This document discusses total enteral and parenteral nutrition in critically ill patients. It begins by outlining normal energy and protein requirements, then discusses the prevalence and consequences of malnutrition in hospitalized patients. It describes the metabolic response to critical illness and trauma as having an "ebb phase" and "flow phase". The document advocates for early initiation of nutritional support via the enteral route when possible using techniques like post-pyloric feeding tubes, but notes total parenteral nutrition may be needed if enteral nutrition is not tolerated. It provides guidelines on calculating protein and calorie needs and discusses considerations, benefits, risks and protocols for both enteral and parenteral nutrition.

1. Total Enteral Nutrition
&
Total Parenteral Nutrition
in
Critically Ill Patients

2. Dr. M. M. PANDITRAO
CONSULTANT
DEPARTMENT OF ANESTHESIOLOGY
&
INTENSIVE CARE
PUBLIC HOSPITAL AUTHORITY’S
RAND MEMORIAL HOSPITAL
FREEPORT, GRAND BAHAMA
THE BAHAMAS

3. Normal Energy & Protein
Requirements
Proteins 10-20%
Carbohydrates
& 80-90%
Fats

4. Normal Energy & Protein
Requirements (Contd.)
• Energy supply by 3 components
• Exception:- Some organs viz. central nervous
system, red blood cells, marrow tissue
• Traumatized/Damaged issues
• These tissues are absolutely and obligatory
demanders of glucose for their energy
derivation.

5. Starvation
Definition
Lack of exogenous energy substrate
and may be relative or absolute.

6. Hospital Malnutrition:
Prevalence
• Numerous studies on hospital malnutrition
have been published.
• Prevalence of malnutrition in U.S. hospitals
today ranges from 30% to 50%.
• Patient‘s nutritional status declines with
extended hospital stay.
Coats KG et al. J Am Diet Assoc 1993

7. Malnutrition Among Hospitalized Patients:
A Problem of Physician Awareness
• Up to 50% of hospitalized patients may be
malnourished on admission
• Before nutritional assessment training:
– Only 12.5% of malnourished patients
are identified
• After 4 hours of training:
– 100% of patients are identified
Roubenoff et al. Arch Intern Med 1987

8. Prevalence of Malnutrition in
Hospitalized Patients
10%
Severely Malnourished
21%
Moderately
Malnourished
69%
Adequate
Nutritional
State
Detsky et al. JPEN 1987

9. Prevalence of Malnutrition in
Hospitalized Patients
In a published British study:
• 46% of general medicine patients
• 45% of patients with respiratory problems
• 27% of surgical patients
• 43% of elderly patients
Percentage of malnourished patients at
time of admission
McWhirter et al. Br Med J 1994

10. Malnutrition and its Consequences
• Changes in intestinal barrier
• Reduction in glomerular filtration
• Alterations in cardiac function
• Altered drug pharmacokinetics
Roediger 1994; Green 1999; Zarowitz 1990

11. Malnutrition and its Consequences
• Loss of weight
• Slow wound healing
• Impaired immunity
• Increase in length of hospital stays
• Increased treatment costs
• Increase in morbidity & mortality

12. Malnutrition and Increased
Complications
Many studies have shown that
complications are 2 to 20 times more
frequent in malnourished patients
than in well-nourished patients.
Buzby et al. Am J Surg 1980
Hickman et al. JPEN 1980
Klidjian et al. JPEN 1982

13. Marasmic starvation/ malnutrition
• Conservation of energy and proteins
• Stored substrates are utilized sparingly
• Fate is depending upon availability of
energy and proteins

14. Utilization of Substrates

15. Starvation
• Muscles derive energy by the Oxidation of
lipids
• Glycogen depletion augments lipolysis
• Glycerol and free fatty acids are released
• The liver synthesizes acetoacetate and beta
hydroxybutyrate
• Keto-adaptation

16. Starvation
• Gluconeogenesis
• Proteins are catabolised to form glucose
viz. carbohydrate residues of amino acids
• Glycerol and lactate from Lipid Pathway

17. Starvation
Ketoadaptation is followed by :
• Breakdown of proteins decreases
• Utilization of glucose as main substrate
decreases
• Ketones are used by tissues like brain
• Urea is replaced by mainly ammonia
• Excretion of ammonia rises, with help of
glutamine

18. Critically ill patients
When these processes are correlated in response
to the injury (trauma) &/ or sepsis, we can
differentiate them in 2 classical phases:
1) Ebb phase
2) Flow phase.

