4. MTB Step 3 - Diarrhea Flashcards

Cards Complete:

1
Q

INFECTIOUS DIARRHEA

What is the most important feature of Infectious Diarrhea on presentation?

A

The Presence of Blood. Blood means the presence of invasive bacterial pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

INFECTIOUS DIARRHEA

What are (8) Invasive Bacterial Pathogens that cause Infectious (bloody) Diarrhea?

A
  • Campylobacter: This is the most common cause of food poisoning. It can be associated with Guillain-Barre syndrome and reactive arthritis.
  • Salmonella: This is transmitted by chickens and eggs.
  • Vibrio parahaemolyticus: This is associated with seafood.
  • E. coli: This can have several variants, some of which are associated with blood.
    • E. coli 0157:H7 is most commonly associated with hemolytic uremic syndrome (via effects of verotoxin). Look for undercooked beef in the history. Do not give platelet transfusions or antibiotics, which can make it worse.
  • Vibrio vulnificus: Look for shellfish (oysters, clams) in a person with liver disease and skin lesions.
  • Shigella: Secretes Shiga toxin. This bacteria is also associated with reactive arthritis.
  • Yersinia: Rodents (rarely other mammals) are the natural reservoir of this bacteria. Transmission is via vegetables, milk-derived products, and meat (case may describe pork) that is contaminated with infected urine or feces.
  • Amebic: Perform 3-stool ova and parasite examinations or serologic testing. Treat with metronidazole. May be associated with liver abscesses.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

INFECTIOUS DIARRHEA

  1. What is the Best INITIAL Test for Infectious (bloody) Diarrhea?
  2. What is the Most ACCURATE Test for Infectious (bloody) Diarrhea?
A
  • Best initial test: Fecal leukocytes
  • Most accurate test: Stool culture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

INFECTIOUS DIARRHEA

What are the treatments for both Mild Infectious Diarrhea and Severe Infectious Diarrhea?

A
  • Mild Disease: This will resolve on its own, and the patient should be hydrated only.
  • Severe Disease: Fluoroquinolones, such as Ciprofloxacin, are the best initial therapy. Severe disease is defined as the presence of the following:
    • Blood
    • Fever
    • Abdominal pain
    • Hypotension and tachycardia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

NONBLOODY DIARRHEA

What are (6) causes of Nonbloody Diarrhea?

A
  • Viruses: Rotavirus, norovirus (also called “Norwalk virus”)
  • Giardia: Look for camping/hiking and men who have sex with men. Stool ELISA antigen is > 90 percent sensitive and specific and is more accurate than 3-stool ova and parasite exams. Look for bloating, flatus, and signs of steatorrhea. Treat with metronidazole or tinidazole.
  • Staphylococcus aureus: Presents with vomiting in addition to diarrhea. It will resolve spontaneously.
  • Bacillus cereus: Associated with refried Chinese rice and vomiting. It resolves spontaneously.
  • Cryptosporidiosis: Look for an HIV-positive patient with < 100 CD4 cells. Diagnose with a modified acid-fast stain. Use antiretroviral medications to raise the CD4 count. Paromomycin is only partially effective. Nitazoxanide is used effectively.
  • Scombroid: This is histamine fish poisoning. This has the fastest onset of diarrhea; within 10 minutes of eating an infected tuna, mackerel, or mahi-mahi, the patient has vomiting, diarrhea, wheezing, and flushing. Treat with antihistamines, such as diphenhydramine.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

CLOSTRIDIUM DIFFICILE

What is the cause of C. difficile Diarrhea?

A
  • C. difficile Diarrhea develops several days to weeks after the use of antibiotics.
  • Although clindamycin is the most common cause, antibiotic-associated diarrhea can be caused by any antibiotic.
  • Recently fluoroquinolones have also come to be associated with Clostridium difficile. There can be both blood and fecal leukocytes with C. difficile colitis.
  • PPIs increase the risk of C. diff in hospitalized patients.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CLOSTRIDIUM DIFFICILE

What are the Best INITIAL and Most ACCURATE Diagnostics Tests for C. difficile Diarrhea?

A
  • Best initial test: Stool toxin assay
  • Most accurate test: Stool PCR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CLOSTRIDIUM DIFFICILE

What is the Best INITIAL and Further treatments for C. difficile Diarrhea?

A
  • Best initial therapy: Vancomycin (PO)
  • If antibiotic-associated diarrhea resolves with vancomycin and then recurs later, the patient should be re-treated with Vancomycin.
  • Severe disease can be treated with Metronidazole + Vancomycin in combination.
    • Fidaxomicin (PO) is an alternative to vancomycin in severe, recurrent cases.
    • Fidaxomicin (PO) does not have more efficacy than metronidazole on the first episode.
    • Fidaxomicin (PO) is used if there is no response to metronidazole and with severe disease.
    • IV vancomycin is not useful.
  • Surgery is used in severe disease, such as toxic megacolon, elevated lactate, leukocytosis, and elevated creatinine.
  • “Bezlotoxumab” is the answer when the question asks, “Which of the following prevents recurrence?”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

CHRONIC DIARRHEA

What is the Definition of Chronic Diarrhea?

A

The production of Loose Stools with or without increased frequency for 4 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

CHRONIC DIARRHEA

What is the Most Common Cause of Chronic Diarrhea?

A

Lactose Intolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

CHRONIC DIARRHEA

What is the best way to both Diagnose and Treat Lactose Intolerance in one step?

A

Remove ALL Milk and milk-related products from the diet except yogurt.

A lactose-intolerance test may also be performed. Stool osmolarity is increased.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

CHRONIC DIARRHEA

What is the presentation of Carcinoid Syndrome?

A

Flushing

and

Episodes of Hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

CHRONIC DIARRHEA

  1. What is the Diagnostic Test finding in Carcinoid Syndrome?
  2. What is the Treatment for Carcinoid Syndrome?
A

Diagnose with a Urinary 5-HIAA level

Treat with the Somatostatin Analog Octreotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly