Total Parenteral Nutrition

(TPN)

What is TPN?

◼ Parenteral nutrition: process of supplying nutrients via the intravenous route

– Total parenteral nutrition (TPN)

– Peripheral parenteral nutrition (PPN)

◼ TPN may reduce morbidity and mortality after major surgery, severe burns, and head trauma, especially in patients with sepsis.

◼ TPN is often used in hospital, long term care, and sub-acute care, and infrequently is used in the home care setting.

Indications

◼ Patients whose GI tract is not functional. – e.g. 50% of metabolic needs met for < 7 days

◼ Undernourished patients who cannot ingest large volumes of oral feedings and are being prepared for surgery, radiation therapy, or chemotherapy.

◼ Disorders requiring complete bowel rest – Crohn's disease

– ulcerative colitis

– severe pancreatitis

◼ Pediatric GI disorders– congenital anomalies

– prolonged diarrhea

Nutritional Content

◼ Water– 30 to 40 mL/kg/day

◼ Energy – 30 to 60 kcal/kg/day (depending on energy expenditure)

◼ Amino acids– 1 to 2.0 g/kg/day (depending on the degree of catabolism)

◼ Essential fatty acids

◼ Vitamins, and minerals

◼ Children who need TPN may have different fluid requirements and need more energy (120 kcal/kg/day) and amino acids (2.5 to 3.5 g/kg/day).

Basic TPN Solutions

◼ Prepared using sterile techniques

◼ Usually in liter batches according to standard formulas. – Normally, 2 L/day of the standard solution is needed.

◼ Solutions may be modified based on laboratory results, underlying disorders, hypermetabolism, or other factors.

◼ Commercially available lipid emulsions are often added to supply essential fatty acids and triglycerides– 20 to 30% of total calories traditionally have been supplied as

lipids.

– Withholding lipids and their calories may help obese patients mobilize endogenous fat stores, increasing their insulin sensitivity.

Special Considerations

◼ Patients who have renal insufficiency and are not receiving dialysis or who have liver failure require solutions with reduced protein content and a high percentage of essential amino acids.

◼ For patients with heart or kidney failure, volume (liquid) intake must be limited.

◼ For patients with respiratory failure, a lipid emulsion must provide most of non-protein calories to minimize CO2

production by carbohydrate metabolism.

◼ Neonates require lower dextrose concentrations (17 to 18%).

Initiating TPN

◼ Vascular Access

– Central venous access

◼ Large vessels such as subclavian vein or internal jugular

vein

◼ Less incidence of extravasation

◼ Solution with dextrose concentration greater than 10%

must be delivered into the central venous system because

of the hypertonicity of the solution

◼ In-line filters are controversial and may not help.

◼ Started slowly at 50% of the calculated requirements, using 5%

dextrose to make up the balance of fluid.

◼ Osmolarity limits– Peripheral: 600-900 mOsm/L

– Central: > 1800 mOsm/L◼ Increased osmolarity limits allows for increased concentrations of

dextrose and amino acids to be delivered

◼ Osmolarity of additivies (per 1% final concentrations)– Amino acids: 100 mOsm/L

– Dextrose: 50 mOsm/L

– Lipids: 1.7 mOsm/L

– Electrolytes: 1-1.4 mOsm/meq

Malnutrition

◼ Incidence: 50 % of hospitalized patients

◼ Common causes:

- Hypermetabolic states: Trauma, Infection, Major surgery, Burn

- Poor nutrition

◼ Consequences: Weakness, Decreased wound healing, increased respiratory failure, decreased cardiac contractility, infections (pneumonia, abscesses), Prolonged hospitalization

Nutritional Support

◼ Enteral Nutrition ( Physiologic, less expensive)

◼ Parenteral Nutrition

- GI should not be used (Obstruction, Pancraitis)

- GI can not be used ( Vomiting, Diarrhea,

Resection of intestine, IBD)

Parenteral Nutrition

◼ Peripheral Parenteral Nutrition (15 lit D5W/day for a 70 kg !!!)

