Download Nutrition in the septic Patient

Nutritional Requirements and Enteral
Support of the Critically Ill, Ventilated
Patient
John P. Grant, MD, CNSP
Director Nutrition Support Service
Professor of Surgery
Duke University Medical Center
Durham, NC
Nutritional Requirements and Enteral
Support of the Critically Ill, Ventilated
Patient
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Optimal Metabolic Care of the
Critically Ill, Ventilated Patient
Optimize milieu for cell metabolism
Minimize stress response
Provide adequate and appropriate
nutritional support
Optimal Metabolic Care of the
Critically Ill, Ventilated Patient
Provide Optimal Metabolic Milieu
Establish and maintain oxygenation
Adjust pH
Ensure adequate tissue perfusion
Control waste (dialysis)
Optimal Metabolic Care of the
Critically Ill, Ventilated Patient
Provide Optimal Metabolic Milieu
Minimize Metabolic Stress Response
Control pain
Debridement of necrotic/infected tissue
Drain abscesses
Dress or cover wounds
Optimal Metabolic Care of the
Critically Ill, Ventilated Patient
Optimize milieu for cell metabolism
Minimize stress response
Provide adequate and appropriate
nutritional support
Importance of Adequate Nutrition
Nutrient balance and mortality in ICU patients
4/15 with positive caloric balance died (27%)
11/28 with 0 to -10,000 kcal balance died (39%)
12/14 with > -10,000 kcal balance died (86%)
Bartlett et al., Surgery 92:771, 1982
Caloric Balance and Outcome in ICU
A = positive caloric
balance
B = 0 to -10,000
kcal balance
C = > -10,000 kcal
balance
Caloric Balance vs % Mortality
86%
90
80
70
60
50
40
30
20
10
0
39%
27%
A
B
Bartlett et al., Surgery 92:771, 1982
C
Days of Survival Without Nutrition
Days = { [(UBW X 2430) x K] - [(UBW - BW) x 2430]}
AEE - Ei
Where:
UBW = usual body weight in kg
BW = current body weight in kg
K = 0.35 with stress; 0.40 with simple starvation
AEE = actual energy expenditure (kcal/d)
Ei = energy intake (kcal/d)
Importance of Adequate Nutrition
in Respirator Dependent Patients
Arora and Rochester evaluated the effects of malnutrition
on diaphragmatic muscle dimensions at necropsy and in vivo
function in patients after prolonged illness (75% UBW) as
compared with well nourished patients
Diaphragmatic muscle mass
Max Inspiratory Vacuum
43% less
35% normal
Max Expiratory Pressure
Max Ventilatory Volume
59% normal
41% normal
Arora and Rochester: Am. Rev. Respir. Dis., 126:5-8, 1982.
Impact of Malnutrition on Pulmonary Function
Sahebjami and Wirman studied the lungs of adult rats
subjected to 3 weeks of semi-starvation (approximately
40 percent loss of total body weight). They found:
•
Marked emphysematous changes
•
An increase in size of air spaces and reduction in
alveolar wall surface tension
•
Elastic fibers were shortened, irregular, and fewer in
number
Sahebjami and Wirman: Am. Rev. Respir. Dis., 124:619-624, 1981.
Impact of Malnutrition on Pulmonary Function
•
Reticular fibers were unchanged
•
Biochemical measurements demonstrated a reduction in
desaturated lecithin. Because lecithin is a major
component of surfactant, it was proposed that alveolar
collapse with emphysematous changes might be expected
•
Refeeding the rats corrected desaturated lecithin
concentrations but failed to reverse the morphological
emphysematous changes
Sahebjami and Wirman: Am. Rev. Respir. Dis., 124:619-624, 1981.
Impact of Malnutrition on Pulmonary Function
Doekel et al. placed volunteers on a balanced 550 kcal/day
diet for 10 days and demonstrated a 20% reduction in
basal oxygen consumption and a 58% reduction in their
ventilatory response to hypercapnea. (N. Engl. J. Med.,
295:358-361, 1976)
Askanazi et al. fed volunteers a hypocaloric (550 Kcal/day),
balanced diet for 10 days and demonstrated a 58%
reduction in ventilatory response to hypoxia. (Anesthesiol.
53(Supp 1):185, 1980)
Refeeding in both studies restored normal function
Impact of Malnutrition on Pulmonary Function
Minnesota Experiment: Routine pulmonary function tests
were performed before and after 24 weeks of semistarvation
•
Vital capacity, tidal volume, and minute ventilation
decreased by 7, 19, and 31 percent, respectively
•
Refeeding resulted in improvement but incomplete
recovery, even after 12 weeks
Keys et al.: The Biology of Human Starvation. Minneapolis, University of
Minnesota Press, 1950.
