1. Fluids, Electrolyte, and Nutrition Management in Neonates N. Ambalavanan MD Neonatologist October 1998

2. FEN Management in Neonates zEssentials of life: yFood (Nutrition) ywater (Fluid/electrolyte) yshelter (control of environment - temperature etc) zEssentials of neonatal care: yFluid, electrolyte, nutrition management ( All babies ) yControl of environment ( All babies ) yRespiratory /CVS/CNS management ( some babies ) yInfection management ( some babies )

3. Why is FEN management important? zMany babies in NICU need IV fluids zThey all don’t need the same IV fluids (either in quantity or composition) zIf wrong fluids are given, neonatal kidneys are not well equipped to handle them zSerious morbidity can result from fluid and electrolyte imbalance

4. Fluids and Electrolytes zMain priniciples: yTotal body water (TBW) = Intracellular fluid (ICF) + Extracellular fluid (ECF) yExtracellular fluid (ECF) = Intravascular fluid (in vessels : plasma, lymph) + Interstitial fluid (between cells) zMain goals: yMaintain appropriate ECF volume, yMaintain appropriate ECF and ICF osmolality and ionic concentrations

5. Things to consider: Normal changes in TBW, ECF zAll babies are born with an excess of TBW, mainly ECF, which needs to be removed yAdults are 60% water (20% ECF, 40% ICF) yTerm neonates are 75% water (40% ECF, 35% ICF) : lose 5-10 % of weight in first week yPreterm neonates have more water (23 wks: 90%, 60% ECF, 30% ICF): lose 5-15% of weight in first week

6. Things to consider: Normal changes in Renal Function zAdults can concentrate or dilute urine very well, depending on fluid status zNeonates are not able to concentrate or dilute urine as well as adults - at risk for dehydration or fluid overload zRenal function matures with increasing: ygestational age ypostnatal age

7. Things to consider: Insensible water loss (IWL) z“Insensible” water loss is water loss that is not obvious (makes sense?): through skin (2/3) or respiratory tract (1/3) ydepends on gestational age (more preterm: more IWL) ydepends on postnatal age (skin thickens with age: older is better --> less IWL) yalso consider losses of other fluids: Stool (diarrhea/ostomy), NG/OG drainage, CSF (ventricular drainage), etc

8. Assessment of fluid and electrolyte status zHistory: baby’s F&E status partially reflects mom’s F&E status ( Excessive use of oxytocin, hypotonic IVF can cause hyponatremia ) zPhysical Examination: yWeight: reflects TBW. Not very useful for intravascular volume ( eg. Long term paralysis and peritonitis can lead to increased body weight and increased interstitial fluid but decreased intravascular volume. Moral : a puffy baby may or may not have adequate fluid where it counts: in his blood vessels )

9. Assessment of fluid and electrolyte status (contd.) zPhysical Examination (contd.) ySkin/Mucosa: Altered skin turgor, sunken AF, dry mucosa, edema etc are not sensitive indicators in babies yCardiovascular: xTachycardia can result from too much (ECF excess in CHF) or too little ECF (hypovolemia) xDelayed capillary refill can result from low cardiac output xHepatomegaly can occur with ECF excess xBlood pressure changes very late

10. Assessment of fluid and electrolyte status (contd.) zLab evaluation: ySerum electrolytes and plasma osmolarity yUrine output yUrine electrolytes, specific gravity (not very useful if the baby is on diuretics - lasix etc), FE Na yBlood urea, serum creatinine (values in the first few days reflect mom’s values, not baby’s) yABG (low pH and bicarb may indicate poor perfusion)

11. Management of F&E zGoal: Allow initial loss of ECT 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. zIndividualize approach (no “cook book” is good enough!)

12. Management of F&E (contd.) zTotal fluids required: yTFI = Maintenance requirements (IWL+Urine+Stool water) + growth yIn the first few days, IWL is the largest component yLater, solute load increases (80-120 Cal/kg/day = 15-20 mOsm/kg/day => 60-80 ml/kg/day to excrete wastes) yStool: 5-10 cc/kg/day yGrowth: 20-25 cc/kg/day (since wt gain is 70% water)

13. Management of F&E (contd.) zGuidelines for fluid therapy

14. Management of F&E (contd.) zFactors modifying fluid requirement: yMaturity--> Mature skin --> reduces IWL yElevated temperature (body/environment)--> increases IWL yHumidity: Higher humidity--> decreases IWL up to 30% (over skin and over respiratory mucosa) ySkin breakdown, skin defects (e.g. omphalocele)--> increases IWL (proportional to area) yRadiant warmer --> increases IWL by 50% yPhototherapy --> increases IWL by 50% yPlastic Heat Shield --> reduces IWL by 10-30%

