Fluid , electrolyte and nutritional
requirements for neonates
Presented by : Maram Mobara
FEN Management in Neonates
One of the essentials of neonatal care
Many babies in NICU need IV fluids
They all don’t need the same IV fluids
(either in quantity or composition)
Things to consider:
Normal changes in TBW, ECF
• the body is composed mainly of water
• body water in early embryo represent 97%
of body weight
• premature infants body water represent
80-90% of their weight
• newborn infant 77%
• adult 60%
So, All babies are born with an excess of TBW,
mainly ECF, which needs to be removed
ECF in infant is 40%of body weight
in adult 20%
as the child grows,, there is muscle growth and
cellular growth ,, more water shifts from ECF
to ICF compartment
infant has less reserve of body fluid ,, more
likely to develop fluid volume deficits
the infant needs more water due to ;
1.large body surface area
2.immature kidneys which cannot concentrate
urine effectively high UOP
Things to consider:
Insensible water loss (IWL)
“Insensible” water loss is water loss that is not
obvious through skin (2/3) or respiratory
tract(1/3)
• depends on gestational age (more preterm:
more IWL)
• depends on postnatal age (skin thickens with
age: older is better --> less IWL)
• also consider losses of other fluids: Stool
(diarrhea/ostomy), NG/OG drainage, CSF
(ventricular drainage), etc
Management of F&E
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Goal: Allow initial loss of ECF over first week
(as reflected by wt loss), while maintaining
normal intravascular volume and tonicity (as
reflected by HR, UOP, lytes, pH).
Subsequently, maintain water and electrolyte
balance, including requirements for body
growth.
Individualize approach
TFI = Maintenance requirements
(IWL+Urine+Stool water) + growth
In the first few days, IWL is the largest
component
Urine: 60 cc/kg/day
Stool: 5-10 cc/kg/day
Growth: 20-25 cc/kg/day (since wt gain is
70% water)
Management of F&E (contd.)
Guidelines for fluid and electrolyte therapy
Fluid rate ml/kg/d
electrolyte meq/kg/d
Term infant
1st day
2nd &3rd
4th
Dextrose10%
60-80
+10-20
+20
Sodium
-
2-4*
2-4*
Potassium
-
1-2 *
2-4*
60-80ml/kg/day will provide 6-7 mg/kg/min of glucose
Factors modifying fluid requirement:
•Maturity --> Mature skin --> reduces IWL
•Elevated temperature (body/environment)-->
increases IWL
•Humidity: Higher humidity --> decreases IWL
up to 30% (over skin and over respiratory
mucosa)
•Skin breakdown, skin defects (e.g.
omphalocele)--> increases IWL (proportional to
area)
•Radiant warmer --> increases IWL by 50%
•Plastic Heat Shield --> reduces IWL by 1030%
•Phototherapy --> increases IWL by 50%
Monitoring of fluid and electrolyte status;
should be done daily for
1.body weight; loss >20%of birth weight during
first week of life = uncompensated IWL , <
2% for first 4-5 days = excessive fluid
administration
2.serum level of ; hematocrit, Na+,K+, BUN,
creatinine, osmolarity, acidosis and base
deficit,, if increased may indicate inadequate
fluid tx
3.fluid input, output; UOP <1ml/kg/hr may
indicate need to increase fluid intake,,,
>3ml/kg/hr may indicate overhydration
4.general appearance and vital signs;
hypotension, poor perfusion, poor pulses all
are signs of inadequate fluid intake
Common electrolyte problems :
Sodium:
Hyponatremia (<127mEq/L)
Hypernatremia (>145 mEq/L)
Potassium:
Hypokalemia (<3.5 mEq/dL)
Hyperkalemia (> 5.5 mEq/dl)
Calcium:
Hypocalcemia (total<7 mg/dL; i<4)
Hypercalcemia (total>11mg/dL; i>5)
Hyponatremia : < 127mEq/l
Sodium levels often reflect fluid status
rather than sodium intake
ECF Excess
Excess IVF, CHF,
Sepsis, Paralysis
ECF Normal Excess IVF,
SIADH, Pain,
Opiates
ECF Deficit Diuretics, NEC
(third spacing)
Restrict
fluids
Restrict
fluids
Increase
sodium
intake
Management :
If baby have seizure:
Emergency
1. hypertonic saline solution (3% sodium chloride )
2.Calculate deficit , give half over 12-24 hour
3.Rapid correction result in brain damage
If due to volume over load : fluid restriction,
decrease maintenance by 20 ml/kg/d
If due to inadequate sodium intake:
• check formula
1.equation: desired level – (sodium
value*weight*0.6(
2.Give for 12-24 hour
Hypernatremia: > 145 mEq/l
•Hypernatremia is usually due to excessive IWL
in first few days in VLBW infants
•Increase fluid intake and decrease IWL.
