Donna M. Kraus, Pharm.D.
Spring 1998

Pediatric Hyperalimentation Calculations

OR

So, what's a peds hyperal order supposed to look like?

Baby Doe is a 2 kg premature infant on day 7 of hyperalimentation. Hyperalimentation was started on day 3 of life. Serum electrolytes (including Ca, Phos and Mg), liver function tests, triglycerides, BUN and SCr are all within normal limits. Patient has a central line.

HYPERALIMENTATION ORDER

Dextrose	20 %
Trophamine	2.3 %
Cysteine	40 mg/gram protein
NaCl	3 mEq [NOTE: additives are per day]
Na lactate	3 mEq
KCl	2 mEq
K Phosphate	3 mEq
MgSO4	0.5 mEq
Ca Gluconate	600 mg
Heparin	1 unit/ml
MVI Pediatric	3.25 ml
Neotrace	0.4 ml
Selenium	4 mcg

Infuse 10.8 ml/hour x 24 hours

Intralipid 20% infuse 1.2 ml/hour x 24 hours.

1. Does this order provide the patient with daily maintenance fluid requirements?

YES it does, in fact, it provides 1.2 x maintenance:

Daily maintenance fluid requirement for a 2 kg patient:

120 ml/kg/day = 120 x 2 kg = 240 ml

This TPN order would deliver:

HAL	10.8 ml/hour x 24 hours =	259.2 ml/day
Intralipid	1.2 ml/hour x 24 hours =	28.8 ml/day
	TOTAL	288.0 ml/day

288 ml/day (being given) divided by 240 ml/day (maintenance) = 1.2 times maintenance (288/240). This amount of fluid (or even greater) would be expected because in order to increase calories, fluids are increased in a stepwise fashion. 1.2 times the normal daily maintenance fluids would be acceptable for an infant who has been on TPN for this amount of time.

2. Does this order provide appropriate amounts of dextrose, protein and fats for this infant ? Yes, Yes, Yes.

a. Dextrose: 20% dextrose requires a central line (patient has one). Dextrose 20% would be appropriate, as long as patient is not hyperglycemic or spilling glucose in urine.

[Note: If you wanted to, you could calculate mg/kg/min of glucose by the following method:

* Remember 20 % dextrose = 20 grams/100 ml = 0.2 grams dextrose/ml

10.8 ml/hour x 0.2 grams/ml = 2.16 grams/hour

2.16 gm/hour divided by 60 min/hour = 0.036 grams/min = 36 mg/min

36 mg/min divided by 2 kg = 18 mg/kg/minute. This is in line with the normal maximum of 18 - 20 mg/kg/minute.]

b. Protein: This order would deliver 259.2 ml/day of a 2.3 % protein solution.

2.3 % = 2.3 grams/100 ml = 0.023 gram/ml

259.2 ml/day x 0.023 grams/ml = 5.96 grams/day

5.96 grams/day divided by 2 kg = 2.98 = 3 grams/kg/day of protein

Remember: For premature and term infants, the daily amount of protein needed to promote nitrogen retention (See your notes) is 2.5 - 3 grams/kg/day, so this hyperal order would provide an appropriate amount.

c. Fats: This order would deliver 28.8 ml/day of a 20% intralipid emulsion.

20 % = 20 grams/100 ml = 0.2 grams/ml

28.8 ml/day x 0.2 grams/ml = 5.76 grams/day of fat

5.76 grams/day divided by 2 kg = 2.88 grams/kg/day of fat

For premature infants or infants SGA the maximum recommended amount of fat/day would be 3 grams/kg/day, so this hyperal order would provide an appropriate amount.

3. What is the nonprotein caloric content of the TPN order? i.e., how many Kcal/kg/day will this infant receive from nonprotein substrates ? Is that calculated amount sufficient for growth?

a. Calories from dextrose. First determine how many grams of dextrose you are giving, and then multiply by the amount of calories per gram.

10.8 ml/hour x 24 hours = 259.2 ml/day of a 20% dextrose solution. [ 20% = 20 grams/100 ml = 0.2 grams/ml]

259.2 ml/day x 0.2 grams dextrose/ml = 51.84 grams/day dextrose.

