Gastroenteritis Flashcards
Acute gastroenteritis
Indicates infection (bacterial, viral, parasitic)
Many foodborne illnesses
Manifests as V+D
Assoc abdominal pain, fever (systemic)
What happens to untreated acute gastroenteritis?
Becomes persistent
50% of diarrhea deaths
Adverse effect on nutritional status -> malnutrition
Dehydration
Loss of body water
Compensatory mechanisms (thirst, antidiuresis, catecholamine stress response release)
Continuing water loss -> failure to compensate -> circulatory inssufiency
Dehydration
Features
Dry mouth and mucosa Reduced urine, sweat and tears Sunken eyes and fontanel Reduced skin turgor Acidotic breathing Restlessness to irritability Prolonged capillary filling time > 3 seconds Hypotension and shock, tachycardia Apathy to coma, convulsions
Gastroenteritis
Bacteria
Salmonella Shigella Staphylococcus aureus Vibrio cholera Yersinia enterocolitica Campylobacter jejuni E coli Clostridium difficile
Gastroentieitis
Viruses
Astroviruses Caliciviruses Noroviruses Enteric adenoviruses Rotavirus CMV HSV HIV
Gastroenteritis
Parasitic infections
Protozoa
Cryptosporidium Entamoeba hystolytica Giardia Lamblia Microsporidium Isospora
Gastroenteritis
Parasitic infections
Helminths
Strongyloides stercoralis Trichuris trichura Schistosoma Trichinella
Gastroenteritis
Bacterial presentation
Summer – bacterial contamination <6 months of age Multiple pathogens isolated stool Shigella: Abrupt onset diarrhoea, prominent CNS symptoms, high fever, no vomiting, blood and mucous in stools
Gastroenteritis
Viral presentation
Rotavirus Winter months, 6-24 months of age Preceding respiratory symptoms and profuse vomiting before onset diarrhoea
Gastroenteritis
Virus mechanism
Small intestinal mucosal damage Invade mucosal cells tips vili Shedding Disaccharidase deficiency - ↓ carbohydrate digestion (osmotic diarrhoea) ↓ Reabsorption fluid and electrolytes
Gastroenteritis
Bacterial mechanisms
Adherence mucosal cell, damage
Enterotoxin production
– stimulate secretion large amounts fluid and
electrolytes
– toxigenic e.coli, vibrio cholera
Cytotoxin production
– mucosal damage (decreased absorptive surface + secondary inflammatory response ↑fluid secretion
Gastroenteritis
Reasons for vomiting
Impaired gastric emptying
Starvation ketosis
Location irritation and stimulation of neurotransmitters
Toxins that stimulate chemoreceptors in vomiting centre
Gastroenteritis
Resus
Shock medical emergency: IV fluids IV access : IV line, interosseus line Ringer’s / 0.9% Saline: isotonic fluids 20ml /kg bolus Reassess : another 10 – 20ml/kg bolus ½ Darrows 10-15ml/kg/h
Gastroenteritis
Diarrhea complications
Dehydration -> shock
ARF, cerebral complications(hypoxic ischemia, cerebral
vascular thrombosis), NEC, shock lung
Acidosis and electrolyte disturbance
Additional features
Fever, convulsions, ileus, protein losing enteropathy,
necrotizing enterocolitis
Dysfunction gut
↓ digestion and absorption nutrients
Gastroenteritis
Metabolic acidosis clinical features
Loss of base in stools, reabsorb HCL gut, poor tissue perfusion, starvation,
decreased renal H+ clearance
– Features dehydration or shock
– Compensatory breathing: deep rapid respiration
pursed lips, no signs pulmonary disease (Kussmaul)
– Severe acidosis peripheral vasoconstriction, poor capillary filling without other features shock
– Neonates sometimes without physical signs
Gastroenteritis
Electrolytes lost
Sodium
Potassium
Chloride
Bicarbonate
Gastroenteritis
Hypokalemia
– Weakness, hypotonia, paralysis, areflexia
– Cardiac arythmias
– Ileus
– Older child inability to hold up head
– Prolonged: renal tubular defects, reduced
concentrating ability, interstitial nephritis
Gastroenteritis
Hyponatremia
<125 mmol/l: nausea, vomiting, muscle twitching,
lethargy
<115 mmol/l: seizures and coma
Gastroenteritis
Hypernatremia
Osmotic gradient water from intracellular to
extracellular compartment- masked clinical signs
dehydration
Symptoms of intracellular water loss from brain cellsdepressed
sensorium, irritability, convulsions
Severity depends on degree and rate of rise of
plasma osmolality
Gastroenteritis
Convulsion causes
Central venous thrombosis Fever Hypoglycemia Hypo/hypernatremia Menigitis, encephalitis Cerebral edema Shigella toxin
Gastroenteritis
Management
Prevent dehydration
Continue feeds to allow maximal digestion and absorption
Gastroenteritis
Dehydration advice
Prevent
Replace amount that is lost in each vomit stool, +/- 15-30ml/kg additional to each feed
ORS small frequent quantities, teaspoon
Give as much as the child wants, 15-30 ml/kg/h
Once stronger, alert, pass urine, want food: offer small feed
Ongoing losses
Maintaining nutrient intake important
recovery
Continue milk feeds
Select solids easily digestable, bland and
soft – starchy porridge, mashed banana
Small quantities at a time, as frequently as
tolerated
Aim to restore normal intake 2nd-3rd day
Gastroenteritis
Home made solution preparation
8 teaspoons cane sugar
1/2 teaspoon salt
1L cleanest water
Gastroenteritis
Additional therapies
Careful oral rehydration is usually
sufficient
Antimotility agents like loperamide are
contraindicated in children
Similarly, due to the potentially serious
side effects (lethargy, dystonia, malignant
hyperpyrexia) of anti-emetics such as the
phenothiazines they are of little value
Ondansetron Selective serotoninergic 5HT3 receptor antagonist No sedative effect or extrapyramidal reactions Effective against placebo in relieving vomiting, reducing the need for intravenous fluids and decreasing hospitalization
Gastroenteritis
Antibiotic treatment
For dysentery
Ciprobay 15mg/kg dose bd po x 3 days
Gastroenteritis
Prevention
Hygiene and sanitation
Exclusive breastfeeding 6mo
Prevent malnutrition (early intervention)
Measles, rotarix vaccines
