Acute gastroenteritis and fluid management

ACUTE GASTROENTERITIS
AND FLUID MANAGEMENT
BROUGHT TO YOU BY PAEDIATRIC TEAM SPONSORED BY Dr F. Mokgoadi

Presentation outline
• Introduction and Epidemiology
• Aetiology
• Pathophysiology
• Signs and symptoms
• Work-up including Classification
• Management
• Fluid and Electrolytes
• Feeding and Nutrition
• Prevention

Definitions and Terms:
Acute Gastroenteritis (AGE): diarrheal disease of rapid
onset, with or without accompanying symptoms,
signs, such as nausea, vomiting, fever, or abdominal
pain
Diarrhea: the frequent passage of unformed liquid
stools (3 or more loose, watery stool per day)
Dysentery: blood or mucus in stools

Diarrhea
• Acute: short in duration of < 7 days
• Persistent diarrhea: starts acutely and lasts longer than 1 week

Epidemiology
• One of the most common illness of infancy
• Second to respiratory illness as a cause of childhood deaths WW
• It represents a major cause of morbidity and mortality
• 3-10 episodes of diarrhea/year/subject in children <5 yrs and
decreases to < 1 for children >5
• Deaths are usually a result of dehydration but malnutrition plays an
important role as it increases the incidence and severity of diarrhea
• By 3 years, virtually all children become infected by the most common
agent

Aetiologies
• AGE is a clinical syndrome produced by a variety of Viral, Bacterial and
Parasitic enteropathogens.
• AGE is almost entirely caused by infections acquired through fecal-
oral route, but ingestion of contaminated food or water also plays a
role
• We have: Non-enteric, Non-infectious and Infectious causes of the
Gastro-intestinal tract
• Episodes usually last 5-10 days

Causes of acute diarrhoea in infancy and
childhood
Non-enteric causes:
 otitis media. Meningitis, sepsis generally
Non-infectious causes:
milk/food allergies, drug side effects, malabsorption
Infections of the gastrointestinal tract
Viral
Bacterial
Protozoal

Common infectious causes of AGE
Viral
Rotavirus
Enterovirus, Calicivirus
Adenovirus, Astrovirus
Bacterial
E.Coli, Shigella
Salmonella, Campylobacter
C.difficile, V. Cholera

parasitic
• Entamoeba Hystolitica
• Giardia lamblia
• Cryptosporidium

Aetiolgy cont
• Rotavirus is known to be the most common pathogen in children
• It is more severe than other causes and more often results in
dehydration, Hospitalization, Shock, Metabolic disturbances and
Death
• Bacterial pathogens are more common where poor sanitation,
hygiene and water supply play a role causing dysenterey

Pathophysiology
The 2 primary mechanisms
(1) Damage to the villous brush border of the
intestinemalabsorption of intestinal contents an
osmotic diarrhea
(2) Release of toxins that bind to specific enterocyte
receptorsrelease of chloride ions into the intestinal
lumensecretory diarrhea

Pathophysiology
• Rotavirus attach and enter mature enterocytes at the tip of the small
intestinal villi
• Cause structural changes to the bowel mucosa, including villous shortening
and mononuclear inflammatory infiltrates in the lamina propria
• This virus induce maldigestion of carbohydrates and their accumulation in
the intestinal lumen (in the absence of lactase)
• Malabsorption of nutrients and concomitant inhibition of water
reabsorption can lead to a malabsorption component of diarrhea
• Rotavirus secretes an enterotoxin, NSP4 which leads to a calcium-
dependent chloride secretory mechanism

Sign & Symptoms
• Nausea & Vomiting
• Diarrhea
• Loss of appetite
• Fever
• Headaches
• Abdominal pain
• Abdominal cramps
• Bloody stools
• Dehydration
• Lethargic

• Vomiting is largely attributed to local factors and poor gastric
emptying, and should not be treated with antiemetic drugs
• Abdominal pains are usually spasmodic due to disordered motility or
is associated with colitis in dysentery
• Diarrhea is the manifestation of secretion or absorption disturbance
and disordered motility, a symptom of damage already done in the
infected gut.

clinical assessment of Hydration
• Recognize poor perfusion and other signs of shock
• Cold peripheries
• Depressed LOC
• Increase capillary refill time (>3sec)
• Poor/weak peripheral pulses
• Reduced urine-output
• signs of dehydration.docx

Work-up
• After resuscitation, in children with severe dehydration, shock or
other signs of metabolic, nutritional or other co-morbidities
• Electrolytes and serum acid base determination
• All severely dehydrated patients, mod dehydration with an atypical
presentation, malnourished children
• Blood glucose disturbances occur in severely ill patients as a result of
glycogen depletion with lack of intake, or associated with the stress response
of dehydration

Electrolyte disturbances
• Large amounts of Sodium are lost in diarrheal stools
• In acidosis, a shift of intracellular potassium to EC compartment
results in a spurious elevation of the serum level despite intracellular
potassium loss
• Give K+ to all patients with severe diarrhea until dehydration and
acidosis are corrected
• Sodium disturbances occur frequently
• Sodium content of the stool water varies from plasma-like in
secretory diarrhea , to very low in pure Osmotic diarrhea

