(11/30) Pham Lecture: Fluids & Electrolytes & Parenteral Nutrition in Pediatric Patients Age-Dependent Changes in Body Composition: As we get older, our fluid begins to shift from ECF to ICF. The elderly have higher intracellular %BW and less TBW; conversely, newborns are big bags of water with ÝECF. The more premature a neonate is, the higher the TNW and ECF. Fluid Therapy: Crystalloid Therapy for: Resuscitation, Replacement, Maintenance

- Resuscitation: 0.9% NS all day. 100% distributes to the ECF - Replacement: When replacing water losses, may be concurrently replacing electrolytes

o D5W provides 100% free water content, excellent for dehydration o LR: Useful for replacing fluids and electrolytes following surgery, though it is

very expensive. o Quarter NS (0.225% NS): It is dangerous to infuse a hypotonic solution such

as this. It can lyse out your blood. It is recommended to give quarter saline as DW5/0.225NS.

- Maintenance: Age and Weight dependent, younger = need more fluid o Neonates and young infants have higher requirements due to having a higher

(1) metabolic weight, (2) BSA:Weight ratio, (3) respiratory rate

- Increased Water Losses: Either by exposure (radiant warmer, burns, phototherapy) or conditions (Fever, D/V) - Decreased Water Needs: Incubation, humidified ventilators, oliguria, and hypothyroidism

Dehydration: occurs when the intake of water and electrolyte is less than combined normal and abnormal loss. - Assessing Severity (% listed below reflect the fluid deficit, or percent dehydration)

o Mild: Infant 5%, Older 3%. Sx: Thirsty, Alert, Normal à Oral Rehydration o Moderate: Infant 9%, Older 6%. Sx: Thirsty, lethargic, irritable, weak pulse. à Oral Rehydration o Severe: Infant 10-15%, Older 10%. Sx: Tachycardia, Hypotension (<90mmHg), RRÝ à IV Admin

§ Other major Sx: Prolonged Capillary Refill time, Impalpable, Anuria (<1mL/kg/h) - Type of Dehydration: Determines the type of solution to choose and speed to use it.

o Isotonic: ~SNa and Osmolarity is balanced, pt without excessive loss, often due to gastroenteritis. o Hypertonic: Shift in fluids, water lost from ECF is greater than solutes. Common in diabetes insipidus,

diarrhea, concentrated formula. Treat? Not soup, give pedialyte o Hypotonic: SNaß ex: Heat Stroke, or excess diluted.

- Using Labs to Identify: o BUNÝ: Not a specific indicator, especially in neonates. There is little muscle mass to contribute. o HctÝ: Dehydration reduces the denominator, leading to elevated findings in serum hematocrit o [HCO3-]ß: Serum bicarb is used to assess the severity of dehydration. < 15 = Severe dehydration.

- Calculate Fluid Deficit: (Previous Weight – Current Weight) / (Previous Weight) *100% = % Fluid Deficit o %Fluid Deficit = %Dehydration, Administer the equal per weight volume. i.e: 15% deficit = 150mL/kg o Though we frequently treat based off S/Sx, it is more accurate if we have the patient’s previous weight

- 3 Phases of Fluid Management/Rehydration o Phase I: Restore Intravascular Volume (Resuscitation) o Phase II: Replace Deficit and Maintenance Fluid o Phase III: Stabilization Phase

Calculate a 12kg infant’s maintenance fluid requirements Weight = 12kg. For weights 3-10kg, 100mL/kg For weights 10-20kg, 50mL/kg (10kg)*(100mL/kg) + (2kg)*(50mL/kg) è 1100mL daily requirement.

