Key Principles

Oral Route First: Whenever possible, use an enteral (oral) route for fluids. Children who are well with normal hydration will rarely require intravenous (IV) fluids.
Safety: The safe use of IV fluid therapy requires accurate prescribing and careful monitoring, as incorrectly administered fluids can be hazardous.

Indications for IV Fluids

Circulatory support in resuscitating vascular collapse (shock).
Replacement of a previous fluid and electrolyte deficit.
Maintenance of daily fluid requirements.
Replacement of ongoing losses.
Severe dehydration with failed nasogastric (NG) tube fluid replacement.
Certain co-morbidities, particularly GIT conditions (e.g., short gut, previous gut surgery).

Acute gastroenteritis is a leading cause of childhood morbidity, primarily due to dehydration and electrolyte loss. The first step is to assess the perfusion and hydration of the child.

Assessment of Dehydration

Assess	Mild (<5%)	Moderate (5-10%)	Severe (>10%)
General Condition	Well, alert	Restless or irritable	Lethargic or unconscious
Sunken Eyes	No	Yes	Yes
Thirst / Drinking	Drinks normally	Drinks eagerly, thirsty	Drinks poorly or unable
Skin Pinch	Goes back immediately	Goes back slowly	Goes back very slowly (>2s)
TREATMENT	PLAN A	PLAN B	PLAN C

Note: Any child in shock (tachycardia, weak pulses, delayed capillary refill >2s, cold peripheries) should go straight to Plan C.

Treatment Plans for AGE

Plan A: Treat Mild Dehydration at Home

Give Extra Fluids: Use ORS, food-based fluids (soup, rice water), or cooled boiled water. (Up to 2 years: 50-100ml after each loose stool. 2+ years: 100-200ml).
Continue Feeding: Continue breastfeeding or usual formula/solid foods.
When to Return: If unable to drink, becomes sicker, develops fever, or has blood in stool.

Plan B: Treat Moderate Dehydration with ORS

Give a recommended amount of ORS over a 4-hour period. An approximate guide is Child's weight (kg) x 75 = ORS amount in ml.
Give frequent small sips. If the child vomits, wait 10 minutes and continue more slowly.
After 4 hours, reassess dehydration and select the appropriate plan (A, B, or C) to continue treatment.

Plan C: Treat Severe Dehydration Quickly

Establish Airway, Breathing, and Circulation (ABCs).
Start intravenous (IV) or intraosseous (IO) fluid immediately. Provide fluid resuscitation for shock.
Once circulation is restored, commence rehydration, provide maintenance, and replace ongoing losses.
Start giving ORS (approx. 5ml/kg/hour) as soon as the child can drink.

Fluid Resuscitation (For Clinical Shock)

This section applies to children with a fluid deficit sufficient to cause impaired tissue oxygenation (clinical shock).

Initial Action: Correct with a fluid bolus of 10-20 ml/kg.
Reassessment: Always reassess circulation after each bolus and repeat as necessary.
Investigate: Look for the cause of circulatory collapse (e.g., blood loss, sepsis) to guide further fluid choices.
Special Considerations for Bolus:
- Diabetic Ketoacidosis (DKA), Intracranial Pathology, Trauma: Use smaller fluid boluses of 10 ml/kg.
- Associated Cardiac Conditions: Use smaller aliquots of 5-10 ml/kg.

Summary of Prescribed Fluids

Purpose	First-Line Fluid Choice	Alternative (Under Specialist Direction)
Resuscitation	0.9% Normal Saline (as a bolus)	Other crystalloids (e.g., balanced salt solutions) or colloids.
Replacement	0.9% Normal Saline or Hartmann's Solution	N/A
Maintenance	0.9% NaCl + 5% Glucose (+/- KCl 20mmol/L)	0.45% NaCl + 5% Glucose (+/- KCl 20mmol/L) or a balanced solution.

Important: Do NOT use starch-based solutions (i.e., Voluven) as resuscitation fluid. Avoid low-sodium (hypotonic) solutions for resuscitation as they may cause hyponatremia.

Calculating Maintenance Fluid Volume (Holliday-Segar)

This method is used to calculate the required maintenance fluid volume over 24 hours:

First 10 kg of body weight: 100 ml/kg
Second 10 kg of body weight (11-20 kg): 50 ml/kg
Weight over 20 kg: 20 ml/kg

24-Hour Cap: Do not exceed 2.5 L for males or 2 L for females.

Calculating and Replacing Fluid Deficit

A child's water deficit is calculated after estimating their degree of dehydration as a percentage of body weight.

Formula for Deficit (ml): (% dehydration / 100) x Body Weight (kg) x 1000
Replacement Strategy: The deficit is typically replaced over 24 hours in addition to maintenance fluids. Reassess clinical status and weight every 4-6 hours.
Rate of Replacement: Rapid in most cases of gastroenteritis. Slower in DKA and meningitis. Very Slow (48-72 hours) in hypernatremic states (ensure serum sodium does not fall by more than 0.5 mmol/l/hr).

Managing Ongoing Losses

Losses from drains, ileostomies, or profuse diarrhoea must be measured and replaced if they exceed 0.5 ml/kg/hr. Base replacement on losses from the previous 1-4 hours.

Initial Assessment & Ongoing Monitoring

Baseline: Before starting routine IV fluids, measure plasma electrolytes and blood glucose.
Monitoring: Repeat these measurements at least every 24 hours (more frequently for ill patients). Also monitor clinical observation, fluid balance, and weight.
Hypoglycaemia: If present, treat with 2ml/kg of 10% Dextrose.

Risk of Hyponatremia & Water Retention (SIADH)

Some acutely ill children with inappropriately increased anti-diuretic hormone secretion (SIADH) may benefit from fluid restriction. Children at high risk of developing iatrogenic hyponatremia should be given isotonic solutions with careful monitoring. This includes children with:

Peri- or post-operative status
CNS infection or Head injury
Bronchiolitis or Sepsis
Excessive gastric or diarrhoeal losses
Chronic conditions such as cystic fibrosis and pituitary deficits.

If there is a risk of water retention, restrict fluids to 50-80% of the calculated routine maintenance volume.

Guide to Paediatric IV Fluid Management