35 Small Bowel Flashcards
(156 cards)
1
Q
Most common causes of small bowel obstruction?
A
Adhesion (requires previous surgery)
Hernia
Cancer
2
Q
Most common causes of large bowel obstruction?
A
Cancer
3
Q
Signs and symptoms of proximal small bowel obstruction?
A
Intermittent pain (intense, colicky, relieved with vomiting)
Large volume vomiting (bilious)
Epigastric or periumbilical tenderness (mild)
No distention
+/- obstipation
4
Q
Signs and symptoms of distal small bowel obstruction?
A
Intermittent/constant pain Low volume vomiting (progressively feculent) Diffuse and progressive tenderness Moderate to marked distention Obstipation
5
Q
Signs and symptoms of closed loop small bowel obstruction?
A
Progressive, intermittent, constant pain; rapidly worsening May have prominent vomiting (reflex) Diffuse and progressive tenderness Absent distention \+/- Obstipation
6
Q
Signs and symptoms of colon and rectum obstruction?
A
Continuous pain Intermittent vomiting (feculent) Diffuse tenderness Marked distention Obstipation
7
Q
Symptoms of bowel obstruction?
A
Nausea and vomiting
Crampy abdominal pain
Failure to pass gas or stool
8
Q
AXR findings in obstruction?
A
Air-fluid level
Distended loops of small bowel
Distal decompression
Absence of air in the colon or rectum
9
Q
Why do you need aggressive fluid resuscitation in obstruction?
A
3rd spacing of fluid into the bowel lumen occurs
10
Q
Why do you get air with a bowel obstruction?
A
Swallowed nitrogen (O2 can be absorbed)
11
Q
Treatment of small bowel obstruction?
A
Bowel rest
NG tube
IV fluids
(Response - 80% of partial SBO, 40% of complete SBO)
12
Q
Indication for surgical intervention in SBO?
A
Progessing pain
Peritoneal signs, Fever, Increasing WBCs (suggestive of strangulation/perforation)
Failure to resolve
13
Q
anatomy and physiology: fund of small and large intestines
A
small = nutrient and water absorption … large = water absorption
14
Q
anatomy and physiology: duodenum - parts
A
bulb = first portion, 90% of ulcers here …. descending = 2nd portion = contains ampulla of vater (duct of Wirsung, panc and CBD ducts meet) and duct of Santorini (accessory duct) … transverse = 3rd … ascending = 4th
15
Q
anatomy and physiology: duodenum - retroperitoneal parts
A
descending (2nd portion with ducts entering) and transverse (3rd)
16
Q
anatomy and physiology: duodenum - unique characteristic of 3rd and 4th portions
A
transition point at the acute angle between the aorta (posterior) and SMA (anterior)
17
Q
anatomy and physiology: duodenum - vascular supply
A
superior (off GDA) and inferior (off SMA) pancreaticoduodenal arteries … both have anterior and posterior branches …. many communications between these arteries
18
Q
anatomy and physiology: jejunum - describe
A
100cm long, long vasa recta, circular muscle folds
19
Q
anatomy and physiology: jejunum - function
A
site of max absorption of everything except B12 (t ileum), bile acids (non conjugated at ileum, conjugated at terminal ileum), iron (duod), folate (t ileum) …. 95% of NaCl and 90% of water absorbed in jejunum
20
Q
anatomy and physiology: jejunum - vasular supply
A
SMA
21
Q
anatomy and physiology: ileum - describe, absorption, vascular supply
A
150cm long, short vasa recta, flat …. absorb non conj bile acids (ileum), conj bile acids, folate, B12 (t ileum)
22
Q
anatomy and physiology: describe jejunum vs ileum
A
jej = 100cm, long vasa recta, circular muscle folds …. ileum = 150cm, short vasa recta, flat
23
Q
anatomy and physiology: absorption throughout small bowel
A
jejunum = max site of all absorption, except …. ileum = non-conj bile acids … t ileum = con bile acids, b12, folate
24
Q
anatomy and physiology: vascular supply throughout small bowel
A
duo = superior (off GDA which is off celiac then common hepatic) and inferior (off SMA) pancreaticoduodenal arteries (both with anterior and posterior branches) … jej = SMA, long vasa recta …. ileum = SMA, short vasa recta
25
anatomy and physiology: enzymes in intestinal brush border
maltase, sucrase, limit dextrinase, lactase
26
anatomy and physiology: normal sizes of small bowel, t colon, cecum
3, 6, 9cm
27
anatomy and physiology: branches of SMA
inferior pancreaticoduodenal artery ... jejunal and ileal branches ... ileocolic artery, appendicular artery, accessory appendicular artery ... right colic artery ... middle colic artery
28
anatomy and physiology: cell types
absorptive cells .... goblet cells (mucin secretion) ... paneth cells (secretory granules, enzymes) ... enterochromaffin cells (APUD, 5-hydroxytryptinase release, carcinoid precursor) ... Brunner's glands (alkaline solution) ... Peyer's patches (lymphoid tissue, increased in ileum) ... M cells (APCs in intestinal wall)
29
anatomy and physiology: IgA
released into gut, also in mom's milk
30
anatomy and physiology: Fe
small bowel has both heme and Fe transporters
31
anatomy and physiology: gut motility
migrating motor complex ... phase 1 = rest .... phase 2 = acceleration and GB contraction ... phase 3 = peristalsis, motilin is most important hormone and acts here .... phase 4 = deceleration
32
anatomy and physiology: bile salts/acids absorption
95% of bile salts are reabsorbed ... 50% passive (non conj), 45% t ileum, 5% colon ... 50% active (conj), only in t ileum (Na/K ATPase) - get gallstones after t ileum resection 2/2 malabsorption of bile acids
33
short gut syndrome: sx
diarrhea, steattorhea, weight loss, nutritional deficiency (lose fat, b12, electrolytes, water)
34
short gut syndrome: dx
based on sx, not length of bowel .... sudan red stain checks for fecal fat ... schilling test = checks for b12 absorption (radiolabeled b12 in urine)
35
short gut syndrome: amnt of bowel needed
about 75cm to survival off TPN, 50cm with competent ileocecal valve
36
short gut syndrome: tx
restrict fat, PPI to reduce acid, lomotil (diphenoxylate and atropine)
37
steatorrhea: causes
(1) gastric hypersecretion of acid ---> dec pH ---> inc intestinal motility ---> interferes with fat absorption ..... (2) interruption of bile salt resorption (i.e. terminal ileum resection) interferes with micelle formation and fat absorption)
38
steatorrhea: tx
control diarrhea (lomotil), dec oral intake esp of fats, pancrease, PPI
39
nonhealing fistula: causes
FRIENDS = Foreign body, Radiation, IBD, Epithelialization, Neoplasm, Distal obstruction, Sepsis/infection
40
nonhealing fistula: high output fistulas
more common with proximal bowel (duo or prox jejunum) and are less likely to close with conservative mgmt
41
nonhealing fistula: colonic fistulas
more likely to close than small bowel fistulas
42
nonhealing fistula: workup of pts w persistent fever
check for abscess (fisulogram, abd CT, upper GI with SBFT)
43
nonhealing fistula: MC causes and mgmt of fistulas
most fistulas are iatrogenic and treated conservatively (NPO, TPN, skin protection / stoma appliance, ocreotide), most close without surgery
44
nonhealing fistula: surgical options
(most heal with conservative mgmt) - resect bowel segment containing fistula and perform primary anastomosis
45
obstruction: MC causes
without previous surgery - small bowel 2/2 hernia, large bowel 2/2 cancer .... with previous surgery - small bowel 2/2 adhesions, large bowel 2/2 cancer
46
obstruction: sx
n/v, crampy abd pain, failure to pass gas or stool
47
obstruction: abd xray