Types of Dehydration

Phase I: Fluid Resuscitation Therapy [Used for Severe Isotonic, Hypotonic, and Hypertonic Dehydration] - Step 1: Diagnose based on Symptoms or %Fluid Deficit. Resuscitation is reserved for severe dx. - Step 2: Slam ‘em. 20mL/kg NS bolus over 15-20 minutes, may repeat up to a max of 60mL/kg in an hour (3x)

Phase II: Replacement+Maintenance Therapy [Isotonic and Hypotonic ONLY] - Replacement and Maintenance are running concurrently. Depending on pt and solution, you may have 2 lines - Step 1: Calculate the fluid deficit. This will be the replacement portion of this step.

o Replacement/Deficit Solution: Cannot be D10%, even in neonates. Use D5W/½NS - Step 2: Calculate the patient’s daily fluid requirement. This will be the maintenance portion of this step.

o Maintenance Solution: Neonates must have D10%, all others may again use D5W/½NS - Administration Volume:

o ½ Fluid Deficit – Bolus (if any) + 1/3 Daily Maintenance Over first 8 hours o Add K if the patient is making urine, Check UO. à D5W/½NS ± KCl 20mEq/L

- Recap: If indicated, Neonates will have 2 lines running (D10 + D5W/½NS) and Non-neonates 1 (D5W/½NS) Phase III: Replacement+Maintenance (Slowed) [Isotonic and Hypotonic ONLY]

- Repeat steps 1 and 2 of Phase II. This will be a slower administration, with a higher maintenance fraction. - Administration Volume:

o ½ remaining deficit + 2/3 Daily Maintenance Over the next 16 hours - Product: Neonate = D10%+Electrolytes, All others, D5W/½NS ± KCl 20mEq/L

Hypertonic Dehydration Fluid Therapy - This is much simpler than the 3 phase treatment series of Isotonic/Hypotonic dehydrated patients

o If a Hypertonic pt requires resuscitation, Phase I applies to them (See above) - Step 1: Calculate the fluid deficit. Step 2: Calculate daily fluids (maintenance). Step 3: Add them together - Administration Volume: Deficit + Maintenance over 48 hours

o ** Use D5W/0.225% NaCl ± KCl 20mEq/L D5 Quarter, Why? Because hypertonic, tx the sodium. Complications and Maximums for Fluid Management

- Hypotonic Dehydration: Maximal correction rate < 0.5mEq/L/h to avoid Central Pontine Myelinolysis (CML) - Hypertonic Dehydration: Maximal correction rate £ 10 mEq/L/day. This slow infusion rate helps avoid Cerebral

Edema, convulsions, and death. Electrolyte Loss

- Depending on the body fluid (gastric, small intestine, ileostomy, diarrhea, sweat), there are different levels of electrolytes that are lost, and should be measured and replaced every 4-8 hours.

- Losing a lot of gastric fluid? à Losing a lot of K and Na - When you think of the gut and poop à Thing Bicarb loss

Indications for Parenteral Nutrition - Neonates: Immature gut, cannot eat enough to sustain. Must feed them slowly - Congenital Anomalies: Born with bowels outside body. Omphalocele, Gastroschisis - GI Complications: Necrotizing Enterocolitis is the most common, necrotizing bowel. - 3-4 Days: Health kid NPO x3-4 days begin breaking down protein, and will require PN

Types of PN: Peripheral or Central - Peripheral: Short-term, limited by osmolarity. Less complications, but difficult to achieve full calories

o Max Calcium Gluconate £ 10mEq/L o Maximal Macronutrients: Dextrose 12.5%, AA 2.5% o Maximum Osmolarity: < 1000mOsm

- Central: Long-term, have many types of lines: Broviac, PICC Caloric Distribution for Parenteral Nutrition

- 55-65% Carb: Where dextrose has a caloric density of 3.4kcal/g - 30-35% Fat: Caloric Density is 9kcal/g - 10-15% Protein: Caloric Density 4kcal/g

Caloric Requirements: Not only do the younger patients require more fluid, they also require more calories. The calorie suggestions to the right do not include protein. Protein is an addition Glucose: Glucose is the primary energy source in neonates and infants

- 2-3mg/kg/min glucose administration is required to support protein deposition and growth. Do minimum 4. - 12-14mg/kg/min is the maximal glucose infusion rate (GIR) - So much? A newborn brain uses 8mg/kg/min!

