Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

GI > Acute Diarrhea/GI infections > Flashcards

Acute Diarrhea/GI infections Flashcards

1
Q

Where are most nutrients absorbed?

A

the proximal 100-150 cms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Features of small bowel infection

A

watery diarrhea, large volume, abd cramping, bloating, gas, wt loss
fever is rare
rare stool WBCs or occult blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Features of large bowel infection

A 
frequent small regular stools
painful BM or tenesmus
fever
bloody, mucoid stools
RBCs and WBC on stool smear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the most common etiology of severe community acquired diarrhea?

A

87% bacterial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define osmotic diarrhea

A

neither SI nor LI can maintain an osmotic gradient
electrolyte absorption is not impaired
osmotic gap is present (>100 mosm/kg)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Features of osmotic diarrhea?

A

can occur due to ingestion of poorly absorbed ions or surgars or sugar alcohols
disappears w/fasting (ie/at night) or cessation of offending substance
monosaccharides but not disaccharides can be absorbed intact across the apical membrane of the intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define secretory diarrhea

A

small osmotic gap (<50 mosm/kg)

osmolality of colonic fluid contents is in equilibrium with body fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Features of secretory diarrhea?

A

can be causes b either net secretion of anions or inhibition of net sodium absorption, enterotoxins, peptides produced by endocrine tumors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How is the osmotic gap calculated?

A

2x([Na+]+[K+])
osmotic gap=serum osm - est stool osm
(normal ~290)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does it mean when the osmotic gap is negative?

A

poorly absorbed multivalent anion (ie/phosphate or sulfate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are signs of surreptitious laxative ingestion?

A

chemical or chromatographic analysis of stool water
large osmotic gap (suggests magnesium ingestion)
negative osmotic gap
-eating disorders, munchausen, secondary gain (disability)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are signs that a stool sample may have been tampered with?

A

if stool osmolarity extremely high-diluted with urine

if stool osmolarity extremely low-diluted with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the number one foodbourne disease in the us? What are features of this pathogen?

A

salmonella typhi
gram negative encapsulated bacilli
found in poultry, eggs and milk, associated with pet turtles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What type of bacteria is shigella?

A

gram negative bacilli

unencapsulated, facultative anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where is shigella commonly contracted?

A

daycare and institutional settings or person to person

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the clinical course of shigella?

A

check for when trying to dx chrons
self limited
usually affects left colon, maybe ileum too
rarely causes HUS< seizures or reactive arthritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are key features of campylobaer jejuni?

A 
leading cause of acute bacterial diarrhea worldwide
undercooked poultry, unpasteurized milk, conaminated water
incubtion up to 8 days
flu like prodrome
self limited
watery or hemorrhagic diarrhea 
small and large bowel symptoms
reactive arthritis/erythema nodosum
guillain barre syndrome
pseudoappendicitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Features of giardia lamblia?

A

drinking from mountain streams
acute or chronic diarrhea with upper abdominal bloating
small bowel disease
flagellated protzoan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Escherischia coli types?

A

ETEC (enterotoxigenic e coli)
EIEC (enteroinvasive e coli)
EAEC (Enteroaggregative ecoli)
EHEC (enterohemorrhagic e coli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the principal cause of traveler’s diarrhea?

A

ETEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What 2 toxins does ETEC produce?

A

heat labile & heat stable (LT & ST)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are key features of EHEC?

A 
aka 0157:H7
undercooked ground beef
39% of cultured pathogens in visibly bloody specimens
associated w/HUS
potentially worse w/abx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Features of vibrio cholerae?

A 
gram negative
contaminated drinking wter
seafood assoicated
worry about after natural disasters
enterotoxin
choleratoxin causes disease: opens CFTR leading to more water in the lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe vibrio cholera infection