Dextrose has 3.4 Kcalories/gram, so

3.4 cal/gram x 51.84 gram = 176.3 Kcalories from dextrose

b. Calories from intralipid. Other additives (not counted in the 20% labeling) add to the caloric density of intralipid, therefore you cannot use the same method for calculating fat calories as you do for calculation of dextrose calories.

You need to memorize:

Intralipid 10 % = 1.1 Kcal/ml

Intralipid 20 % = 2.0 Kcal/ml

Intralipid 20% 1.2 ml x 24 hours = 28.8 ml/day

28.8 ml x 2 Kcal/ml = 57.6 Kcal/day from Intralipid

c. Total nonprotein calories = dextrose calories plus intralipid calories=

176.3 + 57.6 = 233.9 Kcal/day

233.9 Kcal/day divided by 2 kg = 117 Kcal/kg/day.

d. Caloric requirements for 0 to 1 years of age (see notes) are 90 - 120 Kcal/kg/day. This current TPN order should provide enough calories for growth, however, it is most important to make sure that the child is indeed growing. Weight, height and head circumference should be monitored and values plotted on growth charts (Don't worry I will not make you do this on a quiz). If for some reason the child is not growing while receiving 117 Kcal/kg/day, then the hyperal rate can be increased (usually, for this weight of a patient, by 10 ml/kg/day). This will increase calories by increasing the amount of dextrose delivered per day.

4. Please comment on the other additives in the hyperal, i.e., are they dosed appropriately? YES indeedee, they are all OK!!

K Phosphate has 0.68 mmol phosphate per mEq = 3 mEq/day x 0.68 = 2.04 mmol phosphate per day = 1.02 mmol/kg/day.

NOTE: If this was day 1 of hyperalimentation, the hyperal would be started at the initial doses listed in your handout, i.e., Maintenance fluid (most likely) = 120 ml/kg/day

Dextrose 5 % (or if was already on dextrose 5 % perhaps 7.5%)

Trophamine 0.5 grams/kg/day

Intralipid 0.5 grams/kg/day

For a 2 kg patient the first hyperal order may look something like this:

Infuse 9.6 ml/hour x 24 hours -----------------> 230.4 ml/day

Intralipid 10% infuse 0.5 ml/hour x 20 hours---> 10.0 ml/day

TOTAL 240.4 ml/day

This TPN would provide only 50.2 Kcal/day = 25 Kcal/kg/day, a big difference from calories provided in the hyperal on day 7 above.

Pediatric Case

TPN

TG is a 6 year old male with short bowel syndrome secondary to necrotizing enterocolitis during infancy. He is currently hospitalized for failure to gain weight at home while receiving enteral feedings and home hyperal. The patient has been made NPO since admission 3 days ago, when full hyperalimentation was started.

 

PE: Small undernourished male child in NAD, playing quietly with toys in crib. Sterile dressing from central catheter in place.

HR 100

RR 22

BP 100/65

T 98.6o F

Weight 16 kg (less than 5th percentile for weight)

Height 105 cm (less than 5th percentile for height)

LABS: Na, K, Ca, Cl, SCr, glucose, CO₂ all within normal limits for age.

Hgb/Hct 11.4/33 (lower limit of normal for age 11.5/35)

The new pediatric intern orders the following hyperalimentation for TG:

 

HA #4:

Dextrose	10 %
Amino acids	7 %
NaCl	48 mEq/day
KCl	32 mEq/day
MgS04	40 mEq/day
Ca Gluconate	4800 mg/day
Heparin	1 unit/ml
Selenium	48 mcg/day
Infuse at 47.5 ml/hour x 24 hours
Intralipid 20% 6.6 ml/hour x 24 hours

 

1. Do the above orders meet this child's daily maintenance fluid requirements and requirements for protein and fat?

2. Would you fill this hyperalimentation order for this patient?

Why/why not?

3. What other laboratory tests would you like to see done for this patient? Give reasons for your selections.

KEY to Practice Pediatric Nutrition Case

RECITATION LEADERS:

* Remind students of this patient's indication for hyperalimentation. i.e., "short bowel syndrome."

* Remind students of what short bowel syndrome is, i.e., "Short gut syndrome" or "short bowel syndrome" is a condition which is present after a significant amount of intestine has been surgically removed. Often these patients are dependent upon lifetime parenteral nutrition. Depending on the total amount of bowel removed, patients may be NPO and receive full hyperal, or may be on a combination of enteral feeds and hyperal, as in this case. [Hyperal supplements enteral feeds]. Since this patient was not gaining weight, [note pt is less than 5th percentile for height and weight] pt was placed NPO and "full" hyperal was started.

* You may wish to point out that this patient has normal vital signs for age:

HR: 5 - 7 years old = mean 100 range 65 - 133;

RR: 3 - 9 years old = 20 - 25 mean breaths per minute;

BP: systolic bp of 100 = between 50th - 75th percentile for a 6 yr old male.

KEY to Practice Pediatric Nutrition Case

1. Do the above orders meet this child's daily maintenance fluid requirements and requirements for protein and fat?

a. Daily fluid maintenance requirement for 16 kg patient

100 ml/kg/day for first 10 kg = 100 x 10 kg = 1000 ml

50 ml/kg/day for next 6 kg = 50 x 6 kg = 300 ml

TOTAL = 1300 ml

This patient does not have any factors which would increase insensible water loss, therefore daily maintenance fluid should be 1300 ml/day. (also no deficits, no ongoing losses)

Patient receives:

HAL: 47.5 ml/hour x 24 hours = 1140 ml

FAT: 6.6 ml/hour x 24 hours = 158 ml

TOTAL = 1298 ml

 

1298 ml is close enough to 1300 ml, therefore ----> yes, patient is receiving daily maintenance fluids.

b. Protein

Patient is receiving 1140 ml/day of 7 % amino acid solution, therefore: [ note 7 % = 7 grams/100 ml = 0.07 grams/ml]

1140 ml/day x 0.07 grams protein/ml = 79.8 grams protein/day

4.98 grams/day divided by 16 kg = 4.98 grams/kg/day. [YIKES! too high]

Protein requirements for children > 1 yr of age = 1.5 - 2.5 grams/kg/day.

This hyperal would provide TWICE the normal amount of protein.

The MD intern obviously made an error in protein calculation. Correct percent protein should be 3.5 % not 7 %.

c. FATS

 

Patient is receiving 158.4 ml/day of 20% Intralipid.

20 % = 20 grams/100 ml = 0.2 grams/ml

158.4 ml/day x 0.2 grams/ml = 1.98 grams of fat/kg/day. [ AOK ]

Lipid emulsion dosing guidelines for older children = 2 - 3 grams /kg/day. Therefore child is receiving appropriate amount of FAT.

2. Would you fill this hyperalimentation order for this patient?

Why/why not? [Hint: Are there any errors or omissions?]

This hyperal should NOT be dispensed as written!!!! There are too many missing ingredients, errors, and non-optimization of ingredients (dextrose).

a. Protein is too high

b. Dextrose is too low (ie. should have been advanced to higher percent, patient is on day 4 of hyperal and serum glucose is normal)

c. MgS04 is too high (HAL has 2.5 mEq/kg/day; should be 0.25 - 0.5 mEq/kg/day)

d. Selenium dose is greater than maximum of 40 mcg/day.

e. MVI pediatric is missing

f. Trace elements are missing

g. Phosphorus is missing

h. Inquire about iron supplementation

i. Calcium is too high: 300 mg/kg/day for a 6 year old is high. Range given in class for calcium gluconate = 100 - 500 mg/kg/day, but notes also say older children require 1- 2 grams/day.

3. What other laboratory tests would you like to see done for this patient? Give reasons for your selections.

Urine glucose: to check for spilling of glucose in urine. (If patient is spilling glucose, it would indicate that the patient is receiving too high of a dextrose concentration or that advancement of the hyperal's dextrose concentration was too fast.)

Serum magnesium: part of routine monitoring, plus current order is for 10 times the normal amount of MgS0₄. This patient may have been getting this overdose for sometime now and it is important to see if this patients serum Mg is elevated.

Serum phosphorous: part of routine monitoring, plus there is no phosphorous in hyperal order. This patient may have not been receiving any phosphorous, so it is important to see what his level is at this time.

Serum BUN and ammonia: to assess protein catabolism. If BUN and/or ammonia is/are elevated, protein in hyperal may be too high, or may have been advanced too quickly.