•Rarely due to excessive hypertonic fluids
•Decrease sodium intake
Potassium
•Potassium is mostly intracellular: blood levels
do not usually indicate total-body potassium
• pH affects K+: 0.1 pH change=>0.3-0.6 K+
change
(More acid,more K;less acid, less K)
• ECG affected by both HypoK and HyperK:
Hypok: flat T, prolonged QT, U waves
HyperK: peaked T waves, widened QRS,
bradycardia, tachycardia, SVT, V tach, V
fib
Hypokalemia : < 3.5 mEq/dl
arrhythmia ( Diuretics / digitalis ?)
how much receiving by maintenance ?
Diarrhea ? NGT tube output ?
Ileus
Repeat measurement
Renal K+ ( Barrter’s syndrome)
Blood gas level
X-ray
ECG
Tx the cause , slow correction over 24 hr ,
decrease dose once reach high normal level
Hyperkalemia: > 5.5 mEq/dl
•How was the specimen collected ?
•How much is infant receiving ?
•ECG changes ?
•BUN & creatinine ? UOP?
•Blood gases ? Acidosis cause k+ to move
out of the cell
•Tissue necrosis ,NEC (x-ray)
Stop all fluids with potassium
Calcium gluconate 1-2 cc/kg (10%) IV
Sodium bicarbonate 1-2 mEq/kg IV
Glucose-insulin combination
Lasix (increases excretion over hours)
kayexalate, potassium exchange resin 1g/kg/dose
po/rectally (slow action)
Dialysis/ Exchange transfusion
Metabolic alkalosis caused by electrolyte loss,
specifically chloride,
occur with prolonged gastric suction or vomiting
and is easily corrected by replacement of the
appropriate electrolyte
So look for electrolyte loss espcially chloride and
potassium and correct deficiet
If due to prolonged suction , IV fluid transfusion
with ½ normal saline + 20 meq kcl
Metabolic acidosis is usually the result of
poor tissue perfusion and lactic acidosis.
treat the underlying cause of the poor
perfusion and by temporarily administering
buffers, such as sodium bicarbonate, which is
usually done when the pH falls below 7.3.
use this formula to give the dose:
NaHCO3 (mmol) = base excess x body
weight (kg)/3
Hypocalcemia: total<7 mg/dL; i<4
Normal physiology:
3rd trimester Ca from mother
1-2 days of life drop to 7.5 (loss of source,
calcitonin)
3rd day normal ca level (gradual increase in PTH)
In ECF has 3 forms : bound to albumin / anions
ionized 50% : impo. for
coagulation, enzymes, cell membrane,
neuromuscular excitability
Clinically
( DOESN’T correlate with severity)
• no symptoms
• Lethargy, Poor feeding, Vomiting, Abdominal
distension
• Cyanosis, stridor
• Seizures
• Apnea
• Tetany and signs of nerve irritability,
Chvostek sign, carpopedal spasm, Trousseau
sign
• Prematurity, birth asphyxia
• ECG, prolonged QTc (>0.4 s), a prolonged ST
segment, and T wave abnormalities may be
observed
Causes of hypocalcemia
Early neonatal hypocalcemia (48-72 h)
Late neonatal
hypocalcemia (3-7 d)
•Prematurity:.
•Birth asphyxia: renal insuff. ,
•Exogenous
phosphate load: PTH
feeding
metabolic
acidosis,decreased
with phosphate-rich
•Diabetes
mellitus in theformula
mother or
:
milk.
increased req. cow's
by macrosomic
baby
•Magnesium deficiency
•Transient hypoparathyroidism of
newborn
•Hypoparathyroidism due to other
causes
Management
•Screen high risk group (4 mg/kg/d of 10% calcium
gluconate)
•symptomatic patient :Bolus Calcium gluconate (10%
solution) is given IV at 1-2 ml/kg (100 mg/kg) slowly .
Maintenance therapy is given at 200 mg/kg/day IV and
increased as needed to maintain serum calcium level at 7 to
8 mg/dl.
•Should be diluted with 5% dextrose, under cardiac
monitor ( bradyarrhythmia) in NICU
•Look for the cause :
•Mg :HypoCa may not respond to calcium therapy if hypoMg
is not corrected (by 0.2ml/kg of 50 % solution )
•low serum albumin concentration and abnormal pH
•Serum electrolytes and glucose (exclude)
•Phosphorus
•PTH
HYPOGLYCEMIA
Blood sugar level < 40mg/dl ----- 2.2mmol
Send for lab result
Is infant symptomatic? apnea, hypotonic, cyanosis, seizures,
lethargy, temp. instability
How much is infant receiving? Normal requirement 6mg/kg/hr
Possible causes:
Premature ( decrease glycogen stores), IUGR
Diabetic mother( b cell hyperplasia), Beckwith W. syndrome,
tumors
Sepsis
Hypothermia
Asphyxia
Endocrine disorders
Plan
Maintain NORMOglycemia
Send for baseline glucose level
Asymptomatic w glucocheck < 25
mg/dl
IV access 20-40mg/dl
Glucocheck
Give glucose
Feeding
w D5W
6mg/kg/hr
Check every 30 min
If stays low
Increase
gradually
start infusion
until NORMO
6mg/kg/hr
Bolus # in asymptomatic (rebound
hyper)
Symptomatic patient :
Baseline serum level
Infusion of2-4 ml/kg of 10% glucose
solution over 2-3min
Continuous infusion at rate of 6-8ml/kg/min
Check every 30 min
Until 40 mg/dl serum glucose level
Maintain normoglycemia
Goals: Normal growth and development
Nutrient requirements:
Energy
Water
Protein
Fat
Carbohydrate
Minerals
Vitamins
Trace elements
Nutritional requirements in the neonates :
Calories : 50-60 kcal/kg/day to maintain weight
100-120 kcal/kg/day to gain weight
Carbohydrates: 11-15g/kg/d (40-50% of total
calories)
Proteins: 2.25-4 g/kg/d (7-15% of total
calories)
Fats: 4-6g/kg/d (< 50% of total calories)
Vitamins: requirements are not clearly
established. Vitamin supplementation depends on
the formula needed.
Energy needs:
depend upon age, weight, maturation, caloric
intake, growth rate, activity, thermal
environment, and nature of feeds.
•Stressed and sick infants need more energy
(e.g. sepsis, surgery)
• Parenteral nutrition need less energy (less
fecal loss of nutrients, no loss for absorption):
70-90 Cal/kg/day + 2.4-2.8 g/kg/day Protein
adequate for growth
•Count non-protein calories only! Protein to be
preferred used for growth, not energy
•65% from carbohydrates, 35% from lipids
ideal
How to be organized ?
To calculate a neonate’s F,E,& N:
First calculate the amount of fluid (Water)
plan how to give it: Parenteral (IV) or Enteral
(OG/PO)
calculate the amount of energy required
Decide how to provide the energy: amount and
nature of carbohydrates and lipids
Provide proteins, vitamins, trace elements
Carbohydrate
IV:
Dextrose 3.4 Cal/g = 34 Cal/100 cc of D10W.
Tiny babies are less able to tolerate dextrose.
If blood levels >150-180 mg/dL, glucosuria=>
osmotic diuresis, dehydration
Insulin can control hyperglycemia
Hyper- or hypo-glycemia => early sign of sepsis
Avoid Dextrose>12.5% through peripheral IV
Carbohydrate
(cont.)
Enteral:
Human milk 20 Cal/oz formula = 67 Cal/100 cc
Lactose is carbohydrate in human milk and term
formula.
Soy and lactose free formula have sucrose,
maltodextrins and glucose polymers
Preterm formula has 50% lactose and 50%
glucose polymers (lactase level lower in premies,
but glycosidases active)
Fat
Parenteral:
20% Intralipid (made from Soybean) better than
10%
High caloric density
Start low, go slow (0.5-3 g/kg/day)
Avoid higher amounts in sepsis, jaundice, severe
lung disease
Maintain triglyceride levels of < 150 mg/dL.