Fluid and electrolyte management

First treat SHOCK if present
• Always SHOUT for HELP
• A…….B…..
• Circulation
• Establish vascular access or IO if failed venous access after 2 good attempts
• Give 20ml/kg of R/L or Normal Saline rapid infusion or 5ml/kg in aliquots X4 is much
safer
• Watch for signs of circulatory overload i.e hepatomegaly, gallop rhythm or basal
crackles, puffiness of the eyelids, tachy-pnoea and –cardia.
• Repeat R/L 20ml/kg if patient is still shocked. Re-assess and give more if still shocked
• Don’t-Ever-Forget-Glucose
• Re-assess ABC and response so far
• Give 1st dose Ceftriaxone 80mg/kg stat to cover sepsis

Treating Shock in severely Malnourished
• ABC still as essential as the normally nourished patients
• Give 15ml/kg infusion over 30 minutes
• Re-assess and repeat if still shocked
• Give up to 4 boluses and thereafter, T/F to HC or ICU
• Patient response should guide further fluid therapy
• When shock has been treated successfully, proceed to the
management of dehydration.
• But remember your patient can go back into shocked if improperly
rehydrated

Rehydration fluids
• Its NB to use solutions with sufficient Na conc. To prevent Hyponatremia
• ½ DD is appropriate if IV route is used, or ORS for enteral replacements
• Where vomiting is the main source of fluid loss, rehydration fluid (0.45%NaCl and
5% Dextrose) with added K is appropriate
• Dose of ½ DD or ORS for rapid rehydration over 4 hours
• Some Dehydration: 50ml/kg over 4 hrs (12.5ml/kg/hour)
• Severe Dehydration: 100mls/kg/4hours (25mls/kg./hour)
• Rapid rehydration over 4hrs should not be used in severe malnutrition, cardiac
failure, severe pneumonia, encephalopathy etc.
• However, rehydrate over 24hours or even 48 hours
• APPROPRIATE RESPONSE AT 4.docx
• Severely malnourished have a deficient K and elevated Na levels, thus require a
special ORS: ReSolMal

Maintenance fluids
• Should be given enterally wherever possible but intravenously where
nil per Os is absolute
• Fluid restriction to approximately 50-60% of maintenance should be
adhered to, where there is a risk of inadequate secretion e.g in Renal
failure
• NORMAL MAINTENANCE FLUID REQUIREMENTS.docx

Never forget the ongoing losses
• Losses need to be replaced by equal volumes of fluids of similar
composition
• For moderate losses, add 30mls/kg to maintenance requirements. But give
more if there’s a need
• For those taking enterally:
• <2years: 50-100mls AELS
• >2years: 100-200mls AELS
• Small frequent volumes of home based sugar salt solution as little as 5mls
every minute, can be effective in preventing dehydration even in vomiting
cases
• Continue Breast feeding and oral feeding once perfusion is restored

What else might help?
• Zinc: reduces the duration and severity of diarrhea
• Antimotility agents like loperamide are C/I due to potentially serious
side effects (malignant hyperpyrexia, lethargy and dystonia)
• Vit A: reduces the severity of diarrhea, but do not give if a dose was
given in the previous month
• All children with diarrhea get vit A and Zinc according to age
• Other drugs, Any use?

Electrolyte abnormalities
• Hypokalemia (<3): even when the serum K conc. Is normal, these
patients have a depletion of the total body potassium
• Plasma k level doesn’t always provide an accurate est of total body
deficit. There may be K shift from intracellular space to the plasma.
• <3mmol/l: stat dose oral K <5kg= 250mg. 5-10kg=500mg and
>10kg=1g stat
• Ongoing losses: < 5kg: 125mg, 5-10kg:250mg and >10kg: 500mg tds
• Re-assess after 4 hours
• Stop when abnormal losses stop

Hypokalemia
K<2>1.5
• Attach ECG: prolonged QT and Flat
T waves
• Give stat doses as previous slide
• Oral KCl: 100mg/kg 6hrly with max
dose 3g/day
• Plus IV correction
• Add to iv fluids (200mls): ½ DD=2ms
15%KCl, Saline=4mls 15%KCl
• Recheck in 4hrs and manage
accordingly
K<1.5: paralysis, muscle
weakness,apnoea
• Admit to HC/ICU
• Give stat dose accordingly
• Oral K: 100mg/kg 6hrly
• Plus IV correction
• If ICU: 0.3mml/kg in 50mls N saline
via C.Vein over 1hour
• Recheck in 2hours
• Manage ongoing losses and
replacement

Hyponatremia Na<135mmol/l
Mild symptomatic (120-130)
• Evaluate pt: if euvolemic,
manage underlying illness
• Dehydrated: rehydrate over 24-
48 hours
• Recheck electrolytes 4hourly,
manage ongoing losses
Severe symptomatic (<120)
• ABC
• Stop seizures (iv phenobarb
10mg/kg)
• Single dose Hypertonic saline
infusion over 1 hour (formula)
• 4ml/kg 3% saline
• Re-check electrolytes in 1 hour
• Manage on-going losses

References
• Handbook of Paediatrics 7th edition pg 121-129, 461-481
• Std Rx guidelines and Essential Medicines List 2013 (Dept ofHealth)
pg 2.9-2.17
• Gastroenteritis presentation by Prof T Rogers Dept of Clinical
Microbiology
• South African medical journal, vol 102,no.2 2012 (Management
guidelines for Acute infective diarrhea in infants) prof F Wittenburg
• Acute gastroenteritis in children by Dr Alta Terblanche, Professional
Nursing Today 2010

Acute gastroenteritis and fluid management

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