Introduction to Clinical Nutrition NFSC 370 D. Bellis McCafferty.

Introduction to Clinical NutritionIntroduction to Clinical Nutrition

NFSC 370NFSC 370

D. Bellis McCaffertyD. Bellis McCafferty

Illness

Malnutrition

Example : Cancer

Altered Food

Intake

Altered Digestion and

Absorption

Altered Metabolism

Altered Nutrient Excretion

Examples: Loss of appetite, altered food likes/dislikes, difficulty chewing and swallowing, reduced saliva secretion

Examples: radiation enteritis, surgical resection of GI tract, diarrhea

Example: increased energy needs due to altered energy use in cancer

Examples: fecal loss of fat-soluble vitamins and calcium in clients with cancers that affect enzyme secretion or bile salt production

Clinical NutritionClinical Nutrition(Medical Nutrition Therapy)(Medical Nutrition Therapy)

Purpose Purpose – To achieve or maintain good nutritional status.To achieve or maintain good nutritional status.

American Dietetic Association American Dietetic Association – Professional organization representing Professional organization representing

Registered Dietitians (RD) and Dietetic Registered Dietitians (RD) and Dietetic Technicians (DTR)Technicians (DTR)

Patient Care: Team ApproachPatient Care: Team Approach(Interdisciplinary)(Interdisciplinary)

• Physician Physician

• Registered DietitianRegistered Dietitian

• Registered Nurse, Licensed Vocational Nurse, Registered Nurse, Licensed Vocational Nurse, Certified Nursing Assistant Certified Nursing Assistant

• PharmacistPharmacist

• Speech TherapistSpeech Therapist

• Occupational TherapistOccupational Therapist

• Social WorkerSocial Worker

The Nutrition Care Process• Identifying and meeting a person’s nutrient and nutrition

education needs. Five steps:

1. Assess Assessment of nutritional status

2. Analyze Analyze assessment data to determine nutrient requirements

3. Develop Develop a nutrition care plan to meet patient’s nutrient and education needs.

4. Implement: Implement care plan

5. Evaluate: Evaluate effectiveness of care plan: ongoing follow-up, reassessment, and modification of care plan.

THE PATIENT THE PATIENT SHOULD BE AN ACTIVE SHOULD BE AN ACTIVE PARTICIPANT IN THE PARTICIPANT IN THE

CARE PROCESS!CARE PROCESS!

Assessing Nutritional Status

• Historical Information• Physical Examination

• Anthropometric Data

• Laboratory Analyses

Historical Information

• Health History (medical history) - current and past health status

– diseases/ risk factors for disease

– appetite/food intake

– conditions affecting digestion, absorption,

utilization, & excretion of nutrients

– emotional and mental health


• Drug History – prescription & OTC meds – illicit drugs– nutrient supplements, HERBS and other

“alternative” or homeopathic substances – multiple meds (who’s at risk?)

Meds can alter intake, absorption, metabolism, etc.

Foods can alter absorption, metabolism, & excretion of meds.


• Socioeconomic History - factors that affect one’s ability to purchase, prepare, & store food, as well as factors that affect food choices themselves.– Food availability (know local crops/produce)

– occupation/income/education level

– ethnicity/religious affiliations

– kitchen facilities

– transportation

– personal mobility (ability to ambulate)

– number of people in the household

Historical Information• Diet History—analyzing eating habits, food intake,

lifestyle, so that you can set individualized, attainable goals.– Amount of food taken in

– Adequacy of intake – omission of foods/food groups

– Frequency of eating out

– IV fluids

– Appetite

– Restrictive/fad diets

– Variety of foods

– Supplements (overlaps)


• Tools for taking a diet hx:– 24 hour recall– Usual intake – can find trends, such as breakfast/snacks– Food Frequency Questionnaire/Checklist– Food Records– Observing food intake

• Analysis of Food Intake Data• INDIVIDUAL NEEDS FOR NUTRIENTS VARIES


• Historical Information• Physical Examination



Physical Examination: “A picture is worth a thousand words.”

• weight status

• mobility

• confusion

• signs of nutrient deficiencies/malnutrition

– esp. hair, skin, GI tract including mouth and tongue

• Fluid Balance (dehydration/fluid retention)

Physical Examination: “A picture is worth a thousand words.”

