S09C76 - Diarrhea Flashcards
1
Q
Dfn diarrhea:
A
- > 3 BM/d exceeding 200g
- 4 mechanisms: incr secretion, decr absorption, incr osmotic load, abn intestinal motility
- 85% infectious, 15% non-infectious
- acute : 3w
2
Q
Intestional function
A
-usually lose
3
Q
Acute diarrhea
A
- either infxs, ischemic, intoxication of inflm
- most caused by norovirus or rotavirus and most occur in winter
4
Q
Diarrhea + paresthesias + reverse temperature sensation:
A
ciguatera
5
Q
IBD extraintestinal manifestations
A
-oral ulcers, erythema nodosum, episcleritis, anal fissures
6
Q
Reiter syndrome linked to:
A
- salmonella
- shigella
- campylobacter
- yersinia
7
Q
Wright stain
A
- detects fecal leukocytes
- Sn 52-82%, 83% Sp for presence of bacterial pathogen
8
Q
Bacterial Stool culture
A
- expensive
- dx yield is 1.5%-5.6%
- should be performed in: some children, toxic/dehydrated/febrile pts, diarrhea >3d, pts with blood or pus in stool, immunocompromised pt
- systemic illness/fever/blood stool should be tested for salmonella, shigellla, campylobacter, shiga toxin producing e. coli, amoebic infxn
- many labs only culture for salmonella, shieglla, c. jejuni, therefore if something else suspected this should be communicated to the lab
9
Q
O+P
A
- should be done on travelers, those with diarrhea >7d
- may need multiple samples to get a positive result
- direct immunofluorescence staining can improve sensitivity for detecting giardia and cryptosporidium
10
Q
C. diff Toxin assay
A
- 10% flase neg rate
- takes 24h
11
Q
General tx for diarrhea
A
- caffeine-free glucose containing beverage, eg. gatorade
- 30-50ml/kg over 4h for mild dehydration
- 100cc/kg over next 4h for moderate dehydration
- avoid caffeine (stimulates gastric motility), sorbitol, lactose (to allow villi enough time to produce enzymes required)
- BRAT diet
12
Q
Noninfectious diarrhea
A
- almost all true diarrheal emergencies are non-infxs:
- GIB, adrenal insufficiency, thyroid storm, toxins, acute radiation syndrome, mesenteric ischemia
13
Q
Acute infxs and traveller’s diarrhea
A
- south asia: c. jejuni, shigella, salmonella
- bloody stool w/o WBC is common in shiga toxin-producing E.coli (e. coli O157:H7) and e. hystolytica
- hikers with diarrhea >7d should be tested for protozoans (e. histolytica antigen, g intestinalis antigen, cryptosporidium parvum antigen – enzyme immunoassay)
- severe pain, fever, bloody stool should be tested for salmonella, shigella, jejuni, e coli O157:H7, assay for shig toxin and microscopy or antigen testing for e histolytica
- prevention, bottled/boiled water for teeth brushing and preparing food and formula
- vaccine for rotavirus
- tx: ciprofloxacin 500mg once or BID x3d decreases course by 24h for shigella, e. coli
- tx with flagyl 750mg TID for giardia/histolytica
- loperamide can be used if non-bloody or non IBD or non c-diff –** do not use in children b/c of risk of HUS
14
Q
C diff epidemiology
A
- illness ranges from mild diarrhea to pseudomembranous enterocolitis (yellow laques of exudate over necrotic mucosa)
- spore-forming obligate anaerobic bacillus
- secretes 2 toxins: A and B
- toxin A = enterotoxin
- toxin B = cytotoxin
- relapses occur in 10-25% of pts
- complications: arthritis, visceral abscesses, cellulitis, nec fasc, osteomyelitis, prosthetic device infxn
15
Q
C diff pathophys
A
- hospitalized pts are colonized with c. diff in 1- 25% of cases
- recent hospitalization should flag a pt for c diff
- linear relationship with length of stay and colonization
- broad-spectrum Abx are a risk factor (clinda, cephalosporins, amp/amox, fluoroquinolones) as well as PPI
16
Q
Dx c diff
A
- stool is more likely to have fecal leukocytes than benign forms of diarrhea
- may have profuse diarrhea 20-30x per day
- toxic megacolon in 1-3% of cases with pseudomembranous colitis
- usually begins 7-10d after administration of Abx but can occur several wks after Abx have been d/c
- dx: c diff toxin in stool and colonoscopy
- toxin detected with ELISA, latex agllutination, PCR (most labs use ELISA)
- ELISA has Sn of 63-94% and Sp of 75-100%
