Total Enteral Nutrition

& Total Parenteral

Nutrition in Critically Ill

Patients

Dr. M. M. PANDITRAO

CONSULTANT

DEPARTMENT OF ANESTHESIOLOGY &

INTENSIVE CARE PUBLIC HOSPITAL AUTHORITY’S

RAND MEMORIAL HOSPITALFREEPORT, GRAND BAHAMA

THE BAHAMAS

Normal Energy & Protein Requirements

Proteins 10-20% Carbohydrates

& 80-90% Fats

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.

Starvation

Definition

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

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

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

Prevalence of Malnutrition in

Hospitalized Patients

69% Adequate Nutritional State

21% ModeratelyMalnourished

10% Severely Malnourished

Detsky et al. JPEN 1987

Prevalence of Malnutrition in

Hospitalized PatientsIn 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

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

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

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 1980Hickman et al. JPEN 1980

Klidjian et al. JPEN 1982

Marasmic starvation/ malnutrition

• Conservation of energy and proteins

• Stored substrates are utilized sparingly

• Fate is depending upon availability of energy and proteins

Utilization of Substrates

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

Starvation

• Gluconeogenesis • Proteins are catabolised to form

glucose viz. carbohydrate residues of

amino acids • Glycerol and lactate from Lipid

Pathway

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

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.

Metabolic Response to Trauma

Time

Ener

gy E

xpen

ditu

re

Ebb PhaseEbb

PhaseFlow

PhaseFlow

Phase

Cutherbertson DP, et al. Adv Clin Chem 1969;12:1-55

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.

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;12:1-55Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. 1997

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.

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;12:1-55Welborn MB. In: Rombeau JL, Rolandelli RH, eds. Enteral and Tube Feeding. 3rd ed. 1997

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

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

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

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

Nutrition : Basic Principles1. 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.

Nutrition : Basic Principles4. 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

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

Nutrition : Basic Principles

9. Critical monitoring essential10.High degree of suspicion and

constant “looking out” for complications

11.Immunonutriton is still a contentious issue, especially in terms of final outcome!

Pre requisites:1. Routine history taking 2. Assessment of physical status 3. Comparative assessment of

approximate weight & weight loss4. Periods of fasting/ starvation5. 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.

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

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

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 1980Frankenfield D C et al Crit Care Med 1994

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

Pre requisites: (Contd.)

Pre requisites: (Contd.)

9. Micro Nutrients Agent Requirement/

day

Iron 0 – 2 mg

Zinc 1 – 15 g

Copper 1 -5 g

Chromium 10 – 20 g

Selenium 20 – 100 gManganese 150 -800 mg

Vit E 10 – 50 IU

Vit A 2500 IU

Vit C 300 – 500 mg

Vit D 250 IU

Agent Requirement/day

Vit K 10 mg/week

Thiamine 50 – 250 mg

Riboflavin 5 mg

Niacin 50 mg

Pantothenate

15 mg

Pyridoxine 5 mg

Folic acid 600 g

BIZ 12g

Biotin 60g

Routes & Technologies of Administration

ENTERAL

PARENTERAL

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

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

Benefits of Enteral Nutrition Therapy

Improved Patient OutcomesImproved wound healingDecreased risk of complications

– Nosocomial infection

Decreased length of stayDecreased healthcare costs

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!”

Techniques of Access

Enteral Contraindications

• Hemodynamic instability• Pressors• Peritonitis• Bowel obstruction• Proximal fistula*• High output fistula• Bowel ischemia

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

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.

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.

The Total Parenteral Nutrition

Access • Subclaviabn ( Right one preferred)• Internal Jugular

Rarely and to be avoided:- • Femoral vein• Median cubital• Any peripheral veins

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

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

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

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

The recent reviews

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

The recent reviewsLatest 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

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

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!!!!!!