Children with Gastroenteritis

Diarrhoea is defined as a change in bowel habit for the individual child resulting in substantially more frequent and/or looser stools.

Differential Diagnosis

Infections

  • Enteral: viral (commonest cause), bacterial, parasitic
  • Non enteral infections (UTI, pneumonia, Otitis media)- vomiting predominates

Surgical

  • Appendicitis, Intussusception
  • Obstruction
  • Short bowel syndrome

Systemic illness

  • Endocrinopathy (Diabetes, Hyperthyroidism, Congenital Adrenal Hyperplasia, Addison’s disease, hypoparathyroidism)
  • Immunodeficiency
  • Metabolic

Antibiotic associated

  • Whilst taking antibiotics and rarely Pseudo-membranous colitis

Miscellaneous

  • Constipation with overflow
  • Toxins
  • Haemolytic-uraemic syndrome (HUS)
  • Toddler diarrhoea
  • Child Abuse (Munchausen by proxy, sexual)

Dietary

  • Food allergy!
  • Intolerance (Lactose, Cows milk protein)
  • Starvation stools

Malabsorption

  • Cystic fibrosis
  • Coeliac disease

Inflammation

  • Ulcerative colitis/ Crohn’s
  • Hirschsprung’s enterocolitis

Idiopathic/Psychogenic

  • Irritable bowel syndrome

Signs of "Surgical" pathology

  • Abdo pain, +/- guarding
  • Shock
  • Bilious vomiting
  • Pallor or Jaundice
  • Oligo/Anuria
  • Blood in the stool

Estimating dergree of dehydration

Findings Mild (<5%) Moderate (10%) Severe
Mental status Alert Irritable Lethargic
Eyes Normal Sunken Glassy
Fontanelle Normal Flat Sunken
Mucous membranes Normal Dry Very Dry
Tears Normal Decreased Absent
Thirst  Normal Drinks eagerly Drinks poorly
Skin retraction when gently pinched Normal Slow retraction Absent retraction
Capillary refill Brisk Slightly prolonged Prolonged
Volume of urine Normal Reduced Very little
Systolic bp Normal Normal Abnormal
Heart rate Normal Increased Increased

Presence of three of the following signs have a sensitivity of 87% and specificity of 82% for severe dehydration

  • Ill general appearance
  • Absent tears
  • Dry mucous membranes
  • Capillary refill >2 seconds

Features associated with bacterial gastroenteritis

  • Hx of blood +/- mucus in the stool
  • abrupt onset of diarrhoea and no vomiting pre diarrhea
  • Temperature> 400 C
  • 5 or more stools in the previous 24 hours
  • Recent travel abroad
  • Systemically unwell, severe or prolonged diarrhoea
  • A history suggestive of food poisoning

High Risk of dehydration

A significant vomit is anything more than an effortless small volume possett

Management

Assess and treat

  • ABCs
  • Call for help if patient unwell
  • Check Glucose
  • Correct dehydration

 

 

Mild to moderate dehydration can be safely rehydrated with ORS solutions

  • Preferably reduced osmolarity ORS e.g. dioralyte [Cochrane]
  • Delivered "a little, often" over 3-4 hours (5mls every 1-2 min)
  • Replace ongoing losses with 10mls/kg ORS for each loose stool / vomit

 

In severe dehydration, use IV saline or ringers lactate 20m/kg over 1 hour (call for senior paediatric help)

  • If >40ml/kg required, consider ITU / anaesthetic assistance.
  • Once circulation stabilised switch to ORS
  • If ongoing IV fluids are required, use 0.45 saline with dextrose

Example of rehydration therapy

  
Wt
%Dehydration
Fluid Vol
Total
10Kg
10%
100ml/kg
1000ml
20Kg
10%
100ml/Kg
2000ml
30Kg
5%
50ml/kg
1500ml
At the end of the 4 hours the child should be reassessed and the process repeated if necessary.  If the child has persistently vomited over this time, ensure correct diagnosis  and then commence intravenous rehydration with 0.45% saline / 5% dextrose.  Add 10mmol KCl to each 500ml bag once the child has passed urine.  Aim to replace 50% of the deficit in the first 4 hours then the remainder over the next 4 hours. 
Once rehydrated either return to oral rehydration solution or commence 0.18% saline / 4% dextrose as maintenance.  (Only exception to this is in hypernatraemia).

 

Investigations and in-patient care

Links

References