Nutrition Support
of the
Hospitalized Patient
METABOLIC RESPONSE TO INJURY
Ebb Phase
Flow Phase
“Catabolic”
INJURY
0
12
HOURS
24
1
2
WEEKS
3
Severe Injury
Moderate Injury
Mild Injury
Severe Injury
Moderate Injury
Mild Injury
HYPERMETABOLISM
GLUCOSE METABOLISM
• Glucose production ’d (lactate, alanine, glycerol)
• Peripheral uptake/use ’d (non-insulin based)
• Entrance into Kreb’s cycle ’d
• Lactate, pyruvate ’d
• Insulin resistance
• Exogenous glucose can’t suppress GNG
GLUCOSE
CORI CYCLE
LACTATE
GLUCONEOGENIC
AMINO ACIDS
PYRUVATE
Pyruvate dehydrogenase
inhibition
ACETYL COA
TCA CYCLE
LIPOGENESIS
KETONES
HYPERMETABOLISM
GLUCOSE METABOLISM
• Glucose production ’d (lactate, alanine, glycerol)
• Peripheral uptake/use ’d (non-insulin based)
• Entrance into Kreb’s cycle ’d
• Lactate, pyruvate ’d
• Insulin resistance
• Exogenous glucose can’t suppress GNG
Glucose Appearance Rate (GNG)
(mg/kg-min)
14
12
10
8
6
4
2
0
Control
Non-oxidized
Oxidized
Skeletal
Trauma
Sepsis
Burns
Glucose Appearance Rate (GNG)
(mg/kg-min)
6
5
Basal
4
Glucose Infusion
3
2
1
0
Normal
Septic
HYPERMETABOLISM
FAT METABOLISM
• ’d preference as fuel source
• 30-40% non-protein calories
• Ketone body production ’d
• Lipolysis, TG, FA-TG cycle ’d
• Hepatic stetatosis
HYPERMETABOLISM
PROTEIN METABOLISM
• Acute phase reactants ’d
• ’d efflux from periphery
• ’d oxidation amino acids (30%)
PROTEIN TURNOVER IN
HYPERMETABOLISM
8
6
Gram/kg/day
4
2
0
-2
-4
-6
-8
-10
Vo
lun
tee
rs
Tra
um
aB
asa
l
Tra
um
aT
PN
Protein Catbolism
Net Protein Loss
Protein Synthesis
Basal Metabolic Rate (BMR)
Basal Energy Expenditure (BEE)
Resting Energy Expediture (REE)
ENERGY
EXPENDITURE
Activity Level
Thermic Effect of Food
Components of Total Energy
Expenditure
Diet
Other
Induced 2-7%
7-13%
Physical
Activity
15-30%
Basal
Metabolic
Rate
60-75%
Malnutrition and Critical
Illness
• CLASSICAL - Months to years
• STRESSED - Days to weeks
TPN Terminology
TPN - Total Parenteral Nutrition
PPN - Peripheral Parenteral Nutrition
IVN - Intravenous Nutrition
IVH - Intravenous Hyperalimentation
“Hyperal”
What is the effect of EN
vs TPN on infectious
outcome?
Septic Complications in Trauma Patients
Enteral vs Parenteral Nutrition
Major Infections
TEN
(n=29)
1 (3%)
TPN
(n=30)
6 (20%)
p<0.03
4 (14%)
5 (17%)
NS
5 (17%)
11(37%)
NS
(abdominal abscess,
pneumonia)
Minor Infections
(wound, catheter, UTI
miscellaneous)
Total Complications
Septic Complications in Trauma Patients
Enteral vs Parenteral Nutrition
ENTERAL
N
Calories/kg/d
N Balance (mg/kg/d)
51
16
TPN
*
-171
45
19
-190
Pneumonia
Intraadbominal
Abscess
Line Sepsis
12
2
*
*
31
13
2
*
13
Infections/pt
0.4
*
1.2
* p<0.05
More severely injured patients (ATI>40, >20 units blood,
reoperation) benefited most
What is the effect of EN
vs TPN on infectious
outcome?
EN is preferred when possible
How does the timing of
administration of EN
affect infectious m/m in
critically ill patients?
How does the timing of
administration of EN affect
infectious m/m in critically ill
patients?
Begin early at low rates
What’s the down-side to
aggressive enteral feeding in
the critically ill?
Duodenal feeding during
PEEP Ventilation
12
10
8
Hepatic
Gut
Systemic
6
4
2
0
Baseline
Injury
Oxygen consumption
Fed
AJS 1993:165:189
What’s the down-side to
aggressive enteral feeding in
the critically ill?
Begin early - at low rates
Membrane Energy Consumption
• Ion Transport
– Na-K ATPase
– Ca-ATPase
– K-H ATPase
– H leakage mitochondria
• Organic Compound Transport
– AA, Nucl Ac ,Protein, glucose
• Macromolecular Transport
– Membrane proteins, Phospholipids
Protein Related Energy Consumption
• Protein Turnover
– Formation initiation complex
– Peptide bond synthesis
– Protein degradation
• RNA turnover: rRNA, tRNA
• Amino Acid transport
• Regulation and integrity
– 2nd messengers, ion pumps, protein
translocation
• Nitrogen Metabolism
– Glutamine/glutamate; glu/ala; urea
Malnutrition and Critical
Illness
• Hypermetabolism is not
abolished simply by
providing nutrition
Malnutrition and Critical
Illness - Objectives
“Cut Your Losses”
What to Give?