Impact of Malnutrition on Pulmonary Function
Duke data, unpublished: Recovery of Organ
Function With 2 Weeks of TPN in 21 Malnourished,
Non-stressed Patients
Impact of Malnutrition on Pulmonary Function
Recovery of Organ Function With 2 Weeks of TPN in 21 Malnourished,
Non-stressed Patients. Duke data, unpublished
Function
Number
of
Patients
Maximal
expiratory
pressure
21
59%
69%
17
<0.02
Maximal
inspiratory
vacuum
21
43%
52%
23
<0.002
Pre-TPN Post-TPN
Percent
Change
p-value
Impact of Malnutrition on Pulmonary Function
Bassili and Deitel, and Mattar et al. evaluated the effects
of inadequate nutritional support on the ability to wean
patients from mechanical ventilation. Combining their
results:
22 of 25 patients (88%) who received adequate nutritional
support could be weaned from the respirator, whereas
only 10 of 31 patients (32%) who did not receive
adequate support were able to be weaned (p < .001)
Bassili and Deitel: J.P.E.N. J. Parenter. Enteral Nutr., 5:161-163, 1981.
Mattar et al.: J.P.E.N. J. Parenter. Enteral Nutr., 2:50, 1978.
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
- What to Give Protein Support – normal - Adjust for co-existing
illnesses and to achieve positive nitrogen balance, reduce
for renal and hepatic dysfunction
No stress
Mild Stress
0.7 to 0.8 g/kg/day
0.8 to 1.0 g/kg/day
Moderate Stress
Severe Stress
1.0 to 1.5 g/kg/day
1.5 to 2.0 g/kg/day
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
Caloric Support – Ireton-Jones formula
Recently re-designed, specifically for ventilator-dependent
patients in the ICU:
BEE = 1784 - 11(A) + 5(W) + 244(S) 239(T) + 804(B)
Where: A = age in years, W = weight in kilograms,
S = sex (male = 1, female = 0),
and T = trauma and B = burn (present = 1, absent = 0)
Ireton-Jones, C., NCP, 17:29-31, 2002
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
Caloric Support – Cal Long Modification of H-B
AEE (men) = (66.47 + 13.75 W + 5.0 H - 6.76 A) x (activity
factor) x (injury factor)
AEE (women) = (655.10 + 9.56 W + 1.85 H - 4.68 A) x (activity
factor) x (injury factor)
Activity Factor
Use
Injury Factor
Use
Confined to bed
1.2
Minor OR
1.2
Out of Bed
1.3
Skeletal Trauma
1.3
Major Sepsis
1.6
Severe Burn
2.1
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
Caloric Support – Swinamer formula
Specifically for critically ill ventilated patients in the ICU:
REE = BSA(941) + Tmax(104) + RR(24) +Vt(804) - 4243
Where: BSA = body surface area, T = temperature,
RR = respiratory rate, Vt = tidal volume
Swinamer, D.L. et al. Crit. Care Med., 18:657-661, 1990
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
Excessive calories can result in excessive CO2
production, increased arterial pCO2, RQ > 1.0, and
increased ventilatory demand in the already
compromised ventilated patient.
May delay weaning
May render respiratory support difficult
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
In ventilatory dependent patients, a high caloric
load (2 X REE) has been shown to result in
significantly higher O2 consumption and CO2
production than a moderate load (1.5 X REE) in
patients otherwise receiving an identical diet
Van den Berg and Stam: Intensive Care Medicine, 14:206-211, 1988.
Adequate Nutritional Support of
Critically Ill, Ventilated Patients
Clearly, total caloric intake has a greater impact
on CO2 production and respiratory function than
does the ratio of CHO/fat (varying CHO content from
40-75% of total calories has little impact)
Recommend 1.2 to 1.5 times REE
(up to 5 mg/kg/min CHO infusion – 40 to 50% of
total calories as CHO)
Talpers et al: Chest, 102:551-555, 1992.
Van den Berg and Stam: Intensive Care Medicine, 14:206-211, 1988.
Burke et al.,
Ann Surg, 190:274, 1979
As increasing amounts
of glucose are infused, a
maximal rate of glucose
oxidation and whole body
protein synthesis is
obtained at 5.0 to 6.0
mg/kg/min (~630 g/d for
80 kg patient)
Use of Insulin to Stimulate
Glucose Utilization
Does lower blood sugar in most cases
Drives glucose mainly into muscle
No documented increase in glucose
oxidation or nitrogen sparing
Vary et al., JPEN 10:351, 1986
Use of Insulin in Glucose Utilization
Anaerobic Glycolysis
Pyruvate
Pyruvate Dehydrogenase
Insulin
Krebs cycle

Fat Synthesis
Optimal Metabolic Care of the
Critically Ill, Ventilated Patient
Benefits of
Early Enteral Nutrition
vs.
