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Lecture 21 Acute Diarrhea Moshenko
DEFINITION OF DIARRHEA:
• Relatively common disorder seen in practice
• ↑ frequency, fluidity, volume of fecal discharge
• ≥ 3 bowel movements/day
EPIDEMIOLOGY: rate of occurrence and severity differs in
developed & developing countries
DEVELOPED COUNTRIES:
Epidemi-ology
• No exact profile available
• Average of 1.4 episodes/year per person
Impact • Not usually fatal, but accounts for 6000 deaths/year in the US
• Results in considerable morbidity & substantial health care costs
Primary cause
• Infectious sources (bacteria, viruses, parasites)
DEVELOPING COUNTRIES:
Epidemi-ology
• Major problem
• Average 3 episodes/year in children < 3 yrs of age
Impact • In 2008: 1.3-1.9 million deaths/year in children < 5 years of age
• Death rates continually decreasing due to extensive distribution and use of oral rehydration solutions, increased breastfeeding, improved nutrition, better hygiene and sanitation
Primary cause
• Infectious sources (differing frequency profiles from developed countries)
• Poor nutrition status, poor sanitation & contaminated water/food supplies
PATHOPHYSIOLOGY:
NORMAL CONDITIONS (ADULTS):
• ~ 9L enters GIT daily from diet,
saliva, gastric juice, bile, pancreatic
juice & small intestine secretions
• Fluid reabsorbed prior to reaching
colon (500 mL left), then another
350 mL reabsorbed in colon
o Stool weighs 100-200 g (of
which 60-85% is water)
• Net water loss 50-100 mL/d in feces
NATURAL DEFENSE MECHANISMS IN GIT:
• Gastric acidity: prevents viable
pathogens from entering intestine
from stomach
• Peristaltic activity: propels pathogens
and their toxins along GIT
• GIT mucus: forms a protective barrier
• Mucosal tissue integrity
• Intestinal immunity: acquired with
repeated exposure to pathogens
DIARRHEA:
• Diarrhea occurs when absorptive capacity of small intestine is exceeded, and excess
fluid enters colon exceeding its absorptive capacity
• Diarrhea results from imbalance b/w fluid & electrolyte absorption/secretion in GIT
o These processes are regulated by solute movement (ions, AAs, monosacchs)
▪ Na is principal ion absorbed (active transport)
▪ Cl is principal ion secreted (active transport)
o Solute movement controlled by:
▪ Active & passive mechanisms/processes
• Active transport requires glucose (energy dependent)
▪ Hormonal control
o Water moves passively across gut wall following movement of various solutes
(Na+, K+, etc) to balance osmotic gradients
▪ Na is principal ion absorbed (active transport)
▪ Cl is principal ion secreted (active transport)
• With diarrhea, many ions are lost goal is to replace ions + water losses
ETIOLOGIC AGENTS/CAUSES: no specific etiology agent can be
determined/identified in 70-75% of cases
Dietary sources
• Green apples
• Excessive caffeine intake
• Spicy foods
• Sorbitol, mannitol, fructose (sweeteners)
Infection • Bacteria o Invasive = direct damage to GI mucosa
(Shigella, Salmonella) o Non-invasive = produce entero-toxins
which interfere with active ion transport mechanisms (ETEC, V. cholera)
• Viruses (norovirus, rotavirus, adenovirus, calicilviruses)
• Parasites (Giarda lamblia, Entamoeba histolytica,
Cryptosporidia) Drugs • Magnesium containing antacids
• Antibiotics (irritation, bacterial overgrowth, C. difficile, pseudomembranous colitis)
• Overuse of stimulant laxatives
• Anti-arrhythmics (digoxin, quinidine)
• Acid-reducing agents (H2RAs, PPIs)
• Narcotic/opioid withdrawal
• Anti-neoplastics
• Antiretrovirals
• Beta blockers
• Propranolol
• NSAIDs
• Alcohol
• Metoclopramide
• Domperidone
• Colchicine
• Furosemide
• Levothyroxine
• Metformin
• Misoprostol
• SSRIs
• Theophylline
Psych • Stress, anxiety = mild cases
Other • Malabsorption (ex// lactose intolerance)
• IBD (ulcerative colitis)
• Hyperthyroidism, diabetes, cirrhosis
• Carcinoma of intestinal tract
• Pyloric dumping syndrome following GI Sx
CLINICAL PRESENTATION AND HISTORY:
• Abrupt onset of frequent loose, watery stools, flatulence, malaise, abdominal pain/cramps
• Depending on etiology, vomiting, fever & muscle aches may be present as well
• Generally resolves within 72h, but may persist for up to 5-7 days (usually at ↓ frequency)
PATIENT ASSESSMENT (SCHOLAR):
Who? • Child, elder, debilitated, pregnant, chronic disease states = high-risk o ↑ risk dehydration, acid-base imbalances, morbidity & mortality
Sx (frequency & intensity)
• Fever? Blood/mucus in stool? Severe abdominal pain/cramping? N/V? Tenesmus? Weight loss? Signs of dehydration (thirst, tachycardia, decreased urination etc)?
