Nutritional Assessment Workshop Nicola Riley Concord Repatriation General Hospital nicola.riley@sswahs.nsw.gov.au Emma McNamara emma.mcnamara@sswahs.nsw.gov.au

What is Nutritional Assessment? “the evaluation of nutrition needs of individuals based upon appropriate biochemical, anthropometric, physical, and dietary data to determine nutrient needs and recommended appropriate nutrition intake including enteral and parenteral nutrition” - American Dietetic Association

Nutritional Assessment & Clinical Application - Overall View Nutrition Management: Assessment Intervention Follow-up / Review Evaluation Consider: Health care setting Disease / condition Lifecycle / physiological state

Nutritional Status “Nutritional Status expresses the degree to which physiologic needs for nutrients are met” Optimal NS = Balance between intake and requirement Malnutrition state caused by nutritional deficiency Reversible by providing appropriate nutrition support Deficiency vs Overload (can be combination of both) “whole person” focus, not just disease or condition focus.

Nutritional Risk Critically unwell patients may be well nourished but high nutritional risk Illness, injury, infection Metabolic derangements May have significant affect on nutritional status May lead to malnutrition Cannot be corrected by nutrition support alone Patients at high nutritional risk will require early nutritional intervention and close monitoring

Why do we need to identify malnutrition? Malnutrition is associated with:  length of stay in hospital  complications  hospital costs  mortality rates

Screening vs Assessment

Nutrition Screening Tools Requirements quick and simple to administer sensitive enough to identify individuals at risk appropriate for client group being screened capable of being used by non-dietitians reproducible when used by different observers able to guide non dietetic staff into taking appropriate action for findings recorded

Malnutrition Screening Tool (MST) Have you lost weight recently without trying? If NO If unsure If YES, how much weight have you lost? 1 – 5 kg (2 – 11 lb) 6 – 10 kg (1 – 1½ st) 11 – 15 kg (1¾ - 2⅓ st) > 15 kg (> 2⅓ st) Unsure 2 1 3 4 Have you been eating poorly because of a decreased appetite? If YES Total If the score is 2 or more please refer to the dietitian. (Ref: Ferguson M et al, Nutrition 15: 458-464, 1999)

The Short Nutritional Assessment Questionnaire (SNAQ) Score Did you lose weight unintentionally? >6kg in the past 6 month 3 >3kg in the past month 2 Did you experience a decreased appetite over the past month? 1 Did you use supplemental drinks or tube feeding over the past month?

Nutritional Assessment Tools No single / standard way of assessing nutritional status Various validated assessment tools developed some disease specific some age specific 2 examples Mini Nutritional Assessment (MNA) Subjective Global Assessment (SGA)

Mini Nutritional Assessment (MNA) Screening and Assessment tool for the identification of malnutrition in the elderly Considers: Dietary Intake – foods, patterns Weight change, BMI, Muscle circumferences Functional impairment, Independence, Living arrangements Psychological issues, Self assessment

Subjective Global Assessment Valid assessment tool Strong correlation with other subjective and objective measures of nutrition Highly predictive of nutritional status in a number of different patient groups Quick, simple and reliable

Subjective Global Assessment…features Medical History Weight change Dietary intake GI symptoms Functional impairment Physical Examination Loss of subcutaneous fat Muscle wasting Oedema and ascites

Subjective Global Assessment …Classifications A Well nourished B Moderately malnourished or suspected of malnutrition C Severely malnourished

Full Nutrition Assessment Step 1…Data collection Systematic Approach Assessment based on clinical/psychosocial/physical information Dietary Anthropometric Biochemical Physical Including Subjective (eg. signs/symptoms of nutritional problem, appetite) Objective (eg. Lab results)

Data Collection… An Example… A B C D E A Anthropometry B Biochemical Data C Clinical signs and symptoms, medical condition D Dietary Intake E Exercise (Energy balance – expenditure) Consider current level, history and changes

Anthropometry Height Weight Weight history / pattern (% weight change) Weight for Height BMI Growth Pattern, head circumference (paediatrics) MAMC TSF Waist circumference Hip circumference WHR Be aware of fluid status, presence of oedema.

