, altered sensorium, electrolyte disturbances, hypotension
25
Q

Imaging Toxic Megacolon

A

Xray/CT- large colon inflamed

26
Q

Labs Toxic Megacolon

A
  • Stool WBC and cultures if think infectious
  • CBC–> anemia
  • Chem 7
27
Q

Tx Toxic Megacolon

A
Non-operative (first line)
- IVF
- Correct lab abnormalities
- ABX for IBD or infectious (Vanco+Flagy for cdiff)
- intravenous corticosteroids (IBD)
- NPO
- Bowel decompression with NGT
Surgery if no improvement
- subtotal colectomy with end-ileostomy (50% mortality)
28
Q

Mesenteric ischemia

A

ischemia of the small bowel, usually secondary to an acute cause affecting SMA or SMV

29
Q

Ischemic colitis

A

ischemia of the colon with unknown precipitating factor

30
Q

Cause Mesenteric Ischemia

A
  • SMA occlusion (embolism/thrombosis)
  • Nonocclusive Mesenteric Ischemia (atherosclerosis + shock + vasopressors)
  • Mesenteric Venous Thrombosis (primary clotting disroder)
31
Q

Clinical Ischemic Bowel Disorder

A
  • rapid onset of severe, unrelenting periumbilical pain
  • patient is writhing on bed, screaming in agony but stomach is soft and normal
  • N/V
  • forceful/urgent bowel evacuation
32
Q

Test of choice for Ischemic Bowel Disease

A

mesenteric angiography; ID type of AMI and can treat them at that moment

33
Q

Imaging for Ischemic Bowel Disease

A

Xray- thumb printing on edge of bowel due to dilation, swelling, edema
CT- thickened/dilated bowel, intramural hematoma, abdominal wall breaking down

34
Q

Tx for Ischemic Bowel Disease

A
  • IVF
  • Anti-coag (IV heparin)
  • IV vasodilator (glucagon systemically or papverine through a catheter)
35
Q

When does patient need to be in the OR by for Ischemic Bowel Disease?

A

4-6hrs

36
Q

Clinical signs for Ischemic Bowel Disease to an infarct

A
  • fever

- person is writhing around and all of a sudden they are pain free due to bowel dieing

37
Q

Tx for Ischemic Bowel Disease to an infarct

A
  • emergent laporatomy- restoration of interrupted blood flow with arteriotomy/ bypass graft and resection of infarcted bowel
  • look again 24-48hrs later to see if alive or dead bowel
  • need vasodilators
38
Q

What is chronic mesenteric?

A

intestinal angina

39
Q

When does chronic mesenteric occur?

A

after meals patient gets extremely crampy–> food fears due to this–> weight loss

40
Q

What causes chronic mesenteric?

A

atherosclerosis

41
Q

What is the most frequent form of mesenteric ischemia?

A

colonic ischemia

42
Q

Where does colonic ischemia occur?

A

left colon

43
Q

Who is most likely to get colonic ischemia and why?

A

elderly due to atherosclerotic disease

44
Q

Cause of colonic ischemia

A
  • Low- flow state (hypotension)
  • embolus (afib)
  • Post MI
  • Post AAA reconstruction
  • Closed loop construction
  • volvulus
  • mesenteric vein thrombosus
45
Q

What are the watershed areas?

A
  • rectosigmoid junction
  • left colon (splenic flexture)
  • runoff from SMA to IMA vessels
46
Q

What is a watershed area?

A
  • regions of the body that receive dual blood supply from the most distal branches of two large arteries
  • during hypoperfusion, these regions are particularly vulnerable to ischemia because they are supplied by the most distal branches of their arteries, and the least likely to receive sufficient blood
47
Q

Clinical colonic ischemia

A
  • crampy and tender abdominal pain
  • nausea
  • vomiting
  • bloody diarrhea
  • blood per rectum
48
Q

Dx colonic ischemia

A

H/PE mainly
Lab- rule out other diseases (metabolic acidosis and elevated white count over 20K)
Imaging
- CT- normal at first but then thickened bowel wall in segmental pattern and mesenteric stranding; later gas in mesenteric veins and pneumatosis
- Endoscopy- mucosa red and sloughing off and ulcers

49
Q

Tx colonic ischemia

A
Support
-IVF
- NPO
- Empiric ABX for moderate/severe
- NGT
- no meds that promote ischemia
- optimize cardiac and pulmonary functions
Surgery
- laparotomy with resection if clinical deterioration despite support
- patient will receive colostomy bag