Enteral or Parenteral
Nutrition
Intravenous Nutrition Components
•
•
•
•
Water
Glucose
Nitrogen (A.A.)
Lipids
• Electrolytes
• Trace Minerals
• Vitamins
• Additives
Route of Administration
ENTERAL
• Less Expensive
• Delivery Problems
– Diarrhea
– Ileus
– Access problems
• Efficacy
Metabolic Rates of Specific Organs
Miscellan's
20%
Liver
29%
Kidney
11%
Muscle
11%
Heart
8%
Brain
21%
Energy Expenditure
Fick Principle
• Caloric Expenditure ~ Oxygen Consumption
• O2 consumption measured - PA Catheter
• Need to know
– Hemoglobin
– Arterial Oxygen content
– Venous Oxygen content
– Cardiac Output
Energy Expenditure
Fick Principle
(VaO2 - VvO2) x C.O. x 0.06 x 4.83 = kcals/hr
dl/min
kcal/l
60 min/hr x 1L/1000 ml
1.34 x Hb x Sat ml/dl
Impact vs Osmolite HN in ICU Patients
•
•
•
•
326 enrollled (trauma, surgery, sepsis)
Age 60 +/-; sepsis or IRS
Fed within 48 hrs
Post Hoc stratification
– >1150 ml in 96 hrs
– > 7 days fed
– >5 days fed at 1150 ml
– cumulative fed 5750 ml
Crit Care Med 1995;23:436-49
Impact vs Osmolite HN in ICU Patients
• Both tolerated = well, N2 Balance
• Mortality: 15.6% Imp vs 7.6% Osm (ns)
• In selected groups:
• Hosp stay reduced (only survivors)
• Acquired infections/pt reduced
Crit Care Med 1995;23:436-49
TEE=1.32 x REEm
4500
TEE
REEm
4000
3500
3000
2500
2000
1500
1000
500
0
A
C
G
I
MEAN
Ann Surg 1996;23:395-405
Growth Hormone
• 191 aa polypeptide secreted by
anterior pituitary
• Anabolic rather than anti-catabolic
effects on skeletal muscle
• Increases sysnthesis w/o affecting
catabolism
What is the preferred method
of delivering EN ?
What is the preferred method
of delivering EN ?
Stomach or small bowel either acceptable
Does the composition of EN
effect the infectious morbidity
and mortality in critically ill patients
Does the composition of EN
effect the infectious morbidity
and mortality in critically ill patients
Elemental vs polymeric -> polymeric
Fiber - no benefit
Imune enhancing - uncertain
Membrane Maintenance
ENERGY
EXPENDITURE
Protein
Metabolic Transport
Turnover Cycles
Components of energy expenditure in patients with severe sepsis
and major trauma: A basis for clinical care
TEE
TEE/Bwt
Indirect
Harris(kcal/d) (kcal/kg/d) calorimetry Benedict
SEPSIS
Week 1
Week 2
1927 ±
370
3257 ±
370
25 ± 5
1.0 ± 0.2
1.3 ± 0.2
47 ± 6
1.7 ± 0.2
2.3 ± 0.3
2380 ±
422
4123 ±
518
31 ± 6
1.1 ± 0.2
1.4 ± 0.3
59 ± 7
1.8 ± 0.2
2.5 ± 0.3
TRAUMA
Week 1
Week 2
Crit Care Med 1999; 27:1295-1302
Enteral tube feeding in the intensive care unit:
Factors impeding adequate delivery
TABLE 1 -- Reasons for cessation of enteral tube feeding
Reasons for Cessation Proced RV Tube Diag Nurs Other
Patients affected (%)
39
45 41 27 30
32
Infusion time lost (%)
6.4
2.8 1.4 0.8 0.3 6.6
Cessation time (%)
35
15 7.7 4.6 1.4 36
Avoidable (%)
80
70 67 52 99
52
RV, residual volume; Tube, tube displacement; Diag, diagnostic
tests; Nurs, nursing care.
Crit Care Med 1999; 27:1252-1256
TABLE 1 -- Reasons for cessation of enteral tube feeding
Reasons for Cessation
Proced RV
Tube Diag Nurs Other
Patients affected (%)
39
45
41
27
30
32
Infusion time lost (%)
6.4
2.8
1.4
0.8
0.3
6.6
Cessation time (%)
35
15
7.7
4.6
1.4
36
Avoidable (%) 80
70
67
52
99
52
RV, residual volume; Tube, tube displacement; Diag, diagnostic tests; Nurs, nursing c
Enteral tube feeding in the intensive care unit:
Factors impeding adequate delivery
 Physicians ordered a- 65.6% of goal
requirement
 Only 78.1% of the volume was actually infused
 339 days of infusion pts received 51.6% of goal
(range, 15.1% to 87.1%)
 Only 14% of patients reached 90% of goal
feeding (for a single day)
Crit Care Med 1999; 27:1252-1256
Components of energy expenditure in patients with
severe sepsis and major trauma: A basis for clinical
care
Crit Care Med 1999; 27:1295-1302
Critically Ill ?
In the ICU
Apples and Oranges
Trauma
CCU
Pancreatitis
CHF
COPD
Post-op
Abdominal Abscess
CVA
MI
SICU
Pneumonia
ARDS
Hepatic Failure
Urosepsis
MICU
Nutrition Support
in
Critical Illness