Anthropometry – Body Composition Muscle, Fat, Bone, Water Body Mass: LBM – Body mass that contains small % (~3%) essential fat [Essential fat + Muscle + Water + Bone] Fat Free Mass (FFM) Fat Store: Essential Fat for physiological function, eg. fat stored in muscle, liver, heart Storage fat in adipose tissue – visceral fat and subcutaneous fat

Body Compostion cont’d. Practical Methods in Clinical Setting: Weight, height & weight Hx Skinfolds, circumferences TSF, MAMC,WHR More precise, occasional use: Bioelectrical Impedance Analysis (BIA) FFM, % body fat Dynamometry (grip strength) Precise, Expensive, Research purposes: CT, MRI, Dexascan, TBK,TBN

Biochemistry & other Blood Tests (See also disease/condition specific lectures) Objective measures No single test is diagnostic Consider “normal / recommended range” for various and combination of conditions, eg. age, gender, physiological state, disease type and stage Consider clinical significance of test result Test result may reflect immediate intake (eg glucose) or long term status (HbA1c)

Other factors to Consider… Other factors can mask/influence test results eg. Acute phase response due to stress / injury ( reduced albumin) GI bleed (higher urea) blood transfusion (higher serum K and Hb) Surgery (lower Hb and albumin)

Acute Phase Response Inflammatory processes (shock, trauma, sepsis) liver protein synthesis shifts from visceral proteins, e.g. albumin and prealbumin to acute phase proteins Visceral proteins may reflect ‘nutritional risk’ not nutritional status

Nutritional Indicators Ideal indicator or marker is sensitive and specific to nutritional intake Commonly Used “Nutritional Indicators” Albumin Pre-albumin Transferrin Retinol-binding protein

Albumin Synthesised in the liver May be useful indicator of nutritional status in “healthy” person. Not a good indicator of protein status during critical illness (due to acute phase response) Long half life (14-20 days) and large body pool  slow to respond to improvements in clinical status

Factors Affecting Serum Albumin Levels Increased in: Dehydration, blood transfusions, exogenous albumin Decreased in: Overhydration, hepatic failure, inflammation, infection, metabolic stress, post-op, bed rest, pregnancy, nephrotic syndrome.

Pre-albumin Also known as Transthyretin, thyroxine binding protein. Synthesised in the liver Relatively short half life (2 days) Negative acute phase reactant -  with inflammatory response May be useful in healthy population

Transferrin and RBP Transferrin Retinol Binding Protein (RBP) Half life 8-10 days Poor correlation with nutrition status Involved with iron transport, influenced by iron status Retinol Binding Protein (RBP) Half life 12 hours Affected by renal function, Vitamin A and Zn status Unreliable measure of nutritional status

Biochemistry & other Blood Tests, cont’d (See also disease/condition specific lectures) Interference – drugs, sampling Nutrient-nutrient interactions, drug-nutrient interactions Be aware of hydration status Must interpret lab results with other nutritional parameters

Clinical issues to consider: Medical history, treatment and medications Significant factors affecting nutritional intake Fluid balance – input and output, Bowel habits Physical assessment of nutritional status Clinical signs and symptoms

Clinical Signs and Symptoms Subjective, impression Descriptive, observation Appearance Visual examination Needs clinical judgement Eg muscle wasting, malnutrition Symptoms Recall, report by subjects Descriptive Eg nausea, itchiness, diarrhoea, anorexia

Dietary Intake Is intake meeting requirement? (See relevant lectures in dietary intake, RDIs, etc) Is intake meeting requirement? Basic nutrition adequacy Special requirement / disease / conditions Consider factors affecting intake Consider clinical, nutritional and psycho-social issues Methods of collecting information/data ?Relevant and practical

Exercise – Energy Balance Nutrition and exercise closely linked – metabolic and physical fitness Functional capacity and Nutritional status Correlation between muscle mass and physical strength, nutritional status and physical function Energy Balance to attain optimal weight and body composition Bed Rest / Inactivity Negative effects on muscles, bone and CV system, eg. 8 g protein loss / day of bed rest Exercise – affects on appetite, bowel function

