Clinical Nutrition Support Have we got it all wrong

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Clinical Nutrition Support Have we got it all
wrong ?
Dr Mike Stroud FRCP Senior Lecturer in Medicine
Nutrition, Consultant Gastroenterologist Southampt
on
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Apologies

• BSG talk because of NICE Guidelines
• NICE Guidelines 1st Draft
• Contention

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40 of hospital patients are overtly malnourished
on admission, 8 severely
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Causes of Malnourishment
Poor diet - age, poverty, junk,
Conscious level
exercise, alcohol
Depression
Anorexia
Dysphagia
Obstruction
Vomiting
Pancreatic failure
Liver processing
Jaundice
Malabsorption
Increased Metabolic demands
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Effects of Undernutrition
Psychology depression apathy
Ventilation - loss of muscle hypoxic responses
Immunity Increased risk of
infection
liver fatty change, functional declinenecrosis,
fibrosis
Decreased Cardiac output
Renal function - loss of ability to excrete Na
H2O
Impaired wound healing
Hypothermia
Impaired gut integrity and immunity
Loss of strength
Anorexia ? Micronutrient deficiency
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NUTRITIONAL SUPPORT SHOULD
Improve general status
Immunity
Wound healing
Ventilation
Mobility
Psychology
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Feeding gives time for other medical and surgical
interventions to work ITU patients would die at
20 to 30 days Make stronger for discharge
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Southampton CNRD Team Meta-analyses of
oral/enteral nutrition support trials.
30 RCT, n 3258 RR 0.59 (CI 0.48 to 0.72)
10 RCT, n 494 RR 0.29 (CI 0.18 to 0.47)
Controls
Controls
Treatment
Treatment
Decreased complication
Decreased mortality
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So why think we may be wrong ?

• Better understanding of the effects of starvation
• Problems in the evidence for Nutrition Support

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UNDERNUTRITION EFFECTS ON METABOLISM
Reduced physical activity
Decrease in metabolic mass
Decreased protein
Na/K
pumping -30
synthesis -40
Decreased
Decreased
AA transport
glucose transport
Decreases in
GH
Insulin
ILGF1,2
Adrenaline
NA
Glucagon
T4 T3
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REDUCTIVE ADAPTATION
REDUCED FOOD INTAKE
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MARASMUS - Metabolically stable reductive
adaptation
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Adult marasmus in anorexia nervosa
Albumin 42
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REDUCTIVE ADAPTATION DECOMPENSATION
REDUCED FOOD INTAKE
Reduced work, increased efficiency
Reduced Mass
Changed body composition
Changed body composition
Marasmus
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DECOMPENSATED UNDERNUTRITION KWASHIORKOR
Response to infection, injury, fluids, feeding
Reduced intra-cellular GSH
Depletion of K,

Mg, Ca, P
Increased urinary loss of nitrate
Increased cytokines
Variable loss of
fat /muscle
Peroxidation of cell membranes
i.e. marasmus
Massive salt and
water retention
oedema
Leaky membranes
Loss of vascular proteins
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Post-surgical Metabolic decompensation Adult
Kwashiorkor
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(No Transcript)
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Adult, post-surgical Oedematous malnutrition
Albumin 16
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Recovery from oedema Albumin 18
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Albumin before and after the resolution of
Oedema
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The Problems of EBM in Nutrition Support

• Trials use different
• Indications for intervention AND EXCLUSION
• Levels of feeding
• Controls
• Starting times
• Routes of support
• Duration of support
• Outcome measures

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The Evidence
Wanted volunteers for randomized, placebo
controlled trial
Patients with an undoubted need for nutrition
support cannot be randomized
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Nutrition Support and Death

• Recommendation
• You should not let your patients go without any
  form of nutrition whatsoever for 3 months

Grade GPP
Grade IBO
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Why does nutrition support help ?
Jeejeebhoy KN.The benefits of nutritional
support are evident when too little nutrition is
given for too short a time to have any noticeable
influence on lean body mass or circulating
proteins
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• 2. Correction of micronutrients ?
• Many of the detrimental effects attributed to
  undernourishment are more easily ascribable to
  micronutrient rather than macronutrient
  shortages.

