Description of physiological and biochemical changes, measurement of energy expenditure, evidence based discussion on management

1. Dr Bedangshu Saikia
Registrar, Pediatrics and Neonatology
St Stephens Hospital, New Delhi, India
bedangshu@gmail.com

2. Metabolic stress response
Mehta & Duggan, Pediatric Clinics of North America, 2009

3. Nutritional assessment
 History
○ Preexisting malnutrition
○ Underlying disease
○ Recent weight loss
 > 5% in 3 wks or
 >10% in 3 months

4. Nutritional assessment
 Anthropometry
○ Mid upper arm circumference
○ Triceps skin fold thickness
○Weight
○ Length / height
○ BMI

5. Nutritional assessment
 Biochemical assessment
○ Measure – visceral protein pool, acute phase protein pool,
nitrogen balance, REE
○ Albumin (t ½ 14-20 d)
 Reliability questionable
○ Transferrin (t ½ 8 d), prealbumin (t ½ 2 d), retinol
binding protein (t ½ 0.5 d)
○ C – reactive protein
○ Micronutrient deficiency: variable
 Enzymes, cofactors (Se, Zn, Fe, Mn), glutathione, vitamins
(A,B,C,D,E,K), electrolyte, Ca++, HCO3, PO4, Mg++

6. Assessment of the present illness
 Hypermetabolism
○ Burns,
○ Sepsis,
○ MSOF,
○ Trauma
 GI surgical procedures-prolonged NPO
 End-organ failure (Hepatic/renal etc)

7. Resting energy expenditure
equations
Clinical nutrition highlights •
2007

8. Resting energy expenditure
equations
Harris-Benedict Equations (calories/day):
Male: (66.5 + 13.8 X weight) + (5.0 X height) - (6.8 X age)
Female: (665.1 + 9.6 X weight) + (1.8 X height) - (4.7 X age)
[weight in kilograms, height in centimeters, age in years]
Overestimate by 6% to15% the actual energy expenditure
measurements done by indirect calorimetry

9. Resting energy expenditure (REE)
Age (years) REE (kcal/kg/day)
0 – 1 55
1 – 3 57
4 –6 48
7 –10 40
11-14 (Male/Female) 32/28
15-18 (Male/Female) 27/25

10. Normal nutritional requirements
BMR / REE
[37-55 Kcal/kg/d (50% of EE)]
+
Maintenance
+
Activity
+
Growth
Total energy expenditure
in kcal/kg/day

11. Energy Requirements in sick child
REE
+
REE  (Total Factors)
Factors:
Total energy expenditure
in kcal/kg/day
Maintenance + Activity + Growth + Fever + Simple Trauma
+ Multiple Injuries + Burns + Surgery

12. Factors Multiplication factor
Maintenance 0.2
Activity 0.1 - 0.25
Growth 0.5
Fever 0.13/per degree > 38ºC
Simple Trauma 0.2
Multiple Injuries 0.4
Burns 0.5-1
Sepsis 0.4 – 0.5
Major surgery 0.2 – 0.3

13. How reliable are these equations ?
 Inaccurate in critical illness
 May underestimate or overestimate the true
energy requirement
 Often results in underfeeding or overfeeding

14. Indirect calorimetry

15.  Volume of O2 consumed, VO2
(ml/min):
Cardiac output x (CaO2 –
CvO2) [Fick Equation]
 CaO2 is the arterial oxygen
content
 CvO2 is the venous oxygen
content.
 (CaO2 – CvO2) is
the arteriovenous o2 difference
 Volume of CO2 produced,
VCO2 (ml/min):
VE (FECO2- FICO2)
 VE = Volume of air expired in
mL/min
 FECO2 = Fraction of CO2 in
expired air
 FICO2 = Fraction of CO2 in
inspired air

16.  REE
= [3.9 (VO2) + 1.1 (VCO2)] 1.44
[Abbreviated Weir Equation]
 Respiratory
quotient (RQ)
= VCO2/VO2
VO2 = oxygen uptake (ml/min)
VCO2 = carbon dioxide output (ml/min)

