Lower GI 2 Flashcards
Acute intestinal perforation - ssx:
sudden & catastrophic! severe, generalized abd pain signs of shock N/V anorexia
Acute intestinal perforation - causes:
in SI: duodenal ulcer corrosives strangulation of the bowel acute appendicitis
in LI: obstruction diverticulitis IBD toxic megacolon
Acute intestinal perforation - PE:
Work up:
quiet - absent bowel sounds
peritoneal signs: rigidity, guarding
w/underlying GI d/o -> looks like “worsening”
abd x-ray or CT -> free air seen
Gastroenteritis:
inflammation of the lining of the stomach, SI, & LI - most commonly from infx
typically self-limiting; serious in young, elderly, immunocompromised
typical GI inhabited by 500 bacterial species!
Gastroenteritis - ssx:
sudden onset N/V anorexia abd cramps diarrhea malaise myalgia
Gastroenteritis - PE:
Work up:
distended abd
tenderness
borborygmi
stool testing - hemoccult, WBDc, O&P, culture
rapid enzyme - viral, shiga
CBC, CMP (hypokalemia)
Viral gastroenteritis - prevalence:
Types:
30-40% of infectious diarrhea in the US
Rotavirus Norovirus Astrovirus Enteric adenovirus In immunosuppressed -> CMV & enterovirus
Rotavirus:
Ssx:
MC worldwide
33% of hosp admit/20% death assoc w/GE
highly contagious - fecal-oral
peaks in winter (but yr round)
severe dehydrating diarrhea in kids (3-15 mos) mild in adults vomiting fever >102F lasts 5-7 days
Norovirus:
Ssx:
older children & adults
year round
highly contagious
can be endemic -> food, water-borne
acute onset vomiting abd cramps diarrhea fever HA lasts 1-2 days
Astrovirus:
Ssx:
infants, young children
winter months
fecal-oral
six like rotavirus: dehydrating diarrhea vomiting fever lasts 5-7 days
Enteric adenovirus:
Ssx:
kids <2 yrs
year round/summer
fecal-oral
diarrhea - 1-2 wks
followed by mild vomiting
Bacterial gastroenteritis - 3 mechanisms:
exotoxin - secreted by organism, ingested in food; N/V, diarrhea 12hrs from ingestion, no blood/WBC in stool, abate in 36hrs
enterotoxin - cytotoxins specific for mucus membrane in intestine, secreted in vivo, impaired absorption
mucosal invasion - ingest organism, causes ulceration, bleeding, exudate; stool: WBC, RBC, mb gross blood; watery diarrhea - >1L/d, no fever, HA, myalgia; bloody diarrhea - abd pain, tenesmus, N/V, fever, malaise
Gastroenteritis - exotoxin organisms:
Staph aureus - MC
Bacillus cereus
Clostridium perfringens
Clostridium botulinum
Staph aureus GE:
most common food poisoning
introduced by food handlers
milk products, meat, potato salad
sudden, abrupt, severe vomiting - 2-6hrs post-ingest explosive diarrhea abd cramps fever rare lasts 3-6hrs, complete recovery
Bacillus cereus - GE:
spore-forming organism found in soil
contaminates food
survives high heat
emesis - 2-6hrs post-ingest severe vomiting abd pain mb diarrhea no fever/no systemic
diarrhea - 8-16hrs post-ingest foul smelling profuse nausea abd pain tenesmus
resolves 12-24hrs
Clostridium perfringens - GE:
spore-forming anaerobe
feces, soil, air, water
synthesized before ingestion, more after
beef, poultry, improper cooking/re-heating
watery diarrhea foul-smelling severe, crampy abd pain 8-16hrs post-ingest resolves 24-36hrs
Clostridium botulinum - GE:
3 exotoxin types - A, B, E
1/3 of deaths from food-borne dz
improper home canning (A, B)
smoked fish (E)
4-8hr incubation
phase 1 - vague: fatigue, N/V, cramps, diarrhea
phase 2 - visual: diplopia, dec. acuity, ptosis, un-PERRLA
phase 3 - neuro: descending weakness/paralysis, dysphagia, sensorium okay, normal-low temp
65% mortality @2-9days
w/tx <10%
Gastroenteritis - enterotoxins:
Vibrio cholera
Enterotoxigenic E coli
Clostridium difficile
V. cholera - GE:
endemic in Asia
fecal-contaminated food/water
contaminated saltwater crab/freshwater shrimp
1-3day incubation
sudden, painless, profuse, watery diarrhea no fever, N/V, blood, abd pain, tenesmus water loss -> thirst, oliguria, mm cramps, weakness cold, cyanotic skin dehydration hypoTN, tachycardia recover 7-10days (if rehydrated) 50% fatal in untx severe
Enterotoxigenic E. coli - GE:
fecal-oral contaminated food/water
1-3day incubation
tissue invasion or enterotoxin
profuse, watery diarrhea
3-5days
C. diff - GE:
overgrowth of intrinsic organism post-abx
infx via external source (soil, water, pets)
cytotoxin & enterotoxin
pseudomembranous colitis
common nosocomial, iatrogenic
watery diarrhea
cramping abd pain
N/V rare
Toxic Megacolon:
d/t C. diff dilated colon fever abd pain tachycardia
PE: tender abd
absent bowel sounds
work up: elev. WBC
distended bowel on X-ray
colonoscopy contraindicated
Gastroenteritis - mucosal invasion:
salmonella Campylobacter jejuni Shigella Enterohemorrhagic E col Yersinia enterocolitica
Salmonella - GE:
ingestion of raw egg, chicken, milk contact w/reptiles req. large inoculum for infx direct invasion -> exudative diarrhea enterotoxin -> secretory diarrhea
watery (or bloody) stool HA malaise N/V abd pain 6-48hrs post-ingest mb fever self-limited to 7days
