Gastroenteritis

Question 1

2 ways gastroenteritis can occur?

Answer 1

Gastroenteritis may either occur whilst at home or whilst travelling abroad (travellers’ diarrhoea)

Travellers’ diarrhoea may be defined as at least 3 loose to watery stools in 24 hours with or without one of more of:

🌼 abdominal cramps,

🌼 fever,

🌼 nausea,

🌼 vomiting or

🌼 blood in the stool.

>>>>>The most common cause is Escherichia coli

Another pattern of illness is ‘acute food poisoning’. This describes the sudden onset of nausea, vomiting and diarrhoea after the ingestion of a toxin.

Acute food poisoning is typically caused by

🍉 Staphylococcus aureus,

🍉 Bacillus cereus or

🍉 Clostridium perfringens.

Question 2

sterotypical histories

Answer 2

The most common cause of gastroenteritis in children in the UK is rotavirus. (get diarrhoea, vomiting, dehydration)

🍧 Escherichia coli -Common amongst travellers -Watery stools -Abdominal cramps and nausea

🍧 Giardiasis -Prolonged, non-bloody diarrhoea

🍧 Cholera -Profuse, watery diarrhoea -Severe dehydration resulting in weight loss -Not common amongst travellers

🍧 Shigella -Bloody diarrhoea -Vomiting and abdominal pain

🍧 Staphylococcus aureus -Severe vomiting -Short incubation period

🍧 Campylobacter -A flu-like prodrome is usually followed by crampy abdominal pains, fever and diarrhoea which may be bloody -Complications include Guillain-Barre syndrome

🍧 Bacillus cereus -Two types of illness are seen >vomiting within 6 hours, stereotypically due to rice >diarrhoeal illness occurring after 6 hours

🍧 Amoebiasis Gradual onset bloody diarrhoea, abdominal pain and tenderness which may last for several weeks

Question 3

incubation periods

Answer 3

1-6 hrs: Staphylococcus aureus, Bacillus cereus*

12-48 hrs: Salmonella, Escherichia coli

48-72 hrs: Shigella, Campylobacter

> 7 days: Giardiasis, Amoebiasis *vomiting subtype, the diarrhoeal illness has an incubation period of 6-14 hours

Question 4

d+v general expected clinical features according to NICE

Answer 4

NICE suggest that typically:

diarrhoea usually lasts for 5-7 days and stops within 2 weeks

vomiting usually lasts for 1-2 days and stops within 3 days

Question 5

what are the categories of hydration status? eg. in a child w/ d + v

Answer 5

When assessing hydration status NICE advocate using

🍰 normal,

🍰 dehydrated or

🍰 shocked categories

…rather than the traditional normal, mild, moderate or severe categories.

Question 6

s/s of clinical dehydration vs shock

Answer 6

Question 7

what are the types of dehydration?

Answer 7

Dehydration can be classified according to the ratio of fluid to electrolyte loss:

1. isotonic

= isotonic loss of both water and solutes from the extracellular fluid (ECF) e.g., - vomiting, diarrhoea or through inadequate intake

no osmotic water shift from the intracellular fluid (ICF) to the ECF.

2. hypertonic [rare]

water loss exceeds salt loss e.g. - through inadequate water intake, excessive sweating, osmotic diuresis and diuretic drugs

characterised by an osmotic shift of water from the ICF to the ECF

dangerous cos: water drawn out of brain –> cerebral shrinkage within rigid skull = jittery movement, incerase muscle tone, hyperreflexia, altered consciousness, seizures, multiple cerebral hemorrhages

3. hypotonic

sodium loss is higher than water loss e.g. in some instances of high sweat or gastro-intestinal fluid losses or when fluid and electrolyte deficits are treated with water replacement only

characterised by an osmotic shift of water from the ECF to the ICF thus increased brain volume and increased risk of convulsions

less common]

Question 8

Management

Answer 8

If clinical shock is suspected children should be admitted for intravenous rehydration.

For children with no evidence of dehydration

• continue breastfeeding and other milk feeds
• encourage fluid intake
• discourage fruit juices and carbonated drinks

If dehydration is suspected:

• give 50 ml/kg low osmolarity oral rehydration solution (ORS) solution over 4 hours, plus ORS solution for maintenance, often and in small amounts
• continue breastfeeding
• consider supplementing with usual fluids (including milk feeds or water, but not fruit juices or carbonated drinks)

Question 9

calculating maintenance fluids in paeds

eg. Calculate the hourly maintenance fluid rate for a child who weighs 25kg

Answer 9

(100 ml for each of the first 10kg) +

( 50ml for each kg 11-20) +

(20 ml for each additional kg) / 24hour

• (100mL x 10kg) + (50mL x 10kg) + (20mL x 5kg) / 24hrs*
• (1000mL) + (500mL) + (100mL) = 1600mL / 24hrs = 66.7ml/hr*
• Using this formula the hourly fluid maintenance for this child is 67mL/hr*