Characteristic • Consistency (watery, runny, solid, etc)?
• Frequency of bowel movements (any changes)?
• Volume/quantity produced?
History • What has been done so far?
• Has this happened in the past?
Onset • When did it start? How long/duration? Abrupt/gradual onset?
• Any history of travel to high risk countries (recent, past months)?
• Flu? Any other people at home/work who are ill?
Aggravating factors
• What triggers it?
• Eaten anything differently (spicy food, milk products, coffee, alcohol)?
• New diet? Food poisoning? New medications/supplements/NHPs?
• Family history IBD, etc?
Remitting • What treatments have been tried?What helps?
REFERRAL:
Children (<3 years) Older children (>3 years) & adults
• Young (< 6 m) or weight < 18 lb (8.2 kg)
• Chronic or concurrent conditions
• Premature birth
• Fever ≥ 38.4o if < 3m, ≥ 39oC if 3-36 m
• Blood visible in stool
• High output diarrhea
• Persistent vomiting • S/S of dehydration (listlessness, dry mouth, ↓
tearing, sunken eyes, dry diaper, poor skin turgor, tachycardia, irritability, poor responsiveness, lightheadeddness, dizziness)
• Not drinking enough for rehydration
• Elderly individual
• Chronic or concurrent conditions
• Fever ≥ 39oC
• Blood in stool
• Presence of severe abdominal pain
• High output diarrhea; duration > 48 hrs
• Persistent vomiting
• Individual not drinking adequate (dry
mouth, ↓ tearing, excessive thirst, poor skin turgor, oliguria, orthostatic hypotension (light-headedness, dizziness), irritability, apathy, lethargy
• Not drinking enough for rehydration
Lecture 21 Acute Diarrhea Moshenko
PREVENTION:
Nursing homes, day care centers, etc • Isolation procedures to prevent spread of infectious agents
• Good hygiene
Food/dietary sources • Hidden dietary sources (ex// sorbitol in dietetic foods)?
• Milk allergy (lactase deficiency)?
• Food poisoning? Proper preparation & storage to reduce bacterial/viral contamination
Secondary to another illness • Identify and treat primary condition
Traveller’s diarrhea • Food and water precautions
• Prophylaxis in certain cases
SUPPORTIVE THERAPY/MEASURES = most important approach
• Goal: to control secondary effects of fluid and electrolyte loss and acid-base imbalance
o Consists of rapid rehydration (fluids & electrolytes) and re-feeding (introduction of solids)
o Oral rehydration therapy (ORT) now very common versus IV therapy (oral is as effective as IV therapy in mild-moderate cases of dehydration)
• Rationale:
o Fluids & electrolytes to replace losses
o Foods as energy sources for repair/regeneration of villous cells damaged or killed by pathogens/toxins
ADULTS: decrease activity until patient feels better or diarrhea resolves
1. First 24 hours (or until diarrhea and/or vomiting lessens or stops)
• 2-3 L of clear fluids per day (broth-based soups, fruit juices (not fruit drinks = high glucose)), sports drinks in reasonable amounts); gelatin
• Oral rehydration fluids (ex// Gastrolyte, etc)
2. Next 24 hours (or earlier, if frequency ↓ or individual has been rehydrated)
• Introduce foods as tolerated (slowly at first), but ASAP after rehydration (typically shortens course of diarrhea)
o Complex carbs (cooked rice, potatoes, cereals (rice, grain), bread, crackers)
o Cooked fruits & vegetables; lean meats; cooked eggs
o Yogurt (source of lactobacillus = probiotic) – NOTE: some individuals may have temporary lactose intolerance as consequence of diarrhea
• Avoid: fatty foods, high in simple sugars (including tea, soft drinks, excess sports drinks), spicy or other irritating foods (ex// coffee)
3. Progress to normal diet over next 2-3 days (or longer if some degree of diarrhea present)
