Diarrhea Up to Date Flashcards
Diarrhea is defined as
the passage of loose or watery stools, typically at least 3 times in a 24-hour period. Reflects increased water content of the stool, whether d/t impaired water absorption and/or active water secretion by the bowel
Acute diarrhea
14 days or fewer in duration
Persistent diarrhea
more than 14 but fewer than 30 days in duration
Chronic diarrhea
more than 30 days in duration
Invasive diarrhea, or dysentery definition
diarrhea with visible blood or mucus, in contrast to watery diarrhea. Dysentery is commonly associated with fever and abdominal pain.
Most cases of acute diarrhea are due to
infections and are self-limited
The major causes of acute infectious diarrhea include
viruses (norovirus, rotavirus, adenoviruses, astrovirus), bacteria (Salmonella, Campylobacter, Shigella, enterotoxigenic Escherichia coli, Clostridium difficile), and protozoa (Cryptosporidium, Giardia, Cyclospora, Entamoeba)
Office evaluation for acute diarrhea is warranted for individuals with ??
persistent fever, bloody diarrhea, severe abdominal pain, symptoms of volume depletion (eg, dark or scant urine, symptoms of orthostasis), or a history of inflammatory bowel disease
Diarrhea of small bowel origin is typically ??
watery, of large volume, and associated with abdominal cramping, bloating, and gas. Weight can happen if persistent, fever rare, and occult blood or inflammatory cells in the stool are rarely identified.
diarrhea of large intestinal origin often presents ??
with frequent, regular, small volume, and often painful bowel movements. Fever and bloody or mucoid stools are common, and RBC’s and inflammatory cells can be seen routinely on stool microscopy
These inflammatory signs associated with large bowel infection (fever, bloody or mucoid stools) suggest ?
invasive bacteria (eg, Salmonella, Shigella, or Campylobacter), enteric viruses (eg, cytomegalovirus [CMV] or adenovirus), Entamoeba histolytica, or a cytotoxic organism such as C. difficile
Visibly bloody acute diarrhea is relatively uncommon and raises the possibility of ?
enterohemorrhagic E. coli (EHEC). Bloody diarrhea can also reflect noninfectious etiologies such as inflammatory bowel disease or ischemic colitis
Syndromes that begin with diarrhea but progress to fever and systemic complaints, such as headache and muscle aches, should raise the possibility of other etiologies, such as ?
typhoidal illness (particularly in travelers from resource-limited settings) or infection with Listeria monocytogenes (particularly if a stiff neck is also present or the patient is a pregnant woman)
timing/ onset of sx can indicate certain pathogens- within six hours suggests?
ingestion of a preformed toxin of Staphylococcus aureus or Bacillus cereus, particularly if nausea and vomiting were the initial symptoms
timing/ onset of sx can indicate certain pathogens- at 8 to 16 hours ?
suggests infection with Clostridium perfringens
timing/ onset of sx can indicate certain pathogens- at more than 16 hours ?
suggests either viral or other bacterial infection (eg, contamination of food with enterotoxigenic or EHEC or other pathogens)
Exposure to animals (poultry, turtles, petting zoos) has been associated with
Salmonella infection.
Occupation in daycare centers has been associated with infections with ?
Shigella, Cryptosporidium, and Giardia. Can consider Rotavirus but it has decreased substantially in US since the vaccine
why is it important to ask about recent antibiotic use ?
possibility of cdiff
why is it important to ask about PPI’s?
they can increase the risk of infectious diarrhea
why is it important to know if pt is preggo?
pregnancy increases the risk of listeriosis following infections of contaminated meat products or unpasteurized dairy products approximately 20-fold
important to know if pt has cirrhosis because?
cirrhosis has been associated with Vibrio infection
hemochromatosis has been associated with?
Yersinia infection
physical exam for diarrhea focused on?
valuating volume status and identifying complications
s/s volume depletion?
dry mucous membranes, diminished skin turgor, postural or frank reductions in blood pressure, and altered sensorium. These signs can be mild or absent with early hypovolemia.
lab tests for pt with diarrhea?
not routinely warranted for most patients with acute diarrhea
If substantial volume depletion is present (suggested by signs or symptoms such as dark and concentrated urine) should order ?
serum electrolytes should be measured to screen for hypokalemia or renal dysfunction.
is a CBC helpful at all?
yes- it does not reliably distinguish bacterial etiologies of diarrhea from others but may be helpful in suggesting severe disease or potential complications
A low platelet count may prompt concern for the development of ?
hemolytic-uremic syndrome
leukemoid reaction (seen on CBC) consistent with ?
consistent with the diagnosis of C. difficile infection
For most patients who do not have severe illness or high-risk comorbidities, it is reasonable to continue expectant management for several days without performing stool cultures. But when should you get stool studies?
