maintainance & replacement fluid therapy pediatrics ag

MAINTENANCE

&

REPLACEMENT

FLUID THERAPY

Moderated By Dr.Madhuri Engade

Presented By Dr.Akshay

OBJECTIVES

To know the difference in physiology of children.

To know the Goals of maintenance fluid therapy.

Able to Calculate total fluid requirement & do monitoring of the patient.

To know Variations in maintenance water & electrolytes.

To order Replacement fluids in “common” situations.

WHY THE INFANTS ARE MORE VULNERABLE?*

Physiological inability to concentrate urine.

Higher metabolic rate & larger surface area.

Cant express thirst for more fluids.

Larger turnover.

*IAP text book of Pediatrics 5th edition

WHOM TO GIVE MAINTENANCE FLUIDS?

Infants who are sick & whose oral intake is

uncertain.

Babies who are kept NBM for the surgery, with

respiratory distress etc.

neonates kept under radiant warmer.

GOALS OF MAINTENANCE FLUIDS*

Prevent dehydration

Prevent electrolyte disturbance

Prevent ketoacidosis

Prevent protein degradation

*Nelsons Text book of pediatrics 19th edition

AT BIRTH…

75 % of the total body weight

Obligatory diuretic phase


Next 2 – 3 Days

At the end of Ist year


BACK TO PHYSIOLOGY…

Total Body Water 60%*

Intra cellular fluid

(ICF)

40%

Extra cellular fluid

(ECF)

20%

Interstitial

15%Intravasular

5%


What osmolarity means…

What tonicity means…

DISTRIBUTION OF BODY WATER

Intravascular (5%)

Interstitial (15%)

Intracellular (40%)ICF

ECFNa+

K+

Cl-

ELECTROLYTE CONCENTRATIONS

Component ECF ICF

Na+ High Low

K+ Low High

Ca++ Low Low (higher than ECF)

Proteins High High

KEY LEARNING POINT*

Sodium is the Principle electrolyte in ECF

[140mEq/L (+/- 5)]

Potassium is the Principle electrolyte in ICF

[150mEq/L (+/- 5)]


Maintenance fluids consists of-

i. Water

ii. Glucose

iii. Sodium

iv. Potassium

Advantages –

Simplicity, long shelf life, low cost, compatibility.

Prototypical maintenance therapy fluid doesn’t

provide calcium, phosphorus, magnesium or

bicarbonate.*


FLUID LOSSES IN INFANTS

LUNGS

URINE, FECES SKIN

CONCEPT OF MAINTENANCE OF WATER

Crucial component of maintenance fluid therapy.

Maintenance water = Measurable loss of water 65%

(Urine 60%, stools 5%) + Insensible of water 35% (skin

& lungs)

FOR NEONATES

Day 1 60 ml/kg/day

Day 2 90 ml/kg/day

Day 3 120 ml/kg/day

Day 4 150 ml/kg/day (maximum for term infants)

Day 5 to 3 months 150 ml/kg/day

MAINTENANCE REQUIREMENTS*

Weight Requirement

0-10 kg 100cc/kg/24hr

11-20 kg 1000 + 50cc/kg/24hr

>20 kg 1500 +

20cc/kg/24hrUpper limit 2400cc/24hrs


Maintenance Fluids

Hourly Maintenance Fluid Requirement*

“4 - 2 -1 rule”

WEIGHT FLUID

0 - 10 kg 4 ml/kg/hr

10 - 20 kg 40ml/hr + 2 ml/kg/hr

> 20 kg 60ml/hr + 1 ml/kg/hr

Upper limit 100cc/hr


CONCEPT OF MAINTENANCE OF

ELECTROLYTES

Insensible water loss contains no electrolytes*

So, sodium & potassium present in the urine, stools

& sweat would be the amount to be replaced plus

the sodium & potassium required for normal

metabolism of the body.

3mEq of sodium in 100 cc of fluid

&

2mEq of potassium in 100 cc of fluid


Maintenance fluids usually contains 5% dextrose (5

gm/100ml) providing 17 calories/ 100 ml of fluid.

Which is approx. 20% of the daily caloric needs.

Prevents ketone production.

