total parenteral nutrition

1. Total Parenteral Nutrition
By
Dr.venkatesh kolla

2. Definition:
It is pharmacological theraphy where
nutrients,vitamins,electrolytes and
medications are delivered via the
venous route to those patients
whose GIT is not functioning and
are unable to tolerate enteral
nutrition.

3. Basic principles of Nutrition:
1. Avoid malnutrition.
2. If the bowel works use it.(EN preferred over
TPN)
3. Avoid over feeding.
4. The route , timing, type of nutritional
formulation are more imp than the amount.
5. Role of nutritional support is to limit protein
wasting and to supply essential and
conditionally essential nutrients.

4. Avoid malnutrition
• It leads to increased morbidity and even mortality by
increasing the chance of infection , poor wound
healing , fistula formations, delayed callus formation
,pulmonary complications(dec VC and hypoxic
ventilatory response),decreased tolerance to RT &
CT,reduced enzyme synthesis & impaired oxidation of
drugs.
• Longer recovery period and increased duration of
hospitalisation.
• Poor quality of life.

5. AVOID OVER FEEDING ?
Over feeding causes :
1. Uncontrolled hyperglycemia will produce glycosuria,
osmotic diuresis, & non-ketotic hyperosmolar
dehydration and in severe cases, coma.
2. hyperglycemia increases risk of nosocomial infection.
3. Excessive calories can increase O2consumption,Co2
production, minute ventilation and the work of
breathing which can fatigue patients with impaired lung
function.
4. Over feeding can lead to hepatic steatosis, which may
lead to hepatic dysfunction.

6. Goals of parenteral nutrition:
• To maintain or improve the nutritional status by
providing all nutrients for ongoing metabolic functions.
• To minimize the deleterious effects of catabolism by
maximising the protein synthesis , limiting the protein
breakdown and reducing weight loss.
• To boost the immune function & to improve wound
healing.
• To improve the cardiac and respiratory function by
restoring the glycogen storage of the cardiac and
diaphragmatic muscles.
• To maintain or correct acid-base balance &electrolyte
disturbances
• To accelerate rehab and improve the quality of life.

7. INDICATIONS:
A. GENERAL
• In adequate oral or enteral nutrition for atleast 7-
10days.
• Pre-existing severe malnutrition.
B.Anticipated or actual inadequate oral or enteral intake
1.Conditions that impair absorption of nutrients
a.enterocutaneous fistula.
b.short bowel syndrome.
c.small bowle syndrome.
d.effects of RT or CT.

8. 2. Need for bowel rest:
a. severe pancreatitis.
b. IBD
c. ischemic bowel.
d. peritonitis.
e. pre and post operative status.
3.Motility disorders.
• prolonged ileus.
4.Inability to acieve or maintain enteral access
a.haemodynamic instability.
b.massive GI bleeding.
c.Unacceptable aspiration risk.
d.hyperemesis gravidarum,eating disorders.
C. Significant multiorgan system disease.
burns,renal,hepatic&pulmonary and etc

9. CONTRA INDICATIONS:
GENERAL:
1. If enteral nutrition exceeds or meets the
calculated requirements.
2. Patient with good nutritional status who
requires short term support.
3. Severe liver failure,cardiac failure,shock and
blood dyscrasias.
4. Fluid electrolyte imbalances.

10. DISEASE SPECIFIC:
1. avoid excess carbohydrate in patients of
pulmonary compromise and in patients of
ventilatory support during weaning period,as it
may result in production of large amount of Co2.
2. Avoid lipid adminstration, if TG >350mg/dl or in
patients of severe sepsis,moderate degree of
jaudice, low platelet count(<50,000/cumm) and
ARDS or severe respiratory disease

11. When to start parenteral nutrition?
• Even in critically patients,decision to start PN is never
an emergency.
• Risk of adverse effects decreases if patient is
hemodynamically stable, electrolyte abnormalities are
corrected , and there are no blood glucose
disturbances prior to starting PN.
• Early PN is beneficial in patients with preexisting
malnutrition, critically ill patients, acute severe
necrotising pancreatitis and high nutrient loss from
wound and fistulas.