air-fluid level, distended loops of small bowel, distal decompression
48
obstruction: fluid issues
3rd spacing of fluid into bowel lumen, need aggressive fluid resuscitation
49
obstruction: air with bowel obstruction
from swallowed nitrogen
50
obstruction: tx
bowel rest, NGT, IVF ... cure 80% of partial SBO and 40% of complete SBO
51
obstruction: surgical indications
80% partial and 40% complete SBOs can be managed conservatively .... progressing pain, peritoneal signs, fever, increasing WBCs (all signs of strangulation or perforation), or failure to thrive
52
signs and sx of bowel obstruction: pain, vom, tenderness, distenion, obstipation - proximal small bowel, open loop
pain is intermittent, intense, colicky, often relieved with emesis .... vom is large V, bilious, frequent ... tenderness is epigastric or periumbilical, mild unless strangulated bowel ... distention absent .... +/- obstipation
53
signs and sx of bowel obstruction: pain, vom, tenderness, distenion, obstipation - distal small bowel, open loop
pain is intermittent to constant ... vom is low V and frequency, progressively feculent with time ... TTP is diffuse and progressive ... distention is moderate to marked ... +obstipation
54
signs and sx of bowel obstruction: pain, vom, tenderness, distenion, obstipation - small bowel, closed loop
pain is progressive, intermittent, constant, rapidly worsens ... vom may be prominent (reflex) ... TTP is diffuse, progressive ... distention often absent ... +/- obstipation
55
signs and sx of bowel obstruction: pain, vom, tenderness, distenion, obstipation - colon and rectum
pain is continuous .... vom is intermittent, not prominent, feculent when present ... TTP is diffuse ... distention is marked ... obstipation is present
56
signs and sx of bowel obstruction: open loop prox small bowel, open loop distal small bowel, closed loop small bowel, colon and rectum - pain
intermittent, intense, colicky, often relieved w emesis .... intermittent to constant ... progressive, intermittent, constant, rapidly worsens ... continuous
57
signs and sx of bowel obstruction: open loop prox small bowel, open loop distal small bowel, closed loop small bowel, colon and rectum - emesis
large V, bilious, frequent ... low V, low freq, progressively feculent ... may be prominent (reflex) ... intermittent, not prominent, feculent if present
58
signs and sx of bowel obstruction: open loop prox small bowel, open loop distal small bowel, closed loop small bowel, colon and rectum - TTP
epigastric or peiumbilical, mild unless strangulated bowel .... diffuse and progressive ... diffuse, progressive, diffuse
59
signs and sx of bowel obstruction: open loop prox small bowel, open loop distal small bowel, closed loop small bowel, colon and rectum - distention
absent .... moderate to marked .... often absent ... marked
60
signs and sx of bowel obstruction: open loop prox small bowel, open loop distal small bowel, closed loop small bowel, colon and rectum - obstipation
+/- .... present ... +/- .... present
61
gallstone ileus: describe
SBO 2/2 gallstone, usually in t ileum
62
gallstone ileus: imaging findings
classically air in biliary tree in a pt w SBO
63
gallstone ileus: cause
fistula between GB and second portion of the duo
64
gallstone ileus: tx
remove stone from t ileum ... can leave GB and fistula if pt too sick, o/w cholecystectomy and close duod
65
MC cause of painless lower GI bleeds in kids <2yo
Meckel's diverticulum
66
Meckel's diverticulum: rule of 2s
2ft from ileocecal valve, 2% of population, present within first 2 years of life
67
Meckel's diverticulum: true or false
true diverticulum
68
Meckel's diverticulum: caused by?