INFANTS AND CHILDREN:
• Most cases can be handled in same way as adults, IF diarrhea has been present for < 24 hours and there are no signs of dehydration and/or fever
► If signs of dehydration initial rapid oral rehydration over 4-6 hour period, then proceed to maintenance rehydration therapy
► If no dehydration proceed directly to maintenance therapy guidelines
• Refeeding: integral component of optimal oral therapy regimens; best foods for feeding = as listed previously for adults, but age appropriate
► Children who have diarrhea but are not dehydrated continue to feed age-appropriate diets
► Children who require rehydration feed age-appropriate diets as soon as they have been rehydrated
o Unrestricted diets do not worsen course of symptoms of mild diarrhea and can ↓ stool output compared with ORT and IV treatment alone
o Breast-feeding infants can be nursed safely during episodes of diarrhea allows for faster recovery
o Full-strength animal milk or animal milk formula is usually well-tolerated in cases of mild, self-limited diarrhea (in > 80% of children)
o Weaned children: combinations of milk + cereal are appropriate and well-tolerated
o Monitor for signs of milk malabsorption (re: possible, temporary lactase deficiency): foamy stools or ↑ stool frequency once again
GENERAL GUIDELINES FOR CHILD WITH CLINICAL SIGNS OF DEHYDRATION:
1. Initial rehydration: oral rehydration solution with sodium content of 50-90 mEq/L (Pedialyte, Gastrolyte); offered to child ad libitum (small frequent
amounts as spoonfuls or small sips, small volumes in bottles for infants)
MILD DEHYDRATION • Sx: ↑ thirst & oliguria; slightly dry lips; thick saliva
• Txt: 50 mL/kg of oral rehydration solution over 4-8 hr
MOD DEHYDRATION • Sx: marked thirst & oliguria; diminished/absent tears; dry lips & buccal mucosa; ↓ skin turgor; listlessness
• Txt: 100 mL/kg of oral rehydration solution over 4-6 hr
SEVERE DEHYDRATION (typically hospitalized)
• Child with signs of shock must be given IV Ringer’s Lactate or Normal Saline in boluses of 40 mL/kg until normal circulatory status is restored
• ORT should then be initiated
2. Maintenance therapy: use an oral rehydration with a lower sodium content (40-60 mEq/L); give a minimum of 150 mL/kg/day of total fluids
• If solution with high sodium content is used (50-90 mEq/L) then alternate with liquids that have low solute content (water, formula)
• Ongoing stool losses = replace fluids on one-to-one basis with 10 mL/kg of body weight, or 125-250 mL solution for each diarrheal stool
NOTE: oral rehydration solutions (ex// Gastrolyte Powder, Pedialyte Liquid)
• Contain a balance of Na+, K+, Cl-, bicarbonate, citrate, glucose/dextrose
• Often taste quite salty children may therefore not want to drink them willingly
o Start with small amounts frequently at first (every few minutes) as child may adapt to taste
o Freeze solution into “popsicles” (commercially available – ex// Pedialyte Popsicles) will often make ORT solution more acceptable/palatable
Lecture 21 Acute Diarrhea Moshenko
SPECIFIC THERAPY WITH ANTIBIOTICS:
• Used in selected cases – high fever, bloody stools
o Based on identification of pathogen (bacteria C&S)
o Often diarrheal episode has resolved before C&S results are back
• Clinical trials with antibiotics: generally, do not shorten course of diarrhea
o Antibiotics can also cause diarrhea: pseudomembranous colitis, direct irritation (ex// titration, erythromycin)
SYMPTOMATIC THERAPY:
• Non-prescription drugs: common; generally recommended only for acute self-limiting diarrheas