Serum bilirubin and hepatic enzymes: to monitor for adverse effects of hyperalimentation.

Serum protein / albumin: to monitor for hyperal efficacy. If sufficient protein is being given, these would increase to normal values.

Triglycerides and/or cholesterol: to monitor lipid therapy

Serum Fe, TIBC, MCV etc, to monitor anemia ---> r/o iron deficiency anemia

Pediatric Case

Enteral Nutrition

 

RH is a 6 month old who appears at pediatric clinic. His height and weight are 95th percentile for age.

Vital signs: HR 175 RR 30 BP 90/60

 

Diet:

whole cow's milk

6 feedings/day, 6 ounces per feed

LABS:

Hgb/HCT 9.8/29.4

Serum Fe: 12 mcg/dl (nl for age = 40 - 100)

Other indices compatible with iron deficiency anemia

Medications: None

Allergies: Amoxicillin -> rash

1. Why did this patient develop an iron deficiency anemia?

2. List the differences between human breast milk and cow's milk with respect to protein, carbohydrates and fats.

Enteral Nutrition

KEY

RH is a 6 month old who appears at pediatric clinic. His height and weight are 95th percentile for age.

Vital signs: HR 175 RR 30 BP 90/60

Diet:

whole cow's milk

6 feedings/day, 6 ounces per feed

LABS:

Hgb/HCT 9.8/29.4

Serum Fe: 12 mcg/dl (nl for age = 40 - 100)

Other indices compatible with iron deficiency anemia

Medications: None

Allergies: Amoxicillin -> rash

1. Why did this patient develop an iron deficiency anemia?

The iron deficiency anemia is most likely due to the diet of whole cow's milk. The iron in cow's milk is less bioavailable than the iron found in human breast milk. When infants drink only cow's milk without any other source of iron, iron deficiency anemia often occurs.

NOTE: The above answers the question. Other important points to remember:

 

Whole cow's milk is higher in fat than 2% or milk or skim milk. Generally, whole cow's milk, 2% milk and skim milk should not be given to children under 1 year of age and only 2% or skim milk should be given in children > 2 years of age. Also, infants at 4 to 6 months of age should be starting spoon feedings of iron fortified infant cereal.

2. List the differences between human breast milk and cow's milk with respect to protein, carbohydrates and fats.

(*****This answer is straight from the handout*****)

Protein: Human milk contains a lower amount of protein compared to cow's milk, but is easier to digest.

Protein types: Two major types of proteins are found in milk.

Whey protein contains alpha-lactalbumin, beta-lactoglobulin, lactoferrin, albumin, lysozyme and IgA, IgG and IgM. Whey protein is highly soluble and easier to digest.

Casein protein contains a mixture of caseins (alpha, beta, gamma and kappa). Casein is relatively insoluble and forms "tough" curds.

Protein:

	Whey: Casein ratio
Breast milk	60:40 to 70:30
Cow's milk	20:80

 

Human milk contains a lower casein content and therefore is more easy to digest, compared to cow's milk.

Other protein differences: breast milk vs cow's milk:

Lactoferrin is found in greater quantities in human milk then cow's milk. Lactoferrin is an iron binding protein found in whey (1/3 saturated with iron). Lactoferrin increases the bioavailability of iron. It also has an inhibitory effect on E. Coli and may offer some protection against enteric infection.

Secretory IgA is also found in greater quantities in human milk than cow's milk. As an immunoglobulin, it may offer some local G.I. protection against infection.

Lysozyme is found in human milk but not in cow's milk. Lysozyme has bactericidal effects.

Fats: Human milk and cow's milk contain a similar total amount of fat but the type of fats differ.

Human milk contains more of the essential fatty acid, linoleic acid, compared to cow's milk.

Human milk but not cow's milk contains human milk lipase to aid in the digestion of fat.

Human milk contains long chain unsaturated fatty acids as well as medium chain fatty acids. Cow's milk contains short and long (primarily saturated) fatty acids.

Carbohydrates: Because cow's milk contains less carbohydrates than human milk, supplementation of cow's milk with carbohydrates to make milk-based formulas is necessary.

Lactose is the primary carbohydrate for human milk, cow's milk and milk-based infant formulas.

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