Transcript Document

Diarrhea
Dr.K.S.Sunil
MBBS, MD, PGDGM
• Increase in frequency, size or loosening of
bowel movements.
• Differentiate from fecal incontinence or
functional bowel disease- normal stool
weight
• With western diet- less than 200g/day
Pathophysiology
• Increased active anion secretion
• Decreased absorption of water and
electrolytes
Types
• Transmissible agents
• Noninfectious - abnormal mucosa
– Inflammatory Bowel disease
– Celiac disease, microscopic colitis, eosinophilic and
allergic gastroenteritis, radiation enteritis
• Noninfectious - normal mucosa
– Osmotic diarrhea
– Mal-absorption
– Rapid intestinal transit- IBS
Infectious diarrhea
• Mostly feco-oral route
• Bacterial
• Viral
• Parasitic
Bacterial
• Watery
– Enterotoxigenic• Vibrio cholera
• Enterotoxigenic E.coli
– Food borne toxins• Bacillus cereus
• Clostridium perfringens
– Mycobacterium avium-intracellular complex
Bacterial
• Bloody
– Invasive
• Campylobacter jejuni
– Destructive
• Shigella
• Enteropathogenic E.coli
• Clostridium difficile
Viral
• Rotavirus
– Children less than 2 years
– Most common cause of diarrhea in children all over the
world
• Norwalk
– Older children and adults
• These viruses injure the small intestinal mucosa
• Watery diarrhea
• CMV
– Immunocompromised
Parasitic
• Protozoa
– Giardia lamblia
– Entamoeba histolytica
– Cryptosporidium
• Helminths
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Ascaris lumbricoides
Ancylostoma
Strongyloides stercoralis
Trichinella spiralis
Capillaria philippensis
Opportunistic pathogens
• Clostridium difficile
– Nosocomial pathogens in healthcare and long
term care facility
– Poor handwashing
– Clindamycin, cephalosporins, ampicillin
– Exotoxin mediated
In immunocomromised Hosts
• Besides the common pathogens,
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Giardia
Legionella
Candida albicans
Cryptosporidium species
Mycobacterium avium-intralcellulare
CMV
Others
• Tropical sprue
– In those who live or travel to the tropics
– Overgrowth of predominantly coliform bacteria
in the small intestine
• Whipple’s Disease
– Infection by Tropheryma whippelii
– HLA B27
History
• Is it truly diarrhea?
• Duration– acute <3 weeks
– Chronic >4 weeks
• Texture
• Frequency
• Blood?
History
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Fever
Vomiting
Abdominal pain
Fainting or dizzyness
Travel
Drug use
Diet
Weight loss
History
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Alcohol
Abdominal operations
Chemotherapy
Radiation
Immune status
Comorbidities
Physical
• Vital signs
– Orthostatic signs
– Hyperventilation- acidosis
• Volume status
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Skin tenting
Dry mucous membranes
Resting tachycardia
Hypotension
Sunken eyeballs
Scaphoid abdomen
Physical
• Abdominal and rectal exam.
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Distension
Bowel sounds
Tenderness
Masses
• Stool swab- culture
Physical
• Chronic diarrhea
– Malnutrition
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Weight loss
Muscle wasting
Tetany
Oral and skin lesions
Peripheral neuropathy
Ataxia
Edema
Labs
• Stool tests for inflammation
– Pus cells- specific but low sensitivity( about
50%)
– Lactoferrin
• Released from leucocytes during an inflammatory
reaction
• Sensitivity is 90% but less specific
Labs
• Stool culture
– Positive in only 40 to 60%
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Stool for ova and parasites
Stool for Clostridium difficile toxin
Stool Sudan test for fat
Stool Electrolytes-differentiates secretory diarrhea
from osmotic diarrhea
• Stool pH-<7 indicates carbohydrate malabsorption
Other investigations
• Flexible sigmoidoscopy
– Pseudomembranes
– Inflammation
– Melanosis coli
• Blood Hormone levels
– Serum gastrin, VIP, somatostatin, cortisol, neurokinins,
calcitonin
– Carcinoid- serotonin, urine 5-hydroxyindoleacetic acid
Management
• Fluid therapy
• Persons with moderate to severe diarrhea lose large
amounts of Na, CL, K, HCO3 & H20
• Pre renal azotemia, hypokalemia, metabolic acidosis
– ORS
– IV Fluids
ORS-principle
• Saline solution (water plus Na+) by mouth - no
beneficial effect
– Na+ absorption is impaired in the diarrhoeal state
– if the Na+ is not absorbed water cannot be absorbed.
– Excess Na+ in the lumen of the intestine causes
increased secretion of water and the diarrhoea worsens.
ORS
• Glucose - absorbed through the intestinal wall unaffected by the diarrhoeal disease state - sodium
is carried in conjunction through by a co-transport
coupling mechanism. This occurs in a 1:1 ratio,
one molecule of glucose co-transporting one
sodium ion (Na+).
• Starch –
– metabolized in the intestine to glucose and
therefore it has the same properties of
enhancing sodium absorption
– less osmotic effect in the lumen of the intestine.
• Citrate, a base precursor, corrects acidosis
and enhances the absorption of water and
electrolytes
ORS-History
• First developed in the early 1950’s and was
formulated to mirror ions lost in stool.
• In the early 1960’s the mechanism by which ORT
works, the coupled transport of sodium and
glucose, was discovered.6
• In 1971, the efficacy of ORT demonstrated during
an epidemic of cholera in a refugee camp in
Bangladesh.
– ORT reduced the death rate from more than 50% to
only 5%.7 By the early 1970’s a consensus was reached
about the effectiveness of ORT.
ORS
• Lancet- "potentially the most important
medical advance this century"
• World Health Organization estimates that
90% of diarrheal deaths worldwide could be
prevented with appropriate treatment with
ORS
ORS
• Start early
• Rice based ones ( Glucose polymers)
increase intestinal fluid absorption
• In adults – use urine output for monitoring
ORS
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Sodium Chloride 3.5 grams
Sodium Bicarbonate 2.5 grams
Potassium Chloride 1.5 grams
Glucose 20 grams
ORS
Solution
WHO
Rice
Based
Na
K Cl
Mmols
/L
90
20 80
Carb. Osmolality
111
310
90
111
260
20 60
ORS- caution
• A number of studies have addressed the
concern that ORT can lead to hypernatremia
in neonates and infants.
• These studies show that administration of
breast milk or plain water after rehydration
prevents this problem.1
IV Fluids
• Must contain Potassium and a base
– Ringer’s lactate
Chronic Diarrheas
• Zn and Magnesium replacement
Antibiotics
• Invasive bacterial Enteritis- esp.Shigellae
– Quinilone orally twice daily for 3 days
• Cholera
• Traveler's diarrhea
– Prophylactic- not recommended
– A single dose of oral Quinilone at onset
• Clostridium difficile
– Metronidazole
– Oral Vancomycin
Antimotility agents
• Should be avoided
• Concern for promoting bacterial invasion or
prolonging the infection
Food
• Do not withhold
– Withholding food, even for one or two days, greatly
exacerbates the malnutrition
– Coupled with anorexia, caused partly by chronic
potassium depletion, causes a vicious circle
– It is this diarrhoea/malnutrition cycle rather than acute
dehydration that causes almost half of the five million
deaths a year in under five year old children that are
associated with diarrhoeal disease.
Good nutrition and hygiene can
prevent most diarrhea.
Thank You!