Nutrition and Dietetics
in the Normal Patient
Study Aims
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Definition
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Malnutrition
Actual body weight
Ideal body weight
Predicted body weight
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Nutritional assessement
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Calculation of nutritional needs
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Complications of overfeeding
Introduction
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Malnutrition common
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Predisposition to
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Defined as 10% of USUAL body weight
Delayed healing
Post-operative Infection
Added Morbidity and Mortality
Recognition thus important
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Preventable disease
Treatable disease
Introduction (cont . . .)
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Usual / actual body weight
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Ideal body weight
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As measured by scale
Male
Female
H2 * 20
H2 * 25
Predicted body weight
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Male
Female
50 + 0.91 (Height in cm – 152.4)
45.5 + 0.91 (Height in cm – 152.4)
Nutritional Assessment
1.
History and examination
2.
Anthropological markers
3.
Biochemical markers
4.
Calculations of energy and protein
requirements
Nutritional Assessment
History
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Pre- morbid conditions
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Estimates the risk of malnutrition
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Hepatic and renal failure
IBD
Cancer and HIV/AIDS
Burns and head injuries
Conditions that limit intake or increase output
History of recent weight loss
Dietary Hx
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Intake concerning calory (energy), protein, vitamin
and trace elements
Nutritional Assessment
Physical Examination
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Caloric intake
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Protein status
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Subcutaneous fat of buttocks and extremities
Extremity muscle bulk and strength
Temporal wasting
Vitamin intake
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Changes in skin, mucosa and skin appendages
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Skin texture change
Cheilosis and glossitis
Peripheral neuropathy ect
Nutritional Assesement
Physical Examination (cont . . . )
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Trace elements
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Sx similar to vitamin def + menal changes
Nutritional Assessment
History and physical examination
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The above determines the risk for
malnutrition
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Guidelines for identifying patients at risk
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Weight
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Overweight (BMI 30) and underweight (BMI < 18)
Weight loss more than 10% actual weight
Alcoholics
NPO more than 5 days
Medication with anabolic effect / antinutrient porp
Nutritional Assessment
Anthropological Markers
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Body Mass Index (BMI)
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Weight (kg) / height 2
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Gross overweight is a risk for malnutrition
Skinfold thickness (SFT)
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< 18 underweight
< 10 Severely malnouraged
Measures subcutaneous fat and thus energy
reserve (10 - 13 mm)
Midarm circumference (MAC)
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Muscle bulk and therefore somatic protein status
(22 – 23 cm)
Nutritional Assessment
Anthropological Markers (cont . . . )
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Bio-electrical Impedance Analysis
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Single frequency models unreliable
Dual frequency modes in current clinical
assessment
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Expensive initial outlay
Accurate measurement of body composition
Nutritional Assessment
Biochemical anlysis
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Serum proteins
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Estimates visceral protein reserve
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Overall markers include
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Overall poor reliability due to complex factors
Total serum protein, albumin, tansferrin and total lymphocyte count
Due to long half live reflects chronic malnutrition
More sensitive markers due to shorter half live
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Pre-albumin, retinol binding protein, ceruloplasmin
Reflects acute changes in nutritional status
Nutritional Assessment
Biochemical anlysis
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Nitrogen balance
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Measures protein synthesis and breakdown
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Calculations
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Protein intake is the sum of all nitrogen intake (Enteral and parenteral)
Protein breakdown is measured by nitrogen excretion in urine, faeces, fistula
ect
N intake = g protein / 6.25
N output = (urine urea * urine volume/day(l) * 0.028) + losses (3 – 6g)
Balance
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Positive = anabolism
Negative = catabolism
 Mild 5 – 10g
 Moderate 10 – 15g
 Severe 15g
Calculation of nutritional needs
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Energy requirements
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TE = NPE + PE
TE = Total energy requirements, NPE = Non-protein energy,PE = protein energy
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NPE = Carbohydrate + Lipids
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PE = 1.2 – 2 g/kg IBW
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NPE = 25 – 30 Kcal/kg IBW
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Carbohydrates = 5 g/kg
Lipids = 1 – 1.5 g/kg or 20kcal/kg
Complications of overfeeding
Carbohydrates
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Glucose oxidation rate
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No more than 5 mg/kg/min
Delivers 4 cal / g or
Complications
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Hyperglycemia and hyper-osmolar states
Hapaic steatosis due to lipogenesis
Increased CO2 and lactate production
Complications of overfeeding
Lipids
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Lipid infusions
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Maximum rate 1 – 1.5 g/kg
Given as short, medium and long chain
Delivers 9cal / g
Complications of overfeeding
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Hiperlipedaemia and pancreatitis
Fat overload syndrome
Immiunological supression
HSR
Complications of overfeeding
Proteins
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Amino-acid and protein infusion
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1.2 – 2 g / kg
Delivers 4 cal / g
Given as variaty of amino-acids
Complication
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Azothemia