Osmolarity (mOsm/L) = Dextrose (g/L)•5 + AA(g/L)•10 + Cations(mEq/L)•2

(12/4) Pham Lecture: Fluids & Electrolytes & Parenteral Nutrition in Pediatric Patients Neonate/Infant Parenteral Nutrition

- Carbohydrate (Recall, 4 < GIR < 14) Critical for Brain development o Glucose Monitoring: For this sensitive population, use laboratory serum tests rather than strips

§ Booze wipes don’t dry? à Falsely high. ÝHct? à Falsely low. o Serum Glucose Goal: < 120-150mg/dL

§ The fear of hypoglycemia is worse than hyperglycemia. We will try to increase GIR daily as tolerated to reach our goal.

§ Try to avoid insulin unless BG < 250mg/dL o Hyperglycemia: If sugars are high, TG are also likely high. Consider decreasing fat first

- Protein ( >1.5-2g/kg/day) Initiate upon birth 24-32x non-protein kcal for every ‘g’ of protein o Function: Neonates incur high rates of protein turnover, synthesis, catabolism, and deposition. Without

exogenous protein intake, breakdown may overrun synthesis. o Initiation at birth: is associated with preventing catabolism, promoting anabolism, stimulating growth,

and increasing insulin release to help prevent hyperglycemia and hyperkalemia. (Also allows for GIR Ý) o Administer at least 1.5g/kg/day (usually 1.5-2) to prevent breakdown of endogenous tissue. The infant

will lose 1% of their body protein every day that AA is not given. Once hit 10% à Protein Malnutrition. § Excessive Intake ( >6g/kg/day): Aminoacidemia, azotemia, BUNÝ, ‘lower IQ’ § Inadequate Intake ( < 2.5g/kg/day –or- < 24:1 ratio): Edema, slow growth, BUNß

o Daily dose increase (0.5-1g/kg). For pre-term/preemie newborns, starting at 2g/kg/day, the eventual goal is 4g/kg/day, which matches the Utero rate.

- Lipid: (> 0.5g/kg/d, Max 0.15g/kg/h) Critical of Brain development and cell membranes o Function: Serves as an energy substrate (most dense and is isotonic, important for brain development,

prolongs the integrity of peripheral lines Can prevent Phlebitis, Essential Fatty Acid Deficiency (EFAD) § EFAD may develop within first 72 hours of life, especially if not fed 0.5g/kg/day or 1.5g/kg/w § Therefore, initiation at birth is crucial

o Fat Metabolism: Preemies are deficient in Lipoprotein Lipase (LPL) so are unable to break down fat. They may develop Hypertriglyceridemia as a result. Carnitine is essential for transport of long-chain FA to the mito membrane for oxidation – and preemies are often carnitine-deficient.

§ à Supplement carnitine if baby does not tolerate the fat. o Administer the 20% intralipid product (2kcal/mL) – it is better tolerated (has less phospholipid)

§ Max 0.15g/g/h in preemie. Run it over 12-24 hours. § Consider decreasing the fat intake if: Patient is malnourished, has sepsis or trauma, comorbid

liver/renal disease o Monitor: When it comes to fat, the major concern is its affect on the liver. Keep watch of fat status

§ Essential Fatty Acid Status *FFA displace bilirubin from Albumin, see next line § Indirect (Unconjugated) Hyperbilirubinemia *May develop Kernicterus–Hepatic Encephalopathy § Monitor for the development of PNAC or PNALD

o Fish Oil Products: Studies have shown that they decrease inflammatory mediators. The body needs MCT, fish oil alone is not sufficient. Know how our fat source relates to PN-associated liver disease (PNALD)

§ SMOF: Used to prevent PNALD. This is an excellent combo containing MCT. § 100% Fish Oil (Omegaven): Treat and prevent PNALD. However, max 1g/kg/day - nutritionß

Formulation Types: - ‘Starter’ PN Solutions for Very Low Birth Weight

o Using a starter TPN (AA) at birth for very low birth weight (<1500g) patients show: better weight gain, length and head circumference. They show positive nitrogen balance and increase protein accretion.

o Starter PN solutions can only be used on the first day of life, administered peripherally OR centrally - Standard Pediatric Formulations

o Toxic AA: Met, Phe, Gly can all be toxic if the patients are Enzyme Immature, pediatric formulations have low concentrations of these 3 components, since they may accumulate and be toxic

o Conditional Essential: Similarly, Enzyme immaturity confers conditionally essential AA, such as Taurine, His, and Tyr. Taurine especially is critical for brain development. Thus, these are in high concentration.