failure of closure of omphalomesenteric duct
69
Meckel's diverticulum: MC tissue found in Meckel's vs MC to cause sx
pancreatic tissue - which can cause diverticulitis .... sx usually 2/2 gastric mucosa (bleeding is MC sx)
70
Meckel's diverticulum: MC presentation in kids vs adults
painless lower GI bleed in kids <2yo (account for 50% of painless LGI bleed in kids <2yo) .... obstruction in adults
71
Meckel's diverticulum: mgmt if incidental finding
usually not removed unless gastric mucosa suspected (diverticulum feels thick) or has very narrowed neck
72
Meckel's diverticulum: dx
can get meckel's scan (99Tc) if having trouble localizing --> mucosa will light up
73
Meckel's diverticulum: tx
diverticulectomy for uncomplicated diverticulitis or bleeding ... need segmental resection for complication diverticulitis (i.e. perforation), neck >1/3 diameter of the normal bowel lumen or if diverticulitis involves base .... if incidental finding, usually not removed unless gastric mucosa suspected (diverticulum feels thick) or has very narrowed neck
74
duodenal diverticula: workup
need to r/o GB-duo fistula
75
duodenal diverticula: mgmt/tx
observe unless perforated, bleeding, causing obstruction, highly sx .... if sx - segmental resection ... if juxta-ampullary - usually can't resect, do choledochojejunostomy (biliary sx) or ERCP w stent (pancreatitis sx), AVOID whipple
76
Crohn's disease: describe
inflammatory bowel disease causing intermittent abd pain, diarrhea, and weight loss .... can also cause bowel obstructions and fistulas
77
Crohn's disease: MC patients
15-35 yo at 1st presentation, inc in Ashkenazi jews
78
Crohn's disease: extraintestinal manifestations
arthritis, arthralgias, pyoderma gangrenosum, erythema nodosum ocular diseases, growth failure, megaloblastic anemia from folate and vit b12 malabsorption
79
Crohn's disease: location
can occur anywhere from mouth to anus, usually pares rectum ... t ileum is MC involved bowel segment
80
Crohn's disease: anal/perineal disease
1st presentation in 5% .... tx w flagyl ... MC sx in anal disease is large skin tags
81
Crohn's disease: MC sites for initial presentation
t ileum and cecum - 40% ... colon only - 30% ... small bowel only - 20% ... perianal - 5%
82
Crohn's disease: dx
colonoscopy with biopsies and enteroclysis can help make dx
83
Crohn's disease: pathology
transmural involvement, segmental disease (skip lesions), cobblestoning, narrow deep ulcers, creeping fat, fistulas
84
Crohn's disease: medical tx
5-ASA and loperamide for maintenance, steroids for acute flaures ... remicade (infliximab, TNF-alpha inhibitor) for fistulas and steroid-resistant disease .... NO agents exist that affect the natural course of the disease ... TPN - may induce remission and fistula closuer with small bowel Crohn's disease
85
Crohn's disease: % that need surgery
90% eventually need surgery
86
Crohn's disease: surgical indications
surgery is NOT curative (unlike UC) ... do NOT need clear margins, just get 2cm away from gross disease with surgery ..... obstruction (often partial and can be initially treated conservatively) ... abscess (usually treated with perc drainage) ... megacolon (perforation occurs in 15%, usually contained) ... hemorrhage (unusual but can occur) ... blind loop obstruction (need resection) ... fissures (NO lateral internal sphincteroplasty in pts with Crohn's) ... enterocutaneous fistula (can usually treat conservatively but surgery if non healing) ... perineal fistula (unroof and r/o abscess then let it heal on its own) ... anorectovaginal fistulas (may need rectal advancement flapp, possible colostomy)
87
Crohn's disease: mgmt of pts with diffuse disease of colon
proctocolectomy and ileostomy - NO pouches or ilio-anal anastomosis with Crohn's
88
Crohn's disease: mgmt incidental findings of IBD in pt with presumed appendicitis who has normal appendix
remove appendix to prevent future confounding dx
89
Crohn's disease: stricturoplasty - describe
longitudinal incision through stricture, then close transversely
90
Crohn's disease: stricturoplasty - when to consider
if pt has multiple bowel strictures to save small bowel length .... usually not good for 1st operation because it leaves diseased bowel behind
91
Crohn's disease: stricturoplasty - complications
10% leakage/abscess/fistula rate with stricturoplasty (all of which can be treated conservatively)
92
Crohn's disease: stricturoplasty - recurrence rate
50% recurrence rate requiring surgery for Crohn's disease after resection
93
Crohn's disease: complications from removing t ileum
(1) dec B12 uptake --> megaloblastic anemia ... (2) dec bile salt uptake --> osmotic diarrhea (bile salts) and steatorrhea in colon .... (3) decrease oxalate binding to Ca 2/2 intraluminal fat (fat binds Ca) --> oxalate then gets absorbed in colon --> released in urine ---> Ca-oxalate kidney stones (hyperoxaluria) ... (4) gallstones 2/2 malabsorption of bile salt (conj salt actively transported in t ileum)
94
Chron's disease: cancer risk in pancolitis
same colon CA risk as UC
95
carcinoid: hormones involved
release bradykinin and serotonin
96
carcinoid: describe role of 5ht
produced in Kulchitsky cells (enterochromaffin cell or argentaffin cell) ... part of amine precursor uptake decarboxylase system (APUD) ... 5-HIAA is breakdown product of 5HT, can measure in urine
97
carcinoid: carcinoid syndrome - caused by what?