◼ Central Parenteral Nutrition (TPN)

◼ Needs CV-line to administer hyperosmolar solutions

Estimation of energy expenditure

Harris-Benedict equations:

◼ BEE (men) (kcal/day): 66.47+13.75W+5H-6.76A

◼ BEE (women) (kcal/day): 655.1+9.56W+1.85H-4.68A

◼ TEE (kcal/day):

BEE × Stress factor × Activity factor

◼ Stress factors: Surgery, Infection: 1.2 Trauma: 1.5

Sepsis: 1.6 Burns: 1.6-2

◼ Activity factors: sedentary: 1.2 , normal activity: 1.3,

active: 1.4 , very active: 1.5

Stress level

◼ Normal/mild stress level: 20-25 kcal/kg/day

◼ Moderate stress level: 25-30 kcal/kg/day

◼ Severe stress level: 30-40 kcal/kg/day

➢ Pregnant women in second or third trimester:

Add an additional 300 kcal/day

Fluid: mL/day

◼ 30-40 mL/kg

Protein (amino acids)

◼ Maintenance: 0.8-1 g/kg/day

◼ Normal/mild stress level: 1-1.2 g/kg/day

◼ Moderate stress level: 1.2-1.5 g/kg/day

◼ Severe stress level: 1.5-2 g/kg/day

◼ Burn patients (severe): Increase protein until

significant wound healing achieved

◼ Solid organ transplant: Perioperative: 1.5-2

g/kg/day

Protein need in Renal failure

◼ Acute (severely malnourished or hypercatabolic):

1.5-1.8 g/kg/day

◼ Chronic, with dialysis: 1.2-1.3 g/kg/day

◼ Chronic, without dialysis: 0.6-0.8 g/kg/day

◼ Continuous hemofiltration: ≥ 1 g/kg/day

Protein need in Hepatic failure

◼ Acute management when other treatments have

failed:

◼ With encephalopathy: 0.6-1 g/kg/day

◼ Without encephalopathy: 1-1.5 g/kg/day

◼ Chronic encephalopathy

◼ Use branch chain amino acid enriched diets only if

unresponsive to pharmacotherapy

◼ Pregnant women in second or third trimester

◼ Add an additional 10-14 g/day

Fat

◼ Initial: 20% to 40 % of total calories (maximum:

60% of total calories or 2.5 g/kg/day)

◼ Note: Monitor triglycerides while receiving

intralipids.

◼ Safe for use in pregnancy

◼ I.V. lipids are safe in adults with pancreatitis if

triglyceride levels <400 mg/dL

Components of TPN Formulations

Macro:

Calorie: Dextrose 20%, 50%

Intralipid 10%, 20%

Protein: Aminofusion 5%, 10%

Micro:

Electrolytes (Na, K, Mg, Ca, PO4)

Trace elements (Zn, Cu, Cr, Mn, Se)

Dextrose

◼ 20%, 50% ( from CV-line)

◼ 3.4 kcal/g

◼ 60-70% of calorie requirements should be

provided with dextrose

For 1000 ml solution

D50W D10W D5W

D20W 250 ml 750 ml ------

333 ml ------ 667 ml

D30W 500 ml 500 ml ------

555 ml ----- 446 ml

D40W 750 ml 250ml ------

778 ml ------ 222 ml

Dextrose: Contraindications

◼ Hypersensitivity to corn or corn products

◼ Hypertonic solutions in patients with intracranial

or intraspinal hemorrhage

Abrupt withdrawal

◼ Infuse 10% dextrose at same rate and monitor

blood glucose for hypoglycemia

Intralipid

◼ 10%, 20% ( from peripheral or CV-line)

◼ 1.1 kcal/ml (10%), 2 kcal/ml (20%)

◼ 30-40% of calorie requirements should be

provided with Intralipid

1022 Kcal/L

345 mosmol/L1080 Kcal/L

Intralipid: Contraindication

◼ Hypersensitivity to fat emulsion or any

component of the formulation; severe egg or

legume (soybean) allergies

◼ Pathologic hyperlipidemia, lipoid nephrosis,

pancreatitis with hyperlipemia (TG>400 mg/dl)

Aminofusion

◼ 5%, 10% ( from CV-line)

◼ 1-1.5 g/kg/day

◼ Should not be used as a calorie source

200 kcal/L

590 mosmol/L

400 Kcal/L

1030 mosmol/L

Amino acids: Contraindications

◼ Hypersensitivity to one or more amino acids

◼ Severe liver disease or hepatic coma

Case

◼ D.C a 38 y.o man with a 12-year history ofcrohn’s disease is admitted to surgery ward of Imam hospital in Sari for a compliant of increasing abdominal pain, nausea & vomitingfor 7 days and no stool output for 5 days. Because of N & V, he has been drinking only liquids during the past weeks. His crohn disease had several exacerbations during the past 2 years and 10 cm of his ileum has been resected 6 month ago.

case (continue)

Drugs: Mesalamine 1000 mg qid + prednisolone

10mg/d. Abdominal x-ray is consisting with

bowel obstruction. Exploratory laparotomy

was performed and 25 cm of his ileum

resected. Bowel sounds are absent. He has a

right subclavian CV-line. Considering that his

Ht=180cm, Wt=60kg (6 month ago: 70 kg)

and Age=38 y.o, what is your recommended

TPN formula for him?