o US FDA study: only 3 compounding/drugs recommended therapeutically effective: attapulgite, loperamide, polycarbophil
o None of these agents/products should be used for > 2 days without medical supervision
▪ Generally not recommended for children < 2 years
▪ Use cautiously in elderly or debilitated patient
▪ Important to emphasize use of ORT and re-feeding
• Goal: to stop/reduce severity of diarrhea by ↓ frequency, or ↑ consistency of bowel movements
• Note: none of these agents/products should be used for > 2 days without medical supervision
OTC Medication MOA Dose Other notes
Attapulgite, Activated Kaopectate: 600 mg/tablet, 300 mg/chewable tablet; 600 mg/15 mL suspension Also Fowlers
• Adsorbent o Attapulgite =
clay-based o Polycarbophil =
modified cellulose
• Absorbs large amounts of water = = ↑ stool consistency
• May also bind bacterial toxins
• Adults: 1200 mg initially, then 1200 -1500 mg after each BM to a max of 8400 mg/day
• Children (6-12 years): ½ adult dose
• Children (3-6 years): ¼ adult dose
• No significant SEs
• Can use in both adults & children
• Do not use more than 2 days without medical supervision
• Less effective than loperamide
• Should be taken 2 hrs apart from other meds Polycarbophil Prodiem Bulk Fiber Therapy
• Adults: 1 g PO QID or PRN (max 6 g/day)
• Children (6-12 years): 0.5 g PO TID or PRN (max 3 g/day)
• Children (3-6 years): 0.5 g PO BID (max 1.5 g/day)
Loperamide Imodium: 2 mg/capsule or caplet; 0.13 mg/mL liquid; Also available as Imodium Quick Dissolve
• Antimotility agent
• Synthetic opioid analog
• Acts on intestinal µ-opioid receptor to decrease ACh release ↓ GIT motility more time for fluid reabsorption
• ↑ consistency, ↓ frequency of stools
• Adults: 4 mg initially, then 2 mg after each loose BM (max 16 mg/day)
• Children (6-8 years): 2 mg PO up to BID (max 4 mg/day)
• Children (8-12 years): 2 mg PO up to TID (max 6 mg/day)
• SE: abdominal cramps/discomfort, drowsiness, dry mouth, skin rash, constipation
• May worsen diarrhea in some cases (toxins: ↑ contact time more tissue damage)
• Do not recommend if patient has fever (>38.5) or bloody stools
• Contraindicated in children < 2 years (some references < 6 yrs): ↑ incidence CNS depression
• Caution in < 12 years old
Diphenoxylate-atropine Lomotil 2.5 mg diphenoxylate and 0.025 mg atropine/tablet
• Adults: 5 mg initially, followed by 2.5 mg after each loose BM to a max of 20 mg/day
• Children > 4 years: 0.3-0.4 mg/kg daily in divided doses
• SE: nausea, drowsiness, dizziness, blurred vision, constipation
• May worsen diarrhea in some cases (toxins: ↑ contact time more tissue damage)
• Do not recommend if pthas fever, bloody stools
• Do not use in children < 4 years; use with extreme caution in children o CNS depression SEs o Atropine: restlessness, excitement, etc
• Should not be used in pregnancy & breastfeeding
Bismuth subsalicylate Pepto-Bismol
• Stimulates absorption of fluid/electrolytes across intestinal wall
• Anti-inflammatory
• Binds bacterial toxins
• Children > 14 years & adults: 525 mg q30-60 min PO PRN (max 4.2 g/day)
• Not as effective as other meds for acute diarrhea
• May interact with tetracycline, doxy, quinolones, anticoagulants, probenecid, methotrexate
• Contraindications: allergy to salicylates, renal insufficiency, gout, GI bleed
• May blacken tongue/stool, tinnitus
• Not recommended for children < 12 yr (Reye’s)
• Do not use in pregnancy
Probiotics Lactobacillus acidophilus with bifidus (Webber, Jamieson) Bifidobacterial saccharomyces boulardii (yeast, Florastor)
• Restores natural microflora in intestine
• Used for both prevention and treatment of diarrhea
Recommended