19. Metabolic Response to Trauma
Ebb Phase Flow Phase
Energy Expenditure
Time
Cutherbertson DP, et al. Adv Clin Chem 1969;12:1-55

20. Ebb phase
As happens in normal response to
starvation, there is no dearth of availability
of substrate but actually an inability or
decreased ability to utilize it.
Gluconeogenetic activity takes over,
leading to increased protein breakdown
and decrease in lean body mass.

21. Metabolic Response to Trauma:
Ebb Phase
• Characterized by hypovolemic shock
• Priority is to maintain life/homeostasis
Cardiac output
Oxygen consumption
Blood pressure
Tissue perfusion
Body temperature
Metabolic rate
Cuthbertson DP, et al. Adv Clin Chem 1969;12:1-55
Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. 1997

22. Flow phase
After duration of days to weeks, increased
metabolic activity, process of repair /
regeneration is initiated and recovery phase
starts with increased energy demand. If the
supply is well maintained, then the organ
function and structure is restored and normalcy
is achieved.

23. Metabolic Response to Trauma:
Flow Phase
• Catecholamines
• Glucocorticoids
• Glucagon
• Release of cytokines, lipid mediators
• Acute phase protein production
Cuthbertson DP, et al. Adv Clin Chem 1969;12:1-55
Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. 1997

24. Necrobiosis
• Massive trauma / overwhelming sepsis /
infection.
• Improper, inadequate or inappropriate
measures of correction, shock.
• Inherent failure of homeostatic mechanism.
• Any additional systemic / metabolic disorders,
burns.
Then as a result of failure of multiple organ
systems – death ensues as the final outcome

25. Stress starvation
Hypoalbuminemia & Oedema
• Severe acute inflammatory response mediated
through the cytokines
• Transmigration of proteins (albumin) to extra
vascular compartment
• Oedema, hypovolemia and haemodynamic
instability

26. Stress starvation (Contd.)
• Adaptative strategies as in ―normal‖ starvation
glycogenolysis, lipolysis and ketoadaptation: fail
• ―Gluoneogenesis‖ is the only alternative
pathway : especially by catabolising proteins
(muscles) leading to severe negative nitrogen
balance & grave sequelae

27. What’s to be done?
• Metabolic response to critical illness
• Supportive strategies
• Adequate nutritional support
at right time
via right route
in a right proportion
Outcome
• Significantly decreasing morbidity and mortality
in critically ill patients

28. Nutrition : Basic Principles
1. Critically ill : Prone for high energy expenditure and
rapid protein breakdown. E N initiated within 24
hours of admission significantly reduces morbidity.
2. Parenteral support to be administered to all patients
who cannot tolerate enteral regimen within 5 days of
starvation.
3. Factors to be taken into consideration:
preoperative fasting status/ level of starvation
before ICU admittance, number of days anticipated
on ventilator and any associated systemic problems.

29. Nutrition : Basic Principles
4. Intra-operative Jejunal access for enteral nutrition:
better option
5. Optimization of protein and energy requirement
(avoid over/ under feeding)
Protein input - 1.5-2.5 g/kg/day with 50% of
total administered enterally
Total caloric intake of 1500-2000 kcal/ day is
to be achieved (25 kcal/kg/day ) as per BEE
6. Appropriate electrolyte supplementation : Na
P, K & Mg supplementation

30. Nutrition : Basic Principles
7. Substrate for provision of energy is carbohydrates and
lipids in the ratio of 70:30.
 Peripheral insulin resistance and hyperglycemic state,
mainly due to impaired glucose utilization and
gluconeogenesis.
 Overzealous administration of glucose ( eg: > 5 mg/kg/day)
will increase the susceptibility to infection.
8. Proper selection of volume, composition and route of
administration, for patients with
 Renal & hepatic insufficiency
 Cardio-pulmonary diseased

31. Nutrition : Basic Principles
9. Critical monitoring essential
10. High degree of suspicion and constant
―looking out‖ for complications
11. Immunonutriton is still a contentious issue,
especially in terms of final outcome!