Parenteral Nutrition
Early Enteral Nutrition
Initiation of enteral nutrition within 24
to 48 hours of hospitalization or
catastrophic event
Initiation of nutrition support after 72
hours may have no appreciable effect
on morbidity
Early Enteral Nutrition
Reduces hypermetabolism in trauma,
burn, and postoperative patients
Postburn Hypermetabolism and Early
Enteral Feeding
30% BSA burn in
guinea pigs
Enteral feeding via
g-tube at 2 or 72
hours following burn
Mucosal weight and
thickness were similar
RME % Initial
160
175 Kcal - 72 h
150
140
200 Kcal - 72 h
130
120
175 Kcal - 2 h
110
100
0
2
4
6
8
10 12
Postburn day
Alexander, Ann. Surg., 200:297, 1984
Early Enteral Nutrition
Maintains gut mucosal barrier
Bulk stimulation
Fuel source for enterocyte - glutamine
TPN without glutamine = Intestinal
atrophy – bacterial translocation
Glutamine in Cellular Nutrition
Major Fuel For:
Enterocytes
Lymphocytes
Fibroblasts
Bone Marrow
Pancreas
Lung
Tumor Cells
Renal Tubular Cells
Vascular Epithelial Cells
Glutamine
Necessary precursor for protein and
nucleotide synthesis
Regulates acid-base balance through
production of urinary ammonia
Major transporter of nitrogen (along with
alanine)
Oxidation via Krebs cycle yields 30 mole
ATP per mole glutamine (glucose = 36)
Glutamine Metabolism
Gut normally extracts 20 to 30% of
glutamine from blood
During stress, muscle releases amino
acids with glutamine and alanine making
up 60% of total
Muscle glutamine concentration
decreases by up to 50% and serum
concentrations fall with prolonged stress
Adequate Nutritional Support of
Respirator Dependent Patients
Content of Enteral Formulas
Glutamine
g/L
Arginine
g/L
% BCAA
15
4.5
18.5
Immun-Aid
12.5
15.4
36.1
Pulmocare
5
3.3
19
5.9
3-6
14
1-2
17.1
17-22
Formula
AlitraQ
Impact
Standard TF
Early Enteral Nutrition
Maintains GALT system
GALT System
Gut-associated
lymphoid tissue
Intraepithelial
lymphocytes
Lamina propria
lymphoid tissue
Peyer’s patches
Mesenteric
lymph nodes
GALT System
Intraepithelial lymphocytes
First to recognize foreign
antigens
Lamina propria lymphoid
tissue
Source of IgA
Peyer’s patches
Process antigens from intestinal
lumen
GALT System
Responsible for reacting to harmful
foreign antigens (e.g. bacterial or viral
pathogens)
Must not react to non-threatening
antigens to avoid chronic
inflammatory condition
GALT System
Intravenous feeding with bowel rest and
starvation result in significant
suppression of the mass and function of
GALT, with reduction in IgA secretion
and increased gut permeability
Oral and enteral feedings preserve GALT
mass and function
Li, J Trauma, 39:44, 1995
GALT System
Bowel rest (or an elemental diet) reduces
intraluminal nutrients that bacteria need
Induces an adaptive response of bacteria
to increase their adherence to the
intestinal wall as a source of nutrients
Bacterial adherence causes cellular injury,
or even bacterial penetration
(translocation), with an adverse host
response
Early Enteral Nutrition
Better maintenance of endogenous
antioxidant pools
Helps reverse and prevent stressinduced splanchnic ischemia
Nutritional Support of the
Critically Ill, Ventilated Patient
Problems with Enteral: Underfeeding
High gastric residuals
Fear of Aspiration
Constipation/Diarrhea
Abdominal distention
Nausea and vomiting
Nutritional Support of the
Critically Ill, Ventilated Patient
Problems with Enteral: Underfeeding
McClave et al. prospectively evaluated enteral
tube feedings in 44 medical ICU/coronary care
unit patients (mean age, 57.8 years) who
received nothing by mouth and were placed on
enteral tube feeding
McClave et al.: Crit. Care Med., 27:1252-1256, 1999
Nutritional Support of the
Critically Ill, Ventilated Patient
Physicians ordered a daily mean volume of
enteral tube feeding that was only 65.6% of goal
requirements
On average, only 78.1% of the volume ordered
was actually infused
Thus, patients received a mean volume of
enteral tube feeding that was only 51.6% of goal
McClave et al.: Crit. Care Med., 27:1252-1256, 1999
Nutritional Support of
Critically Ill, Ventilated Patient
Only 14% of patients reached or exceeded
90% of goal feedings (for a single day) within
72 hours of the start of enteral tube feeding
Of 24 patients weighed before and after, 54%
were lost weight on enteral tube feeding
Declining albumin levels correlated significantly
with decreasing percent of goal calories
infused
McClave et al.: Crit. Care Med., 27:1252-1256, 1999
Nutritional Support of
Critically Ill, Ventilated Patient
NOTE: This may not be of major concern,
perhaps it is actually beneficial – avoidance of
overfeeding
Some contend that the problems with
parenteral nutrition are due to overfeeding,
since what is prescribed is more commonly
given to the patient
Nutritional Support of the
Critically Ill, Ventilated Patient
Problems with Enteral: Aspiration
Most feel TF is associated with an increased
incidence of pneumonia – not aspiration
Most common event is aspiration of saliva
Consider use of feeding tube distal to stomach:
Nasojejunal, gastrojejunal, or jejunostomy
Fluoroscopic
Placement
Nasojejunal
Tube
Note:
Note:injection
ofinjection
Gastrografin
of
toGastrografin
evaluate
small
to evaluate
bowel
anatomy
small bowel
and
motility.