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Prevalence of Micronutrient Deficiencies
National Dietary and Nutrition Survey (1998)
Free Living gt65 yr
Institution gt65yr
Deficiency
incidence
incidence
Folate
29 (8 severe)
35 (16 severe)
Thiamine
9
14
Vitamin B12
6
9
Vitamin D
2
5
Vitamin C
14 (5 severe)
40 (16 severe)
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Sub-clinical deficiency
Optimal level
Impaired biochemical function
Plasma levels may be normal
Functional deficiency Metabolic
Immunological Cognition Work capacity
Clinical Deficiency
Death
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Metabolic evidence that Vitamin B12, Folate
Vitamin B6 occur commonly in elderly people
Jorsten et al. Am J Clin Nutr 1993
Levels of homocysteine other metabolites
accumulate if B12, folate or B6 are deficient -
better indicator of vitamin status
SUBJECTS 99 younger healthy controls (19 - 55)
vs 64 healthy elderly (65 - 88) vs. 286
hospital patients (61 - 97)
Elevated levels reverted to young healthy levels
with vitamin supplements
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Supplementation and metabolism
Vitamin X
Substrate A
Product B
Supplementation of Vitamin X can cause Vitamin
X toxicity Shortage of Substrate A Excess of
product B or C Deficiency of Vitamin Y
Vitamin Y
Product C
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Food First ??
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• 3. Metabolic switching ?
• 400g carbohydrate pre-op alters insulin
  resistance and decreases post-operative L.O.S. by
  20
• Nygren J, Thorell A, Ljungqvist O. Preoperative
  oral carbohydrate nutrition an update.
• Curr Opin Clin Nutr Metab Care. 2001
  4(4)255-259

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Issues in Nutrition Support
WHY ?
WHEN ?
WHAT ?
HOW ?
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Starvation Weight loss
(After Allison)

Decision Box
b
o
d
y
w
e
i
g
h
t
Days
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MALNUTRITION AND THE CATABOLIC RESPONSE
Pre -existing malnourishment Catabolism
MALNUTRITION
METABOLIC RATE
Feeding
30
10
20
Safe to Feed
Need to feed
No
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Our nearest ancestor
Teleology n. the doctrine of the final causes of
things interpretation in terms of purpose
(Oxford English Dictionary)
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Teleology, anorexia and survival

• To ensure rest ( ? death) after injury

Sequestration of nutrients e.g. Iron

• Metabolic machinery is depleted, broken or
  diverted
• Micronutrient electrolyte depletion
• Inadequate hepatic processing
• Diet contains incorrect substrates for acute
  phase response

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Issues in Nutrition Support
WHY ?
WHEN ?
WHAT ?
HOW ?
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PREDICTING ENERGY REQUIREMENTS
Schofield/Harrison Bendict BMR
10 - 50 Stress
Fever (10/degree C)
10 Thermic effect of feeding
Activity
-10 ventilated
10 lying in bed
20 Bed to chair
40 up around ward
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Energy expenditure in patients
2500
2000
Predicted REEs (Schofield BMR 30)
Estimated REE - kcals/day
vs. Deltatrak measurements of REE
1500
0
500
1000
1500
2000
2500
3000
Measured REE - kcals/day
Why are current recommendations 35 - 40 kCals/kg
/day non-protein calories ?
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Problems of overfeeding energy

• Ventilatory demands - O2 and CO2
• Lipid
• Liver dysfunction
• Immunosuppression
• Carbohydrate
• Re-feeding syndrome
• Wernicke Korsakoff
• Hyper-glycaemia

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THE REFEEDING SYNDROME
Mg
abnormalities of renal salt
and water handling
K
acute circulatory
failure and death
Na
PO4
ATP
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PENG Guidelines

• Check K, PO4, Phos if low check Mg
• Correct levels
• Thiamine
• 20 kcal/kg
• Monitor K, PO4, Ca (Mg if supplements were given)

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Lynne 51

• 1 yr 45 wt loss ?pathology, ? Eating disorder
• Wt 35kg, BMI 15
• Na 137, K 2.5, PO4 0.54, Mg 0.8, Ca 3.3

Given 240 kcals/day via NG tube IV fluids 2 l/24
hr Thiamine, vitamin B co, K, PO4, Mg supplements
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Lynne contd

• Day 1 Day 2
• Creat 166 110
• Urea 15.5 11.4
• K 2.5 3.4
• Ca 3.0 2.37

PO4 0.54 0.17 Mg 0.8 0.4
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Intensive Insulin Therapy in Critically Ill
PatientsVan den Berghe et al. NEJM 2001
3451359-1367.

• PRCT in 1548 adults on surgical ICU. Insulin to
  maintain glucose lt6.0 mmol vs. insulin to
  maintain glucose lt12 mmol
• Also reduced in-hospital mortality by 34,
  bloodstream infections by 46, ARF requiring
  haemofiltration by 41.

Plt0.005
Plt0.04
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Peritonitis (animal model)
Peck et al 1989
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Energy Requirements
Initial refeeding or ongoing "stress" - cover
RMR (approx 20kcal/kg)
Start slowly with generous micronutrient
intracellular electrolytes
Low threshold for giving insulin
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Problems of overfeeding nitrogen ?

