Prior to 1968, many chronically/critically
ill pts died of malnutrition; not 1˚ condition
Parenteral nutrition, meeting all or part of pts
nutritional needs via intravenous feeding, met a
great medical need.
Improperly managed, PEN has serious
complications including liver dysfunction,
bone diseases, kidney failure, and
MANY nutrient deficiencies.
Ingredients to be considered in PN
CHO
Protein
Lipids
Vitamins
Minerals
Trace Elements
FLUIDS
Composition of intravenous solutions
Crystalline amino acids: 10 & 15% stock Sol’n
Normal and special purpose formulations
Available (renal= essential aa [ ], liver dz=
High BCAA)
4.0 kcal/g
Carbohydrate: Dextrose= 3.4 kcal/g
Available in 2.5 to 70% sol’n
Lipid: Provides essential fa (linoleic, linolenic)
10% = 1.1 kcal/ml (500 ml bottle = 550 kcal)
20% = 2.0 kcal/ml (500 ml bottle = 1000 kcal)
EFA Requirements can be met:
500 ml of 10% lipid emulsion 2 to 3 times/ week
or
200 ml per day
Substrates in Parenteral Nutrition
Substrate
Carbohydrate
Protein (CAA)
Lipids
Usual Amount
(% of kcals)
40-60%
1-2
gm/kg/day
20-40%
Maximum
Units
< 5 mg/kg/day
2-2.5 g/kg/day
2 g/kg/day
< 1 g/kg/day
in High Stress
Calculating the Nutrient Content of IV Solutions
Example:
Pt receiving 3 liters consisting of:
1500 ml 50% dextrose (3.4 kcal/g)
1500 ml 7% CAA (4 kcal/g)
CHO:
50 g/100 ml = x g / 1500 ml
x = 750 g dextrose x 3.4 kcal/g = 2550 kcal
Protein:
7 g/ 100 ml= x g / 1500 ml
x = 150 g x 4.0 kcal/g =
Total
=
420 kcal
2970 kcal
Types of Parenteral Feedings
Simple IV Solutions
Composition:
Use:
Nutrients:
Water, Dextrose, Electrolytes
When pts are NPO after surgery,
trauma or illness.
5% dextrose in normal saline
(0.85% NaCl) often used.
% means “grams per 100 mL”
3 liters delivers 150 g dextrose
or ~500 kcal per day.
Types of Parenteral Feedings
Peripheral Parenteral Nutrition (PPN)
Use:
Short-term nutrition support for those
with normal renal fxn and normal fluid/
electrolyte regulation.
Can be used to supplement diet of those
with limited oral intakes.
Composition: Crystalline amino acids, dextrose,
lipid emulsion, MVI, electrolytes,
trace elements.
Types of Parenteral Feedings
PPN (con’t)
Lipid Emulsion typically provides ~50% of kcals
(Isotonicity of lipids helps peripheral veins tolerate
the hyperosmolar dextrose solutions)
Prolonged IV lipids can cause hepatomegaly, enlarged
spleen, dyslipidemia.
Can deliver ~2500 kcal and ~ 150 g CAA via PPN.
Total Parenteral Nutrition by Central Vein
Placed in large diameter central vein or threaded
to central vein via catheter (PICC).
Who are candidates?
Paralytic ileus due to surgery, radiation trt, GI obstructions,
etc.
AIDS
Unusable GI tract expected > 14 days (e.g. hypermetabolism,
severe N/V)
Severe pancreatitis
Intractable diarrhea or vomiting
High output enterocutaneous fistulas
Mr. Rossi, 37 yo mail carrier
Admitted to hospital for deteriorating GI due to Crohn’s
Appearance:
Emaciated, face appears drawn
Medical Prognosis:
Poor; recommend small
bowel resection.
Serum Albumin: 2.5 mg/dL
What Factors indicate need for Nutriton
Support?
1.
Lack of functional GI tract.
2.
Chronic GI disorder (Crohn’s Dz)
3.
Evidence of protein-energy malnutrition
(e.g., physical signs, low serum albumin)
Mr. Rossi is placed on central TPN prior to surgery.
WHY?
Surgery in high risk PEM pts can exacerbate the
condition
Because surgery produces catabolic
stress that can further deplete
somatic protein stores.
What are the goals of TPN?
•
Stabilize nutritional status in
in post-operative period.
•
weight restoration
(improved nutritional status)
•
Increased strength and endurance.
Use the GI tract (begin enteral feeding)
as soon as bowel function returns.
Mr. Rossi received three (3) liters of a solution
containing D50W and 10% amino acids.