anatomy and
motility.
Adequate Nutritional Support of
Respirator Dependent Patients
Use of Pulmonary Enteral Formulas
No clear benefit has been demonstrated
Problem of hypercarbia is due mostly to total
caloric infusion rather than CHO/fat content
Effectiveness of fat in supporting the
hypermetabolic response of critical illness and
enhancing nitrogen balance remains in question
Malone, A.M.: Nutr. Clin. Pract. 12:168-171, 1997
Adequate Nutritional Support of
Respirator Dependent Patients
Available “Pulmonary” Enteral Formulas
CHO
% calories
Protein
% calories
Fat
% calories
Nutri-Vent
27
18
55
Pulmocare
28
17
55
Respalor
39
20
41
38-53
15-22
30-45
Formula
Regular TF
Adequate Nutritional Support of
Respirator Dependent Patients
Use of Pulmonary Enteral Formulas
Disadvantages include:
• Decreased gastric emptying
• Increased gastrointestinal side effects
• Possible inadequate CHO intake
• Significantly increased cost
Malone, A.M.: Nutr. Clin. Pract. 12:168-171, 1997
Adequate Nutritional Support of
Respirator Dependent Patients
Use of Standard Enteral Formulas
Avoids above problems of Pulmonary Enteral
Formulas
Formulas exist to adjust for liver and renal failure
Malone, A.M.: Nutr. Clin. Pract. 12:168-171, 1997
Adequate Nutritional Support of
Respirator Dependent Patients
Use of specialized immunoenhancing products
may be of some benefit – although not proven
Much concern recently over ratio of
W-3/W-6 fatty acids
Optimal is about 1:2
Soy-based emulsions 1:5 TO 1:7
Malone, A.M.: Nutr. Clin. Pract. 12:168-171, 1997
Adequate Nutritional Support of
Respirator Dependent Patients
Branched-Chain Amino Acids
Alanine
Leucine
Isoleucine
Organ Specific Substrate Support
Branched-Chain Amino Acids
Main energy source for skeletal muscle
during stress and sepsis
Not metabolized by the liver: safe to give
during liver failure
Give 30 - 40 grams/day: 100 -160
kcal/day (45% BCAA Solution)
Protein
BCAA can
enhance nitrogen
balance during
periods of
maximal stress
Cerra et al., Crit Care Med, 11:775, 1983
Nutritional Support of the
Critically Ill, Ventilated Patient
Problems with Parenteral
Intestinal atrophy – bacterial translocation
Possible overfeeding
Catheter-related sepsis
Nutritional Support of the
Critically Ill, Ventilated Patient
Problems with Parenteral
Immunosuppression – especially with lipids
No W-3 rich lipid emulsion yet available
In Europe there is a 10% fish oil emulsion in use
Hamawy et al demonstrated deposition of lipid
emulsions in macrophages with increased susceptibility
of mice to pneumococcal infections
Hamawy et al: J.P.E.N. J. Parenter. Enteral Nutr., 9:559-565, 1985.
Nutritional Support of the
Critically Ill, Ventilated Patient
Preferred Route for Nutritional Support
Some evidence that TPN is immunosuppressive
and harmful
No real evidence that Enteral is better – but it
probably is… and it is cheaper
Conclusion
Do what is effective in your clinical situation!
Nutritional Requirements and Enteral
Support of the Critically Ill, Ventilated
Patient
Optimize milieu for cell metabolism
Minimize stress response
Provide adequate and appropriate
nutritional support
Standard Enteral Support > TPN