• Catabolism evolved for survival to provide AAs
  for immunity, inflammation and repair.
• AA demands are greater AND different to normal
  requirements.
• THEREFORE
• Diet/conventional nutritional support not only
  fails to meet AA needs but supply excess unwanted
  (toxic) AAs

Why are current recommendations 0.2 - 0.3g N/kg
with higher levels for catabolic patients ?
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The influence of Nitrogen intake on Nitrogen
Balance
Severe injury/ illness
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• Current recommendations for nitrogen 0.2 - 0.3g
  N/kg with higher levels for catabolic patients
• Mainly based on improvements in nitrogen balance
  NOT outcome.
• Maintaining N balance with GH is harmful
• Studies of lower levels of feeding required

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Peritonitis (animal model)
Peck et al 1989
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Collins et al. Am J Clin Nutr 1998 Somalia
relief camp during famine 92/93 573 adults 83
oedematous, 377 non-oedematous Weight 35 kg, BMI
13.1 kg/m2 Overall mortality 21 (oedematous 37)
Low protein (8.5) High protein
(16.4) Mortality 14/52 14/27 Appetite bet
ter poor Oedema -7.2 g/kg/d 6.3 g/kg/d
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NUTRITIONAL SUPPORT Go for Balance
MACRONUTRIENTS
Protein
Carbohydrate
Fat
MICRONUTRIENTS
Fat soluble - A, D, E, K
Water soluble - B Group, C, etc
ELECTROLYTES
Na, K, Ca, Mg
Phosphate
ELEMENTS
Iron
Zn, Se, Cu, Mn
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NUTRITIONAL SUPPORT
MAINTAIN
REPAIR
REPLETE
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Issues in Nutrition Support
WHY ?
WHEN ?
WHAT ?
HOW ?
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MEETING PATIENTS NUTRITIONAL NEEDS
ASSESSMENT- Dietitians Ward staff /-
NST PROVISION - Pharmacy enteral feeds /-
catering and sip feeds ACCESS - via NG, NJ, PEG
MONITORING - At least 2 x weekly clinical
reassessment weekly wt intake records
biochemistry
ASSESSMENT - Ward staff PROVISION - Catering
MONITORING - Admission weekly wt
NORMALLY NOURISHED
Undernourished BMIlt20 Wt Loss gt10
IF
Partial IF
ASSESSMENT - Ward Staff dietitians PROVISION -
Catering /- oral supplements MONITORING -
Admission weekly wt intake records
biochemistry
ASSESSMENT - Nutrition support team PROVISION -
Pharmacy PN via /- enteral or oral ACCESS -
CVP or peripheral line MONITORING - Daily
reassessment including intake, fluid balance and
biochemistry weekly wt
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Parenteral nutrition
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Total parenteral nutrition in the critically ill
patient A meta analysis. Heyland et al. JAMA
280, 1998

• 26 RCTs in 2211 surgical and ICU patients
  compared TPN vs standard care.
• NO effect on mortality
• NO effect on complication rate
• Potentially dangerous in ICU patients
• Why ?

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Problems with PN studies

• Subject selection excludes patients requiring PN
• Control groups receive PN when patients develop
  prolonged ileus or other persisting gut
  dysfunction (USA Veterans PN trial 13 of
  controls received PN).
• Overfeeding (nearly all patients hyperglycaemic)
• PN studies therefore reflect
• effects of PN performed badly in patients who
  dont need it.

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PN The 7 day myth
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Are enteral vs. PN studies valid ?

• Repeated studies show benefits of enteral vs. PN
  feeding.
• BUT
• Enteral feeding is almost always limited in sick
  patients
• THEREFORE
• all studies compare different routes AND
  different levels of early feeding.
• e.g. Meta-analyses in pancreatitis patients shows
  no advantage of EN vs. PN if hyperglycaemic
  patients left out.

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Enteral versus parenteral nutrition a pragmatic
study. Woodcock et al. Nutrition 200117(1)1-12.

• Clinicians assessed GI function in 562 patients
  needing support. 231 ETF 267 PN 64
  randomised ETF or PN
• adequate nutrition in randomised patients 22 ETF
  vs. 75 PN (plt 0.001).
• No differences in sepsis rates between groups
• Feeding complications more frequent in elective
  and randomised ETF patients.
• Higher mortality in both non-randomised and non
  randomised ETF groups.

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THE SOUTHAMPTON COURSE IN PRACTICAL NUTRITIONAL
SUPPORT

• Sep 2006

Course Directors Brendan Moran - Consultant
Surgeon Mike Stroud - Consultant Physician