CONCEPT OF MAINTENANCE OF GLUCOSE*


COMMONLY USED FLUIDS FOR

MAINTENANCE*

I. 0.9% Normal Saline – Think of it as ‘Salt and water’ Principal fluid used for intravascular resuscitation and replacement of

salt loss e.g diarrhoea and vomiting

Contains: Na+ 154 mmol/l, Cl- - 154 mmol/l; K+ - Absent, But K+ is often added

IsoOsmolar compared to normal plasma

Distribution: Stays almost entirely in the Extracellular space

Does not provide free water or calories. Restores NaCl deficits.

*The Harriet Lane Handbook 19th edition

CONTENTS OF IV FLUID PREPARATIONS*Na

(mEq/L)

K

(mEq/L)

Cl

(mEq/L)

HCO3

(mEq/L)

Dextrose

(gm/L)

mOsm/L

NS 154 154 308

DNS 154 154 50 564

½ NS 77 77 143

5%D +

1/2NS

77 77 50 350

D5W 50 278

Ringers

Lactate

(RL)

130 4 109 28 50 273

Iso P 23 20 23 30 50 367

Iso M 37 35 37 30 50 415.5

*The Harriet Lane Handbook 19th edition

II. Lactated Ringer’’s (RL): Isotonic, 273 mOsm/L.

Contains 130 mEq/L Na+, 109 mEq/L Cl, 28 mEq/L lactate, and 4 mEq/L K+, 3 mEq/L Ca++

Lactate is used instead of bicarb because it's more stable in IVF during storage.

Lactate is converted readily to bicarb by the liver.

Has minimal effects on normal body fluid composition and pH. More closely resembles the electrolyte composition of normal blood serum.

Does not provide calories.

COMMONLY USED FLUIDS FOR MAINTENANCE

HOW TO CHOOSE?*0.9% sodium chloride Suitable for initial volume resuscitation in hypovolaemia

and for ongoing fluid therapy in older children with

normal serum glucose. Fluid of choice in patients with

head injury

5% dextrose + 0.9%

sodium

chloride

Suitable for ongoing fluid therapy in infants and

children, including post-operative cardiac patients. Use

in head injured patients with hypoglycaemia.

5% dextrose + 0.45%

sodium

chloride

Suitable for ongoing fluid therapy in infants and

children, including post-operative cardiac patients

10%dextrose + 0.45%

sodium

chloride

Suitable for ongoing fluid therapy in neonates or older

infants who are hypoglycaemic, including post-operative

cardiac patients

*Leeds Teaching Hospitals NHS Trust Paediatric Intensive Care Units

MONITORING WHILE ADMINISTERING FLUIDS*

Child should be weighed prior to the commencement of

therapy, and daily afterwards.

Children with ongoing dehydration/ongoing losses may

need 6 hourly weights to assess hydration status

All children on IV fluids should have serum electrolytes

and glucose checked before commencing the infusion

(typically when the IV is placed) and again within 24 hours

if IV therapy is to continue.

*Royale Children’s Hospital Melbourne Guidelines

MONITORING WHILE ADMINISTERING FLUIDS*

For more unwell children, check the electrolytes and

glucose 4-6 hours after commencing, and then according

to results and the clinical situation but at least daily.

Pay particular attention to the serum sodium on measures

of electrolytes. If <135mmol/L (or falling significantly on

repeat measures) If >145mmol/L (or rising significantly on

repeat measures)

Children on iv fluids should have a fluid balance chart

documenting input, ongoing losses and urine output.


MAINTENANCE FLUIDS & HYPONATREMIA*

Production of ADH leading to water retention leading to water intoxication.

Patients producing ADH due to subtle volume depletion can be safely treated with fluids containing higher sodium concentration, decrease in fluid rate or the combination of both.

Persistent ADH production due to underlying disease requires less than total maintenance fluids

Individualization & careful monitoring is must.


VARIATIONS IN MAINTENANCE WATER &

ELECTROLYTESSource Causes of increased water

needs

Causes of decreased water

needs

Skin Radiant warmer Incubator

Phototherapy

Fever

Sweat

Burns

lungs Tachypnea Humidified ventilator

Tracheastomy

GI tract Diarrhea

Vomiting

Nasogastric secretion

renal Polyuria Oligo/anuria

Misc. Surgical drain hypothyroidism

Third spacing

REPLACEMENT FLUIDS*

In addition to normal maintenance fluid

requirements, unwell children may need:

Fluid resuscitation for shock

Replacement of pre-existing fluid losses

Replacement of ongoing fluid losses


REPLACEMENT FLUIDS*

GI losses are accompanied with loss of potassium,

bicarbonate leading to metabolic acidosis.