A

usually asymptomatic/mild
severe disease-watery diarrhea and vomiting
incubation 1-5 days
may lose up to 1L/hr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How common is norovirus?
half all gastroenteritis worldwide from contamination or person to person schools, cruise ships, etc
26
What is the leading cause of death worldwide?
rotavirus -children bwn 6 and 24 mo most vulnerable vaccines now available
27
What parasites frequently cause diarrhea?
ascaris lumbricoides strongyloides necator americanus and ancylostoma duodenale
28
What is the leading cause of iron deficiency anemia in the developing world?
necator americanus and ancylostome duodenale | hookworms
29
What are common causes of diarrhea in immunocomprimised hosts?
parasites-crytp, isospora belli, cyclospora, microsporia bacteria-salmonella, campylobacer, shigella, mac viral-cmv, hsv, adenovirus
30
What is the definition of nosocomial diarrhea?
new diarrhea at least 72 hours after admission
31
A history of fever directs the DDX to what causes?
invasive bacteria, enteric viruses, cytotoxic organism (C diff, Ent hist), ischemia, IBD
32
What does diarrhea within 6 hours of eating something indicate?
ingestion of a toxin | ie/staph aureus-potato salad, bacillus cereus-chinese food/rice
33
What does diarrhea within 8-14 hours of eating something indicate?
clostridium perfringens infection (toxin producing)
34
Diarrhea that began more than 14 hours after food ingestion indicates what?
viral or bacterial, non specific
35
When and how to order stool culture for ova and parasites?
``` when: 3 times, 3 consecutive days (24hrs apart) order w/ persistent diarrhea >14 days travel to mountainous regions exposrue to daycare immune comprimised community waterbourne outbreak ```
36
How is infectious diarrhea treated?
``` oral rehdration (preferred, IV ok) oral rehydration solution-has sal, citrate, bicarb, KCl, glucose & sucrose in water ```
37
How to dx EHEC?
need 3 of the following: - bloody stool - no reported fever - WBC >10,000 - abdominal tenderness
38
What empiric antibiotics are used for travelers diarrhea?
fluoroquinolong or TMP-SMX
39
What are the indications for empiric antibiotics?
fever, bloody diarrhea, presence of occult blood in stool
40
When can antimotility agents be used for diarrhea? Which agents do you use?
if fever is absent and stools are not bloody | loperamid or diphenoxylate may be used
41
What is the risk with giving and antimotility agent?
can facilitate the development of HUS in EHEC
42
What are some general features of C difficile?
gram positive spore forming anaerobic bacteria assoc w/use of clinda cause of anti-biotic associated pseudomembranous colitis
43
What are risk factors for C diff?
``` recent abx use age duration of hospital stay chemo IBD AIDS gi surgery or g tube? antacids? ```
44
How is Cdiff transmitted?
fecal-oral
45
What is the time it takes to go from Cdiff exposrue to symptoms?
2-3 days | risk of contraction for weeks after abx though
46
What toxins does C diff produce?
toxin A-enterotoxin | toxin B-cytotoxin
47
What is the clinical presentation for C diff?
``` bloody watery diarrhea fever abd pain leukocytosis pseudomembranous colitis severe-toxic megacolon (stop having diarrhea, ominous sign) sepsis, colonic perforation, death ```
48
C diff presention?
wearing gloves wash hands (not w/hand gel) isolation gowns
49
What are the two mainstays of C diff tx?
metronidazole and vancomycin***
50
What is the rate of C diff recurrence?
10-35%
51
Options for tx for C diff recurrence?
``` switch from metronidazole to vancomycin vancomycin taper rifaximin chaser fidaxomicin (lower recurrance, narrower spectrum than vanco) probiotics ?? fecal transplant IVIG (anti IgG anti-toxin A) ```
52
What is a common bacterial used as a probiotic for c diff?
sacchromyces boulardii
53
What is irritiable bowel syndrome?
chronic and relapsing abd pain, bloating, and changes in bowel habits including diarrhea nad constipation
54
What are lab findings in IBS?
normal cbc, lytes and LFTs
55
What criteria does a patient's symptoms have to fit to be IBS?
Rome III Criteria 3days sx/mo in the last 3mo w/2 or more of the follwoing -improvement w/defecation -onset associated w/change in freq of stool -onset associated w/ a change in form (appearance) of stool
56
What is diverticular disease?
actually pseudodiverticular outpouchings of the colonic mucosa and submucosa -occurs near where nerves and arterial vasa recta penetrate the inner circular muscle coat to create discontinuities in the muscle wall
57
Where does diverticular disease usually occur?
sigmoid colon
58
What occurs when diverticula become inflamed?
diverticulitis
59
What exacerbates diverticulosis?
diets low in fiber, which reduce stool bulk
60
What can occur with diverticular perforation?
formation of pericolonic abscesses, development of sinus tracts (fistula), and occasionally peritonitis
61
What are the symptoms of diverticular disease?
~20% develop symptoms -intermittent cramping, continuous lower abdominal cramping, continuous lower abdominal discomfort, constipation and diarrhea
62
Features of acute appendicitis?
males adolescents/young adults luminal obstruction/fecalith ischemic injury and stasis favors bacterial proliferation
63
Sx of acute appendicitis?
periumbilical pain that moves to RLQ nausea, vomiting, low grade fever, mildly elevated white count mcburney's sign
64
What causes ischemic colitis?
``` mucosal infartction -hypotension -arterial spasm transmural infarction -arterial thrombotic/embolitic occlusion ```
65
Where does ischemic colitis usually occur?
watershed zones (splenic flexure, sigmoid colon and rectum)
66
Features of ischemic colitis?
``` segmental and patchy distribution hemorrhagic and ulcerated mucosa self limited resolves when inciting event resolves older ppl, usually w/coexisting cardiac or vascular disease ```
67
What are the symptoms of acute transmural infarction?
sudden severe abd pain and tenderness | sometimes accompanied by nausea, vomiting, bloody diarrhea, or grossly melanotic stool
68
What cytokines do Th1 cells produce?
IFN-gamma
69
What cytokines do Th2 cells produce?
IL-4, IL-5, IL-13
70
What cytokines do Th17 cells produce?
IL-17

GI (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions