Transcript Fluids, Electrolytes, and Nutrition for the Neonate:

FLUIDS, ELECTROLYTES, AND
NUTRITION FOR THE NEONATE:
Melissa Nelson, MD
Neonatal-Perinatal Fellow
Yale-New Haven Hospital
LECTURE OBJECTIVES:
 Understand
principles of fluid balance in
neonates and appropriate postnatal fluid
management
 Learn concepts of electrolyte balance in neonates
 Recognize signs and symptoms of certain
electrolyte abnormalities and learn how to treat
them
 Learn about neonatal nutritional requirements
and feeding methods
PRINCIPLES OF FLUID BALANCE:
TBW = ICF + ECF
 ECF = Intravascular + Interstitial

http://akramania.byethost11.com/OHCM/16%20-%20Clinical%20Chemistry.htm
TOTAL BODY WATER
COMPOSITION:
Adult TBW = 60% (40% ICF + 20% ECF)
 Full-term TBW = 75% (35% ICF + 40% ECF)
 Pre-term TBW = 90% (30% ICF + 60% ECF)
* Excess TBW esp. ECF at birth, hence diuresis within 1st week of life

(up to 10% in FT, up to 15% in pre-term)
http://www.revivenaturally.com/dr-yoshitaka-ohno-md-phd/maintaining-intracellular-hydration-water.html
SENSIBLE VS. INSENSIBLE WATER LOSS:
 Sensible

water loss (SWL): Easily measured
Urine, stool, NG/OG output, CSF
 Insensible




water loss (IWL): Not readily measured
Evaporation from skin (66%) or respiratory tract (33%)
IWL greater in lower GA (immature skin)
Factors that increase: Immature skin, fever, radiant warmers,
phototherapy, skin defects/breakdown
Factors that decrease: Mature skin, humidity, heat shields
RENAL FUNCTION IN NEONATES:
Decreased capacity to concentrate or dilute urine
in response to intravascular fluid status
 Risk dehydration or fluid overload

Adults: FENa < 1%
vs.
Term infants: FENa < 1%
(except transient increase during diuretic phase)
vs.
Pre-term infants: FENa 5-6%
http://www.yalemedicalgroup.org/stw/Page.asp?PageID=STW028984
ASSESSING FLUID STATUS:

Factors that can affect fluid status:
 Maternal history: Neonate’s status reflects
mother’s
 Neonatal history (ie. In utero hypoxemia
associated with ATN and hypervolemia)
 Clinical evaluation: weight changes, UOP,
IWL factors (humidity, phototherapy,
ventilation, etc.), vital signs, perfusion
 Laboratory evaluation: serum electrolytes,
BUN/Cr
FEN MANAGEMENT:

Goals:
 Maintain ICF and ECF volumes and osmolalities

Allowing diuresis within 1st week of life

Maintain appropriate electrolyte concentrations

Provide adequate nutrition for growth
TOTAL FLUID REQUIREMENTS:

Total fluids = Maintenance + Growth

Maintenance = SWL + IWL
http://www.champ-sportsline.de/en/nutrients-active-ingredients/fluids.html
STARTING POINTS AND ADVANCEMENT:


Starting Points:
 BW < 1250g: TF = 80 - 100
 BW 1250-1750g: TF = 60 - 80
 BW > 1750g: TF = 60
Advancement Example: ELBW infant






Start DOL 1 with TF = 100
Adjust daily to maintain wt loss within 10% BW
DOL 2 with TF ~100-120
DOL 3-4 with TF ~120-130
DOL 4-5 with TF ~130-140
Goal TF ~140-150
FLUID ISSUES ASSOCIATED WITH
COMMON NEONATAL
CONDITIONS:
 Issues




requiring fluid restriction:
RDS: Excessive fluid can lead to fluid overload and
increased risk of BPD
BPD: Excessive fluid can worsen therefore treated with
diuretics to reduce pulmonary edema
PDA: Volume overload can open ductus and worsen
respiratory status
HIE: Associated with ATN and/or SIADH and can lead
to subsequent volume overload
COMMON FLUID PROBLEMS:

Hypervolemia/volume overload

Hypovolemia/dehydration

Oliguria: UOP < 1 mL/kg/hr
 Pre-renal, Renal, Post-renal
ELECTROLYTE REQUIREMENTS:
 First

 At
24h of life: No electrolytes (except Ca)
Ca especially important for preterm infants
24h of life:
Na: 1-3 mEq/kg/day
 K: 1-2 mEq/kg/day

 At
1 week of life:
Na: 3-5 mEq/kg/day
 K: 2-3 mEq/kg/day

* Extremely pre-term infants with metabolic acidosis (loss
of bicarb in urine) may benefit from sodium acetate
** Electrolyte requirements vary based on medications, etc.
COMMON ELECTROLYTE ABNORMALITIES:

Hypo/hypernatremia

Hypo/hyperkalemia

Hypocalcemia


Hypermagnesemia
http://www.coconutwaterlife.com/electrolytes
SODIUM ABNORMALITIES:

Hyponatremia: Na < 130 mEq/L




Causes: Usually due to excess free water but can be
increased Na losses/inadequate Na intake
Signs/sx: lethargy, seizures, coma
Tx: Restrict fluids and/or Na supplements
Hypernatremia: Na > 150 mEq/L

Causes: Usually due to high water losses, rarely excess
intake
Signs/sx: lethargy, seizures, coma

Tx: Increase fluids and/or restrict Na

POTASSIUM ABNORMALITIES:

Hypokalemia: K < 3.5 mEq/L




Causes: Diuretics, NG losses
Signs/sx: EKG changes (flat T waves, prolonged QT, U
waves), arrhythmias, ileus, lethargy
Tx: Slowly correct IV or orally
Hyperkalemia: K > 6 mEq/L



Causes: Iatrogenic, severe acidosis, ARF, RBC
breakdown s/p transfusion, CAH
Signs/sx: EKG changes (peaked T waves, wide QRS,
brady/tachycardia, SVT, V Tach, V fib), arrhythmias,
death
Tx: D/C all K, Ca gluconate, sodium bicarbonate,
albuterol, insulin + glucose, lasix, kayexalate,
dialysis/exchange
* Most K is intracellular, thus serum levels might not accurately depict total body stores
** pH affects K levels: Acidosis drives K out of cell vs. Alkalosis pushes K into cell
CALCIUM ABNORMALITIES:

Hypocalcemia: Ca < 7 mg/dL (iCa < 1)




Causes: Prematurity, IUGR, IDM, HIE,
hypoparathyroidism, Vitamin D deficiency
Signs/sx: Asymptomatic, jitteriness, irritability, seizures
Tx: Observation, repletion (Ca gluconate), or
supplementation
Hypercalcemia: Ca > 11mg/dL (iCa > 5)

Rare in neonates

Usually associated with preterm fortifiers (HMF)
*
Important to follow Ca levels as well as Phos and Alk Phos levels
~every 2 weeks once on full feeds to screen for osteopenia
MAGNESIUM ABNORMALITIES:

Hypermagnesemia: Mg > 2.3 mEq/L



Causes: Maternal treatment with magnesium for PEC
or tocolysis
Signs/sx: Respiratory depression, apnea, hypotonia,
decreased GI motility
Tx: Self-limited, resolves within a few days
PRINCIPLES OF NUTRITION:

Nutrient requirements:






Carbohydrates
Protein
Fat
Water
Minerals and trace elements
Vitamins
ENERGY REQUIREMENTS:

Depend on:








GA
Postnatal age
Weight
Route of intake (less calories if parenteral)
Growth rate
Activity level
Thermal environment
Medical problems
Ideally energy from: 65% carbohydrate + 35% lipid
 Protein building block for growth

ENERGY REQUIREMENTS:
 Typical


needs: 100-120 cal/kg/day for growth
Term = 100 vs. Preterm = 120 cal/kg/day
Many need more! (ie. BPD or CHD might need 160-180)
 “Healthy”
enterally fed premie: 125 cal/kg/day
Resting energy expenditure: 50 cal/kg/day
 Activity level (minimal): 5 cal/kg/day
 Occasional cold stress: 10 cal/kg/day
 Stool loss (10-15% of intake): 15 cal/kg/day
 Growth (4.5 cal/g of growth): 45 cal/kg/day

METHODS OF PROVIDING NUTRITION:



Total Parenteral Nutrition (TPN):
 Peripheral vs. Central
Combination Parenteral/Enteral Nutrition:
 Advancing feeds but still giving TPN
Total Enteral Nutrition:
 Per oral route (PO) (ie. Bottle/breast)
 Per gavage route (PG) (ie. NG/OG on pump)
 Chronic feeding tube feeds (ie. G-tube)
TOTAL PARENTERAL NUTRITION:



Goal: Provide energy and nutrients to promote growth
when unable to adequately feed by enteral means
Calculations typically based on birth weight for first week
of life, then use actual weight thereafter
Must account for:






Total fluid volume (mL/kg/day)
Total daily caloric requirements (cal/kg/day)
Dextrose concentration and glucose infusion rate (mg/kg/min)
Protein (g/kg/day)
Lipid (g/kg/day)
Electrolytes, trace elements, minerals, vitamins
STARTING POINTS AND ADVANCEMENT:
Variable:
Starting Point:
Advancement:
Goal:
Dextrose & Glucose
Infusion Rate:
Initial GIR: 6-8
(Usually start D10)
1-2/day depending on
glucose levels
Typical max ~14-15
Protein (g/kg/day):
3
0.5-1/day
<1500g/32 wks :4
>1500g/32 wks: 3
Lipid (g/kg/day):
< 1000g: 0.5
1000-2000g: 1-2
>2000g: 2-3
*Start at 24-30h life
0.5-1/day
1-2/day
1-2/day
3
*Check TG levels prn
@ 2-3g
Vitamins:
MVI for neonatal/peds
Minerals:
“Electrolyte-free” except
Ca for first few days
Trace Elements:
Zn, Cu, Mn, Cr, Mo, I
-Start Na at ~2 days
-Start K once voiding
& serum K<3.5
-Ca, Mg, Phos, Cl,
Acetate
OFF-HOURS TPN FOR PREMIES BW < 1750G:

Goal: Provide protein and calcium within first 24h of life
(when can’t order regular TPN yet)

Rationale: ELBW infants lose >1% of protein stores daily,
must provide protein to balance loss

Run at 50 mL/kg/day

Components:
Dextrose 10%
Protein (60 g/L): 3g/kg/day
Calcium (4 mEq/L)
Minimal electrolytes
 Heparin




TYPES OF ENTERAL NUTRITION:
 Breast


milk is the best milk!
Lactation counselors can help NBSCU moms
Donor breast milk an option for some premies
 Variety



of formulas available:
Term (20 cal): Good Start, Enfamil, Similac
Late Pre-term/Transitional (22cal): Enfacare,
Neosure
Pre-term (24 cal): Similac Special Care
 Supplements

to increase calories, etc.:
HMF (protein, Ca), Neosure powder, MCT oil
TYPES OF ENTERAL NUTRITION:

Specialty formulas available:
 Lactose Intolerance/Galactosemia: Soy varieties
 Feeding Intolerance: GentleEase, Similac sensitive
 Semi-Elemental: Alimentum, Nutramigen,
Pregestimil
 Elemental: Neocate, Elecare
 Renal disease: Similac PM 60/40
 Chylothorax: Enfaport
INITIATION OF ENTERAL
FEEDING:
 Preterm < 1250g:
 Goal to start preterm feedings within first 12 hours of life
 Start with non-nutritive feeds q4h:




Low volume (usually 10-15 mL/kg/day)
Acclimate the GI tract to feeds
Stimulate gut hormone secretion
Promote GI tract maturation
 Preterm 1250-1750g:
 Start within first 12 hours of life with ~20 mL/kg/day (ie. 4-5
mL/kg/feed q2-3h)
 Preterm > 1750g or Fullterm:
 If stable, start feeds within first 6 hours of life q3-4h
 May consider ad lib feeds
ADVANCEMENT OF ENTERAL FEEDING:



Goal: Advance slowly to reach full enteral feeds
within ~2 weeks of life
Advance daily as tolerated per feeding protocol
(~10-20 mL/kg/day for premies)
Monitor for symptoms of intolerance:
Abdominal distension
 Vomiting
 Bilious aspirates/residuals

ADVANCEMENT OF ENTERAL FEEDING:
Feeding
Day
(Volume –
mL/kg/d)
< 0.550g
0.5510.650g
0.6510.750g
0.7510.850g
0.8510.950g
0.9511.050g
1.0511.150g
1.1511.250g
1
(~12)
1.0 mL
q4h
1.2 mL
q4h
1.4 mL
q4h
1.6 mL
q4h
1.8 mL
q4h
2.0 mL
q4h
2.2 mL
q4h
2.4 mL
q4h
2
(~24)
2.0 mL
q4h
2.4 mL
q4h
2.8 mL
q4h
3.2 mL
q4h
3.6 mL
q4h
4.0 mL
q4h
4.4 mL
q4h
4.8 mL
q4h
3
(~36)
1.5 mL
q2h
1.8 mL
q2h
2.1 mL
q2h
2.4 mL
q2h
2.7 mL
q2h
3.0 mL
q2h
3.3 mL
q2h
3.6 mL
q2h
4
(~48)
2.0 mL
q2h
2.4 mL
q2h
2.8 mL
q2h
3.2 mL
q2h
3.6 mL
q2h
4.0 mL
q2h
4.4 mL
q2h
4.8 mL
q2h
5
(~60)
2.5 mL
q2h
3.0 mL
q2h
3.5 mL
q2h
4.0 mL
q2h
4.5 mL
q2h
5.0 mL
q2h
5.5 mL
q2h
6.0 mL
q2h
6
(~72)
3.0 mL
q2h
4.0 mL
q2h
4.0 mL
q2h
5.0 mL
q2h
5.0 mL
q2h
6.0 mL
q2h
6.0 mL
q2h
7.0 mL
q2h
•After Feeding Day 6: increase 1 mL/feed q24h for 2-3 days and then increase 1 mL/feed q12h until full enteral feeds
•Adapted from Y-NHH NBSCU guidelines
ADVANCEMENT OF ENTERAL FEEDING:
 As
enteral feedings increase, amount of
parenteral feedings decrease


Write TPN for NPO rate in case feeds stopped
Decrease lipid rate accordingly (ie. Decrease to
50% once at ½ full feeds, etc.)
 Fortify
feeds with HMF once infant
receiving 100 mL/kg/day of human milk

First fortify to 22 cal then to 24 cal
 Consider
further increase in calories
overtime from to 27 or 30 cal formula +/MCT depending on growth curves
TRANSITION FROM PG TO PO FEEDING:
 Infant must:
 Weight > 1000 grams and corrected GA > 32 wks
 Clinically stable with full strength feeds
 Developmental cues of readiness (suck/swallow)
 Advancement:
 Start with trial of po once daily
 Then twice daily
 Then every few/every other feed (PG/PG/PO, PO/PG, PO/PO/PG)
 Then all po (PO Ad Lib with minimum, PO Ad Lib)
* Some infants 32-34 weeks might not be ready for all po, consider
alternating po/pg feeds
ADDITIONAL NUTRITIONAL CONSIDERATIONS:
 Iron
fortification: Prevent Fe-deficient anemia
Fe supplement given to breast-fed term/pre-term infants
 Some formula-fed might need if insufficient volume

 Vitamin

supplementation:
Polyvisol for term/pre-term breast-fed infants once full feeds
 Vitamin
D supplementation:
Term/pre-term breast-fed infants need 400 IU daily
 Supplement amount depends on feeding method/amount

PREP BOARD REVIEW QUESTION #1:
Item 34 (2011):
A mother in your pediatric practice recently delivered a 28 weeks’
gestation infant who is in the NICU. She exclusively breastfed her
previous child who was born at 36 weeks’ gestation. She is concerned
that something is wrong with her milk for this infant because it is
being combined with HMF. You reassure her that fortification helps
to meet the additional needs of her preterm infant.
Of the following, the MOST important role of such fortification is to:
A. augment the immunologic properties of human milk
B. boost the carbohydrate content of human milk
C. decrease the osmolality of human milk
D. enhance the absorption of iron from human milk
E. increase the protein content of human milk
PREP BOARD REVIEW QUESTION #1:


Answer: E. increase the protein content of human
milk
Preterm infants need more protein.
Preterm 3-4 g/kg/day
 Term 1.5-2 g/kg/day


HMF provides extra protein to be added to breast
milk.
PREP BOARD REVIEW QUESTION #2:
Item 226 (2010):
A 30 weeks’ gestation very low-birthweight (VLBW) 1,400-g infant has
respiratory distress syndrome (RDS). He is receiving assisted ventilation
following administration of 3 doses of surfactant. On his second postnatal
day, his mother asks if she can breastfeed her infant. You explain that he
will not be able to breastfeed until he is extubated and able to suckle. She
asks whether she should pump her breast milk.
Of the following, the BEST response is that expressed human milk
feedings:
A. are contraindicated in VLBW infants who have RDS
B. are too difficult for VLBW infants to digest
C. can be fed by NG tube
D. have no net benefit for VLBW infants once frozen
E. have too much protein for VLBW infants
PREP BOARD REVIEW QUESTION #2:

Answer: B. are too difficult for VLBW infants to
digest
Breast milk is the best milk!
 NG feeds can be given when babies cannot yet
tolerate po feeds.

PREP BOARD REVIEW QUESTION #3:
Item 50 (2011):
A 27 weeks’ gestation preterm male infant who weighs 900g is delivered
at a community hospital by emergent cesarean section. After intubation
in the delivery room, he is taken to the nursery for stabilization, including
umbilical venous line placement, prior to transfer to a tertiary care center.
Of the following, the MOST appropriate initial solution for parenteral
administration would include:
A. 5% dextrose
B. 5% dextrose and 0.2% sodium chloride
C. 10% dextrose
D. 10% dextrose and 0.2% sodium chloride
E. 0.9% sodium chloride
PREP BOARD REVIEW QUESTION #3:

Answer: C. 10% dextrose
Preterm babies are at risk of hypoglycemia and
need to have careful blood glucose monitoring.
 Initial parenteral fluids typically include 10%
dextrose solutions.
 Infants do not need sodium administration
within the first few days of life.

PREP BOARD REVIEW QUESTION #4:
Item 174 (2011):
A 4-month-old male infant presents with abdominal distension, vomiting,
and poor weight gain. His temperature is 37.3°C, heart rate is 110
beats/min, respiratory rate is 32 breaths/min, and blood pressure is 96/56
mm Hg. On physical examination, you note abdominal distension, with a
palpable mass above the pubic symphysis. Results of laboratory tests
include:
Na 136, K 7.2, Cl 110, Bicarb 16, BUN 25, Cr 1.3, Ca 9.5, Mg 1.8, P 5.5
Of the following, the next BEST step in the management of this patient’s
electrolyte abnormality is administration of:
A. intravenous calcium gluconate
B. intravenous dextrose and insulin
C. nebulized albuterol
D. oral furosemide
E. oral sodium polystyrene sulfonate
PREP BOARD REVIEW QUESTION #4:


Answer: A. intravenous calcium gluconate
All treatment options are correct but first-line
approach to decrease K level rapidly is Ca
gluconate. (See NBSCU algorithm)
The infant has abdominal distension, FTT,
palpable suprapubic mass, hyperkalemia,
azotemia, and normal anion gap metabolic
acidosis.
 Diagnosis is likely obstructive uropathy
(posterior urethral valves) with Type IV RTA and
hyperkalemia.

References:
Fanaroff and Martin’s Neonatal-Perinatal Medicine: Diseases of the Fetus and Infant
Ambalavanan, N et al. Fluid, Electrolyte, and Nutrition Management of the Newborn.
emedicine.com, Last updated June 29, 2010.
Yale-New Haven Hospital NBSCU Guidelines:
- Basic Concepts: Fluid, Electrolyte, and Nutritional Management of Preterm Infants
(June 2009)
- Basic Concepts: Total Parenteral Nutrition in the Newborn (June 2009)
- Breastfeeding Initiation and Advancement (April 2006)
- Feeding Intolerance Assessment (April 2006)
- Oral Feedings Initiation and Advancement (April 2006)
- Iron Supplementation (September 2011)
- Vitamin D Supplementation (October 2011)
- Nutrient Contents: Preterm Formulas, Fortified Human Milk Admixtures (June 2008)
PREP Self-Assessment Pediatrics Review and Education Program, AAP, 2009-2011