Total parenteral nutrition and
By dr. Venkatesh kolla
Preoperative parenteral nutrition in severe
malnourished patients reduces the rate of post
operative complications and improves the
outcome and also reduces non infectious
complications(pulmonary emboli & delayed
wound healing. In this condition it requires 7 to
14 days for restoration in malnourished patients .
But in mild malnutrition patients parenteral
nutrition leads to more infectious complications
like pneumonia and wound infection.
Post operative PN
1.Patients unlikely to resume oral feed with in
10days.most commonly used because of
paralytic ileus post operative or concern about
disrupting a new bowel anastomosis.
2. As a continuation of preoperative PN support
3.In previously sever malnourished patients
undergoing emergency surgery.
4.Major burns and trauma.
A. Parenteral nutrition should not be used routinely in
patients undergoing major cancer operations or along
with CT & RT.
B. PN is provided only in clinical improvement with
quality survival is expected.
C. PN is indicated if CT or RT is likely to cause GI toxicity
which will prevent oral/enteral intake for more than
one week. Immediate morbidity is reduced if
glutamine supplement is added to PN solution.
D. PN unlikely to benefit patients with rapidly
progressive malignancy and in terminal stages of
In cardiac surgery patients , EN should be deferred until
the patient is hemodynamically stable.
Patients requiring PN after cardiac surgery increases
the risk of volume overload, hyponatremia , metabolic
acidosis & uremia.
To avoid fluid overload in CHF , use maximally
concentrated PN solutions.
Cardiac patients with anasarca and HTN need flid and
In patients receiving diuretics, requirement of
potassium , magnesium and zinc increases.
“Death from starvation is death from pneumonia”
Malnutrition inadequate calorie
intakeskeletal muscle protein utilized as a
source of calories muscle wasting aggravate
respiratory failure(decreased respiratory drive
and decreased response to hypoxia).
It also adversely effect weaning from mechanical
Impaired immune function reduces pulmonary
defense mechanism and increases susceptibility
Effect of pulmonary disease on nutritional status:
advanced disease leads to malnutrition and
weight loss, due to increased work of breathing
and poor food intake.
Nutritional repletion improves diminished
respiratory function.ventilation drives returns to
normal with refeeding and weaning from
In COPD recommended energy intake is 1.7times their
resting energy expenditure.
avoid excess calories from dextrose so as to prevent
excessive Co2 production and increased work of breathing.
Lipid is preferential as it provides more energy with less
Co2. however excess or to rapid infusion will alter the
pulmonary gas exchange.
Dextrose and lipids 70:30 ratio is safe
50:50 ratio is beneficial in weaning of patients from
ventilator.(low carbohydrate formula)
Amino acid requirement is 1gm/kg/day. Amino acids also
increase the drive and sensitivity of respiratory centers for
In ARDS patients, administer fluid restricted nutrient
formulation, if hemodynamic necessitates.
Avoid hypophosphatemia,hypocalcemia and
hypomagnesemia which can reduce
respiratory muscle strength.
Important causes of malnutrition in burn
1. Large loss of protein and micronutrients
through damaged skin.
2. Large loss of heat through exposed surface
causes increased energy expenditure.
3. post burn hypermetabolism and
current practice is to provide 20-30-% extra
calories or 35 to 35kcal/kg/day for most of
patients with major burns.
Atleast 15% of calories should be supplied by
fat but should not exceed 30-35%.
Enteral nutrition can be given into jejunum, distal
to ligament of treitz or parenteral nutrition is to
provide adequate nutrition without stimulating
the pancreatic enzymes secretion and to prevent
further damage to pancreas.
a)Who develop paralytic ileus , pseudocyst, fistulae,
pancreatic abscess or pancreatic ascites.
b)If enteral feeding leads to exacerbation of
When to start PN?
Patients with acute severe necrotising
pancreatitis are highly catabolic and if not
provided adequate and timely nutrition, are
predisposed to malnutrition.
Nutritional support with in 48-72hours of
hospitalization is beneficial.when PN was
delayed beyond 72hours in these patients,
complications and mortality rates were three
times higher compared to similar patients
Lipid: up to 2gm/kg/day
Role of parenteral nutrition is supportive and
should be provided to patients with GI fistula
with anticipated inadequate oral or EN
beyond 7-14days. In patients with GI fistula,
bowel rest and PN have contributed
significantly to the improvement in clinical
outcome(lower mortality rate, higher
spontaneous fistula closer and higher surgical
• Liver is work horse for metabolic activity. It
consumes approximately 20% of resting
• It is a major site for metabolism of protein,
• Nutritional requirements in patients with liver
diseases vary depending upon preexisting
malnutrition, type of disease and severity of
illness and its complications.
Compensated cirrhosis of liver,non-protein energy
requirement is 25-35kcal/kg/day. In cirrhotic patients
with complications(post operative period,sepsis, GI
bleed and hepatic failure) the energy requirement is
considerably high (35-45kcal/kg/day).
a)Compensated cirrhosis not>1gm/kg/day if patient is
malnourished and repletion is desired,protein
supplementation can be increased by 20%.
b)Cirrhosis with encephalopathy restricted to
0.5gm/kg/day. Administration of branched chain amino
acids is helpful because they promote better nitrogen
balance and prevent formation of aromatic amino