D50W = 50 g dextrose per 100 mL
= 250 g dextrose per 500 mL bottle
kcal = 250 g x 3.4 kcal/gram = 850 kcal per
500 mL bottle
Protein:
10% amino acid sol’n= 10 g / 100 mL or 50 g/500 mL
bottle
50 g X 4.0 kcal/gram = 200 kcal per 500 mL
bottle
Lipids:
1- 500 ml bottle 10% emulsion
X 3 per week
500 mLs X 1.1 kcal/mL = ~500 kcal
How will Mr. Rossi be started on central TPN?
Slowly!
Hyperosmolar solution!
Starting rate?
40 mL per hour for 24 hours
Increase one liter per day until
desired volume per 24 hours is
reached.
MONITOR!
Blood glucose, electrolytes!
Transitioning Mr. Rossi to Enteral Diet
When?
If >60% of kcals is being met
by enteral formula, oral intake
of solid food, or both
TPN can be discontinued.
If solid foods are consumed BUT, after 3 days intakes
are <50% of needs, START enteral feedings.
1.
Maintenance of the gut barrier.
2.
Improvement in immune function.
3.
Maintenance of digestive and absorptive
function.
4.
Promotion of secretion of gut trophic
hormones.
1.
Catheter-Related Problems:
Sepsis: infection in bloodstream resulting
from contaminated catheter or
catheter site.
Others: pneumothorax, air embolus, arterial
puncture, et al.
2.
Metabolic Problems:
Hyperglycemia, glycosuria, compromised
respiratory function
mineral and electrolyte abnormalities
Elevation of hepatic enzymes (usually
2˚ to FATTY LIVER)
3.
GI Complications:
GI Atrophy (Disuse Atrophy)
Sample TPN Calculation:
60 yo male with small bowel resection
5’10” (178 cm), 140# (63.6 kg)
1.
Estimate daily energy needs:
35 kcal/kg x 63.6 kg = 2230 kcal/day
2.
Estimate daily protein needs:
1.5 g/ kg x 63.6 kg = 95 kg or
95 g/ 6.25 = 15.3 g Nitrogen
3.
Estimate Fluid Needs:
30 mL fluid/ kg x 63.6 kg = 1910 mL
4.
Based on these data, assume a final volume
of 2,000 mL or 2 L will be used.
Assume <10% of total volume will be used
for additives.
5.
Two more assumptions:
25% of kcal from fat
Standard solutions: 20% lipid, D70W, 10% AA
Lipids Calculation:
2230 kcal/ day X 0.25 (25% of kcal) =
560 lipid kcals
560 lipid kcals X 1 mL/ 2 kcal (20% lipid emulsion)
=
280 mL/ day or 140 mL in each liter
Calculate Amino Acids:
95 g protein/ day X 100 mL/ 10 g AA =
950 mL 10% AA or 475 mL per liter
Options:
Can either count or NOT count
protein kcals in total.
In either case, must KNOW how much
will be delivered to prevent UNDERor OVER-feeding.
If we assume we will NOT include protein kcals:
75% of kcals will be met from DEXTROSE.
2230 total kcals X 0.75 = 1675 kcals from dextrose
1675 dextrose kcals X 1 gram/ 3.4 kcal/gram =
495 grams dextrose/day
Volume of D70W needed:
495 grams dextrose X 100 mL / 70 g = 710 mL
70% D/ day
or 355 mL/ L of TPN solution
Based on above: Each liter contains-140 mL 20% lipid emulsion
475 mL 10% AA solution
355 mL 70% dextrose
30-70 mL additives
Use this info to calculate FINAL [ ] of nutrients:
Lipids:
140 mL/ liter X 20 g lipid/ 100 mL X 1 L/ 1000 mL =
0.028 g lipids/ mL X 100 mL = 2.8% lipids
Amino Acid [ ]:
475 mL / liter X 10 grams AA / 100 mL X 1 L / 1000 mL=
0.0475 g AA/ mL X 100 = 4.75% amino acids
Dextrose [ ]:
355 mL/ liter X 70 g dextrose / 100 mL X 1 L / 1000 mL =
0.2485 g dextrose/ mL X 100 = 24.85 % AA
Summary and TPN Order
Total Volume= 2,000 mL / 24 hrs; 83 ml/ hr.
Nonprotein energy:
Protein:
Kcal: N ratio =
2235 kcal (25% lipid, 75%
dextrose)
95 grams
2235 nonprotein kcal/ 15.3 g N
= 146: 1
Sample TPN Order:
2 L/ day of 25% dextrose, 2.8% lipid emulsion,
and 4.75% amino acid solution with STD
additives to run at 83 cc/hr.