Gastroeneteritis

Question 1

Define

Answer 1

Enteric infection with viruses, bacteria or parasites

• Major cause of mortality in developing countries and morbidity in developed countries
• 10% of children < 5 years present with gastroenteritis annually within the UK

Question 2

Aetiology

Answer 2

In developed countries, the MOST frequent cause is rotavirus (It is particularly prevalent in winter and early spring)

Other viruses which can cause outbreaks:
1. Adenovirus
2. Norovirus
3. Calicivirus
4. Coronavirus
5. Astrovirus

Bacterial causes are LESS common in developed countries but may be suggested by the presence of blood in stools (CHESS C):

1. Campylobacter jejuni is the MOST COMMON bacterial cause of gastroenteritis in developed countries. It is often associated with severe abdominal pain
2. Shigella and salmonellae produce dysenteric type of infection, with:
   * Blood and pus in stool
   * Pain
   * Tenesmus NOTE: Shigella infection may be accompanied by high fever
3. Cholera and haemorrhagic enterotoxigenic E. coli are associated with profuse, rapidly dehydrating diarrhoea
4. Entamoeba histolytica
5. (Yersinia Enterocolitica)

Protozoan parasites can also cause gastroenteritis, such as Giardia and Cryptosporidium

Question 3

Presentation

Answer 3

SUDDEN change to loose or watery stools

Increased frequency of stool passage

Vomiting

Recent travel abroad

Contact with an infected individual

Dehydration leading to SHOCK - the most serious complication of gastroenteritis

The following children are at increased risk of dehydration:

• Infants (especially < 6 months or with low birthweight)
• If ≥ 6 diarrhoeal stools in the past 24 hours
• If vomited ≥ 3 times in the past 24 hours
• If unable to tolerate (or not offered) extra fluids
• If they have malnutrition

NOTE: infants are at particular risk of dehydration because:
* Greater surface area-to-weight ratio – so more insensible water losses
* Higher basal fluid requirements
* Immature renal tubular reabsorption
* Unable to obtain fluids for themselves when thirsty

Question 4

Investigations

Answer 4

• A –> E
• Examination - abdo exam (may want to do other exams)
• Basic observations
• Check weight
• Usually CLINICAL DIAGNOSIS and NO investigations
• Consider stool sample analysis

May be needed to identify cause (if reveal causative culture, seek specialist advice regarding antibiotic treatment)

Perform if
* suspect septicaemia
* blood/ mucus in stool
* immunocompromised
* history of recent hospitalisation
* recent antibiotic treatment
* recent travel
* diarrhoea has not resolved by day 7

DDx
1. UTI
2. Meningitis
3. Bowel obstruction
4. Chron’s
5. Coeliac’s

Question 5

Management of dehydration

Answer 5

Assess for:

• Features of DEHYDRATION and SHOCK
• Features that might suggest an alternative diagnosis
• Severity and possible cause of gastroenteritis
• Consider hospital admission
• Give rehydration advice - TRY WITH ORAL BEFORE CONSIDERING IV (unless in shock)

MUST KNOW THIS!!

Maintenance fluid volumes (with 0.9% saline + 5% dextrose) given over 24 hours:

1. Give bolus - 20mL/kg over 10 mins until shock resolves then maintenance fluids after
2. First 10 kg = 100mL/kg over 4 hrs

+ Next 10kg = 50 mL/kg

+ there after = 20 mL/kg

OR

0-10kg= 100mL/kg over 4 hrs

10-20kg= 1000mL + 50mL/kg for each kg > 10kg

> 20kg= 1500mL + 20mL/kg for each kg > 20kg

Males rarely need > 2500mL and females 2000mL per day

Measure electrolytes and glucose when starting IV fluids and at least every 24 hours

Modes of rehydration for oral:

1. ≤ 5 years= 50ml/kg for fluid deficit replacement over 4 hours as well as maintenance with oral rehydration solution
2. > 5 years= 200mL ORS after each loose stool since presenting (don’t overload yet)

