Tuesday 2 May, 2006

IV rehydration therapy in children

Posted in Emergency Dept., Michael Tam, Paediatrics, Wards at 17:25 by Michael Tam

Index: Intravenous fluid therapy :: Printer friendly

Original article by: Michael Tam

Before you start with intravenous rehydration therapy in children, you should ask yourself the following questions:

  1. Can I use oral rehydration?
  2. Do I need to take blood for blood tests? (if so, do it from the intravenous cannula immediate after insertion)
  3. Do I need to give resuscitation fluids?
  4. Do I need to replace any special / continuing losses for the child?

If you are happy and confident that you need to give intravenous fluids to a dehydrated child, you need to first assess the “degree” of dehydration. A rough guide:

Minimal to mild dehydration (“3% dry”)

  • The child is usually alert and looks well;
  • mostly normal thirst;
  • moist mucous membranes though lips may be dry;
  • normal to slightly decreased urine output (or only slightly less number of wet nappies);
  • less than 3 percent weight loss;
  • normal heart rate;
  • no tachypnoea;
  • good tissue perfusion wtih capillary refill less than 2 seconds;
  • normal skin turgor.

Moderate dehydration (“5% dry”)

  • The child may be irritable and unhappy;
  • increased thirst;
  • dry mucous membranes (though usually still have tears);
  • decreased urine output (less number of wet nappies);
  • normal to slightly tachycardic;
  • normal to slightly tachypnoeic;
  • tissue perfusion is good, but extremities may be cool;
  • capillary refill at or less than 2 seconds;
  • skin turgor normal;
  • may have slightly sunken eyes and fontanelles.

Severe dehydration (“7% dry”)

  • The child is irritable to listless;
  • dry mouth but may be uninterested in oral intake;
  • significantly decreased urine output (dry nappy for most of the day);
  • tachycardia;
  • tachypnoea;
  • tissue perfusion is impaired, cool peripheries – some mottling;
  • capillary refill > 2 seconds
  • skin turgor noticably impaired > 2 seconds

Extreme (dangerous / pre-arrest) dehydration (“> 7% dry”)

  • The child is listless to unconsious;
  • dry mucous membranes, no tears;
  • minimal to no urine output;
  • significant tachycardia with weak thready pulse;
  • significant tachypnoea;
  • cool mottled skin peripherally and centrally (on chest and abdomen);
  • capillary return significant impaired > 2 seconds
  • skin turgor significantly impaired > 2 seconds
  • sunken eyes and fontanelles.


Extreme dehydration and severe dehydration

  • The child should be given fluid resucitation.
  • Boluses of 10-20 mL/kg of 0.9% NaCl solution until clinically stable and then procede to below.

Moderate and mild dehydration

  • Plan to replace fluids and return to euvolaemia over 24 hours.
Replacement fluids (up to 5% dry)

Volume of fluid (mL/day) = “Percentage dry” x weight (kg) x 10


8 week old infant, 5.5 kg, 3% dehydrated

Replacement fluid:

  • 3 x 5.5 x 10 (in mL/day)
  • = 165 mL/day
  • ~ 7 mL/hr

Maintenance fluid:

  • 4 mL/kg/hr x 5.5 kg
  • = 22 mL/hr

Total IV fluid infusion rate:

  • replacement fluid + maintenance fluid
  • = 7 + 22 mL/hr
  • = 29 mL/hr

Fluid type in dehydration

Traditionally, you would have used 0.45% NaCl + 2.5% dextrose + 10 mmol KCl (in a 500 mL bag) and this is still a valid choice. However, there is reasonable evidence now that especially in children with gastroenteritis, that there is increased secretion of anti-diuretic hormone (ADH) (1) and that in some children, using “half normal saline” can precipitate hyponatraemia.

There is evidence through a trial of children with gastroenteritis (2) at the Sydney Children’s Hospital (Randwick), that rehydration with “normal saline”, i.e., 0.9% NaCl, is protective against hyponatraemia and does not appear to cause hypernatraemia.

Research articles

(1) Neville KA. Verge CF. O’Meara MW. Walker JL. High antidiuretic hormone levels and hyponatremia in children with gastroenteritis. Pediatrics. 116(6):1401-7, 2005 Dec.

(2) Neville KA. Verge CF. Rosenberg AR. O’Meara MW. Walker JL. Isotonic is better than hypotonic saline for intravenous rehydration of children with gastroenteritis: a prospective randomised study. Archives of Disease in Childhood. 91(3):226-32, 2006 Mar.

Updated: Michael Tam (19 June 2006)

Please read the disclaimer


  1. Kelly Gate said,

    What about hypokalaemia when using NaCl as a rehydration fluid. Do you advise adding extra K+ to the infusion if the child K+ borders on the lower end of normal

  2. Michael Tam said,

    Yes. 10 mmol KCl in a 500 mL bag.


  3. reycalitis19 said,

    good day sir! could you kindly explain for me what is “D5IMB” and “D10IMB” which was a solution of D5050 and D5IMB?..thank you and hoping for your quick reply..im a 3rd year nursing student-philippines.

  4. Michael Tam said,

    I’ve never seen that acronym before in Australia so I don’t know. A search with Google seems to indicate that this is a specific Filipino used term.

  5. Eliza said,

    the formula u are using to calculate maintanance fluid is it the same when you use 100mls for first 10kg the 50mls for the next 10kg and 20mls for other kgs

  6. MARIA said,

    Can you help me with this What is the manintenance IVF rate for an 8 Kg child?

  7. MARIA said,

    What is the preferred IV fluids for a Pediatric pt whose lelectrolytes are normal?
    Thanks, waiting with your help.

    • Jay Carl Del Rosario said,

      NSS is my first choice for IV Fluid for those Pediatric Patient with normal electrolytes.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: