Download Diarrhea - ISpatula

Spring 2015
DEFINITIONS – IDSA & WGO
“Diarrhea” is an alteration in a normal bowel movement characterized by an increase in
the water content, volume, or frequency of stools.
In adults, a decrease in consistency (i.e., soft or liquid) and an increase in frequency of bowel
movements to >3 stools per day (24 hrs) have often been used as a definition for
epidemiological investigations.
Diarrhea is defined as daily stools with a mass greater than 15 g/kg for children younger than
2 years and greater than 200 g for children aged 2 years and older.
“Infectious diarrhea” is diarrhea due to an infectious etiology, often accompanied by
symptoms of nausea, vomiting, or abdominal cramps. Dysentery describes an infectious
diarrhea with visible blood and mucus in the stool.
“Acute diarrhea” is an episode of diarrhea of <14 days in duration.
“Persistent diarrhea” is diarrhea of 14 or more days in duration.
Some experts refer to diarrhea that lasts 30 days or more as “chronic.”
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Normal feces contain 60–85% water, and 70–200mL
water is lost per day from the body through defecation.
In diarrhea, water loss of up to four times this volume
per loose stool occurs; sodium and potassium alkaline
salts are excreted along with the water, leading to a fall
in plasma pH (acidosis), which can have serious
metabolic consequences. Fluid and electrolyte losses are
increased further if vomiting also occurs.
The situation is especially hazardous in babies and
young children, as a relatively high proportion of total
body weight is lost, and dehydration can occur very
rapidly.
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Infectious diarrhea
Infectious diarrhea is further
inflammatory diarrhea.
classified
into
non-inflammatory
Non-inflammatory diarrheas
Inflammatory diarrheas
Generally a less severe illness
Generally a more severe illness
and
Patients present with nonbloody, watery stools; Patients present with bloody diarrhea, severe
patients are afebrile and without significant
abdominal pain, and fever.
abdominal pain.
Examination of stool specimens does not
reveal the presence of fecal white blood cells
(WBC) or occult blood.
Examination of stool specimens reveals the
presence of large numbers of fecal leukocytes.
Typically caused by rotaviruses, noroviruses,
Staphylococcus aureus, Bacillus cereus,
Clostridium perfringens, Cryptosporidium
parvum, and Giardia lamblia.
Caused by invasive pathogens including
Campylobacter jejuni, Shigella species,
Salmonella species, Clostridium difficile, Shiga
toxin-producing Escherichia coli (STEC), and
Entamoeba histolytica.
Most patients require only supportive therapies Selected persons may benefit from
antimicrobial therapy directed at the causative
pathogen.
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Classification of Diarrhea by Etiology
Acute diarrhea. Self-limiting lasting 2-3 days but may last up to
2 weeks. Caused by the following:
1) Infections. Most common.
 Viral infections. Rotavirus: affect children under 2 years of
age. Onset 1-2 days and lasts 5-8 days. High risk for
dehydration. Norwalk virus (Noro virus) affects older
children and adults. Onset 1-2 days and lasts for 24-48 hrs.
viral infections are not usually associated with pus or blood
in stool.
 Bacterial infections. Onset within 8 hrs and lasts for few
days. Toxigenic bacteria. Release of enterotoxins in small
intestines which leads to large-volume stools that are watery
or greasy.
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Invasive bacteria results from invasion of colon mucosa which
results in dysentery-like diarrhea with an extreme urgency to
defecate, abdominal cramping, fever, small volume stools that
may contain blood or pus.
 Protozoal infections. Cause explosive foul smelling large
volume watery stools. Thought to be due to invasion of
mucosal layer of small intestines. May last for months and
therapy should be considered to eradicate the organism.
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2) Diet induced acute diarrhea. Food allergies, high fiber
diets, fatty or spicy foods, large amounts of caffeine or milk
intolerance.
3) Drug induced acute diarrhea.
Examples include
parasympathomimitic drugs, digoxin, quinidine, magnesium
hydroxide, laxatives.
4) Chronic diarrhea. Lasts more than 4 weeks. Protozoal
infections, food, IBS, hyperthyroidism.
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Patient Evaluation: All of the following must be considered
before selecting the most appropriate management.
Age
Onset and duration or diarrhea
Description of stool
Other symptoms
Medications
Recent travel
Medical history.
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When to refer to a physician
 Very young or very old.
 Bloody stool.
 High fever (greater than 38.5 ˚C).
 Dehydration or weight loss greater than 5 % of total body
weight. Signs of dehydration: dry mouth, sunken eyes,
crying without tears, dry skin that is less elastic than
normal skin.