• Give ORS frequently and in small amounts
• Do NOT give sugary or carbonated drinks
• Avoid solid food until dehydration is corrected

NOTE: notify the Local Authority if a notifiable disease is diagnosed or suspected e.g. cholera

IMPORTANT: anti-diarrhoeal Drugs (e.g. Loperamide) and antiemetics are NOT used in children

Question 6

Management of gastroenteritis

Answer 6

The MOST ACCURATE measurement of dehydration= degree of weight loss during diarrhoeal illness

If clinical dehydration is NOT present, the aim is prevention

If clinical dehydration IS present, ORS is the mainstay of therapy

IV fluids are ONLY indicated for:
* Shock
* Deterioration
* Persistent vomiting

Antibiotics
* NOT routinely required to treat gastroenteritis (even if the cause is BACTERIAL)

Only indicated for:
* Suspected OR confirmed SEPSIS
* Extra-intestinal spread of bacterial infection
* Salmonella gastroenteritis if aged < 6 months
* Malnourished or immunocompromised children with Salmonella
* Specific bacterial or protozoal infections e.g. C. difficile associated with pseudomembranous colitis, cholera, shigella, giardiasis)

Nutrition
* Can continue breastfeeding whilst rehydrating with ORS
* Nutritional intake needs to be INCREASED after diarrhoeal illness
* Diarrhoea may lead to zinc deficiency and supplementation may be necessary

Notify the Health Protection Unit if caused by:
* Campylobacter
* Listeria
* E. coli O157
* Shigella
* Salmonella

Give advice on:
* Preventing spread- washing hands, preparing + cooking food, contact with others

Follow up (and safety net!)
* Diarrhoea: usually lasts for 5-7 days and stops within 2 weeks
* Vomiting: usually lasts 1-2 days and stops within 3 days

Question 7

Complications

Answer 7

1. Dehydration and electrolyte disturbance
2. IBS
3. Transient Lactose intolerance
   * Common complication after viral gastroenteritis
   * Removal of lactose from the diet for a few months followed by a gradual reintroduction usually resolves the problem
4. Haemolytic uraemic syndrome
   * Thrombocytopenia
   * Microangiopathic haemolytic anaemia
   * Acute renal failure

The commonest trigger is Escherichia coli 0157:H7 serotype causing bloody diarrhoea. This should be considered in any child coming with diarrhoea and developing pallor and jaundice. Send Stool samples, FBC, blood film and renal function with electrolytes.

1. Reactive complications- arthritis, carditis, erythema nodosum, conjunctivitis, Reiter’s syndrome
2. Guillain Barre syndrome
3. Malnutrition
4. Post-gastroenteritis Syndrome

Occasionally after an episode of gastroenteritis, the introduction of a normal diet results in a return of watery diarrhoea

Oral rehydration therapy should be restarted

Avoid giving fruit juices or carbonated drinks in children with diarrhoea (due to high osmolarity in these drinks) as it can worsen diarrhoea

NOTE: sometimes a temporary lactose intolerance can occur after illness

Question 8

PACES

Answer 8

Name of Diagnosis:
* Suneet has gastroenteritis commonly known as the stomach flu. Have you ever heard of this before?

Briefly explain what it is:
* It is an infection in the tummy which often causes symptoms like tummy pain, vomiting and diarrhoea.

How is it managed:
* From the vomiting and diarrhoea, Suneet has become quite dry and since he is feeding much less than usual, we are going to keep him in hospital

We will try something called a fluid challenge
* This means we are going to give Suneet some fluids to drink to check that he can keep it down.

Once we are sure that he can, we will give him some oral fluids for 4 hours

But if he becomes more dehydrated or he’s unable to keep the fluids down, we may need to give him some fluids through a drip

Risks/Safety net:
* Once Suneet is home, it’s important to keep giving him plenty of fluids
* If he’s still vomiting or has diarrhoea after 2 days or if he becomes drowsy, then please bring him back in
* His appetite will slowly start to come back but in the meantime, give him plain, dry foods like toast
* To stop this infection from spreading, please keep Suneet at home until 48
hours after his symptoms resolve