32. Pre requisites:
1. Routine history taking
2. Assessment of physical status
3. Comparative assessment of approximate
weight & weight loss
4. Periods of fasting/ starvation
5. Investigations:- blood urea, serum creatinine,
serum electrolytes and serum proteins
 Albumin level of less than 3.5g/dl is indicative
strongly of sepsis and associated with high post-
abdominal surgical morbidity and mortality.

33. Pre requisites: (Contd.)
6. Nutritional requirements : Protein requirements in terms
of ‗Nitrogen balance‘ (NB)
N.B. = N (in) – N (out)* = Protein _ N (out)
6.25 (gm/day)
* N (out) = Urine Urea N/0.8 (gm/day) + GI losses (2 – 4
gms/ day) + cutaneous losses (0-4 gm/day)
= Urine Urea N + 4 -- as a constant factor
0.8
NB =(Protein intake) – (Urine urea nitrogen + 4)
6.25 0.8
keep positive nitrogen balance of 2 – 4 gm / day

34. Pre requisites: (Contd.)
Calculating Basal Energy Expenditure (BEE)
• Harris-Benedict Equation
– Variables
gender, weight (kg), height (cm), age (years)
Men:
66.47 + (13.75 x weight) + (5 x height) – (6.76 x age)
Women:
65.51 + (9.56 x weight) + (1.85 x height) – (4.67 x age)
Calorie requirement = BEE x Activity factor x Stress
factor

35. Pre requisites: (Contd.)
7. Resting Energy Eexpenditure (REE)
REE = BEE x 1.1 – 1.4
 Old Concept :Injury, sepsis and burns increase
energy requirements by 30%, 60% and 100%.
 Actual requirement rises only by 14% more
than calculated BEE
 Calories to be supplied are not more than
calculated REE
Asknazi J. et al Ann Surg 1980
Frankenfield D C et al Crit Care Med 1994

36. Pre requisites: (Contd.)
8. Electrolyte requirements
• Na+ : 100-120 meq/day
• K+ : 80 – 120 meq/day
• Mg+ : 12 – 15 mmol/day
• Ca+ : around 5 mg/day
• Phosphorus : 14 – 16 mmol/day

37. Pre requisites: (Contd.)
9. Micro Nutrients
Agent Requirement/day Agent Requirement/day
Iron 0 – 2 mg Vit K 10 mg/week
Zinc 1 – 15 g
Thiamine 50 – 250 mg
Copper 1 -5 g
Riboflavin 5 mg
Chromium 10 – 20 g
Niacin 50 mg
Selenium 20 – 100 g
Pantothenate 15 mg
Manganese 150 -800 mg
Vit E 10 – 50 IU Pyridoxine 5 mg
Vit A 2500 IU Folic acid 600 g
Vit C 300 – 500 mg BIZ 12 g
Vit D 250 IU Biotin 60 g

38. Routes & Technologies of
Administration
ENTERAL
PARENTERAL

39. The Total Enteral Nutrition (TN)
DEFINED :
Delivery of all the necessary substrates (Amino
acids + Carbohydrates + Lipids) via an access
either through the natural anatomical GI route
or surgically created one

40. Benefits of Enteral Nutrition Therapy
• Maintains GIT structure, integrity and function
• Easier, more Physiological
• Enhances intestinal immune function
• Reduces bacterial translocation
• Decreases risk of sepsis
• Fewer complications than with parenteral
nutrition
• Lower costs, Less expensive

41. Benefits of Enteral Nutrition Therapy
Improved Patient Outcomes
Improved wound healing
Decreased risk of complications
– Nosocomial infection
Decreased length of stay
Decreased healthcare costs

42. Benefits of Enteral Nutrition Therapy
Early Intervention as Part of Initial Care
Enteral Nutrition
• Oral supplements
• Tube feeding
Parenteral Nutrition
• Total
• Peripheral
If the gut works, use it!”