• Limitations of Physical Findings– Depends on assessor!– Many physical signs are nonspecific: ie. cracked lips

from sun/windburn vs. from malnutrition, dehydration…


• Historical Information

• Physical Examination

• Anthropometric Data• Laboratory Analyses

Anthropometric Data - physical measurement of the body

anthropos = human metric = measure

• Indirect assessment of body composition and development• Used in Nutrition Assessment:

– Measures using height and weight– Measures of body composition (fat vs. lean tissue)– Functional Measures

Anthropometric Data Measures Using Height and Weight

BMI Body Mass Index

wt (kg)

ht (cm)2

orwt (lb) X 705

ht (inches) 2


• 18.5-24.9• 25+• 30+• Pros:

– many studies have identified the health risks associated with a wide range of BMIs

– easy to look up on chart – screening tool


• Cons: BMI can misclassify up to one out of four people.– Does not account for fat distribution– Doesn’t account for LBM - may misclassify

frail/sedentary or very muscular people

Met Life Insurance weight-for- height tables– Weights based on lowest mortality

Example: Height & Weight Table For Women

Feet Inches SmallFrame MediumFrame LargeFrame

5' 1" 106-118 115-129 125-140

5' 2" 108-121 118-132 128-143

5' 3" 111-124 121-135 131-147

5' 4" 114-127 124-138 134-151

5' 5" 117-130 127-141 137-155

5' 6" 120-133 130-144 140-159

5' 7" 123-136 133-147 143-163

5' 8" 126-139 136-150 146-167

5' 9" 129-142 139-153 155-176

Weights at ages 25-59 based on lowest mortality. Weight in pounds according to frame (in indoor clothing weighing 3 lbs.; shoes with 1" heels)


Assessing “Ideal Body Weight”

Hamwi Equation:

• Females: 100# for first 5’ of height, plus 5# per inch over five feet

• Males: 106# for first 5’ of height, plus 6# per inch over five feet

• +/- 10% to calculate a range

(for those under 5’ tall, subtract 2 lb. per inch under 5’)

** Amputations, immobility:

7%

43%

Whole arm 6.5%

Whole leg 18.5%

Below elbow 3%

Hand 1%

Above knee 13%

Below knee 6%

Foot 1.8%

Interpretation

%IBW

Actual (present) weight X 100 = %IBW

IBW

• example: 5’6” woman weighs 160#. What is her % IBW?

• 160 130 = 123%

Interpreting % IBW 200% IBW = morbidly obese (or 100# over IBW)

120 % (130%) = obese

110 - 120 = overweight

90 - 109 = normal

80 - 89 = mildly compromised nutrition status (mild malnutrition)

70-79 = moderate

< 70% = severe


• Assessing “Usual Body Weight”

Actual (present) weight X 100 = % UBW

UBW

• example: 110# female lost 10# over past month

• 110/120 x 100 = 91.6% UBW, or loss of about 8%

Interpreting % UBW

85-90% mild

75-84% moderate

<75% severe

OR wt. change (unintentional weight loss)

mild moderate severe

1 week 1-2% >2

1 month 5 >5

3 months 7.5 >7.5

6 months 10 10-15 >15

Anthropometric Data Measures of Body Composition(fat vs. lean tissue)

Body Fat Measurements

• fatfold (skinfold)

• waist-to-hip ratios

• hydrodensitometry (hydrostatic weighing)

• bioelectrical impedance

Anthropometric Data Measures of Body Composition

Midarm muscle circumference – indirectly measures protein status by estimating arm muscle mass.

• Midarm circumference and triceps fatfold

• plug into an equation:mmc (cm) = mc (cm) - [.314 x triceps fatfold (mm)]

Anthropometric Data Functional Measures of Nutrition Status

Hand Grip Strength

• Dynamometer

• Not appropriate w/arthritis/muscular disorders

Interpreting Measurements

• Requires caution

• Interpreting Measurements – Sometimes difficult to measure 2’ mobility

problems, injury, loose, hanging skin– Hydration/dehydration affects weight, fatfolds,

and MAMC– Standards used are controversial

Summing Up

• Anthropometric measures provide valuable information regarding body wt. and composition

• Do not reflect nutrition status alone

• Accuracy requires on the skill of the assessor

• Caution interpreting results


• Historical Information

• Physical Examination



Laboratory Analyses

• Help determine what’s happening on the inside of the body

• Automated measurements of several blood components from a single blood sample

• serum -

• plasma -

Laboratory Analyses

Interpreting Biochemical Tests

• Many can be skewed with fluid retention or dehydration.

• Over-hydration can cause _____ numbers

• Dehydration can cause ______ numbers

• These are clues that anthropometrics are probably skewed as well.

Normal hydration

Overhydrated = diluted blood

Dehydrated = concentrated blood

1 dl blood

10 mg/dl 5 mg/dl 20 mg/dl

Laboratory Analyses:Biochemical Tests Of Protein Status

• Somatic proteins - physical work• Serum/visceral proteins (circulating proteins &

proteins found in the liver, kidneys, pancreas, and heart)

maintain fluid balancesynthesize enzymes and hormonesmount immune responseheal wounds

• Therefore, protein status is an indicator of immune response.


• Synthesized in the liver – May reflect liver function– Measurements skewed if liver diseased

• Remember, when kcals are inadequate, protein is used to make glucose.


Serum Albumin:– >50% total serum protein

– Helps maintain fluid and lyte balance

– Transports many nutrients, hormones, drugs, etc.

– Used as indicator of protein status (visc. protein stores)

– Half life ___________

3.5-5.0 = adequate

2.8-3.4 = mildly depleted

2.1- 2.7 = moderately depleted

<2.1 = severely depleted visceral protein stores


Problems with albumin:– not very sensitive, long half life levels reflect prolonged depletion, but

– normal levels may not reflect short term changes in nutritional status.

