Ch. 16 - Diarrhea Flashcards
1
Q
Diarrhea
A
- Abnormal increase in stool frequency, liquidity, or weight
- > 3 bowel movements per day considered abnormal
- Acute: <14 days, manage with fluids and electrolytes replacement, dietary intervention, and non-Rx drugs
- Persistent: 14 days - 4 weeks; Chronic: > 4 weeks
- These are secondary to a condition and need medical intervention
- Causes 1.9 million death per year in kids <5 y.o.
- ~179 million bases of acute gastroenteritis yearly
- Highest prevalence in kids <5 y.o., lowest in older adults
2
Q
Diarrhea Pathophysiology
A
- Attendance/employment at daycare centers, food handlers, caregivers, congregate living conditions, eating unsafe foods, presence of medical conditions (AIDS or diverticulitis) all increase diarrhea
- Can also be caused by poisoning, medications, intolerance of certain foods, or various non-GI acute or chronic illnesses
3
Q
Viral Gastroenteritis
A
- Norovirus - most common cause in adults and second most common in kids
- Often transmitted by contaminated foods but can also be by person-person contact or via contaminated surfaces
- Rotavirus causes most severe gastroenteritis before vaccines, seasonal infection peaking November-February
- Spread by fecal-oral route, can cause severe dehydration and electrolyte disturbances resulting in death
- Less common causes: adenovirus, astrovirus, and hepatitis A virus
4
Q
Bacterial Gastroenteritis
A
- Bacteria causes ~10% of acute diarrheal illnesses each year, usually food borne
- Campylobacter spp., Salmonella spp., Shigella spp., E. Scherichia coli, enterotoxigenic E. Coli, DAEC, Staph, Clostridium, Yersinia, Bacillus cereus (in order of decreasing likelihood of causality)
- Cause diarrhea through elaboration of enterotoxin attachment and production of local inflammatory changes in gut, or by invading mucosal epithelial cells
- Toxin produced: watery diarrhea, involves small intestine
- Invasive organism: dysentery-like diarrhea (bloody) with fever, cramps, straining, and frequency small stools
- Enteric infection: prolonged bowel dysfunction including IBS (abdominal pain and discomfort)
- IBS develops in 2-30% of patients with gastroenteritis
- May also unmask underlying chronic conditions like celiac disease, Crohn’s, and ulcerative colitus
5
Q
Protozoal Diarrhea
A
- Giardia lamblia, Entamoeba histolytica, Isospora belli, and Cryptosporidium spp.
- Can’t self-treat, need Rx treatment
6
Q
Food-Borne Gastroenteritis
A
- Causes ~47.8 million acute gastroenteritis episodes
- 59% by virus, 39% by bacteria, and 2% by protozoa
- Salmonella and campylobacter most common bacterial pathogens
- Traced to poor sanitation, poor manufacturing practices, and contamination of foods
- Specific foods can also increase infections, so question about food intake 48-72 hours before onset
- Illness by E. Coli O157:H7 and other STECs are a major health issue; toxins by these organisms cause acute bloody diarrhea
- Can lead to fatal complications like hemolytic uremic syndrome or thrombotic thombocytopenic purpura
7
Q
Traveler’s Diarrhea
A
- Acute, secondary diarrhea from ingesting contaminated food or water
- Usually caused by bacterial enteropathogens
- ETEC found in 50-76% of traveler’s with diarrhea
- Found often in fruits, vegetables, raw meat, seafood, and even hot sauces (less commonly water/ice cubes)
- ETEC produce 2 plasmid mediated enterotoxins that closely resemble cholera toxin
- Other organisms may cause diarrhea by entero of cytotoxins
- Experience 3-8+ watery stools each day, usually subsides in 3-5 days
8
Q
Food-Induced Diarrhea
A
- Diarrhea from food allergies or ingestion of excessively fatty, spicy, or high amounts of fiber/seeds
- If carbs aren’t hydrolyzed, they pool in lumen of intestine and promote osmotic imbalance by drawing fluid into lumen and causing diarrhea
- Temporary milk tolerance can occur from infectious diarrhea, use lactase enzyme products