caused by bulky liver mets
98
carcinoid: carcinoid syndrome - sx
intermitted flushing (kallikrein), diarrhea (5ht) are hallmarks ... also asthma-like sx (bradykinin) and R heart valve lesions
99
carcinoid: carcinoid syndrome - workup
chromogranin A level - highest sensitivity for detecting carcinoid ... octreotide scan - best for localizing tumor not seen on CT
100
carcinoid: carcinoid syndrome - significance in pt w small bowel primary
indicates mets to liver (liver usually clears 5ht)
101
carcinoid: carcinoid syndrome - surgical mgmt
if resect liver mets then you should also do cholecystectomy in case of future embolization
102
carcinoid: MC site
appendix (50% here), ileum and rectum are the next most common
103
carcinoid: small bowel
patients at inc risk for multiple primaries and other unrelated malignancies
104
carcinoid tumor tx
if in appendix and <2cm, do appy .... if in appendic and >=2cm or involving base, do R hemicolectomy .... other places in GI tract, treat like any cancer (segmental resection with lymphadenectomy) .... chemo (streptozocin, 5FU) used for unresectable disease)
105
carcinoid syndrome palliation
octreotide
106
carcinoid: assoc bronchospasm tx
aprotinin
107
carcinoid: assoc flushing tx
alpha blockers (i.e. phenothiazine)
108
carcinoid: false + 5-HIAA
fruits
109
intussusception in adults: vocab, causes, px, tx
intussusceptum is the segment of bowel that invaginates into the intussuscipiens .... can be 2/2 small bowel or cecal tumors (worrisome in adults b/c often malignant lead point) ... MC px is obstruction ... tx w resection
110
benign small bowel tumors: list
adenomas, peutz-jeghers syndrome
111
benign small bowel tumors: ademoas - MC location, px,
most found in duodenem .... p/w bleeding, obstruction ... tx w resection when identified (often done w endoscope)
112
benign small bowel tumors: peutz-jeghers syndrome - inheritance, dsecribe px, cancer risk, mgmt
autosomal dominant .... hartomas throughout GI tract (small and large bowel), mucocutaneous melanotic skin pigmentation ... pts have inc extraintestinal malignancies (MC breast cancer) and small risk of GI malignancies ... NO role of ppx colectomy
113
malignant small bowel tumors: list
adenocarcinoma (most common malignant small bowel tumor, but rare overall), leiomyosarcoma, lymphoma
114
malignant small bowel tumors: adenocarcinoma - epi, location, sx, tx
rare overall, MC malignant small bowel tumor ... high proportion in duodenum ... sx = obstruction, jaundice ... tx = resection and adenectomy, Whipple if in 2nd portion of duodenum
115
malignant small bowel tumors: adenocarcinoma - duodenal CA risk factors
FAP, Gardner's, polyps, adenomas, von Recklinghausen's
116
malignant small bowel tumors: leiomyosarcoma - MC locations, dx, r/o what, tx
jejunum and ileum, most extaluminal ... hard to differentiate from leiomyoma (>5 mitoses/HPF, atypia, necrosis) .... r/o GIST (check for c-kit) .... tx = resect, NO adenectomy needed
117
malignant small bowel tumors: lymphoma - MC location
ileum
118
malignant small bowel tumors: lymphoma - assoc w what
Wegener's, SLE, AIDS, Crohn's, celiac sprue
119
malignant small bowel tumors: lymphoma - type
usually NHL B cell type
120
malignant small bowel tumors: lymphoma - post-transplant risk
inc risk bleeding and perforation
121
malignant small bowel tumors: lymphoma - dx
abd CT, node sampling
122
malignant small bowel tumors: lymphoma - tx
wide en bloc resection (include nodes) unless 1st or 2nd portion of the duodenum (chemo-XRT, NO whipple)
123
malignant small bowel tumors: lymphoma - survival
40% 5 year survival
124
stomas: parastomal hernias
highest incidence w colostomies, generally well tolerated and do not need repair (unless symptomatic)