• Levels :

• Remember, number affected by plasma volume, so in over-hydration and in dehydration.


Serum Transferrin

= (TIBC x 0.76) + 18– Shorter half-life ____________– Transports iron:

– If Fe deficiency present, doesn’t accurately reflect protein status

– Transferrin levels RISE with Fe deficiency! Inverse relationship

levels may indicate __________________ levels may indicate __________________


– Levels :– Levels :

Normal: >200 mg/dl

Mild 150-200 mg/dl

Moderate 100-149 mg/dl

Severe <100 mg/dl


Prealbumin (thyroxine-binding prealbuin or transthyretin TTHY) – Being used more: some facilities using in place of

albumin– Half life: ______________– Sensitive indicator of protein status– Good indicator of pt. response to MNT $$ to run than albumin


Prealbumin– Levels :– Levels :

Normal: 15-40 mg/dl

Mild: 10-15 mg/dl

Moderate: 5-10 mg/dl

Severe: <5 mg/dl


Nitrogen Balance Studies

(usually only used in severe metabolic stress)1. Track the patient’s UUN (Urinary Urea Nitrogen)

2. 24 hour record of protein intake

3. Plug into nitrogen balance equation:

N balance (g) = protein intake - (UUN + 4)

6.25

Amino Amino Acids Acids C-C-C-C-NN C-C-C-C-NN

Urea Urea (BUN)(BUN)NN-C--C-NN

Excreted via Excreted via kidneyskidneys

(UUN)(UUN)

Remember how this works?

N balance (g) = protein intake - (UUN + 4) 6.25

• “4” represents non-urea N+ lost in feces, urine, skin, and respiration

• every 6.25 grams of protein contains 1 gram of nitrogen

0 or - =

+ =

• Goal for repletion :

Laboratory Analyses:Biochemical Tests Of Immune Function

• Total WBCs• Normal: 5,000-10,000/mm3

• Possible critical values: <2500 or >30,000/mm3 • High vs. low values?

• Total Lymphocyte Count (TLC)Measured from % lymphocytes and total WBC countEquation: TLC = % lymphocytes X Total WBC/mm3

Normal: >1500 mm3

Mild: 1200 - 1500Moderate: 800-1199Severe: <800

What do unusually high numbers indicate?

Laboratory Analyses:Hematological Assessment – looking at blood cells and detecting anemias

Hematology Assessment – morphology & physiology of blood cells. Helps detect the presence of anemias.

• Hemoglobin (Hgb, Hb) – main functional constituent of the RBC, serving as

the oxygen-carrying protein level may indicate depleted iron stores BUT

•

•

• 12-16 g/dl females

14-18 g/dl males

Laboratory Analyses:Hematological Assessment

• Hematocrit (Hct) – % of RBCs in the total blood volume. – Commonly used to diagnose Fe def., but also

inconclusive– values indicate incomplete Hgb formation,

which is manifested by ____________, ______________ RBCs

Males: 42%-52%

Females: 37%-47%

Laboratory Analyses:Hematological Assessment

• Mean Corpuscular Volume (MCV) - the average volume (size) of a single RBC. levels: levels:

normal: 80-953

Anemias:

• Normocytic, normochromic anemia: – Iron def detected early (RBCs)

• Microcytic hypochromic: – Fe-def detected late (or lead poisoning)

• Microcytic, normochromic: – Renal disease (2’ loss of EPO)

• Macrocytic, normochromic: – B12 or folate def (or chemo)

Laboratory Analyses:Other Labs Used in Nutrition Assessment

• Glucose – Indicates glucose tolerance/diabetes.– Levels 2° _______________, pancreatitis,

pancreatic CA, & with use of steroids (solumedrol and prednisone),caffeine, antidepressants and several other drugs.

– Normal Fasting:

• Blood Urea Nitrogen (BUN) – Major end product of protein metabolism– Levels with impaired ____________ function – Also with:

Amino Amino Acids Acids C-C-C-C-NN C-C-C-C-NN

Urea Urea (BUN)(BUN)NN-C--C-NN

Excreted via Excreted via kidneyskidneys

(UUN)(UUN)

Laboratory Analyses:

Other Labs Used in Nutrition Assessment

• Creatinine (blood)– Breakdown product of phosphocreatine, present in

skeletal muscle– Daily production of creatine, (and thus creatinine)

depends on muscle mass– Creatinine is excreted in ________ on a daily

basis. – If _________ function is impaired, Creatinine

levels will rise (decreased clearance).

Laboratory Analyses:

Other Labs Used in Nutrition Assessment

• Sodium (Na+) – Indicator of hydration level. Look at Na+ level to

evaluate other labs. – Overhydration -– Dehydration -

• eg. albumin

Introduction to Clinical Nutrition NFSC 370 D. Bellis McCafferty.

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