1. Clinical Nutrition Support Have we got it all wrong ?
Dr Mike Stroud FRCP
Senior Lecturer in Medicine & Nutrition, Consultant Gastroenterologist
Southampton

2. Apologies BSG talk because of NICE Guidelines
NICE Guidelines 1st Draft
Contention

3. 40% of hospital patients are overtly malnourished on admission, 8% severely

4. Causes of Malnourishment
Conscious level
Poor diet - age, poverty, junk,
Depression
exercise, alcohol
Anorexia
Dysphagia
Obstruction
Vomiting
Pancreatic failure
Liver processing
Jaundice
Malabsorption
Increased Metabolic demands

5. Effects of Undernutrition
Psychology –
depression & apathy
Ventilation - loss of
muscle & hypoxic
responses
Immunity – Increased risk of infection
liver fatty change,
functional decline necrosis, 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

6. NUTRITIONAL SUPPORT SHOULD:
Improve general status
Immunity
Wound healing
Ventilation
Mobility
Psychology

7. Feeding gives time for other medical and surgical interventions to work
ITU patients would die at 20 to 30 days
Make stronger for discharge

8. Southampton CNRD Team Meta-analyses of oral/enteral nutrition support trials.
10 RCT, n = 494;
RR 0.29 (CI to 0.47)
30 RCT, n = 3258
RR 0.59 (CI 0.48 to 0.72)
Controls
Controls
Treatment
Treatment
Decreased complication %
Decreased mortality %

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

10. UNDERNUTRITION: EFFECTS ON METABOLISM
Reduced physical activity
Decrease in metabolic mass
Decreased protein
Na/K
synthesis: -40%
pumping: -30%
Decreased
Decreased
glucose transport
AA transport
Decreases in: GH
Insulin
ILGF1,2
Adrenaline NA
Glucagon
T4 & T3

11. Metabolically stable BUT loss of reserve and functional capacity
REDUCTIVE ADAPTATION
REDUCED FOOD INTAKE
Changed body composition
Reduced Mass
Changed metabolism
Reduced work, increased efficiency
Metabolically stable BUT
loss of reserve and functional capacity
‘Marasmus’

12. MARASMUS - Metabolically stable reductive adaptation

13. Adult marasmus in anorexia nervosa
Albumin 42

14. REDUCTIVE ADAPTATION DECOMPENSATION
REDUCED FOOD INTAKE
Reduced work, increased efficiency
Reduced Mass
Changed body composition
Changed body composition
Marasmus
Infection, trauma, small bowel overgrowth, specific deficiency,
abnormal losses, excessive intake, unbalanced intake
Loss of homeostasis
‘Kwashiorkor’

15. 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

16. Post-surgical
Metabolic decompensation
Adult ‘Kwashiorkor’

18. Adult, post-surgical
Oedematous malnutrition
Albumin = 16

19. Recovery from oedema
Albumin = 18

20. Albumin before and after the resolution
of Oedema

21. 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

22. Wanted – volunteers for randomized, placebo controlled trial
The Evidence
Wanted – volunteers for randomized, placebo controlled trial
Patients with an undoubted need for nutrition support cannot be randomized

23. 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

24. 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

25. 2. Correction of micronutrients ?
Many of the detrimental effects attributed to undernourishment are more easily ascribable to micronutrient rather than macronutrient shortages.

26. 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)

27. Sub-clinical deficiency
Optimal level
Impaired biochemical function
Plasma levels may be normal
Functional deficiency
Metabolic
Immunological
Cognition
Work capacity
Clinical
Deficiency
Death

28. 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 ( ) vs
64 healthy elderly ( ) vs.
286 hospital patients ( )
Healthy elderly
Elderly patients
low B12 6%
12.5%
low folate 5%
19%
low B6 9%
51%
Raised metabolites
63%
83%
Elevated levels reverted to young healthy levels with vitamin supplements

29. 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

30. Food First ??

31. 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):

32. Issues in Nutrition Support
WHY ?
WHEN ?
WHAT ?
HOW ?

33. Starvation & Weight loss
(After Allison) % 50 55 60 65 70 75 80 85 90 95
100 10 20 30 40
Catabolic
Complete starvation
Partial starvation b
Decision Box o d y w e i g h t
Days

34. MALNUTRITION AND THE CATABOLIC RESPONSE
Pre -existing malnourishment
Catabolism
MALNUTRITION
METABOLIC
RATE
Feeding 30 10 20 No
Need to feed
Safe to Feed

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

36. 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

37. Issues in Nutrition Support
WHY ?
WHEN ?
WHAT ?
HOW ?

38. 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

39. Energy expenditure in patients
2500
500
1000
2000
Predicted REEs (Schofield BMR + 30%)
Estimated REE - kcals/day
vs. Deltatrak measurements of REE
1500
500
1000
1500
2000
2500
3000
Measured REE - kcals/day
Why are current recommendations kCals/kg /day non-protein calories ?

40. Problems of overfeeding energy
Ventilatory demands - O2 and CO2
Lipid
Liver dysfunction
Immunosuppression
Carbohydrate
Re-feeding syndrome
Wernicke Korsakoff
Hyper-glycaemia

41. THE REFEEDING SYNDROMEMg
+ abnormalities of renal salt
and water handling K
= acute circulatory
failure and death Na
PO4
ATP

42. 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)

43. 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

44. Lynne – cont’d Day 1 Day 2 Creat 166 110 Urea 15.5 11.4 K 2.5 3.4Ca PO Mg

45. Intensive Insulin Therapy in Critically Ill Patients Van 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

46. Peritonitis (animal model)
Peck et al 1989

47. Energy Requirements Initial refeeding or ongoing "stress" - cover
RMR (approx 20kcal/kg)
Start slowly with generous micronutrient
& intracellular electrolytes
Low threshold for giving insulin

48. 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 g N/kg with higher levels for catabolic patients ?

49. The influence of Nitrogen intake on Nitrogen Balance
Severe injury/
illness

50. Current recommendations for nitrogen 0. 2 - 0
Current recommendations for nitrogen g 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

51. Peritonitis (animal model)
Peck et al 1989

52. 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/ /27
Appetite better poor
Oedema g/kg/d g/kg/d

53. 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

54. NUTRITIONAL SUPPORT
MAINTAIN
REPAIR
REPLETE

55. Issues in Nutrition Support
WHY ?
WHEN ?
WHAT ?
HOW ?

56. 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

57. Parenteral nutrition

58. 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 ?

59. 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.

60. PN – The 7 day myth

61. 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.

62. Enteral versus parenteral nutrition: a pragmatic study. Woodcock et al
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; PN; 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.

63. THE SOUTHAMPTON COURSE IN PRACTICAL NUTRITIONAL SUPPORT
Sep 2006
Course Directors:
Brendan Moran - Consultant Surgeon
Mike Stroud - Consultant Physician