◼ BEE= 66.47+13.75×60+5×180-6.76×38=1535 kcal/d

◼ TEE= 1535×1.2×1.2 = 2200 kcal/d

◼ Intralipid 10%= ? 2200 × 30%= 660 kcal

1ml ≡ 1.1 kcal 660 : 1.1 = 600 ml ( 500ml)

◼ Dext 50%= ? 2200 – 550= 1650 kcal

1g dextrose ≡ 3.4 kcal 1650 : 3.4= 485 g Dext

50g ≡ 100 ml 485 g ≡ 970ml (1000ml)

◼ Aminofusion 10 %= ? 1.5 g/kg/d × 60 kg=

90g/day 10g ≡ 100 ml 90g ≡900 ml (1000ml)

Electrolytes (daily requirements for TPN):

◼ Na: 80-100 mEq (50 - 100 ml NaCl 5%)

◼ K: 60-80 mEq (30 ml KCl)

◼ Cl: 50-100 mEq

◼ Mg: 8-16 mEq (5 -10 ml MgSo4 20%)

◼ Ca: 5-10 mEq (10-20 ml Ca Gluconate 10%)

◼ P04: 15-30 mEq

◼ Acetate: 50-100 mEq

Special Considerations

◼ Max infusion rate of dextrose: 0.5g/kg/h (to

avoid hyperglycemia, glycosuria, fatty liver,

hyperosmolar coma)

◼ K should be added to dextrose solutions

◼ Slow starting & slow tapering of Dext 50%

◼ If BS>200, Insulin should be added

◼ some brands of lipids can be mixed with

Dext+Aminifusion in the same IV container

Special Considerations

◼ Intralipid contraindications:

◼ Severe egg allergy

◼ Hyperlipidemia

◼ Special aminoacid products:

◼ Hepatamine: for Hepatic Failure

◼ ↑ branched chain aa ( leu, isoleu, val)

◼ Nephramine: for Renal Failure

◼ Primarily essential aa with lower concentrations

Monitoring:

◼ Baseline: Wt, Na, K, BUN, Cr, Glu, Ca, P, Mg, CBC, PT,

INR, TG, LFT, Alb, Pre-Alb

◼ Daily: Wt, V/S, I-O, Na, K, BUN, Cr, Glu,

Sign/Symptoms of infection

◼ 2-3 times a week: CBC, Ca, P, Mg

◼ Weekly: Alb, Pre-Alb, LFT, INR, Nitrogen Balance

Adding other drugs to TPN

◼ INS

◼ Heparin

◼ H2-blocker

◼ Alb

◼ Aminophylline

◼ Vit K & Bicarbonate should not be added

Complications◼ Endocrine & metabolic

◼ Fluid overload, hypercapnia, hyperglycemia, hyper-

/hypokalemia, hyper-/hypophosphatemia, refeeding

syndrome

◼ Hepatic

◼ Cholestasis, cirrhosis (<1%), gallstones, liver function tests

increased, pancreatitis, steatosis, triglycerides increased

◼ Renal

◼ Azotemia, BUN increased

◼ Infectious

◼ Bacteremia, catheter-induced infection, exit-site infections

◼ Other: Pneumothorax, Thrombophlebitis

Refeeding syndrome

◼ In patients with long-standing or severe

malnutrition

◼ Is a medical emergency, consist of:

◼ Electrolyte disturbances (eg, potassium, phosphorus)

◼ Respiratory distress

◼ Cardiac arrhythmias, resulting in cardiopulmonary

arrest

◼ Do not overfeed patients; caloric replacement

should match as closely as possible to intake

Conclusion

◼ Malnutrition is a common problem & Nutritional support is indicated in many hospitalized patients

◼ Enteral nutrition is better, but some patients with GI problems need TPN

◼ Dextrose & Intralipid should be used as calorie sources and Aminofusion as aminoacid source

◼ Special monitoring should be considered for patients especially I-O, Na, K and Glu

Terima Kasih