Gastroenteritis in Infancy & Childhood

1. Gastroenteritis in Infancy & Childhood Dr Jonny Taitz Sydney Children’s Hospital, Randwick April 2003

2. Introduction • Very common problem in Paediatrics • Causes Diarohea, vomiting & fever • Usually viral • Rotavirus, Adenovirus, Enterovirus • Bacterial • E-coli, Shigella, Salmonella, Yersinia, Campylobacter • Parasitic • Giardia, Entomeba

3. What is Gastroenteritis? • Damage to gut mucosa • Disturbance of balance between mechanisms controlling secretion & absorption • Net effect = Diarohea • Most cases self limiting with full recovery • BUT small proportion  • Severe dehydration + • Electrolyte abnormalities • Shock, cerebral oedema + • Death

4. Review of Dehydration • Weight changes are still the most accurate • 3% Mild (oral, breast, gastrolyte) • Thirst is first •  Urine output • Dry mucous membranes • 5% Moderate(oral/nasogatric, breast/gastrolyte, consider IV) •  Urine output • Obviously dry mucous membranes • Sunken eyes & fontanelle • Tachycardia (mild)

5. Review of Dehydration (contd) • 7% Moderate-Severe (IV N/2 or N saline) • Severe tachycardia • Apathetic •  Turgor • Sunken eyes & fontanelle 10% Severe (N saline bolus 10-20 mls/kg then n/2 or N saline) • = Shock • Circulatory failure • Altered consciousness • Small volume pulses • NB hypotension is a late sign

6. Principles of Fluid Management • Enteral route preferable to parenteral route for mild/moderate dehydration • Oral rehydration therapy (oral or nasogastric) • Breast, dilute fruit juice • Hydrolyte ice-block & parent’s chart • Aim • 1 ml/kg every 10 mins or 5 ml/kg very hour • For moderate or severe dehydration IV access & fluids required

7. Principles of Fluid Management • Shock • Rx aggressively • 10 – 20 mls/kg IV Bolus over 10-20 mins • Use normal saline • DO NOT USE ½ or ¼ saline !!!

8. Principles of Fluid Management • Rehydration • This can be done slowly usually over 24 hrs • If hyponatremic aim for 48 hrs • AVOID RAPID FLUID SHIFTS !!! • No magic bullet • Careful regular assessment is the key

9. 3 Fluid Types • Maintenance • Rehydration • Ongoing losses

10. Maintenance • Age & weight dependent • 1st yr - 120 mls/kg/day • 2nd yr - 100 mls/kg/day • 2-4 yrs - 85 mls/kg/day • 4-6 yrs - 70 mls/kg/day • > 6 - adult • I.e 1 yr old 10kg infant Needs  120 mls x 10kg x 24 hrs = 1200 mls maintenance

11. Rehydration • Depends on fluid deficit • 5% = 50 mls/kg/day • 3% = 30 mls/kg/day • Same 10kg infant 5% dry = 50 mls x 10 x 24 hrs = 500 mls/day rehydration fluid

12. Ongoing Losses • Not part of guidelines • But in profuse, watery diarohea add 10-20 mls/kg/day to account for regular losses

13. Which Rehydration Fluid to Use • SIMPLE • N/2 • N Saline • New evidence • N saline probably the best (SCH) • Na+  130 mmols  N Saline

14. What about Electrolyte Imbalance • Initially EUC, BSL if 5% or more dehydrated • VBG if shocked • Repeat if markedly abnormal / child not improving • Na+ < 132 mmol/l or > 145 mmol/l • K+ < 3 or > 5.5 mmol/l

15. Pitfalls • Watch the salt !!! • Evidence that SIADH occurs with gastroenteritis • Changes to serum Na+ can lead to cerebral oedema, seizures & death • Do not forget the Potassium • Once urine passed  add 3 mmol/kg/day • May require up to 5mml/kg/day if hypokalaemic •  Add 10 mmol KCl / 500 mls fluid

16. Pitfalls (continued) • Be Sweet  add Dextrose • Particularly in younger children • New evidence 2.5% Dex should be sufficient • Milk (if tolerated) is better then intravenous fluid for the patient and the gut mucosa

17. Medications • No indications for • Anti-vomiting • Anti-diaroheal • Anti-motility • Antibiotics only for proven bacterial gastroenteritis

18. Differential Diagnosis • Think of other options: • Abdo distension • Bile stained vomiting • Fever > 39oC • Vomiting, but NO Diarohea • Blood in Urine/stool } Bowel obstruction strangulated hernia - Sepsis, Meningitis, Dysentry, UTI - UTI, Meningitis, DKA, raised intracranial pressure - IBD, HUS, Dysentry

19. Questions