17. The respiratory quotient (RQ)
RQ is a measure of substrate use and in individual patients has a low
specificity
RQ <0.85 is s/o underfeeding [low sensitivity, 63%; high specificity,
89%; and high negative predictive value,90%]
RQ >1.0 is s/o overfeeding [poor sensitivity, 21%; high specificity, 97%;
and a high positive predictive value , 93%]

18. Pre – requisite for IC
 Important considerations or conditions to improve the
REE measurement:
 Individual should rest for at least 30 minutes in bed or a
recliner before the test, should not be asleep.
 No food for at least 2 hours before the test.
 Maintain quiet surroundings and normal temperature. The
individual should not move arms or legs during the test.
 Normal room temperature should be maintained, avoid drafts
or any condition that might result in shivering.
 Medications taken should be noted, such as stimulants or
depressants.
 Steady state should be achieved, which would be identified
clinically by the following:
5 minute period when average minute VO2 and VCO2
changes by less than 10% and the average RQ changes
by less than 5%.
 Stable interpretable measurements should be
obtained in a 15 to 20 minute test.

19. Pre – requisite for IC
 Additional considerations for hospitalized
individuals:
 If the individual is on specialized nutrition support
(enteral or parenteral nutrition) continuous 24-hour
infusion does not need to be stopped.
 The nutrients infused should be constant for at least 12
hours.
 If feedings are intermittent or cyclic, the feeding should
be held for at least 2 hours. Document the product
and the rate the individual is receiving.
 Discontinue any supplemental sources of oxygen
 If the individual is on a ventilator, the settings should
remain constant for at least 1-1/2 hours before the test.
 No recent chest therapy or physical procedures.
 Renal failure patients requiring hemodialysis should
not be tested during dialysis therapy.

20. Nutrition in critical illness is very
important
CRITICAL ILLNESS + POOR NUTRITION
Prolonged ICU stay
Prolonged ventilator dependency
Increased susceptibility to nosocomial infections
Multi system dysfunction
Increased mortality

21. Nutrition: overall goals
ACCP consensus statement,
1997
 Provide nutritional support appropriate for the individual
patient’s
 Medical condition
 Nutritional status
 Available routes for administration
 Prevent/treat macro/micronutrient deficiencies
 Dose nutrients compatible with existing metabolism
 Avoid complications
 Improve patient outcome

23. What guidelines say ?
Thibault &Pichard, Medical Clinics of North America, 2010

24. Thibault &Pichard, Medical Clinics of North America, 2010

25. What happens if
EN is used alone in the early course ?
Thibault &Pichard, Medical Clinics of North America, 2010

26. EN alone causes an energy debt
Thibault &Pichard, Medical Clinics of North America, 2010

27. Enteral with parenteral :
is the combination better ?
 120 adult medical and surgical patients
 Combination vs enteral feeds alone
 Prospective, double blinded, RCT
 RBP, pre albumin increased significantly D 0-7
 Reduced hospital stay (by 2 days)
 No reduction in ICU morbidity
 No reduction in ICU LOS/ ventilatory requirement, MSOF,
dialysis
 Mortality at 90 days and 2 years was identical
Bauer et al, Intensive care med, 2000

28. Advantages of the combination
Thibault &Pichard, Medical Clinics of North America, 2010

29. Impact of no – enteral nutrition
 Negative nitrogen balance
 Morphological changes in
the gut
 Mucosal thickness
 Cell proliferation
 Villus atrophy
 Functional changes
 Increased permeability
 Decreased absorption
of amino acids
 Enzymatic/Hormonal changes
 Decreased sucrase/lactase
 Impact on immunity
 Cellular: Decreased T cells,
atrophied germinal centers,
 Humoral: Decreased
complement, opsonins, Ig,
reduced secretory IgA
 Increased bacterial
translocation