12. NUTRITIONAL REQUIREMENTS
Balance of fluid, carbohydrates, fats, proteins,
minerals, trace elements and vitamins.
FLUID REQUIREMENTS:
Normal requirement+abnormal losses.
1500 for 20kg+20ml/kg for additional weight or
35ml/kg.
Vol of fluid delivered by enteral route shud be
substracted from the estimated total
requirement.

13. • REE: RESTING ENERGY EXPENDITURE
• TEE:TOTAL ENERGY EXPENDITURE
• W:WEIGHT
• H:HEIGHT
• A:AGE
• AF:ACTIVITY FACTOR(1.2-BED REST;1.3-OUT OF
BED)
• DF:DISEASE FACTOR(1.25-GENERAL SURGERY;1.3-
SEPSIS;1.6-MULTIORGAN FAILUE;1.7-30-
50%BURN;1.8-50-70%BURN;2.0-7-90%BURN)
• TF:THERMAL FACTOR(1.1-38DEG,1.2-39DEG,1.3-
40DEG,1.4-41DEG)

14. ENERGY REQUIREMENTS:
1. SIMPLE BODY WEIGHT BASED CALCULATION:
REE(Kcal/day)=25 * weight
2.Harris-benedict equation:
REE(man)=66+(13.7*W)+(5*H)-(6.7*A)
REE(women)=65+(9.6*W)+(1.8*H)-(4.7*A)
TEE=REE*AF*DF*TF
3.Indirect calorimetry:
REE(man)(3.9*Vo2)+(1.1*Vco2)-61

15. For accurate determination of energy expenditure in
critical patients ,indirect calorimetry should be
measured with the instrument metabolic cart.
Simple weight based calculation and HB equation over
estimates the energy expenditure.
 PROPORTION OF MACRONUTRIENTS:
50-70% -CARBOHYDRATE
20-30%-FAT
10-20%-PROTEIN ,which is mainly for anabolic process.

16. Carbohydrate requirements:
50-70% of Total energy requirements
Functions & advantages:
1. Low cost: dextrose least expensive
2. Supplies calories:min 100 to 150gm needed.
3. Nitrogen sparing effect:glucose+
insulinreduces muscle protein
breakdownand decreases hepatic glucose
release.

17. Disadvantages:
1. Low calorie supply : dextrose poor source of calorie
(4kcal/gm vs fat 9kcal/gm).
2. Increased Co2 production: not preferable in patients in
respiratory disease patients.
3. Thrombophelbitis: >10%D
 Maximum rate of dextrose infusion is approx 5mg/kg/min
or 7.2g/kg/day . if extra infusion is given there will be
overfeeding consequences.
 Dextrose infusion should be monitored closely, with an
aim to maintain blood sugar between 120-180mg/dl.

18. FAT requirements:
CONTENTS: an emulsion of long chain TG’s derived from
soyabean oil or combination of soyabean and
sunflower oil. It also contains egg yolk phospholipids as
an emulsifying agent and glycerin to achieve isotonicity
with plasma. Latest contain medium chainTG.
CALORIC VALUES, PREPARATIONS AND REQUIREMENTS:
20-30% Of total calories . Limit the total dose to
2g/kg/day.lipid emulsions are available as
10%(1.1Kcal/ml),20%(2kcal/ml),30%(3kcal/ml).
A minimum of about 5% of total calories as a lipid
emulsion is necessary to prevent essential FA
deficiency in patients continuously receiving PN.

19. FUNCTIONS AND ADVANTAGES:
1.CALORIE SUPPLEMENTION:major calorie fuel,important in
critically ill,volume overloaded patients
2.glucose sparing, avoids hyperglycemia.
3.Protein sparing.adequate calorie supplementation spares
protein by conserving body nitrogen economy and
supporting protein metabolism.
4. Less Co2 production:lipid produces less Co2 and preferred
in respiratory compromised patients. Respiratory
quotient(RQ) of fat is 0.7<0.8protein<1 carbohydrate.RQ is
ratio of Co2 production to O2 consumption.
Thus lipid emulsion has advantage of better glucose
tolerance,less hyperinsulinemia,less production of Co2 and
less fatty infiltration of liver.
5.Prevention of essential FA deficiency.
6. Reduced risk of thrombophelbitisBecause of low
osmolarity of lipid emulsion 260mosm.

