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Flashcards in GI 4 Deck (49):
1

Anatomy difference between colon and small bowel

Small bowel is attached to mesentery and aorta; free moving
Colon is attached to the abdominal wall and cannot move

2

Patho SBO

- occurs when the normal flow of intestinal contents is interrupted
- focal point of narrowing--> obstruction of flow

3

Causes of SBO

- Postoperative adhesions
- Hernias
- Intus susception
- Volvulus
- Crohn's disease
- Gallstones

4

Clinical SBO

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

5

Labs SBO

CBC with diff
Chem 7 because vomiting so much and metabolic alkalosis is common

6

Imaging SBO

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

7

Tx SBO

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

8

Patho Ileus

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

9

Clinical Ileus

- vomit
- abdomen distended
- not passing gas
- Xray/CT show the whole bowel is dilated without a transition pt

10

Appendix anatomy

- located where the tenia joins at cecum
- intraperitoneal organ
- true diverticulum
- supplied by superior mesenteric artery

11

Who gets appendicitis?

young people

12

Patho appendicitis

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

13

MC organism in appendicitis

E. coli

14

What can cause obstruction at the lumen of appendix?

- Fecaliths
- calculi
- lymphoid hyperplasia
- infection
- tumors

15

Clinical appendicitis

- Crampy abdominal pain
- N/V
- low grade fever
- anorexia
- malaise

16

Different physical tests for appendicitis

McBurney Point
Rovsing Sign
Psoas Sign
Obturator Sign

17

Labs appendicitis

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

18

Imaging appendicitis

US- can ID appendix
CT- highest sensitivity/ specificity; not always necessary

19

Tx appendicitis

NPO
IVF
IV ABX- broad spectrum
Surgery- appendectomy

20

Def Toxic Megacolon

total or segmental non-obstructive colonic dilation plus systemic toxicity

21

Causes Toxic Megacolon

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

22

Patho Toxic Megacolon

- 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

Possible precipitating agents of toxic megacolon

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

24

Dx Essentials Toxic Megacolon

- 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

Imaging Toxic Megacolon

Xray/CT- large colon inflamed

26

Labs Toxic Megacolon

- Stool WBC and cultures if think infectious
- CBC--> anemia
- Chem 7

27

Tx Toxic Megacolon

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

Mesenteric ischemia

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

29

Ischemic colitis

ischemia of the colon with unknown precipitating factor

30

Cause Mesenteric Ischemia

- SMA occlusion (embolism/thrombosis)
- Nonocclusive Mesenteric Ischemia (atherosclerosis + shock + vasopressors)
- Mesenteric Venous Thrombosis (primary clotting disroder)

31

Clinical Ischemic Bowel Disorder

- 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

Test of choice for Ischemic Bowel Disease

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

33

Imaging for Ischemic Bowel Disease

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

34

Tx for Ischemic Bowel Disease

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

35

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

4-6hrs

36

Clinical signs for Ischemic Bowel Disease to an infarct

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

37

Tx for Ischemic Bowel Disease to an infarct

- 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

What is chronic mesenteric?

intestinal angina

39

When does chronic mesenteric occur?

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

40

What causes chronic mesenteric?

atherosclerosis

41

What is the most frequent form of mesenteric ischemia?

colonic ischemia

42

Where does colonic ischemia occur?

left colon

43

Who is most likely to get colonic ischemia and why?

elderly due to atherosclerotic disease

44

Cause of colonic ischemia

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

45

What are the watershed areas?

- rectosigmoid junction
- left colon (splenic flexture)
- runoff from SMA to IMA vessels

46

What is a watershed area?

- 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

Clinical colonic ischemia

- crampy and tender abdominal pain
- nausea
- vomiting
- bloody diarrhea
- blood per rectum

48

Dx colonic ischemia

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

Tx colonic ischemia

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