Estimating Nutritional requirements Consider Energy Protein Fluid RDIs for micronutrients

Estimating Energy Requirements Indirect Calorimetry preferred method use of a metabolic monitor/cart measures respiratory gas exchanges Differences in oxygen and carbon dioxide content between air going in and air coming out  respiratory exchange  energy expenditure (Ref: Mann & Truswell(ed) Essentials of Human Nutrition, Chap. 5)

Harris Benedict Equation Devised in 1919 Multiple regression analysis of the gender, age, height and weight of 239 healthy volunteers Recent review of data and methodology - still valid (Frankenfield et al, 1998, JADA) Basal energy expenditure (BEE) = energy expended by a fasting subject at rest in a ‘thermoneutral’ environment

Harris Benedict Equation Males (kJ/24hr) BEE = 278 + (57.5 x W) + (20.9 x H) - (28.3 x A) Females (kJ/24hr) BEE = 2741 + (40.0 x W) + (7.7 x H) - (19.6 x A) W = actual weight in kg, H = height in cm, A = age in years.

Schofield Equation Original equation (Schofield, 1985) derived from a study group of 5000 healthy adults Modified by COMA Panel on Dietary Reference Values (UK Dept of Health, 1991) excluded some data from developing nations additional equations for people over age of 75 yrs, based on Italian data Limitations - ?validity with obese clients, some ethnic groups, ?applicable to Australian population.

Original Schofield Equations (1985) Males Age (yrs) kJ /24hr 15-18 74W + 2754 18-30 63W + 2896 30-60 48W + 3653 60+ 49W + 2459 Females Age (yrs) kJ / 24hr 15 - 18 56W + 2898 18-30 62W + 2036 30-60 34W + 3538 60+ 38W + 2755

Modified Schofield Equations (1991) Males Age (yrs) kJ /24hr 10-17 74W + 2754 18-29 63W + 2896 30-59 48W + 3653 60-74 50W + 2930 75+ 35W + 3434 Females Age (yrs) kJ / 24hr 10-17 56W + 2898 18-29 62W + 2036 30-59 34W + 3538 60-74 39W + 2875 75+ 41W + 2610

Estimating Energy requirements Estimate BMR/BEE for healthy adult using predictive equation Adjust for stress using injury factor Adjust for activity using activity Energy requirement = BEE x Injury/Stress factor x Activity factor

Activity Factors Resting sedated +/- ventilated 1.0 Resting conscious 1.1 Bedrest (moving self around bed) 1.2 Light (mobilizing around ward) 1.3 Moderate (regular, intense physio) 1.4

Injury Factors Medical (IBD, liver/pancreatic d) 1.1-1.2 Surgical (transpl, fistula) 1.2-1.4 Cancer (tumour/leukaemia) 1.2-1.4 Trauma (or minor burns) 1.2-1.4 Sepsis (or other major infection) 1.3-1.4 Major burns 1.5-1.6 * Refer also to nutrition support and specific clinical lectures

Estimating Protein / Nitrogen Requirements From measuring Nitrogen losses from the body (urine, faeces, fistulae/drain losses, burn exudates) Urinary nitrogen excretion can be estimated by measuring urinary urea nitrogen(UUN) excretion from a 24hr urine sample. Urea production influenced by liver failure, sepsis, stress  insensitive and unreliable in clinically unstable patients

Estimating Protein / Nitrogen Requirements Using RDA’s Healthy adult 0.75g/kg BW Increased metabolic needs during periods of stress Mild/intermediate stress state eg surgery, fractures 1-1.5g/kg BW Cancer 1.2-1.5g/kg BW Multiple trauma, 1.5+/kg BW extensive burns(>30%)

Fluid Requirements Different methods used: 35 – 45 mL/kg body weight 30mL for older adults 40 – 45 mL for active young adult 0.24mL/kJ energy given 1500mL + add 20mL per additional kg over 20kg