15. Let there be lytes! zElectrolyte requirements: yFor the first 1-3 days, sodium, potassium, or chloride are not generally required yLater in the first week, needs are 1-2 mEq/kg/day ( 1 L of NS = 150+ mEq; 150 cc/kg/day of 1/4 NS = 5.9 mEq/kg/day which is too much ) yAfter the first week, during growth, needs are 2-3 or even 4 mEq/kg/day

16. F&E in common neonatal conditions zRDS: Adequate but not too much fluid. Excess leads to hyponatremia, risk of BPD. Too little leads to hypernatremia, dehydration zBPD: Need more calories but fluids are usually restricted: hence the need for “rocket fuel”. If diuretics are used, w/f ‘lyte problems. May need extra calcium. zPDA: Avoid fluid overload. If indocin is used, monitor urine output. zAsphyxia: May have renal injury or SIADH. Restrict fluids initially, avoid potassium. May need fluid challenge if cause of oliguria is not clear.

17. Common ‘lyte problems zSodium: yHyponatremia (<130 mEq/L; worry if <125) yHypernatremia (>150 mEq/L; worry if >150) zPotassium: yHypokalemia (<3.5 mEq/L; worry if <3.0) yHyperkalemia > 6 mEq/L (non-hemolyzed) (worry if >6.5 or if ECG changes ) zCalcium: yHypocalcemia (total<7 mg/dL; i<4) yHypercalcemia (total>11; i>5)

18. Sodium stuff : Hyponatremia zSodium levels often reflect fluid status rather than sodium intake

19. Sodium stuff : Hypernatremia zHypernatremia is usually due to excessive IWL in first few days in VLBW infants (micropremies). Increase fluid intake and decrease IWL. zRarely due to excessive hypertonic fluids (sod bicarb in babies with PPHN). Decrease sodium intake.

20. Potassium stuff zPotassium is mostly intracellular: blood levels do not usually indicate total-body potassium zpH affects K + : 0.1 pH change=>0.3-0.6 K + change (More acid, more K; less acid, less K) zECG affected by both HypoK and HyperK: yHypok:flat T, prolonged QT, U waves yHyperK: peaked T waves, widened QRS, bradycardia, tachycardia, SVT, V tach, V fib

21. Hypo- and Hyper-K zHypokalemia: yLeads to arrhythmias, ileus, lethargy yDue to chronic diuretic use, NG drainage yTreat by giving more potassium slowly zHyperkalemia: yIncreased K release from cells following IVH, asphyxia, trauma, IV hemolysis yDecreased K excretion with renal failure, CAH yMedication error very common

22. Management of Hyperkalemia zStop all fluids with potassium zCalcium gluconate 1-2 cc/kg (10%) IV zSodium bicarbonate 1-2 mEq/kg IV zGlucose-insulin combination zLasix (increases excretion over hours) zKayexelate 1 g/kg PR (not with sorbitol! Not to give PO for premies!) zDialysis/ Exchange transfusion

23. Calcium stuff zAt birth, levels are 10-11 mg/dL. Drop normally over 1-2 days to 7.5-8.5 in term babies. zHypocalcemia: yEarly onset (first 3 days):Premies, IDM, Asphyxia If asymptomatic, >6.5: Wait it out. Supplement calcium if <6.5 yLate onset (usually end of first week)”High Phosphate” type: Hypoparathyroidism, maternal anticonvulsants, vit. D deficiency etc. Reduce renal phosphate load

24. Things we aren’t going to discuss (i.e.) homework: zAcid-base disorders: Acidosis or Alkalosis, Metabolic or Respiratory or Mixed zHypercalcemia zMagnesium disorders zMetabolic disorders zMethods of feeding: Continuous vs. Intermittent; TP vs OG vs NG vs NJ; Trophic feeds; Complications of TPN (We can discuss these, if time permits)

25. Common fluid problems zOliguria : UOP< 1cc/kg/hr. Prerenal, Renal, or Postrenal causes. Most normal term babies pee by 24-48 hrs. Don’t wait that long in sick l’il babies! Check Baby, urine, FBP. Try fluid challenge, then lasix. Get USG if no response zDehydration: Wt loss, oliguria+, urine sp. gravity >1.012. Correct deficits, then maintenance + ongoing losses zFluid overload: Wt gain, often hyponatremia. Fluid+ sodium restriction

26. Nutrition zGoals: Normal growth and development ( as compared to intrauterine growth for preterm neonates, or as compared to growth charts for term neonates ) zNutrient requirements: Energy (Cals)Carbohydrate WaterMinerals ProteinVitamins FatTrace elements

27. Energy { E = mc 2 } zEnergy needs: depend upon age, weight, maturation, caloric intake, growth rate, activity, thermal environment, and nature of feeds. zGrowing premies: (Cal/kg/day) yResting expenditure: 50 yMinimal activity: 4-5 yOccasional cold stress: 10 yFecal loss (10-15%):15 yGrowth (4.5 Cal/g +):45 125 E=energy required m =mass of baby c = cry loudness