125
stomas: MC infection
candida
126
stomas: diversion colitis
i.e. Hartmann's pouch .... 2/2 lack of short-chain fatty acids ... tx w short-chain fatty acid enemas
127
stomas: MC cause of stenosis
ischemia ... tx w dilation if mild
128
stomas: MC cause of fistula near stoma site
Crohn's
129
stomas: abscesses
often underneath stoma site 2/2 irrigation device
130
stomas: inc rate of what with ileostomy
gallstones and uric acid kidney stones
131
appendicitis: px
1st anorexia, 2nd peiumbilical pain, 3rd emesis ... pain gradually migrates to the RLQ as peritonitis sets in .... kids more often have higher fever and more vomiting and diarrhea .... elderly can have minimal signs/sx
132
appendicitis: MC age
20-35yo
133
appendicitis: WBC count
can be normal
134
appendicitis: CT findings
diameter >7mm or wall thickness >2mm (looks like bull's eye), fat stranding, no contrast in appendiceal lumen .... try to give rectal contrast
135
appendicitis: area most likely to perf
midpoint of anti-mesenteric border
136
appendicitis: MC cause in kids vs adults
hyperplasia (i.e. after viral illness) vs fecalith
137
appendicitis: pathophys
luminal obstruction (hyperplasia in kids vs fecalith in adults) ---> distention of appendix ---> venous congestion and thrombosis ---> ischemia ---> gangrene necrosis ---> rupture
138
appendicitis: mgmt of CT showing walled-off perforated appendix in elderly
usually non-operative ... perc drainage and interval appendectomy at later date if sx are improving (but may need R hemicolectomy if suspect cancer) ... consider sollow-up barium enema or colonoscopy to r/o perf'ed cecal CA
139
appendicitis: MC to rupture
children and elderly 2/2 delayed dx
140
appendicitis: in infants
infrequent
141
appendicitis: perforation
patients more ill overall, can have evidence of sepsis
142
appendicitis: during pregnancy - most likely to _______ in each trimester
MC cause of acute abd pain in 1st trimester ... more likely to occur in 2nd trimester (just isn't the MC cause of abd pain then) ... more likely to perforate in 3rd trimester
143
appendicitis: during pregnancy - surgical approach
make incision where the pt is having pain ... appendix is more likely to migrate cephalad (more superiorly)
144
appendicitis: during pregnancy - px in 3rd trimester
may have RUQ pain
145
appendicitis: during pregnancy - mortality w rupture
35% fetal mortality
146
appendicitis: during pregnancy - w/u of suspected appendicitis in pregnancy
beta-hcg and abd u/s to r/o ob/gyn causes of pain
147
appendix mucocele: causes
benign or malignant mucous papillary tumor
148
appendix mucocele: mgmt
resect .... open so you don't spill tumor content ... R hemicolectomy if malignant
149
appendix mucocele: complications of rupture
pseudomyxoma peritonei (spread of tumor implants throughout peritoneum)
150
appendix mucocele: MCC of death
SBO from peritoneal tumor spread
151
regional ileitis
can mimic appendicitis, 10% develop Crohn's
152
gastroenteritis
n/v, diarrhea
153
presumed appendicitis but find ob/gyn problem: common problems, mgmt
often ruptured ovarian cyst, thrombosed ovarian vein, regional enteritis not involving cecum ... still perform appendectomy (prevents future confounding dx)
154
ileus vs obstruction
ileus = dilation is uniform throughout stomach, small bowel, colon, rectum, WITHOUT decompression ... obstruction = the IS bowel decompression distal to the obstruction
155
causes of ileus
surgery (MC), electrolyte abnormalities (dec K), peritonitis, ischemia, trauma, drugs
156
typhoid enteritis: cause, px, tx
salmonella .... kids, RLQ pain, diarrhea, fever, HA, maculopapular rash, leukopenia, rare bleeding/perforation .... tx w bactrim