 Duration of diarrhea for more than 5 days.
 Severe vomiting..
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Treatment.
 Oral-rehydration
solutions. For a child without
dehydration 10 ml/kg or ½-1 cup for each loose stool. For a
child who is vomiting administer smaller amounts 1-2
teaspoonfuls every 2-5 minutes as tolerated.
 Fluids to be avoided include hypertonic fruit juices,
carbonated beverages, caffeine containing beverages.
 Oral replacement therapy should contain sodium chloride,
potassium chloride, sodium bicarbonate and glucose.
 Pharmacologic treatment, including antibiotics for select
cases.
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Rice-based ORS is superior to standard ORS for adults and children with
cholera, and can be used to treat such patients wherever its preparation
is convenient.
Rice-based ORS is not superior to standard ORS in the treatment of
children with acute non-cholera diarrhea, especially when food is given
shortly after rehydration, as is recommended to prevent malnutrition.
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Treatment of children based on the degree of dehydration
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ORT is not intended to stop diarrhea, but acute diarrhea
is self-limiting and normally ceases within 24–48 hours. ORT
can be recommended for patients of any age, even when
referral to a doctor is considered necessary.
An oral rehydration product (Dioralyte Relief [SanofiAventis]) containing powdered rice starch in place of glucose
is claimed to achieve even greater rehydration than glucose
over time, and the rice starch is claimed to help produce
firmer stools, leading to faster recovery compared with
glucose.
A Cochrane Review found that polymer (including rice)based ORS showed some advantages compared with glucosebased ORS for treating diarrhea of any cause.
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The contents of one sachet of ORS should be dissolved in
200mL water; for infants the water should be freshly
boiled and cooled. It is important to make up the solution
exactly to the recommended volume, as too concentrated
a solution will be hyperosmolar, drawing more water into
the intestine and exacerbating the diarrhea and
dehydration. To avoid risk of possible exposure to further
infection, the solution should be discarded not later
than 1 hour after reconstitution, or it may be kept for
up to 24 hours if stored in a refrigerator.
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The recommended dose of ORS for an adult is 200–400 mL
after every loose motion, or 2–4 L over 4–6 hours. (Diabetic
patients can use ORS, but they should be reminded to
monitor blood glucose levels carefully.) Patients may prefer to
sip one or two teaspoonfuls every few minutes rather than
drink large quantities less frequently.
Children over 2 years of age should be offered a cupful (200
mL) of solution after each loose stool.
Children under 2 years of age should be offered one-quarter
to one-half a cupful. Infants should be given one to one-anda-half times the normal feed volume.
Both breastfed and formula-fed babies should be fed
normally during diarrhea; formula feed should not be
diluted.
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Seven Up should really be avoided due to high osmolarity (WHO recommends 245
mmol/L and Seven Up has more than twice that: may actually aggravate diarrhea!!)
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Antiperistaltic drugs. Act by stimulating mu opioid receptor on the
circular and longitudinal smooth muscles of small and large
intestines. Loperamide, narcotics, diphenoxylate. Effective in nonspecific diarrhea and traveler’s diarrhea. Contraindicated in children
less than 2 and not preferred in those less than 6.
Contraindicated in acute invasive bacterial diarrhea. Why??
Shouldn’t be used for more than 48 hrs in acute diarrhea.
Adult dose of loperamide: 4 mg initially followed by 2 mg after each
unformed stool, not to exceed 8 mg in most patients even though the
maximum allowed daily dose is 16 mg daily.
Side effects include dry mouth, dizziness, drowsiness and abdominal
pain.
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Products
* Loperamide
– several brands available
* Loperamide with simethicone
– Imodium Plus
McNeil
Loperamide (2 mg) is formulated with the surfactant compound
simethicone (125 mg) in a chewable tablet. The manufacturers claim that
the combined formulation relieves the cramping and bloating that can
accompany diarrhoea, and that it improves the effectiveness of
loperamide. A study carried out by the manufacturers involving nearly
500 patients has shown that the combination product considerably
reduced the duration of diarrhea and relieved gas-related discomfort in
comparison with loperamide alone.
The dosage of this product is two tablets initially for adults over 18 years
of age (one tablet for young adults aged 12–18 years) followed by one
tablet after each loose stool (for all ages from 12 years). The maximum
dosage is four tablets daily for 2 days.
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Other Treatments
 Adsorbents. Kaolin and bismuth subsalicylate.
 Probiotics. Lactobacillus. For prevention.
 Lactase. For lactose intolerant patients.
 Antibiotics.