30.  Probably enteral nutrition is better as it is more
physiological
 Frequently associated with insufficient coverage of
energy requirements, correlated with a worsened
clinical outcome.
 All-in-one PN - no significant negative effect on
mortality and infectious morbidity in ICU patients

31. Initiation of EN
 When: as soon as
possible
 Usually within 24 hours
in all cases
 Small volume trophic
feeds is a good choice
 Contraindications
 Absolute
○ Occlusive intestinal stenosis
○ Pseudo-obstruction with complete food
intolerance,
○ Clinically or endoscopically severe colitis
 Others: allow the intestine to "rest"
○ Digestive fistulae with a high flow
○ Inflammatory bowel disease (Crohn's
disease, irradiated bowel disease)
○ Severe peritonitis
○ Severe shock states, gut ischemia

32. Routes of EN
• Requires good gastric motility
• Requires good gastric emptying
Nasogastric
• Effective in gastric atony/ ileus
• Silicone/polyurethane tubing
• Positioning: fluoroscopic/ pH
monitoring / endoscopic guidance
Transpyloric
• PEG if > 4 weeks nutritional support
anticipated
• Jejunostomy - GER, gastroparesis,
pancreatitis
Percutaneous
or
Surgical
placement

33. POTENTIAL DRAWBACKS
OF ENTERAL FEEDS
 Gastric emptying impairments
 Aspiration of gastric contents
 Diarrhea
 Sinusitis
 Esophagitis /erosions
 Displacement of feeding tube

34. Methods of EN
Bolus
feeding
• More chances
of aspiration
Intermittent
feeding
• Given as
2ml/kg 4 – 6
hrly
• Each time for
20 – 45 mins
Continuous
drip feeding
• Least potential
for aspiration,
bloating,
diarrhea
• Chances of
bacterial
overgrowth

35. Different enteral formulas
Type of formula Contents Amount Nutrition Value/ 100ml
Elemental Protinex powder 50 gm Calories 110 kcal
Glucose 100 gm Proteins 2.6 gm
Refined oil 30 gm Carbs 19.5 gm
Water To make 1000 cc Fats 3 gm
Polymeric
(Milk based)
(Suji kheer)
Milk 500 gm Calories 150 kcal
Sugar 50 gm Proteins 4 gm
Suji 20 gm Carbs 4 gm
Oil 20 gm Fats 7.5 gm
Polymeric
(Lactose free)
Rice 50 gm Calories 66 gm
Sugar 45 gm Proteins 3 gm
Oil 30 gm Carbs 8.4 gm
Water To make 1000 cc Fats 3.7 gm
PGIMER, Chandigarh

36. Enteral formulas in SSH

37. Immune modulation
Glutamine
Arginine
Fatty acids (w-3)
Nucleotides
Vitamins and minerals
 Pediatric burn patients: Arginine & w-3 fatty acid supplements reduce
infections, LOS
 Mortality, bacteremic episodes reduce
 More pronounced effect in APACHE II
(J Parenter. Ent. Nutr.,1990; CCM, 2000)

38. Enteral formulas
Children older than 10 years
can be fed adult formulas

39. Complications of EN
Mechanical Gastrointestinal Metabolic
Tube blockage Diarrhea Hyperglycemia
Pulmonary
aspiration
Abdominal
distension
Dehydration
Poor or shifted tube
position
Nausea and
vomiting
Hypokalemia
Accidental tube
withdrawl
Intestinal
obstipation
Hyperkalemia
Hypernatremia
Hypophosphatemia
Hypercapnia

40.  Tolerance
 Nutrition and metabolic
 Daily weight
 SE, osmolality, acid base balance, RBS, Mg, Ca, Po,
urine, LFT
 Mechanical
 Tube patency and position
 Irrigation
Monitoring in EN

44. Goals PN Clinical nutrition highlights • 2007
 Maximal preservation of major organ system function
during the acute phase of illness
 Minimization of the catabolic response
 Prompt restoration of the pre - morbid nutritional state
without producing treatment related complications

