[ Pobierz całość w formacie PDF ]
an ileoanal pouch.
References: See page 255.
Acute Diarrhea
Acute diarrhea is defined as diarrheal disease of rapid onset,
often with nausea, vomiting, fever, and abdominal pain. Most
episodes of acute gastroenteritis will resolve within 3 to 7
days.
I.Clinical evaluation of acute diarrhea
A.The nature of onset, duration, frequency, and timing of
the diarrheal episodes should be assessed. The appear-
ance of the stool, buoyancy, presence of blood or mucus,
vomiting, or pain should be determined.
B.Contact with a potential source of infectious diarrhea
should be sought.
C.Drugs that may cause diarrhea include laxatives,
magnesium-containing compounds, sulfa-drugs, and
antibiotics.
II.Physical examination
A.Assessment of volume status. Dehydration is sug-
gested by dry mucous membranes, orthostatic hypotension,
tachycardia, mental status changes, and acute weight loss.
B.Abdominal tenderness, mild distention and hyperactive
bowel sounds are common in acute infectious diarrhea.
The presence of rebound tenderness or rigidity suggests
toxic megacolon or perforation.
C.Evidence of systemic atherosclerosis suggests
ischemia. Lower extremity edema suggests malabsorption
or protein loss.
III.Acute infectious diarrhea
A.Infectious diarrhea is classified as noninflammatory or
inflammatory, depending on whether the infectious
organism has invaded the intestinal mucosa.
B.Noninflammatory infectious diarrhea is caused by
organisms that produce a toxin (enterotoxigenic E coli
strains, Vibrio cholerae). Noninflammatory, infectious
diarrhea is usually self-limiting and lasts less than 3 days.
C.Blood or mucus in the stool suggests inflammatory
disease, usually caused by bacterial invasion of the
mucosa (enteroinvasive E coli, Shigella, Salmonella,
Campylobacter). Patients usually have a septic appearance
and fever; some have abdominal rigidity and severe
abdominal pain.
D.Vomiting out of proportion to diarrhea is usually
related to a neuroenterotoxin-mediated food poisoning from
Staphylococcus aureus or Bacillus cereus, or rotavirus (in
an infant), or Norwalk virus (in older children or adults). The
incubation period for neuroenterotoxin food poisoning is
less than 4 hours, while that of a viral agent is more than
8 hours.
E.Traveler's diarrhea is a common acute diarrhea. Three
or four unformed stools are passed/per 24 hours, usually
starting on the third day of travel and lasting 2-3 days.
Anorexia, nausea, vomiting, abdominal cramps, abdominal
bloating, and flatulence may also be present.
F.Antibiotic-related diarrhea
1.Antibiotic-related diarrhea ranges from mild illness to
life-threatening pseudomembranous colitis. Overgrowth
of Clostridium difficile causes pseudomembranous
colitis. Amoxicillin, cephalosporins and clindamycin have
been implicated most often, but any antibiotic can be the
cause.
2.Patients with pseudomembranous colitis have high
fever, cramping, leukocytosis, and severe, watery
diarrhea. Latex agglutination testing for C difficile toxin
can provide results in 30 minutes.
3.Enterotoxigenic E coli
a.The enterotoxigenic E coli include the E coli
serotype 0157:H7. Grossly bloody diarrhea is most
often caused by E. coli 0157:H7, causing 8% of
grossly bloody stools.
b.Enterotoxigenic E coli can cause hemolytic uremic
syndrome, thrombotic thrombocytopenic purpura,
intestinal perforation, sepsis, and rectal prolapse.
IV.Diagnostic approach to acute infectious diarrhea
A.An attempt should be made to obtain a pathologic
diagnosis in patients who give a history of recent ingestion
of seafood (Vibrio parahaemolyticus), travel or camping,
antibiotic use, homosexual activity, or who complain of
fever and abdominal pain.
B.Blood or mucus in the stools indicates the presence of
Shigella, Salmonella, Campylobacter jejuni, enteroinvasive
E. coli, C. difficile, or Yersinia enterocolitica.
C.Most cases of mild diarrheal disease do not require
laboratory studies to determine the etiology. In moderate
to severe diarrhea with fever or pus, a stool culture for
bacterial pathogens (Salmonella, Shigella, Campylobacter)
is submitted. If antibiotics were used recently, stool should
be sent for Clostridium difficile toxin.
V.Laboratory evaluation of acute diarrhea
A.Fecal leukocytes is a screening test which should be
obtained if moderate to severe diarrhea is present.
Numerous leukocytes indicate Shigella, Salmonella, or
Campylobacter jejuni.
B.Stool cultures for bacterial pathogens should be
obtained if high fever, severe or persistent (>14 d) diarrhea,
bloody stools, or leukocytes is present.
C.Examination for ova and parasites is indicated for
persistent diarrhea (>14 d), travel to a high-risk region, gay
males, infants in day care, or dysentery.
D.Blood cultures should be obtained prior to starting
antibiotics if severe diarrhea and high fever is present.
E.E coli 0157:H7 cultures. Enterotoxigenic E coli should
be suspected if there are bloody stools with minimal fever,
when diarrhea follows hamburger consumption, or when
hemolytic uremic syndrome is diagnosed.
F.Clostridium difficile cytotoxin should be obtained if
diarrhea follows use of an antimicrobial agent.
G.Rotavirus antigen test (Rotazyme) is indicated for
hospitalized children
finding of rotavirus eliminates the need for antibiotics.
VI.Treatment of acute diarrhea
A.Fluid and electrolyte resuscitation
1.Oral rehydration. For cases of mild to moderate
diarrhea in children, Pedialyte or Ricelyte should be
administered. For adults with diarrhea, flavored soft
drinks with saltine crackers are usually adequate.
2.Intravenous hydration should be used if oral
rehydration is not possible.
B.Diet. Fatty foods should be avoided. Well-tolerated foods
include complex carbohydrates (rice, wheat, potatoes,
bread, and cereals), lean meats, yogurt, fruits, and
vegetables. Diarrhea often is associated with a reduction
[ Pobierz całość w formacie PDF ]