- stool Cx for is 100% Sn but not necessarily very specific
- colonoscopy = yellow plaques, often R colon
17
Q
Tx c diff
A
- mild: d/c offending Abx
- mod/severe: flagyl 500mg PO QID x10-14d
- severe: vanco 125-250mg PO WID x10c
- colectomy may be required (WBC >20, lactate >5, >75yo, immunosuppression, shock, toxic megacolon, perforation) for fulminant colitis
18
Q
Crohn Dz: pathology
A
- chronic granulomatous inflammatory dz
- mouth to anus, often ileum, 20% of cases only colon involved, 30% only small bowel
- involves all layers of bowel wall with extension into lymph nodes
- skip lesions, discontinuous
- deep ulcers, fissures, fistulas, abscesses, cobblestone muscosa
19
Q
Crohn Dz: presentation
A
- pain, anorexia, diarrhea, wt loss
- 1/3 of pts develop perianal fissures, fistulas, abscesses, rectal prolapse
- may present with sx of obstruction, obstipation, intra-abdo abcess with fever, palpable mass
- extraintestinal: arthritis, uveitis, liver dz, erythema nodosum, pyoderma gangrenosum, episcleritis, uveitis
20
Q
Crohn Dz: Dx
A
- CT is very helpful
- colonoscopy detects early lesions and defines extent of colonic involvement
21
Q
Crohn Dz: DDx
A
- lymphoma
- ileocecal amebiasis
- sarcoidosis
- deep chronic mycotic infections
- GI TB
- kaposi sarcoma
- campylobacter enteritis
- yersinia ileocolitis
22
Q
Crohn Dz: extraintestinal manifestations
A
Arthritic: peripheral arthritis, ank spon, sacroiliitis Ocular: episcleritis, uveitis Derm: EN, PG Hepatobiliary: cholelithiasis, fatty liver, pericholangitis, cholangiocarcinoma, pancreatitis Vascular: thromboembolic dz -malnutrition -chronic anemia -nephrolithiasis
23
Q
Crohn Dz: Tx
A
-4 classes: symptomatic agents, anti-inflammatories, Abx and immunomodulators
-sulfasalazine 3-5g/d for mild/mod crohn
SE: n/v/d, anorexia, arthralgias, h/a, male infertility
-5-ASA, pentasa, asacol
Symptomatic mgmt:
- glucocorticoids (40-60mg OD)
- loperamide for diarrhea
Immuno-suppressive:
- azathioprine - helps heal fistulas (SE: leukopenia, fever, hepatitis, pancreatitis)
- MTX
Abx:
- cipro induces remission
- flagyl goo for perianal dz and fistulas
- rifaximin
Biologics:
- infliximab (remicade)
- humira (adalimumab)(more effective than remicade)
24
Q
Crohn’s complications:
A
- abscess - think of retroperitoneal abscess in a pt with IBD and hip or back pain and difficulty ambulating
- fissure
- fistula - suspect if change in BM frequency, pain, wt loss
- obstruction - due to edema and also due to stricture formation, distal small bowel most common
- toxic megacolon - can be assoc with massive bleeding
- malnutrition
- malignancy (3x higher than general popn)
25
Crohn's dispo
- hospitalize if fulminant colitis, peritonitis, obstruction , hemorrhage , severe dehydration, fluid/lyte imbalance
- surgery for obstruction, hemorrhage, perforation, abscess, fistula, toxic megacolon, perianal dz
26
Ulcerative colitis: pathology
- more severe distally, rectum nearly always involved
- involves mucosa and submucosa
- micro: crypt abscesses, epithelial necrosis, mucosal ulceration
27
UC: clinical picture
-mild:
28
UC: dx
- leukocytosis
- anemia
- thrombocytosis
- decreased serum albumin
- abnormal liver functions studies
- abdo CT
- antineutrophil cytoplasmic antibody
- anti-saccharomycis cerevisiae antibodies
- in the ED the dx is clinical: cramps, diarrhea, mucoid stool, negative O+P and c+s, confirmed with colonoscopy
29
UC: DDx
-infxs colitis, crohn, ischemic colitis, radiation colitis, toxic colitis, pseudomembranous colitis
30
UC: ED Tx (same as for crohn)
- restore fluid and lytes
- NPO
- NG for obstruction, ileus, suspected toxic mega.
- parenteral narcotics for pain
- Abx (cipro and flagyl)
- look for complications (obstruction, perf, TM, hemorrhage, abscess, fistula)
31
UC; maintenance tx
- mesalamine suppositories or enemas
- topical steroids or glucocorticoids (induce remission)
- pentasa, asa
- glucocorticoids plus immunomodulators for refractory cases (infliximab only)
- antidiarrheals not used and may precipitate toxic mega.
32
UC: complications
- hemorrhage
| - TM: occurs in more advanced UC