- Advantages of Pediatric formulations (ProteinÝ): Positive nitrogen balance, lower incidence of cholestasis (liver disease) in VLBW, lower pH increasing the solubility of Ca/Phos, Adequate weight gain

Electrolytes

- Restrictions: No Na or K until they start urinating, due to the high incidence of hyperkalemia. Avoid Mg (Unless mama is taking Mg supplements)

- Sodium: Adjust Na by adjusting fluids. - Potassium: Do not touch it. - Metabolic Acidosis occurs in 90% of preemie, avoid Cl supplementation for first 5-7 days. - More young = More Ca and P needed – greatest accretion of Ca and P occurs during last trimester

o Ideal: Ca : P = 2 : 1 (mEq to mMol) or 1.7:1 (mg to mg) o To meet this ratio when imbalanced, the best option is to reduce P

Calcium Phosphorous Solubility - Consequences of precipitation range can range from mild to life-threatening, small precipitates can obstruct

pulmonary arterioles. Sx of Ca-P ppt accumulation include: Respiratory distress, pulmonary emboli, interstitial pneumonitis

pH (ppt at ÝpH) Temperature/Light [Ca, P] Calcium Salt Order of Addition Cysteine pHß AA+Dextrose pHß Lipid - pHÝ

Warmer temperatures lead to ppt Light exposure à ppt

Add together when in most miniscule amounts to aovid ppt

NEVER use CaCl Use Ca(Gluconate)

Separate their admin as far as possible.

Trace Elements - Zinc: High amounts required. Give additional for pt with stoma, fistula, or diarrhea - Copper: Eliminated via the biliary tract, avoid in Liver disease pt - Manganese: Avoid in liver disease pt - Chromium: Avoid in renal disease - Selenium: Avoid in renal disease

Other Supplements - Heparin – This is often included in some of the pediatric formulations

o (1) Reduces formation of fibrin sheaths around the catheter, helping to reduce the incidence of phlebitis o (2) Stimulates the release of Lipoprotein Lipase (LPL), helping with TG and lipid clearance o (3) Reduces the amount of CRS infections – likely due to cleaning the lines

- IV Iron – For patients NPO for a long time, this may need to be supplemented o Though it is controversial

Transitioning from PN to EN - It takes a very long time and much effort to ween off long-term TPN. Stop TPN when EN intake is 75% - Slowly decrease PN nutrients while increasing EN feeds

Nutritional Assessment - Weight gain: This needs to be monitored daily, there should be significant growth - Height and Length: Measure this weekly, we are just concerned about linear growth - Head circumference: Especially in neonates and young infants, this needs to be measured weekly - Serum Albumin: Poor indicator for acute, affected by too much shit - Prealbumin: May be decreased in liver disease, falsely elevated in renal failure - BUN: Low in inadequate AA intake, high in excess AA intake

Treatment of Complications - Phlebitis/Infiltration/Tissue Damage: Use hyaluronidase injections instead. Can also supplement in Heparin,

decrease the osmolarity, or co-infuse with IV fat. - Central Line Infections: Gram(+) are the most common (Staph, Enterococcus)

o Prevention: Catheter locks (ethanol 70%, Vancomycin) or continuous infusion heparin o Treatment: Catheter removal or antibiotics

- PNALD: This is a liver injury due to long-term PN use, identified by high direct bilirubin, often occurring as early as 2 weeks after initiation. FAT is the number 1 cause, Carb is the second.

o Management: Cut down the intralipid (SMOF as a preventative), cut down on the carb (limit 10-12mg/kg/min). Try cycling the PN. Can also remove the copper/manganese

o Treatment: Ursodiol, Oral Metronidazole, Oral Bactrim - Metabolic Bone Disease (MBD): Occurs in up to 55% of ELBW and VLBW infants. The cause is usually

prematurity, inadequate Ca + P, drugs, aluminum. o Dx: ALT > 650 (#1 marker), Low serum P, normal serum Ca o Tx: Optimize Ca : P ratio to 2:1. Give elemental Ca and P. Maybe human Milk, even Vit D