Nutrition and Dietetics Nutrition and Dietetics in the Normal in the Normal

PatientPatient

Study AimsStudy Aims Definition

Malnutrition Actual body weight Ideal body weight Predicted body weight

Nutritional assessement

Calculation of nutritional needs

Complications of overfeeding

IntroductionIntroduction Malnutrition common

Defined as 10% of USUAL body weight

Predisposition to Delayed healing Post-operative Infection Added Morbidity and Mortality

Recognition thus important Preventable disease Treatable disease

Introduction Introduction (cont . . .)(cont . . .)

Usual / actual body weight As measured by scale

Ideal body weight Male H2 * 20 Female H2 * 25

Predicted body weight Male 50 + 0.91 (Height in cm –

152.4) Female 45.5 + 0.91 (Height in cm –

152.4)

Nutritional AssessmentNutritional Assessment1. History and examination

2. Anthropological markers

3. Biochemical markers

4. Calculations of energy and protein requirements

Nutritional Assessment Nutritional Assessment HistoryHistory

Pre- morbid conditions Estimates the risk of malnutrition

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 Intake concerning calory (energy), protein,

vitamin and trace elements

Nutritional Assessment Nutritional Assessment Physical ExaminationPhysical Examination

Caloric intake Subcutaneous fat of buttocks and extremities

Protein status Extremity muscle bulk and strength Temporal wasting

Vitamin intake Changes in skin, mucosa and skin

appendages Skin texture change Cheilosis and glossitis Peripheral neuropathy ect

Nutritional Assesement Nutritional Assesement

Physical Examination Physical Examination (cont . . . )(cont . . . )

Trace elements Sx similar to vitamin def + menal changes

Nutritional Assessment Nutritional Assessment History and physical History and physical

examinationexamination The above determines the risk for

malnutrition

Guidelines for identifying patients at risk Weight

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 AssessmentNutritional AssessmentAnthropological MarkersAnthropological Markers

Body Mass Index (BMI) Weight (kg) / height 2

< 18 underweight < 10 Severely malnouraged

Gross overweight is a risk for malnutrition

Skinfold thickness (SFT) Measures subcutaneous fat and thus energy

reserve (10 - 13 mm)

Midarm circumference (MAC) Muscle bulk and therefore somatic protein

status (22 – 23 cm)

Nutritional AssessmentNutritional AssessmentAnthropological Markers Anthropological Markers

(cont . . . )(cont . . . )

Bio-electrical Impedance Analysis Single frequency models unreliable Dual frequency modes in current clinical

assessment Expensive initial outlay Accurate measurement of body composition

Nutritional AssessmentNutritional AssessmentBiochemical anlysisBiochemical anlysis

Serum proteins Estimates visceral protein reserve

Overall poor reliability due to complex factors

Overall markers include 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 Pre-albumin, retinol binding protein, ceruloplasmin Reflects acute changes in nutritional status

Nutritional AssessmentNutritional AssessmentBiochemical anlysisBiochemical anlysis

Nitrogen balance Measures protein synthesis and breakdown

Protein intake is the sum of all nitrogen intake (Enteral and parenteral) Protein breakdown is measured by nitrogen excretion in urine, faeces, fistula

ect Calculations

N intake = g protein / 6.25 N output = (urine urea * urine volume/day(l) * 0.028) + losses (3 – 6g)

Balance Positive = anabolism Negative = catabolism

Mild 5 – 10g Moderate 10 – 15g Severe 15g

Calculation of Calculation of nutritional needsnutritional needs Energy requirements

TE = NPE + PETE = Total energy requirements, NPE = Non-protein energy,PE = protein energy

NPE = Carbohydrate + Lipids

PE = 1.2 – 2 g/kg IBW

NPE = 25 – 30 Kcal/kg IBW Carbohydrates = 5 g/kg Lipids = 1 – 1.5 g/kg or 20kcal/kg

Complications of Complications of overfeedingoverfeeding

CarbohydratesCarbohydrates Glucose oxidation rate

No more than 5 mg/kg/min Delivers 4 cal / g or

Complications Hyperglycemia and hyper-osmolar states Hapaic steatosis due to lipogenesis Increased CO2 and lactate production

Complications of Complications of overfeedingoverfeeding

LLipids ipids Lipid infusions

Maximum rate 1 – 1.5 g/kg Given as short, medium and long chain Delivers 9cal / g

Complications of overfeeding Hiperlipedaemia and pancreatitis Fat overload syndrome Immiunological supression HSR

Complications of Complications of overfeedingoverfeeding

ProteinsProteins Amino-acid and protein infusion

1.2 – 2 g / kg Delivers 4 cal / g Given as variaty of amino-acids

Complication Azothemia