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Clinical Nutrition Support Have we got it all wrong ?. Dr Mike Stroud FRCP Senior Lecturer in Medicine & Nutrition, Consultant Gastroenterologist Southampton. Apologies. BSG talk because of NICE Guidelines NICE Guidelines 1 st Draft Contention.

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clinical nutrition support have we got it all wrong

Clinical Nutrition Support Have we got it all wrong ?

Dr Mike Stroud FRCP

Senior Lecturer in Medicine & Nutrition, Consultant Gastroenterologist

Southampton

apologies
Apologies
  • BSG talk because of NICE Guidelines
  • NICE Guidelines 1st Draft
  • Contention
slide4

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

slide5

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

slide6

NUTRITIONAL SUPPORT SHOULD:

Improve general status

Immunity

Wound healing

Ventilation

Mobility

Psychology

slide7

Feeding gives time for other medical and surgical interventions to work

ITU patients would die at 20 to 30 days

Make stronger for discharge

southampton cnrd team meta analyses of oral enteral nutrition support trials
Southampton CNRD Team Meta-analyses of oral/enteral nutrition support trials.

10 RCT, n = 494;

RR 0.29 (CI 0.18 to 0.47)

30 RCT, n = 3258

RR 0.59 (CI 0.48 to 0.72)

Controls

Controls

Treatment

Treatment

Decreased complication %

Decreased mortality %

so why think we may be wrong
So why think we may be wrong ?
  • Better understanding of the effects of starvation
  • Problems in the evidence for Nutrition Support
slide10

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

slide11

Reduced work, increased efficiency

Reduced Mass

Changed metabolism

Changed body composition

Metabolically stable BUT

loss of reserve and functional capacity

‘Marasmus’

REDUCTIVE ADAPTATION

REDUCED FOOD INTAKE

slide14

Infection, trauma, small bowel overgrowth, specific deficiency,

abnormal losses, excessive intake, unbalanced intake

Loss of homeostasis

‘Kwashiorkor’

REDUCTIVE ADAPTATION

DECOMPENSATION

REDUCED FOOD INTAKE

Reduced work, increased efficiency

Reduced Mass

Changed body composition

Changed body composition

Marasmus

slide15

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

slide16

Post-surgical

Metabolic decompensation

Adult ‘Kwashiorkor’

slide18

Adult, post-surgical

Oedematous malnutrition

Albumin = 16

the problems of ebm in nutrition support
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
the evidence
The Evidence

Wanted – volunteers for randomized, placebo controlled trial

Patients with an undoubted need for nutrition support cannot be randomized

nutrition support and death
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

slide24

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

slide25

2. Correction of micronutrients ?

Many of the detrimental effects attributed to undernourishment are more easily ascribable to micronutrient rather than macronutrient shortages.

slide26

Prevalence of Micronutrient Deficiencies

National Dietary and Nutrition Survey (1998)

Free Living >65 yr

Institution >65yr

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)

sub clinical deficiency
Sub-clinical deficiency

Optimal level

Impaired biochemical function

Plasma levels may be normal

Functional deficiency

Metabolic

Immunological

Cognition

Work capacity

Clinical

Deficiency

Death

slide28

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

slide29

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

slide31
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

slide32

Issues in Nutrition Support

WHY ?

WHEN ?

WHAT ?

HOW ?

slide33

100

95

90

85

80

Catabolic

75

Complete starvation

70

Partial starvation

65

60

55

50

0

10

20

30

40

50

60

70

Starvation & Weight loss

(After Allison)

%

Decision Box

b

o

d

y

w

e

i

g

h

t

Days

slide34

MALNUTRITION AND THE CATABOLIC RESPONSE

Pre -existing malnourishment

Catabolism

MALNUTRITION

METABOLIC

RATE

Feeding

30

10

20

No

Need to feed

Safe to Feed

slide35

Our nearest ancestor

Teleology n. the doctrine of the final causes of things: interpretation in terms of purpose (Oxford English Dictionary)

slide36

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
slide37

Issues in Nutrition Support

WHY ?

WHEN ?

WHAT ?

HOW ?

slide38

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

energy expenditure in patients

1000

500

0

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 ?

slide40

Problems of overfeeding energy

  • Ventilatory demands - O2 and CO2
  • Lipid
    • Liver dysfunction
    • Immunosuppression
  • Carbohydrate
    • Re-feeding syndrome
    • Wernicke Korsakoff
    • Hyper-glycaemia
slide41

THE REFEEDING SYNDROME

Mg

+ abnormalities of renal salt

and water handling

K

= acute circulatory

failure and death

Na

PO4

ATP

peng guidelines
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)
lynne 51
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

lynne cont d
Lynne – cont’d
  • Day 1Day 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

slide45

Intensive Insulin Therapy in Critically Ill PatientsVan den Berghe et al. NEJM 2001; 345:1359-1367.

  • PRCT in 1548 adults on surgical ICU. Insulin to maintain glucose <6.0 mmol vs. insulin to maintain glucose <12 mmol
  • Also reduced in-hospital mortality by 34%, bloodstream infections by 46%, ARF requiring haemofiltration by 41%.

P<0.005

P<0.04

slide47

Energy Requirements

Initial refeeding or ongoing "stress" - cover

RMR (approx 20kcal/kg)

Start slowly with generous micronutrient

& intracellular electrolytes

Low threshold for giving insulin

problems of overfeeding nitrogen
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 ?

slide50

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
slide52

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 better poor

Oedema -7.2 g/kg/d + 6.3 g/kg/d

slide53

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

slide54

NUTRITIONAL SUPPORT

MAINTAIN

REPAIR

REPLETE

slide55

Issues in Nutrition Support

WHY ?

WHEN ?

WHAT ?

HOW ?

slide56

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

BMI<20

Wt Loss >10%

Partial

IF

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

slide58
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 ?
slide59

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 don’t need it.
slide61

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.
slide62

Enteral versus parenteral nutrition: a pragmatic study. Woodcock et al. Nutrition 2001;17(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 (p< 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.
the southampton course in practical nutritional support

THE SOUTHAMPTON COURSE IN PRACTICAL NUTRITIONAL SUPPORT

Sep 2006

Course Directors:

Brendan Moran - Consultant Surgeon

Mike Stroud - Consultant Physician