Decrease infusion if >200-300 mg/dL
Fat
(cont.)
Enteral:
Approximately 50% of the calories are derived
from fat. >60% may lead to ketosis.
Medium-chain triglycerides (MCT) are absorbed
directly. Preterm formula have more MCT for
this reason.
At least 3% of the total energy should be
supplied as EFA
Proteins:
2.25-4 g/kg/d (7-15% of total calories)
Restrict in stressed infants or infants with
cholestasis to 1.5 g/kg/day
Very high protein intakes (>5-6 g/kg/day)
may be dangerous
Minerals
(other than Na,K, Cl)
Calcium & Phosphorus:
Third trimester Ca accretion (120150mg/kg/day) and PO4 (75-85 mg/kg/day)
is more than available in human milk. Hence,
HMF is essential. Premie formula has
sufficient Ca/PO4.
Magnesium: sufficient in human milk & formula
Iron: Feed Fe-fortified formula. Start Fe in
breast feed infants at 4 months of age, and in
premies once full feeds are reached.
Vitamins
Fat soluble vitamins: A, D, E, K
Water soluble vitamins: Vitamins B1,B2, B6,
B12, Biotin, Niacin, Pantothenate, Folic acid,
Vitamin C
All neonates should get vit K at birth
Term neonates: No vitamin supplement required,
except perhaps vit D
Preterm: Start vitamin supplements once full
feeds established if on human milk without HMF.
No need if on human milk with HMF, or preterm
infant formula.
Trace elements
Zinc, Copper, Selenium, Chromium, manganese,
Molybdenum, Iodine
Most preterm formulas contain sufficient
amounts
Fluoride supplementation not required in
neonatal period
Important points to consider
Postoperative Feeding : Neonates have most
difficulty in feeding
the work of feeding accounts for most of a neonate
caloric expenditure, and a stressed neonate tires
easily
For this reason, gavage or gastrostomy tube
feedings are generally employed for the early
stages of postoperative feeding in neonates.
evidence that the bowel is beginning to function is
the disappearance of the bilious green color of the
gastric aspirate and the decrease in the volume of
the aspirate from the nasogastric or gastrostomy
tube.
Cont.
Always start with small volumes of rehydration
fluid.
If these are tolerated, the feedings are
increased gradually until the nutritional goals for
the patient have been reached.
Infants tolerate increases in volume more than
increases in osmolarity. Accordingly, it is often
best to start with diluted formulas (threequarter-strength, half-strength, or quarterstrength
In infants, whenever possible, oral feedings or
oral stimulation should accompany tube feedings.
Surgical cases associated with F,E&N problems
Abdominal Wall Defects
The exposure of bowel results in greater
insensible loss of fluid and heat
It is crucial to place children with gastroschisis in
a warm environment and to protect the bowel (by
the help of a plastic bowel bag).
Intravenous access should be established
immediately, and resuscitation should be initiated
before any surgical intervention
I.V. line should be placed in the upper extremities
or the neck
Surgical cases associated with F,E&N problems
Intestinal Obstruction
These patients usually present with choking
or vomiting
They may show signs of severe dehydration
with metabolic alkalosis (hypochloremic,
hypokalemic )
the maintenance requirements and thirdspace losses ,can be replaced with 5%
dextrose in 0.25 normal saline with
supplemental potassium chloride at 3
mEq/kg/24 hr.
Consider TPN
Surgical cases associated with F,E&N problems
Diaphragmatic Hernia
acute respiratory distress and hemodynamic
instability
Babies will require immediate resuscitation,
correction of acidosis, and, in most cases,
endotracheal intubation.
Thank you
References
•Neonatology a Lange clinical manual,3rd edition,Gomella T.
et.al,Appleton& Lange.
•Neonatology pathophysiology and management of the newborn,
5th ed,Gordon B.et.al.Lippincott Williams & Wilkins.
•Arnold G. Coran, M.D., F.A.C.S., Professor, Division of Pediatric
Surgery, Department of Surgery, University of Michigan Medical
School, Surgeon-in-Chief, Section of Pediatric Surgery
Department of Surgery, C. S. Mott Children's Hospital,ACS
Surgery. 2000; ©2000 WebMD Inc.