Diarrhea Flashcards
What is diarrhea?
It is the increased frequency and volume of stools caused by decreased water and electrolyte absorption in the intestine
How much water do infants usually lose in their stool?
5-10g/kg per day
How much water does the small intestine usually reabsorb?
80-90%
How long does acute diarrhea last for?
14 days
How long does chronic diarrhea last for?
> 14 days
What are the two types of acute diarrhea?
- Osmotic diarrhea
2. Secretory diarrhea
What is osmotic diarrhea?
This is due to the increased intraluminal osmolality due to sugar malabsorption or ingestion of sorbitol which decreases the absorption of water
What is secretory diarrhea?
It is diarrhea that leads to increased secretion of water and electrolytes induced by a variety of stimuli caused by bacterial toxins etc.
How are carbohydrate malabsorption stools?
They are water stools that are forceful and have tons of gas
The younger child cries a lot and is irritable prior to stooling
The older child has abdominal pain
How do we diagnose carbohydrate malabsorption?
The stool is usually acidic and has a pH<4 and an abnormal hydrogen breath test
How can we resolve carbohydrate malabsorption diarrhea?
A lot of the time removing lactose from the diet helps
What is intraluminal digestion largely dependent on?
Rly dependent on the delivery of adequate exocrine pancreatic enzymes and bile salts
What typically causes fat malabsorption?
- Cystic fibrosis in white kids
- Colic disease
- Giardia lamblia and abdominal TB in disadvantaged communities
What investigations do we usually do for persistent and chronic diarrhea?
- Stool cultures
- Microscopy
- Viral studies
How do we determine whether there is secretory or osmotic diarrhea?
The facael osmolar gap can help
280-(2x(NA+K))
If it less than 50 it is secretory diarrhea
If it 100-125 it is osmotic diarrhea
What other special investigations can we use to determine the type of acute diarrhea?
- Hydrogen breath test
- Pancreatic elastase-!
- Stool alpha 1 anti-trypsin
- Determination of stool fat
In poor communities hope many diarrheal can we expect in children?
5 times a year
What are the most common causes of death in acute viral diarrhea?
- Dehydration
- Shock
- Electrolyte abnormalities (hypokalaemia and hypernatraemia)
What are the common comorbidities that lead to death in diarrhea?
- Immunocompromise
- Malnutrition
- Pneumonia
- Bacteriemia
What are the common organism groups that cause acute diarhea?
- Viruses
- rotavirus, norvirus - Bacteria
- E.coli, Shigella, Salmonella, Campylobacter - Parasites
- cryptosporidium, giardia lamblia
What are the signs of moderate dehydration in children?
- Irritability, restless
- More thirsty, drinks eagerly
- Sunken eyes
- Skin pinch goes back slowly
What are the signs of severe dehydration?
- Sunken eyes
- Lethargic or unconscious
- Not able to drink and eat properly
- Skin turbo very slow
What are the signs of hypovolaemic shock?
- Hypotension
- Tachycardia
- Cold extremities
- Low and threads pulse
- Lerthargic or unconscious
- Delayed capillary
What is dysentery?
The presence of blood and mucus in the stool
What are the causes of dysentery?
- Infective-salmonella, shigella, compylobacter
- Non-infective
- allergic proctolitis
What should we think of if mucus and blood passes without stool?
Intussusception
What is the differential diagnosis for dysentery?
- Meckels diverticulum
- Inflammatory bowel disease
- Polyps
What should we think of if there’s blood on the stool?
Ano-rectal pathology like fissure in ano
What are the complications of acute diarrhea?
- Hypoglycaemia
- CNS-convulsions
- Dehydration
- Electrolyte abnormalities
- Renal failure
What are the electrolyte abnormalities we can expect?
- Hyponatraemia
- Hypokalaemia
- Hypernatramia
- Hypocalcaemia
- Hypomagnesaemia
How does hypokalaemia present?
- hypotonia
- paralytic ileus
- bradycardia
- respiratory failure
What complication does hyperkalemia cause?
Cardiac arrhythmia and death
How can we supplement the potassium?
We supplement it intravenously or orally
What are the complications of hypernatraemia and hyponatraemia?
- CNS-irritability, and seizures, Cerebral vein thrombosis, Cerebral oedema
What type of diarrhea usually causes hyponatraemia?
Secretatory (shigella, cholera)
What do we do to manage metabolic acidosis?
- Correct the shock and dehydration with fluid replacement
2. If the the metabolic acidosis is very severe then we use bicarbonate
What type of renal failure is usually a complication of diarrhea?
Pre-renal failure
What is the management for hypovolaemic shock in these children?
- Start with IV access then Ringers Lactate or normal saline
- Diff cannot get access, use intra-osseaous line
What is the management for children that are moderately dehydrated and above 3 months?
- Start oral rehydration over 4-6 hours
- if they continue to vomit or refuse oral rehydration then use nasogastric tube
In which patients do we not use oral rehydration in?
- Cardiac or respiratory disease
2. Severely malnourished children
How much rehydration do we give at first?
20ml/kg/hour and re-evaluate after 2 hours
-if the hydration and weight improves then we can reduce it 10ml/kg/hour and start feeds
Why must we still continue breastfeeding even in a shocked or severely dehydrated child while re-hydrating?
This causes an increase the nutrients that the baby gets
Which children typically receive antibiotics?
Children with pneumonia, bacteriremia, but specifically dysentery and cholera
What other treatment modalities do we have that we can give to the infants?
- Probiotics
- Anti-diarrheal drugs-but more in chronic diarrhea
- Vitamin A
- Zinc
When must infants who had an acute diarrheal attack return for their check-up?
2 days later for a weight and wellbeing check
What vaccine can we give to children that can dramatically reduces the incidence of acute diarrhea?
- Rotavirus vaccine given in the first 6 months
What is the organism that causes cholera?
Vibrio cholera
How is cholera passed?
Via the faceal oral route
What are he clinical features of cholera?
Watery Diarrhea and vomiting with no nausea
- the stools are colourless with mucus(rice water)
- dehydration
- shock
- Electrolyte abnormalities ensue
What is the incubation period for cholera?
1-5 days
What is the management of cholera?
- Fluid replacement and rehydration
- Antibiotic use in only severe forms of dehydration
- we use ciprofloxacin children under 8 years and tetracycline over 8 years
Which organism causes the most common cause of dysentery in South Africa?
- Shigella flexneri
How does dysentery present in children?
After an incubation period of one to four days the child presents with fever, abdominal pain, watery stools which can include blood and mucus
What antibiotics do we treat shigella with?
Ciprofloxacin and ceftriaxone and Nalidixic acid
What are the causes of chronic diarrhea?
- Congenital diarrhea
- Pancreatic insufficiency
- Infection
- Celiac disease
- HIV
- Short bowel syndrome
What is persistent diarrhea?
Acute episodes of Diarrhea that last more than 14 days
Which patients are at a higher risk of developing persistent diarrhea?
- Malnourished
- Early breast feeding weaning
- Immune-compromised
- Those with E.coli, shigella, and salmonella