43. Techniques of Access

46. Enteral Contraindications
• Hemodynamic instability
• Pressors
• Peritonitis
• Bowel obstruction
• Proximal fistula*
• High output fistula
• Bowel ischemia

47. Complications of TEN
Complications
 Complications of GI access:-
 Dislodgements
 Small bowel volvulus, infarction
 Catheter/tube occlusion
 Leakage/skin breakdown
 Tube malposition
 Gastric distention and aspiration
 Diarrhea and GI complications
 Other infections

48. Protocol for TEN
• Tube placement, confirmed with X ray
• Raise HOB to 30
• Start with 15 ml/hr with increments of 15 ml/hr every
12th hourly to 60 ml/hr.
• Continue 60 ml/hr for 24 hrs.
• Increments 15 ml/hr every 12 hrly. After that to reach
TEN max of 100 – 120 ml/hr.
• Intermittent aspiration (every 4th hourly) assess
if <150 Continue,
if < 150 – 300 Prokinetic like Metaclopramide,
if > 300 ml reduce rate by 50% & try other alternative.
• Irrigate tube 4th hourly with 30 ml of water,
12th hourly with 10 ml of sodabicarb.

49. The Total Parenteral Nutrition (TPN)
DEFINED:
Delivery of all the necessary, required substrates
(combination of amino acids + concentrated
glucose + lipids) via central vein (to overcome
high osmolarity of the preparation due to high
concentration of glucose) with the help of a
pump for prolonged duration as required in
critically ill patients.

50. The Total Parenteral Nutrition
Access
• Subclaviabn ( Right one preferred)
• Internal Jugular
Rarely and to be avoided:-
• Femoral vein
• Median cubital
• Any peripheral veins

51. The Total Parenteral Nutrition
Formulations
• Multiple preparations
• Energy providers:- Glucose + lipids (a
combination of medium chain + long chain –
MCT / LCT : triglyceride) in the ratio of 60% -
70% + 30% - 40%
• Proteins in the form of amino acid preparation
provides nitrogen up to 8 – 16 g/lit
• Micro nutrients, electrolytes and other additives
like anticoagulants

52. Complications of TPN
• Procedure complications
 Pneumothorax, chylothorax, haemothorax, air
embolism, hydrothorax
 Carotid arterial puncture
 Subclavian arterial puncture
• Mechanical
 Wrong position in to the peripheral vein.
 Blockade of catheter
• Metabolism related to all electrolytes & glucose
• Infection / Sepsis

53. Protocol for starting TPN
• Confirm proper placement of central venous
catheter
• Absolutely thorough aseptic precautions while
handling
• Carbohydrates at rate of
– Not more than 4 mg/kg/min
– Lipids not more than 0.1 gm/kg/hr
• Infusion pump to be used ―all in one‖ system
• Calculate nitrogen requirement and titrate
• Continuous monitoring

54. The recent reviews
Meta analysis of 5, level 2 randomized controlled
trials carried out by Hemdon (1987)8 , Hemdon
(1989) 9, Dunham (1994) 10 , Chiarelli (1996) 11
and Bauer (2000) 12 revealed
• Parenteral nutrition in combination with enteral
nutrition in critically ill provides no added benefit
to enteral nutrition alone
• Parenteral nutrition with enteral nutrition is
associated with high cost to enteral nutrition alone

55. The recent reviews
Same findings were confirmed by, Dhaliwal R ,
Jurewitsch B et al,13 after doing systematic
review of the evidence

56. The recent reviews
Latest guidelines about the enteral nutrition and
parenteral nutrition in terminally ill cancer
patients by Dy SM (2006) 14 confirm
• Enteral and parenteral nutrition combined may
help improve survival, functional status and
quality of life
• These benefits appear to be primarily limited to
the patients with good functional status
• The risks and the complications as mentioned in
the past are confirmed

57. Summary
• Recognize when nutritional support is
warranted
• Choose route of nutrition (enteral vs.
parenteral)
• Plan nutrient prescription
• Discuss benefits vs. complications of enteral
and parenteral nutrition
• Describe how to monitor patients receiving
nutrition support

58. Conclusion
• A Few, Basic & Fundamental Concepts
• ―Critically ill‖: a Misleading word
• Multiple Factors have multiple roles!
• Magnitude of Malnutrition—Unimaginable!
• Understand, Estimate, Strategize and Execute!
• EN or PN ?????
• Use Your own Discretion!!!!!!