Azithromycin,
ciprofloxacin,
sulfamethoxazole/trimethoprim,
metronidazole,
vancomycin. If used to prevent traveler’s diarrhea, start 1
day before and continue until 2 days after departure.
 Anticholinergic medications. Atropine, hyoscyamine.
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Adsorbents
The following compounds are available:
* kaolin
* pectin
* attapulgite
* bismuth subsalicylate.
Kaolin is a natural hydrated aluminum silicate that has been used in the
treatment of diarrhea since ancient Greek times. It is not absorbed from
the gastrointestinal tract, and about 90% of the drug is metabolised in the gut
and excreted in the feces.
Pectin is a purified carbohydrate obtained from the rind of citrus fruit or pomace
(crushed apple); its mode of action is uncertain.
Attapulgite is a naturally occurring clay mineral, consisting of hydrous
magnesium aluminum silicate. Its adsorptive capacity can be increased by
thermal treatment; the heat-treated form is known as activated attapulgite. In
vitro alkaloidal adsorptive studies have shown activated attapulgite to have an
adsorptive capacity for certain toxic compounds that is five times greater than that
of kaolin. Both kaolin and attapulgite have varying and relatively weak adsorptive
properties in respect of diarrhea-producing bacteria.
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Background
Probiotics are live organisms that are ingested to
provide therapeutic or preventative benefit for the
host. The most commonly used are the lactic acidproducing bacteria bifidobacteria and lactobacilli.
Probiotics also include the yeast Saccharomyces
boulardii. Probiotics are commonly promoted to
strengthen the immune defenses.
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 Bifidobacteria spp
 Saccharomyces boulardii
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Probiotics, Beneficial Microbes
Beneficial microbes such as bifidobacteria live in the
intestinal ecosystem with potentially pathogenic
bacteria. Beneficial microbes prevent the overgrowth
of “bad bacteria” by producing antimicrobial agents.
Additionally, beneficial microbes competitively limit
pathogenic bacterial overgrowth by occupying
receptor sites and vying for space and nutrients.
Beneficial microbes may also increase intestinal
production of mucin, which stimulates the production
of mucus, forming a protective barrier on the
intestinal lining
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In order to be effective, probiotics must be able to
withstand a wide range of pH variation. Many
microbes cannot withstand the protective acid barrier
of the stomach and the effects of bile. An effective
probiotic also must be able to colonize the gut and be
able to attach to the intestinal epithelium.
Additionally, the probiotic should not disturb healthy
intestinal microbes
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Probiotic Bacteria and Yeasts
Bifidobacteria are anaerobic, rod-shaped, grampositive bacteria. Bifidobacteria are the most
prominent beneficial microbes in the colon.
Bifidobacteria produce antimicrobial substances that
have a broad spectrum of antimicrobial activity
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Bifidobacteria that are commonly used as probiotics
include Bifidobacterium longum, B. breve, B. infantis, B.
bifidum, B. lactis, and B. adolescentis. Bifidobacteria
supplements are most commonly combined with other
probiotics. Lactobacilli are a group of gram-positive
rods that are obligate and facultative anaerobes.
Lactobacilli are in the colon in much lower numbers
than bifidobacteria. Lactobacilli also produce a range of
antimicrobial agents. Lactobacilli that are commonly
used as probiotics are Lactobacillus rhamnosus, L.
acidophilus, L. casei, L. reuteri, and L. bulgaricus.
Lactobacilli supplements are used alone or in
combination with other probiotics.
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Other bacteria sometimes used as probiotics include
Streptococcus thermophilus and Leuconostoc species.
The yeasts Saccharomyces boulardii and S. cerevisiae
are also used
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Probiotics for Diarrhea
Probiotics may be useful as adjunctive treatment of
adults and children with infectious diarrhea. Several
species of Lactobacillus seem to reduce the duration of
diarrhea, particularly in rotaviral infections. For
antibiotic-associated
diarrhea,
Lactobacillus
rhamnosus GG, S. boulardii, and probiotic mixtures
appear to be effective prophylactic agents. Given along
with antibiotics, these probiotics can reduce the
incidence of diarrhea by about 60% to 65%. The
effectiveness of probiotics on treatment of antibioticassociated diarrhea is less clear.
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Results of studies looking at probiotics for
traveler’s diarrhea have been mixed. Studies
using Lactobacillus species have shown very
modest or no effect. Combination treatment
with L. acidophilus, L. bulgaricus, B. bifidum,
and S. thermophilus may be better for
reducing the frequency of diarrhea, but there
have been no head-to-head comparisons
with single agents. S. boulardii also may
modestly reduce traveler’sdiarrhea.
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Other Probiotic Uses
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SAFETY
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SUMMARY
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