if pt with acute community acquired diarrhea also has:
- severe illness: profuse watery diarrhea with signs of hypovolemia, passage of ≥6 unformed stools per 24 hours, severe abdominal pain
- s/s of inflammatory diarrhea: bloody diarrhea, passage of many small volume stools containing blood and mucus, fever of 101.3 or higher
- is a high risk host: immunocompromised, 70+ years old, IBD, preggo, or has serious co-morbidities such as cardiac dx, which may be exacerbated by hypovolemia or rapid infusion of fluid
- if sx persist for longer than 1 week OR
- public health concerns (day cares, food handlers contaminating things)
most infectious cases of acute diarrhea are self-limited and of viral etiology, and the rate of positive stool cultures in pts with acute diarrhea is generally low but if it is bacterial- 3 most common causes of bacterial diarrhea in the United States
Salmonella, Campylobacter, and Shigella
testing for parasitic organisms is only reasonable in patients with persistent diarrhea which has not responded to empiric tx- 3 most common parasitic pathogens in patients with persistent diarrhea ?
Giardia, Cryptosporidium, and E. histolytica. (Infants/ day care centers associated with giardia and crypto more so)
What should be a consideration in immunocompromised patients with persistent diarrhea?
Microsporidium
The most critical therapy in diarrheal illness is?
rehydration- preferably by the oral route, with solutions that contain water, salt, and sugar. Such as- diluted fruit juices and flavored soft drinks along with saltine crackers and broths or soups
The composition of the oral rehydration solution (per liter of water) recommended by the World Health Organization consists of:
●3.5 g sodium chloride
●2.9 g trisodium citrate or 2.5 g sodium bicarbonate
●1.5 g potassium chloride
●20 g glucose or 40 g sucrose
empiric ab only used if:
(same as when to get stool studies)
●Severe disease (fever, more than six stools per day, volume depletion warranting hospitalization)
●Features suggestive of invasive bacterial infection (bloody or mucoid stools)
●Host factors that increase the risk for complications, including age >70 years old and comorbidities such as cardiac disease and immunocompromising conditions
●Prolonged disease (more than one week) that has not improved with conservative measures
●Public health concerns (such as diarrheal illness in food handlers, health care workers, and individuals in day care centers)
most cases of infectious diarrhea are likely ?
viral; however, bacterial causes are responsible for most cases of severe diarrhea
T or F- Most adults with acute diarrhea do not present to medical care.
True. because of the mild or transient nature of the symptoms.
For those who present to medical care, the initial evaluation should assess ?
for extracellular volume depletion (eg, dark yellow urine or scant amount of urine, decreased skin turgor, orthostatic hypotension) and determine the duration of symptoms, the frequency and characteristics of the stool, and associated symptoms (eg, fever and peritoneal signs). Laboratory tests are not usually warranted except in cases of substantial volume depletion, high fevers, or systemic illness.
Inflammatory features (eg, fever, or bloody or mucoid stool) suggest infection of ?
the large bowel, which is associated with pathogens distinct from small bowel infection
Further diagnostic testing depends on the presenting features. Grossly bloody diarrhea warrants testing for
Shiga toxin (to identify enterohemorrhagic Escherichia coli [EHEC]) and fecal leukocytes or lactoferrin, if available
Testing for parasites is not warranted in the majority of patients with acute diarrhea. It is useful, however, in patients with ?
persistent diarrhea, in men who have sex with men, in immunocompromised hosts, during a community waterborne outbreak (associated with Giardia and Cryptosporidium), or with bloody diarrhea with few or no fecal leukocytes (associated with intestinal amebiasis)
most of the time abx for diarrhea
can reduce the duration of diarrhea and other symptoms by several days, but potential drawbacks include side effects, promotion of bacterial resistance, eradication of normal flora (and increased susceptibility to C. difficile infection), and cost. The benefit of symptom reduction does not outweigh these drawbacks in most individuals with acute diarrhea
empiric antibiotic therapy for patients with ?
severe disease, features suggestive of invasive bacterial infection (bloody or mucoid stools), host factors that increase the risk for complications, or disease longer than one week, and in cases of public health concern
For patients in whom empiric antibiotic therapy is warranted, we suggest
Fluoroquinolones- given for three to five days.
even if you want to tx with abx, should rule out this first before you start them
EHEC or Shiga toxin production. EHEC specifically should NOT be treated with antibiotics.
For patients who desire symptomatic therapy, could give
the antimotility agent loperamide can be used cautiously in patients in whom fever is absent or low grade and the stools are not bloody
For patients with clinical features suggestive of dysentery (fever, bloody or mucoid stools) ?
avoid antimotility agents unless antibiotics are also given because of concerns of prolonging disease in such infections- could use bismuth salicylate in these pts