Impossible to predict the loses for next 24 hrs, so

measure & replace excess GI losses as they occur.

So each ml of the diarrheal stool or the vomitus

should be replaced by the same amount every 1 to

6 hourly.


REPLACEMENT FLUIDS

Replacement fluid for Diarrhea*

Average composition of Diarrheal stools (except cholera)

Na 55 mEq/l

K 25 mEq/l

Bicarbonate 15 mEq/l

Approach to Replacement of Ongoing Losses

D5 0.2% NS + 20 mEq/l sodium bicarbonate + 20 mEq/l KCl

Replace stools ml/ml every 1 to 6 hrs


REPLACEMENT FLUIDS

Replacement fluid for Emesis or Nasogastric losses*

Average composition of Gastric Fluid

Na 60 mEq/l

K 10 mEq/l

Chloride 90 mEq/l

Approach to Replacement of Ongoing Losses

NS + 10 mEq/l KCl

Replace Output ml/ml every 1 to 6 hrs


REPLACEMENT FLUIDS

Replacement fluid for Altered Renal Output*

Oligouria / Anuria

Place patient on insensible fluids (25 to 40% of maintenance)

Replace Urine output ml/ml by half NS

Polyuria

Place patient on insensible fluids (25 to 40% of maintenance)

Measure urine electrolytes

Replace Urine output ml/ml by solution based on measured urine

electrolytes


CASE I

5 day old baby boy weighing 3 kg having total

billirubin 18.0 is to be kept under phototherapy.

Baby having no other risk factors & accepts DBM

well.

What fluid at what rate should we prescribe?

Rate Day 5 (150 ml/kg/day)

Weight 3 kg

So,

150 * 3 = 750 ml is the total maintainence.

For the babies under phototherapy we should give half of the maintainence.

So 375 ml/24 hrs i.e 125 ml / 8hrly

Fluid of choice is 5% dextrose + 0.45% NS or iso P will also be suitable.

CASE II

7 year old girl (weight 20 kg) admitted for

bronchopneumonia with respiratory rate of 44/min &

fever of 102 F. later developed 4 episodes of

vomiting (each of 25 ml quantity) & loose stools 3

episodes (each of 80 ml quantity)

Weight 20 kg.

So, Total maintenance fluid will be

(100*10) + (50*10) = 1500 ml/ day i.e 500 ml / 8 hrly

Choice of fluid will be 0.45% DNS + 20mEq/L KCl

Replacement fluid for vomiting (each of 25 ml quantity) =

25 * 4 =100 ml of NS + 10 mEq/l KCl

Replacement fluid for loose stools (each of 80 ml

quantity) = 80 * 3 =240 ml of 0.2% DNS + 20 mEq/l

sodium bicarbonate + 20 mEq/l KCl.

TACHYPNEA

Respiratory Alkalosis

Increase in rate and depth of breathing

Loss of CO2

Causes of hyperventilation (tachypnea): Fear, pain, fever, CHF, anemia

FEVER

Each degree of fever increases basal

metabolic rate (BMR) 10%, with a

corresponding fluid requirement

VOMITING Metabolic Alkalosis

Loss of acid from stomach

pH

HCO3

H+

Treatment: Prevent further losses and replace lost electrolytes

DIARRHEA

Metabolic Acidosis

loss of HCO3 from G.I. Tract

pH

HCO3

Treatment: Correct base deficit, replace losses of with NaHCO3

TAKE HOME MESSAGE

Fluid is like “prescription” so give it with caution.

Children are more vulnerable for rapid fluid loss.

Maintenance calculation by “4-2-1” rule or Holliday Segar’s formula.

Vigilant Monitoring of WEIGHT, URINE OUTPUT, SERUM SODIUM CONCENTRATION while giving fluid is must.

As far as possible try to give maintenance fluid requirement orally.

0.45% DNS + 20 mEq/l KCl is ideal fluid in most of the children requiring maintenance therapy.

Replacement of fluids should be prompt & appropriate.

!! THANK YOU !!

maintainance & replacement fluid therapy pediatrics ag

Health & Medicine

iap text book of pediatrics

maintenance water electrolytes

goals of maintenance

editionconcept of maintenance

cc of fluid

total fluid requirement

replacement fluids

physiologytotal body