65: Diarrhea Flashcards
diarrhea physiology
-9 liters of fluid enters small intestine every day
-if SI water scapacity exceeded, chyme overloads colon
Increased intestinal motility causes
diarrhea
decreased intestinal motility causes
constipation
Segmenting contractions
-delay passage and mix intestinal contents allowing for greater absorption
-fewer in pt w diarrhea
Diarrhea
-inc frequency and dec consistency of fecal discharge
-episodes begin abruptly and usually subside 1-2 days w/o tx
-often symptom of systemic disease
Fecal Incontinence
-inability to control bowels
-stool leaking from rectum
-may occur temporarily during diarrhea bout
-can be chronic/recurring
-more common in women and in the elderly
Diarrhea epidemiology
-not routinely reported to CDC
-big time in daycare centers
-5% population
-Norovirus most common foodborne cause
-leading cause of childhood death in developing countries (typhoid fever)
Types of diarrhea
-Secretory
-Osmotic
-Exudative
-Altered Intestinal Transit
Secretory diarrhea
-change in active ion transport
-either dec Sodium absorption or
-or inc chloride secretion into lumen (water follows)
Causes of secretory diarrhea
-pancreatic tumors, unabsorbed fat
-laxatives
-bacterial toxins
-LARGE STOOL volumes >1L/day
-normal ionic stool content
-not altered by fasting
Osmotic diarrhea
-when poorly absorbed substances retained in intestinal fluids
-results in influx of water and electrolytes into lumen
Causes of osmotic diarrhea
-malabsorption syndromes
-LACTOSE intolerance
-admin of divalent ions (mg antacid)
-consumption of poorly soluble CHOs
-improves with fasting! (no eating no diarrhea)
Exudative diarrhea
-subset of secretory
-secondary to IBD
-IBD discharge mucus, proteins, and blood into gut
-characterized by LARGE stool volumes
Bacterial causes of diarrhea
-shigella
-salmonella (most common in US)
-campylobacter
-staph
-e. coli
viral causes of diarrhea
-Norovirus #1
-Rotavirus
Drug-induced diarrhea
-laxatives
-antacids w Mg
-electrolytes
-sorbitol in liquid formulations
-antimicrobials
-motility agents
-cholinergic meds
-antiHTN
-misoprostol
-colchicine
-PPI and H2RAs
-mycophenolate
-metformin
Drug induced diarrhea in cancer pts
-antineoplactics (-ecan)
-lots of mABs
-oral, IV, immunotherapy
Diarrhea presentation
-small intestinal involvement: cramps, sounds, lower right pain w cramping
-Large intestinal involvement: aching sensation with straining (tenesmus)
-N/V, HA, pain, fever, chills
-weight loss if chronic
-hyperperistalsis w generalized local tenderness on exam
Diarrhea diagnosis
-stool analysis
-endoscopic visualization and biopsy
-radiographic studies
Complications of diarrhea
-QOL
-social isolation
-DEHYDRATION
-electrolyte imbalance = cardiac
Dehydration from Diarrhea
-dry mucous membranes
-concentrated urine
-skin tenting
-dizziness when standing
-orhtostatic hypotension
Desired outcomes of diarrhea tx
-manage diet
-prevent excessive water/electrolyte disturbances
-provide symptomatic relief
-treat curable causes
-manage secondary causes of diarrhea
Non-pharma tx of diarrhea
-diet
-electrolyte replacement
Diet managment for diarrhea
-more important w OSMOTIC
-need to eliminate causative agent
-do not stop feedings in children w bacterial diarrhea
-mild, digestable, low-residue
-Bananas, Rice, Applecause, Toast
Electrolyte replacement
-re-hydrate and prevent electrolyte disturbances
-infants and elderly at most risk
-enteral admin preffered
-IV for pt in shock, severe dehydration, or cant stop vomitting
-pedialyte and enfalyte
Diarrhea pharma tx goals
-eliminate cause
-dec fluid in lumen
-dec PROPULSIVE contraction
-inc MIXING contractions
Treatment of acute diarrhea with no fever
-fluid/electrolyte replacement
-loperamide, diphenoxylate or absorbent
-diet
Tx of acute diarrhea WITH fever/symptoms
-check for parasites
-if no parasites treat like regular
-if positive, use antibiotic and symptomatic therapy
Tx of chronic diarrhea
-treat specific cause
-if no diagnosis:
-replete hydration
-D/C potential drug inducer
-adjust diet
-loperamide or absorbent
Traveller’s Diarrhea
-most caused by bacteria
-acute watery diarrhea
-lasts 2-3 days
Prevention of traveller’s diarrhea
-drink bottled water and drinks
-wash fruits and veggies
-antimicrobial prophylaxis should NOT be used routinely, consider for pt at high risk of complications then use rifaimin
-Bismuth subsalicylate may be considered for any traveler
-NOT fluoroquinolones
Treatment of traveler’s diarrhea
-oral rehydration solutions for all
-loperamide adjunctive therapy
tx of mild traveller’s diarrhea
-no antibx
-loperamide of BSS 60ml 2 tabs QID
tx of moderatte traveler’s diarrhea
-antibx MAY be used
-Loperamide alone or w antibiotic
tx of severe traveler’s diarrhea
-antibx SHOULD be used
-single-dose preffered
-loperamide considered as adjunctive
Drug-induced diarrhea etiology/presentatino
-dec transit time leads to irregular absorption and secretion
-alteration of bowel flora (antimicrobials)
-mild to life-threatening
-varied duration depending on causing agent
Tx of drug induced diarrhea
-d/c offender if possible
-oral rehydration solutions
-anti-motility agents
Antimotility drug action
-activate mu opioid receptors on smooth muscle of bowel to reduce peristalsis and inc segmentation
=delayed transit of intraluminal contents
Antimotility drug concerns
-should NOT be used long term (esp opioid derivatives)
-not to be used w C. diff diarrhea
Antimotility drugs
-diphenoxylate/atropine not for young kids
-loperamide OTC
-codeine
Loperamide
-antimotility
-4mg start, 2mg after each loose stool no more than 16mg.day
-high doses can lead to death and bad heart problems
Absorbents
-absorbe nutrients, toxins, drugs, juices
-symptomatic relief
-used for some patients w chronic diarrhea when they have trouble forming solid stools
-absorb water and reduce intestinal motility
-effectiveness if a lil iffy
Absorbents
-Psyllium (metamucil)
-polycarbophil (fibercon) (can absorb more)
-use for diarrhea or constipation
Antisecretory tx of diarrhea
-reduce secretions in gut
-bismuth subsalicylate
Bismuth subalicylate
-pepto-bismol, kaopectate
-antimicrobial/antiinflammatory effects
-2 tabs every 30-60 min as needed up to 8 doses/day
-may potentiate anticoagulants
-cause stool and tongue to turn black
-do not use in kids