9
Q
Diarrhea Clinical Presentation
A
- Medical history can usually determine cause, but may need lab tests in some cases
- Classifications: osmotic, secretory, inflammatory, or motor
- Osmotic and secretory cause acute diarrhea usually
- Inflammatory and motor cause chronic diarrhea
- Enterotoxins evoke the release of endogenous secretagogues that increase secretory reflexes, some by directly stimulating GI secretomotor neurons to increase secretion
- Inflammatory mediators can also be activated which can stimulate GI motility and cause urgent defecation
- Fluid and electrolyte imbalance is a major complication and causes the need to assess for dehydration; kids < 5 y.o. and adults >65 y.o. are at the greatest risk
- <2 y.o. most likely to require hospitalization form complications
- Severe dehydration = 10%< loss of body weight
- Increased likelihood of death in adults >65 y.o. form enteric infections
10
Q
Meaning of Poop Characteristics
A
- Undigested food particles - disease of small intestine
- Black, tarry stools - upper GI bleed
- Red stools - lower bowel or hemorrhoidal bleeding; or from eating red foods or drug induced
- Secretory diarrhea - high in sodium
- Small-volume stools- colonic disorder
- Yellow stools - bilirubin and serious liver pathology
- Whitish tint - fat malabsorbance disease
11
Q
Diarrhea Treatment Goals
A
- Prevent or correct fluid/electrolyte loss and acid-base distribution
- Control symptoms
- Identify and treat the cause
- Prevent acute morbidity and mortality
12
Q
Diarrhea General Treatment
A
- Often self-limiting
- Self-treat mild to moderate, uncomplicated diarrhea in kids and adults
- Focus on fluid replacement and dietary measures
- Can also use symptomatic control with non-Rx
- Normal function usually restored 24-72 hours without treatment
- Diarrhea in <6 mo. or moderate diarrhea in <2 y.o. need PCP or ER treatment
- Conditions that last >48 hours in adults need med. referral
- Blood/mucus stools, diabetes, CV disease, renal disease, chronic/unstable medical conditions, severe bowel pain, immunocompromised, preggo ==> PCP
13
Q
Diarrhea Nonpharmacologic - Fluid/Electrolyte Management
A
- Rehydration with ORS - preferred for mild to moderate diarrhea; equally effective to IV in mild-moderate diarrhea in kids
- Water follows ions, especially sodium
- Sodium-glucose cotransport mechanism not adversely affected by most diarrhea cases - use hypotonic ORS with low glucose concentration
- Rehydration over 3-4 hours replaces water/electrolyte deficits
- Maintenance: electrolyte solutions given to maintain normal body compositions
- If otherwise healthy, can just increase clear fluid intake
- Premixed solutions are preferred for kids
- Different organizations recommend different sodium concentrations in ORS
- Rehydration solutions: 70-90 mEq/L of sodium; maintenance: 45-50 mEq/L
- Cereal-based ORS good for kids with cholera
- Don’t use household oral solutions, can have too high of a carb or sodium content and make diarrhea worse
- Don’t use soda, tea, apple juice, chicken broth in <5 y.o.
- Sports drinks in 5 y.o.+ with bland carbs is okay
14
Q
Diarrhea Nonpharmacologic - Diet Management
A
- Early refeeding with maintenance hydration improves outcomes by decreasing diarrhea duration, stool output, and increasing weight gain
- Encourage reintroducing food as soon as rehydrated
- Don’t withhold food for more than 24 hours
- Don’t use BRAT diet, low in necessary nutrition, especially if used long term
- Avoid spicy foods and drinks with caffeine
15
Q
Diarrhea Preventative Measures
A
- Isolate individuals with diarrhea, washing hands, sterilize areas to reduce transmission in congregate homes
- Strict food handling, sanitation, and hygienic practices
- Short term BSS prophylaxis for traveler’s diarrhea (not enough evidence to support this)
- Prophylactic antibiotics only recommended for traveler’s at high risk