45. Goals PN Ann Med Interne (Paris) 2000 Dec
 Nutritional support
 Must be complete
 Must be conducted according to a rigorous written protocol
specific for each indication
 Avoid iatrogenic and metabolic risks
 Enhance the efficacy of the nutritional support
 Avoid inappropriate prescriptions, notably for
parenteral administration
These allows a better risk/benefit ratio evaluated with nutritional standards

46. Indication : PN Ann Med Interne (Paris) 2000 Dec
 Absolute
 Occlusive intestinal stenosis
 Pseudo-obstruction with complete food intolerance,
 Clinically or endoscopically severe colitis
 Others: allow the intestine to "rest"
 digestive fistulae with a high flow
 inflammatory bowel disease (Crohn's disease, irradiated
bowel diseasenutrition )
 Complementary:
 Poorly tolerated quantitatively insufficient oral or enteral
nutrition

47. Study at SGRH -2007 related to
PN
 Results:
 80 delegates
 Already using PN - 20
 Reasons for not using PN(n=60)
○ Fear of sepsis – 48(80%)
○ Non availability of CV access- 42 (70%)
○ Very expensive – 39(65%)
○ Non availability of PN fluids( lipids) – 30(50%)
○ Complications of PN – 38(63%)
○ Difficult to calculate – 24 (40%)
○ No laminar flow – 21(35%)
○ Don’t have ELBW Babies in unit -21 (35%)

48. Types of PN:
Peripheral (<3 weeks)
Central (>3 weeks)
Lipid, amino – acids and dextrose: infused through
separate IV sets which are attached to the IV
cannula through a 3 – way stop cock

49. Suggested parenteral solution:
PGIMER, Chandigarh
Nutrients Volume (ml/kg/day) Amount (kg/day)
Aminoven (10%) 25 2.5 gm
Intralipid (10%) 10 – 30 0.5 – 3 gm
Glucose (50%) 10
KCl (15%) 1 2 – 3 meq
MgSO4 (50%) 0.04 20 mg
Calcium gluconate (5%) 3.5 1.5 meq
NaCl (25%) 6 3 meq
Trace metals 1 Zn, Cu, Mn, Se, Cr, I
MVI 1
Glucose 10% to make 120ml
Vit K – 1 mg, Vit B12 – 50 ugm, Folic acid – 1 mg: weekly supplementation

51. Laminar flow system

52. Laboratory Monitoring
 Serum electrolytes
 Blood urea
 Serum lactate
 Serum ammonia
 Serum proteins
 Arterial blood gas
 Blood glucose
 Serum triglycerides and
 Nitrogen balance

53. Complications of PN
Mechanical Septic Metabolic
Pneumothorax, Exogenous
[ Extraluminal
and
Intraluminal ]
Hypo/ Hyperglycemia
Hemothorax
Hyperlipidemia/ Increased AA
Dyselectrolytemia
Hematoma
Tracheal puncture Endogenous Hypophosphatemia
Catheter blockage Hypocalcemia / Hypercalcemia
Catheter migration Hypomagnesemia
Venous thrombosis Trace element deficiency
Cholestasis
Overfeeding syndrome

54. Overfeeding syndrome
 Occurs when TPN intake exceeds need, resulting in increased fat synthesis
 Fatty infiltration of the liver, hyperglycemia, hypertriglyceridemia, increased
metabolic rate, and electrolyte disturbances
 Increases in oxygen uptake, CO2 production, and CO2 retention may be seen in
children with pulmonary or cardiac insufficiency.
 Hypermetabolic and malnourished patients are more susceptible to these
respiratory problems
 Another potential complication, an increase in infectious complications, as
hyperglycemia represents a risk factor for infection
 To avoid overfeeding, nutritional status must be assessed and monitored to
achieve a balanced supply of nutrient needs

55. Conclusion
Deeper knowledge of the physiopathology of
metabolic stress, the application of new
concepts in nutrition and metabolism and the
deployment of multidisciplinary nutritional
therapy teams within the hospital setting can
bring about improvements in the quality of
nutritional intervention