Gastroenteritis (paeds)

Question 1

What is the definition of diarrhoea?

Answer 1

Change in the consistency of stools (loose or liquid), and/or increase in the frequency of evacuations (typically >3 in 24 hours), with or without fever or vomiting which lasts less than 7 days and not longer than 14 days

Question 2

What are the most common infective causes of acute diarrhoea in children in developed countries?

Answer 2

Viruses:
Rotavirus (25-40%)
Calcivirus (1-20%)

Bacteria:
Camyplobacter jejuni (4-8%)
Salmonella (3-7%)
E.coli (2-5%)

Parasites: 
Giardia lamblia (1-3%)

Question 3

What other (non-GI) infections can cause diarrhoea in children?

Answer 3

Otitis media, tonsillitis, pneumonia, sepsis, UTI, meningitis

Question 4

How does gastroenteritis present?

Answer 4

Diarrhoea +/- blood (e.g. in dysentry)

Fever +/- vomiting

Dehydration and reduced consciousness

Question 5

How do you assess for significant dehydration? (>5%, approaching shock levels)

Answer 5

Best indicators are prolonged capillary refill time, abnormal skin turgor (slow = skin fold visible for <2s; very slow = >2s) and absent tears

<5% dehydration has no reliable clinical findings

Other possible findings = restlessness/irritability, sunken eyes, thirst (5%); then lethargy, drop in LOC, mottled/pale skin, cold extremities, weak pulses, tachycardia/pnoea (10%)

Question 6

How do you investigate gastroenteritis?

Answer 6

Stool microbiology if: suspected sepsis, blood/mucous in stool, child is immunnocompromised; consider for recent travel, nil improvement by day 7 or uncertain about Dx

Bloods: U+E (hypernatraemic dehydration?), Glu, renal function etc.

Question 7

What is hypernatraemic dehydration?

Answer 7

Serum Na >145 mEq/L

Characterized by a deficit of total body water (TBW) relative to total body sodium levels likely secondary to loss of free water - water shifts from intra-extracellular

Uncommon but serious

Presentation:
Irritable
Characteristic doughy skin 
Jittery movements 
Increased tone, hyperreflexia 
Convulsions 
Drowsiness or coma 

Slow rehydration is essential

Question 8

How do you manage gastroenteritis?

Answer 8

Supportive - with fluids, pain relief if needed, probiotics

Antibiotics - bacterial GE can become septic

No antiemetics or anti-motility drugs

Question 9

What is chronic diarrhoea?

Answer 9

> 2wks

Continued infection with first pathogen or concomitant infection

May also be other non infective reason - reassess diagnosis (food intolerance, malabsorption etc.)