1. Theoretical Nutrition and Patient Assessment
T R Wilson

2. WHY IS Nutrition important?

3. Prevalence Malnutrition in Hospital
30% Overtly malnourished
8% Severely malnourished
Screen all hospital admissions
Weigh (BMI)
Ask if they have lost weight
Ask when they last ate properly
MUST
SCORING

4. Malnutrition and Surgical Complications
Percentage Patients

5. Assessing patients

6. Who is at risk nutritional problems?
Hospital patients (1/3)
Prolonged ITU stay
Prolonged fasting
Cancer patients
Crohn's Disease
Post (and Pre) bariatric surgery
Elderly
Chronic alcoholic abuse
Anorexia Nervosa

7. MUST Score Screening tool 3 elements Score from 0 to 6
BMI
>20 = = <18.5 = 2
% Weight loss last 3-6 months
<5% = % = >10% = 2
Acute disease effect
Acute illness, no nutritional intake ≥ 5 Days = 2
Score from 0 to 6
2 or more is high risk → dietician input

8. Assessment Nutritional Status
Where has patient come from?
Long term history of nutritional problem
Risk factors
History of weight loss
History of inadequate intake
Where is patient currently?
On going / current pathologies (cancer?)
Sepsis
Hydration/electrolyte status
What you can do? – Where are you going?
What is likely course of their pathology
What is their likely nutritional intake in next 48 hours / week / longer?

9. Meeting Nutritional Needs
Assessment
Provision
Monitoring
Normally Nourished
Ward Staff
Catering
Admission weight
Weekly Weight
Under Nourished
(BMI < 20)
(Weight loss >10%)
Dieticians
+/- Sip Feeds
Intake Records
Biochemistry
Partial Intestinal Failure
(Functioning Gut)
+/- NST
Enteral Feed
+/- Catering
Via NG/NJ/PEG
Clinical (≥2x/week)
Intestinal Failure
(Gut not functioning)
NST
Parenteral Nutrition
+/- Enteral Feed
Via CVP line
Daily Assessment
(Clinical, fluid balance, biochem)
Weight 2x/week

10. PATHOPHYSIOLOGY (What goes wrong and how to fix it safely)

11. Reductive Adaptation of Malnutrition
Reduced Intake
Reduced Mass
Reduced Work
Altered Body
Composition
Altered Metabolism
and Physiology
Loss of Reserve
Brittle Metabolism
Excess Energy/Protein
Abnormal Losses
Specific Deficiency
Infection
Trauma
Small bowel overgrowth
Loss Homeostasis

12. Basal Metabolic Demand
Mechanical Work
Cardiac Output/Ventilation/Movement
Turnover Substances
Amino acids / Protein
Glucose / Glycogen
Fatty acids / TAG
Transport across membranes
Substrates / Products
Electrolytes (Na/K pumps)
10%
20%
70%
(67%)

13. Electrolyte Shifts Down regulation of Na/K pumps
Leaking of K, Mg, PO4 out of cells
→ High serum K/Mg/PO4
→ Renal excretion
→ Decreased body levels
Leaking of Na into cells
→ Low serum Na
→ Renal conservation
→ Increased body levels Na
Fluid follows Na
→ General fluid retention → Oedema
→ Fluid shift into cells

14. Nutritional Oedema Impaired membrane function Salt and water retention
Down regulation Na/K pumps
Free radical damage
Salt and water retention
Impaired renal function
Potassium/phosphate depletion
Acid-base imbalance
Hypoalbuminaemia
Decreased synthesis (minor long term)
Third space loss (SIRS, Sepsis, Membrane damage)

15. Problems of Na, Cl and Fluid excess
Left ventricular failure
Oedema
Skin breakdown
Hyperchloraemic acidosis
Ileus
Anastomotic and wound dehiscence
↑ PN requirement
↑ Length of Stay
↑ Death

16. Loss Homeostasis Increased Toxins / Free radicals Reduced protection
Infection / Trauma
Iron (from RBC breakdown)
Small bowel overgrowth
Reduced protection
Vitamins: B1, B2, B6, C, E, niacin, β carotene
Elements: Cu, Se, Zn, Mn
Other: Glutamine, Glycine, Cystine
Electrolyte and fluid shifts
Decreased body stores – e.g. glycogen

17. Micronutrients Starvation PN AA AA AA AA PROTEIN Refeeding Catabolism
Enzyme
Co Enzyme AA AA AA AA
Catabolism
(e.g. Thiamine, Riboflavin, Pyridine, Iron, Zinc, Copper)
PROTEIN

18. Sepsis and malnutrition
Malnourished → immunosuppression
May not mount typical immune response
Normal bloods
Hypothermia rather than temperature
Refeeding / over feeding → further immunosuppression
BEWARE THE DEADLY TRIAD
Low BMI
Hypoglycaemia
Hypothermia

19. Problems of over feeding / over enthusiastic early nutritional support
Excess Nitrogen delivery
May produce toxic amino-acids
Drive ammonia and urea production
High renal solute load → contribute to Na retention
Metabolic instability
Insulin resistance and hyperglycaemia
Liver dysfunction/diversion
Immunosuppression
Re-feeding syndrome

20. Refeeding Syndrome (definition)
Potentially lethal
Occurs in malnourished patients undergoing re-feeding
Can occur with any route of feeding
Results in severe electrolyte and fluid shifts
Associated with metabolic abnormalities
(Nearly 1% all hospital patients)

21. Refeeding Pathophysiology
Starvation
Protein catabolism
Gluconeogensis
↑ Insulin resistance
↓ soluble B vit levels
Down regulation cellular pumps
Extracellular leakage K/PO4/Mg
Excretion of K/PO4/Mg
Intracellular Na retention
Renal Na conservation
Refeeding
On going aa metabolism
↑glucose metabolism
↑Insulin
↑ Thiamine utilisation
Reactivation cellular pumps
Intracellular uptake Na/PO4/Mg
Low serum levels

22. Specific refeeding problems
Electrolyte disturbance
Weakness, seizures, arrhythmias, tetany, paraesthesia
Heart failure / pulmonary oedema
Infection (CRP and WCC may not rise)
Hyper/hypoglycaemia
Risk of brain damage / Wernicke's

23. Avoiding all refeeding syndromes
Start at appropriate low rate
5 Kcal/Kg/Day in extreme cases
10 Kcal/Kg/Day in severe cases
Half requirements 20/Day for less severe re-feeding risk
Gradually increase over 4-7 days
Replace electrolytes aggressively
Vitamin supplementation (Thiamine)
Monitor observations