20. DISADVANTAGES:
 High cost compared to dextrose.
ADVERSE EFFECTS:
 Increased TG levels at very high infusion levels
 SEPSISwhen adminstered separately for long time.
 Fat embolism:Lipid is less stable when adminstered along
with aminoacids and glucose.destabilised fat particles
coalesce into larger droplets to form fat emboli.
 RARE :immediatedyspnea,cyanosis,nausea or
vomiting,headdache,flushing,chest and backpain or
thrombocytopenia.
Delayed hepatic dysfunction,fat overload,pancreatitis &
delayed gastric emptying.

21. Contraindication
1.hypelipidemia( s.TG>350mg/dl)
2.acidosis(ph<7.3)
3.Anemia
4. Evidence of intravascular coagulation
5.Impaired circulation
6.Any patients at risk of developing fat
embolism.

22. Rate of lipid infusion should not exceed
0.7kcal/kg/hr

23. PROTEIN
Aminoacids are essential components of PN.
10-20% of total calorie requirement.
Standard AA solution contains 40-50%
essential aminoacids and rest 50%
nonessential aminoacids + semi essential AA.
10% solution contains 100gm/L.

24. CLINICAL CONDITION PROTEIN REQUIREMENTS(G/KG)
NORMAL 0.8
Metabolic stress (illness/injury) 1-1.5
ARF (undialysed) 0.8-1
ARF receiving dialysis 1.2-1.5
Critically ill patients 1.5
COMPENSATED CIRRHOSIS 1-1.2
HEPATIC encephalopathy <0.5
Acute sepsis 1.7

25. Functions and advantages
1. Calorie supplement-1g-4kcal
2. Protein synthesis
3. Reduces rate of protein catabolism.
CONTRAINDICATIONS AND ADVERSE EFFECTS:
1. Hepatic insufficiency-infusion leads to metabolic
alkalosis,prerenal azotemia,increased level of
ammonia,stupor or coma
2. Renal failure-leads to increased BUN.
3. metabolic or respiratory alkalosis
4. Infusion at rapid rate causes nausea,vomiting, headache,
flushing,chills or fever.
5. Excess of protein or insufficent calorie supplements lead
to increased urea. renal losses of nitrogenleads to loss of
H2o and may cause hypertonic dehydration.

26. Nitrogen balance =nitrogen intake-nitrogen loss
Nitrogen loss={[24-urine urea nitrogen(G)+4]*6.25}
Positive nitrogen balance suggests anabolism.
DISEASE SPECIFIC AMINOACIDS:
A.Hepatic encephalopathybranched chain AA should be
used because there are metabolised in muscle and adipose
tissue leaving liver.
Further BCAA compete with aromatic AA for the carrier,which
is responsible for transport in to brain which might
contribute to encephalopathy.
B. Renal failure patientslarge amounts of essential AA are
recommended for patients who acute renal
failure.(nitrogen of essential AA is partially recycled to
produce non-essential AA.
C. For volume overloaded patients –modified solution with
15% concentrated AA base solution provides higher calorie
and protein supplementation in lesser volume.

27. SPECIAL FORMULAS
Immune enhancing enteral diet—(glutamine, arginine
and omega-3 fattyacids) was found to reduce the risk
of infection, ventilator days and hospital length of stay
without influencing mortality.
Glutamine helps in mucosal cell proliferation, xylose
absorption and decreases permeability of gut which
helps to maintain mucosal integrity and prevents
translocation of bacteria and endotoxins to circulation.
So glutamine can be useful in patients with inflammatory
bowel disease, a short bowel syndrome , extensive
burns ,multiple trauma and septic shock .

28. Omega-3 fatty acids—may reduce the catabolic
response of burn injury, trauma and radiation
by reducing the synthesis of prostaglandins
that enhances the inflammatory response.
ARGININE—Important in nitrogen and ammonia
metabolism, in generation of nitric oxide and
has potential role in immunomodulation.
Electrolytes , trace elements and vitamins.