28. Energy zStressed and sick infants need more energy (e.g. sepsis, surgery) zBabies on 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 zCount non-protein calories only! Protein to be preferred used for growth, not energy z65% from carbohydrates, 35% from lipids ideal z>165-180 Cal/kg/day not useful

29. Calculations zTo calculate a neonate’s F,E,& N: yFirst calculate the amount of fluid (Water) yThen calculate how you plan to give it: Parenteral (IV) or Enteral (OG/PO) yThen calculate the amount of energy required yDecide how to provide the energy: amount and nature of carbohydrates and lipids yProvide proteins, vitamins, trace elements

30. Calculations: practical hints for TPN zDo not starve babies! The ones who don’t complain are the ones who need it the most. zUse birthweight to calculate intake till birthweight regained, then use daily wt zStart TPN on 2nd or 3rd day if the baby will not be on full feeds by a week zStart with proteins (1 g/kg/d) and increase slowly. zAfter a few days (3rd or 4th day), add lipids (0.5 kg/kg/d) zAim for 90-100 Cal/kg/day with 2.5-3 g/kg/d Protein (NPC/N of 150-200)

31. Carbohydrate zIV: yDextrose 3.4 Cal/g = 34 Cal/100 cc of D10W. yTiny babies are less able to tolerate dextrose. If < 1 kg, start at 6 mg/kg/min. If 1-1.5 kg, start at 8 mg/kg/min. yIf blood levels >150-180 mg/dL, glucosuria=> osmotic diuresis, dehydration yInsulin can control hyperglycemia yHyper- or hypo-glycemia => early sign of sepsis yAvoid Dextrose>12.5% through peripheral IV

32. Carbohydrate zEnteral: yHuman milk/ 20 Cal/oz formula = 67 Cal/100 cc yLactose is carbohydrate in human milk and term formula. Soy and lactose free formula have sucrose, maltodextrins and glucose polymers yPreterm formula has 50% lactose and 50% glucose polymers (lactase level lower in premies, but glycosidases active) yLactose provides 40-45% of calories in human milk and term formula

33. Fat zParenteral: y20% Intralipid (made from Soybean) better than 10% yHigh caloric density (2 Cal/cc vs 0.34 for D10W) yStart low, go slow (0.5-3 g/kg/day) yAvoid higher amounts in sepsis, jaundice, severe lung disease yMaintain triglyceride levels of 200-300 mg/dL.

34. Fat zEnteral: yApproximately 50% of the calories are derived from fat. >60% may lead to ketosis. yMedium-chain triglycerides (MCT) are absorbed directly. Preterm formula have more MCT for this reason. yAt least 3% of the total energy should be supplied as EFA

35. Protein zTerm infants need 1.8-2.2 g/kg/day zPreterm (VLBW) infants need 3-3.5 g/kg/day (IV or enteral) zRestrict stressed infants or infants with cholestasis to 1.5 g/kg/day zStart early - VLBW neonates may need 1.5-2 g/kg/day by 72 hours zVery high protein intakes (>5-6 g/kg/day) may be dangerous zMaintain NP Calorie/Protein ratio (at least 25-30:1)

36. Minerals (other than Na,K, Cl) zCalcium & Phosphorus: yThird trimester Ca accretion (120-150mg/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. Ratio should be 1:7:1 by wt. zMagnesium: sufficient in human milk & formula zIron: Feed Fe-fortified formula. Start Fe in breast fed term infants at 4 months of age, and in premies once full feeds are reached. (Does not prevent Anemia of Prematurity )

37. Vitamins zFat soluble vitamins: A, D, E, K zWater soluble vitamins: Vitamins B 1,B 2, B 6, B 12, Biotin, Niacin, Pantothenate, Folic acid, Vitamin C zAll neonates should get vit K at birth zTerm neonates: No vitamin supplement required, except perhaps vit D zPreterm: 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 (except: add vit D if on SSC24).

38. Trace elements zZinc, Copper, Selenium, Chromium, manganese, Molybdenum, Iodine zMost preterm formulas contain sufficient amounts zFluoride supplementation not required in neonatal period

39. Special formula zSoy formula: yNot recommended for premies: impaired mineral and protein absorption; low vitamin content yUsed if galactosemia, CMPI, secondary lactose intolerance following gastroenteritis zPregestimil: (Alimentum is similar, but with sucrose) yHydrolyzed casein; 50% MCT; glucose polymers yUsed if malabsorption or short bowel syndrome zPortagen: yCasein; 75% glucose polymers+25% sucrose; 85% MCT yUseful for persistent chylothorax. Can cause EFA def.

40. Special formula (contd.) zSimilac PM 60/40: yLow sodium and phosphate; high Ca/PO4 ratio yUsed in renal failure, hypoparathyroidism zSimilac 27: yHigh energy with more Protein, Ca/Po4, Lytes yUsed for fluid restricted infants: CHF, BPD zNutramigen: yHypoallergenic, lactose and sucrose free yUsed for protein allergies, lactose intolerance