Basic Principles of Fluid and Electrolyte Therapy in Paediatric Surgery

1. Fluids and Electrolytes
Therapy in Paediatrics
Arravindh Vivekananthan

2. Body Composition
Water; main constituent of the body.
Initially, fetus has high TBW.  Term infant has 75%.
1st
year of life; decreases to 60%, maintains till puberty.
MALE (60%) vs FEMALE (50%)

3. • Normal daily fluid requirements for children are higher than
those of adults due to greater insensible losses.
• Infants a limited ability to concentrate urine due to immature
kidneys.
• Total body water is a higher percentage of body weight
(75% in children vs. 60% in adults)
• Postoperative fluid replacement should be adjusted to support
urine output between 1 and 2 mL/kg/hour.

4. Total
Body
Water
Composition of Solute
ICF
Potassium, protein, phosphate
_______________________
Na+,K+-ATPase pump
-----------------------------------
ECF
Sodium, Chloride

5. Maintenance Fluid
• Maintenance intravenous (IV) fluids are used in children who cannot be fed
enterally.
• Maintenance fluid is the volume of daily fluid intake.
• Maintenance fluids are composed of a solution of water, glucose, sodium,
potassium, and chloride. This solution replaces electrolyte losses from the
urine and stool, as well as water losses from the urine, stool, skin, and lungs. EX :
Normal saline, ringer lactate

6. provides approximately 20% of the normal caloric needs of the
patient.
to prevent the development of starvation ketoacidosis and
diminishes the protein degradation.

7. Measurable/non- measurable

9. • 5% dextrose (D5) in 1⁄4 normal saline (NS) + 20 mEq/L of
potassium chloride (KCl)
• D5 in 1⁄2 NS + 20 mEq/L of KCl.
• high risk of hyponatremia should be given isotonic solutions
(i.e. 0.9% saline ± glucose)
• Daily potassium requirements are 1 to 2 mEq/kg.
• Daily sodium requirements are 2 to 3 mEq/kg.
Children weighing <10 kg/6 mo. do best with the solution
containing 1⁄4 NS (38.5 mEq/L) because of their high water
needs per kilogram. In contrast, >10 kg/6 mo. may receive

11. DEHYDRATION AND REPLACEMENT
THERAPY
Normal source of water
loss

12. clinical situations
1.premature infants
2.BURN : FLUID/ELECTROLYTES
3.FEVER : INSENSIBLE LOSS
4.EVAPORATIVE LOSS
5.DM, D.Insipidus, ATN
6.Drains; measured, replaced
7.Edema,ascites. Cant quantify, but
anticipate in burn, abd. surgeries

13. • Studies indicate that clear liquids ingested 2 hours before induction of
anesthesia do not increase the risk of aspiration in children at normal risk
of aspiration during anesthesia.
• In addition, children permitted fluids in a less restrictive fashion have a
more comfortable preoperative experience in terms of thirst and hunger
(Cochrane Database Syst Rev. 2009;(4):CD005285).
Nil-by-Mouth Status.

14. DEFICIT
assess the degree of dehydration  urgency of the situation and the
volume of fluid needed for rehydration

15. Hypotension indicates  organ hypoperfusion  Shock
immediate and aggressive intravenous therapy is indicated

16. Minimum urine output
hould be 1-2 mls/kg /hr.

17. Calculation of Fluid Deficit
percentage of dehydration multiplied by the patient’s weight
(for a 10-kg child, 10% x 10 kg =1 L deficit)
rapid restoration of the circulating intravascular volume, which should be done
with an isotonic solution, such as normal saline (NS) or Ringer’s lactate.

18. • fluid bolus, usually 20 mL/kg of the isotonic solution, over about 20 minutes.
• severe dehydration may require multiple fluid boluses and may need to receive fluid
at a faster rate.
Improvement of vital signs plan the fluid therapy for the next 24 hours

19. To ensure that the intravascular volume is restored,

20. Ongoing losses (e.g. from drains, ileostomy, profuse diarrhea)
• These are best measured and replaced. Any fluid losses > 0.5ml/kg/hr needs to
be replaced.
• Calculation may be based on each previous hour, or each 4 hour period
depending on the situation. For example; a 200mls loss over the previous 4
hours will be replaced with a rate of 50mls/hr for the next 4 hours).
• Ongoing losses can be replaced with 0.9% Normal Saline or Hartmann’s
solution. Fluid loss with high protein content leading to low serum albumin (e.g.
burns) can be replaced with 5% Human Albumin.

21. References
1. Nelson Essentials of Pediatrics, 7th
Edition
2. PAEDIATRIC PROTOCOLS For Malaysian Hospitals, 3rd
Edition
3. The Washington Manual of Surgery, 6th
Edition 2012
4. CHAPTER 5 : Fluids and Electrolyte Therapy in the Paediatric Surgical Patient by
Mark W. Newton, Berouz Banieghbal, Kokila Lakhoo