Nutritional Assessment PDF
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Dr.Awatif Almehmadi
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This document covers nutritional assessment, including biochemical assessment, protein malnutrition, and nitrogen balance. It explains the importance of laboratory measurements and physical examinations in evaluating nutritional status.
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Nutritional Assessment Course Code:NUT3153 Biological Assessment Physical examination Le 4 Dr.Awatif Almehmadi Biochemical Assessment Laboratory measurements is systematic evaluation of nutritional status using laboratory tests to measure specific nutri...
Nutritional Assessment Course Code:NUT3153 Biological Assessment Physical examination Le 4 Dr.Awatif Almehmadi Biochemical Assessment Laboratory measurements is systematic evaluation of nutritional status using laboratory tests to measure specific nutrients or their metabolites in various bodily fluids and tissues e.g. Blood, urine, saliva, hair, or tissue samples e.g., serum micronutrient levels, lipids and immunological parameter. Importance of biochemical assessment : Laboratory assessment is used primarily to detect subclinical deficiency status, also to confirm a clinical diagnosis. Help to determine what is happening to the body internally. Lab values help to present a clearer picture when utilized with other assessment data. Provides objective data on: Nutritional deficiencies. Nutritional excesses. Metabolic imbalances. Validity Of Biochemical Assessment An accurate interpretation of laboratory data requires knowledge of the appropriate test to order as well as nutritional and non- nutritional factors that alter blood chemistries. A complete diet history, including supplement usage and physical symptoms, can provide important supportive information. Non-nutritional factors, such as disease processes, treatments, medications, and hydration status, can alter blood and urine chemistries and must be considered. Total boy protein 16 % (about 11 kg in 70 kg individual) Mostly distributed in skeletal muscle and visceral protein Assessment pool (serum protein, erythrocyte, granulocyte, lymphocyte organs e.g.liver kidney heart and pancreas. of total Somatic protein skeletal muscle protein (i.e. creatinine) protein Visceral protein which are metabolically available protein (albumin& Globlin). Other major component of protein in the body is found in extracellular, connective tissue protein of cartilaginous ,fibrous and skeletal tissue (non exchangeable with other body pools of protein). Definition: A condition resulting from inadequate protein intake or utilization by the body. Causes: Poor diet (insufficient protein intake). Malabsorption disorders (e.g., celiac disease, inflammatory bowel Protein disease). Increased protein needs (e.g., during pregnancy, wound healing, or severe Malnutrition illness). Overview Consequences: Muscle wasting and weakness. Impaired immune function, leading to increased susceptibility to infections Delayed wound healing. Edema (swelling) due to decreased oncotic pressure. Assessment methods: Combination of biochemical markers and physical examination findings. Two form of protein malnutrition Marasmus – low-income countries, inadequate energy Protein intake (energy, carbohydrate, protein and fat) also may occur in patient with sever illness- prolonged reduction malnutrition in food intake ( loss of muscle mass and adipose tissue or visceral protein). Kwashiorkor – children from certain region of low- income countries, also it may occur in patient in response to diseases associated Inadequate intake of protein and with increase in metabolic demand. It's associated with visceral protein loss and edema may occur. Nitrogen balance is a comparison between the intake of nitrogen( mainly as protein) and the excretion of nitrogen (mainly in the form of undigested protein in feces and urea and ammonia in the urine). The normal healthy adult should be in equilibrium , with intake=losses. Protein Positive nitrogen balance Indicates anabolism (tissue growth and repair) Intake and occurs in significant degree during child development, during pregnancy and in a convalescing adult when there is accumulation of proteins in the Nitrogen body. Balance Negative nitrogen balance Indicates catabolism (tissue breakdown) occurs when : (1) dietary intake is insufficient ,or (2) one of the essential amino acids is deficient or lacking in the diet. Negative nitrogen balance can occur when the body is under stress condition as in cases of burn, injury, sepsis or cancer , where there is increased amount of nitrogen excretion. Nitrogen Balance=Nitrogen Intake−Nitrogen Output Nitrogen intake is estimated from dietary protein intake. Nitrogen output is measured through urinary urea nitrogen and estimated non-urinary losses. Used to assess protein status and requirements, especially in critically ill patients. Limitations: Requires accurate dietary intake data and 24-hour urine Nitrogen collection. Balance Nitrogen equilibrium: When nitrogen intake equals nitrogen output. Positive nitrogen balance: When nitrogen intake exceeds nitrogen excretion, indicating protein synthesis is greater than degradation. Negative nitrogen balance: When nitrogen excretion exceeds nitrogen intake, indicating protein degradation is greater than synthesis Serum Proteins Protein Function Clinical Significance Serum proteins are essential Maintains oncotic Low levels may indicate components of the blood that play Albumin pressure, transports malnutrition, liver disease, crucial roles in various bodily substances. or kidney disease. functions. Measuring their concentrations can provide valuable Transports thyroxine Sensitive marker of acute Prealbumin insights into a patient's nutritional and retinol. changes in nutritional status. status, risk of medical complications, and response to nutritional support. Low levels may indicate iron Transferrin Transports iron.. deficiency or protein Primary Serum Proteins for Nutritional Assessment. deficiency. C-reactive Acute-phase reactant, Elevated levels may indicate protein increases during inflammation or infection. (CRP) inflammation. Serum albumin is the most abundant serum protein and is often used as a marker of protein status. However, its value as an indicator is limited by several factors: Long half-life and large body pool: Serum albumin levels respond slowly to changes in nutritional status. Not sensitive or specific for acute PEM: Cannot accurately assess acute protein depletion or repletion. Influenced by other factors: Synthesis rate, distribution, catabolism, abnormal losses, and fluid status. Extravascular albumin: Can temporarily mask low serum levels during early PEM. Serum albumin Acute-phase reactants: Can decrease albumin synthesis during catabolic phases. Albumin administration: Can interfere with its use as a protein status indicator. Limitations: Affected by hydration status Influenced by acute stress and inflammation May not reflect recent changes in nutritional status due to long half-life Serum Transferrin: A More Sensitive Marker of Protein Status Serum transferrin is a protein that binds and transports iron in the bloodstream. Compared to albumin, it has a smaller body pool and shorter half-life, making it a more sensitive indicator of changes in protein status. Key Points: Serum Sensitive to changes in protein status: Better reflects acute changes in nutritional status compared to albumin. Transferrin Clinical outcomes: Associated with clinical outcomes in children with malnutrition. Measurement: Can be measured directly or indirectly using TIBC. Factors affecting levels: Protein status, chronic infections, protein-losing enteropathy, wounds, nephropathy, acute catabolic states, pregnancy, estrogen therapy, and acute hepatitis. Total Body Water ~50-70% of body mass TBW = ~0.73 x fat free mass Hydration Terminology Euhydration – “normal” body water content within homeostatic range. Dehydration – the process of dynamic loss of body water – e.g., the transition from euhydration to hypohydration. Rehydration – the process of dynamic gain of body water (via fluid intake) – e.g., the transition from hypohydration to euhydration. Hypohydration – state of body water deficit. Over- or Hyperhydration – state of body water excess. Hydration Assessment Are you hypohydrated? Is my body mass >1% lower than normal? Yes / No Likely Likely Very Is my urine dark Likely Am I Thirsty? yellow? Yes / No Likely Yes / No Assess first thing in the morning (before breakfast) Role of Sodium in Fluid Balance Plasma Na + Na+ Na+ NaNa + + KK+ + Na Na+ + Sodium (Na+) is the most abundant electrolyte in the ECF Na+ Na+ Na+ extracellular space. K+ ISF Na+ Na+ Na+ Na+ Na+ Sodium controls water K+ K+ movement between fluid Na+ K+ K+ compartments. K+ K+ ICF K+ Water follows solute to K+ Na+ K+ maintain osmotic K+ equilibrium. Role of Sodium in Fluid Balance Stimulates thirst – leading to increased fluid intake and better maintenance or restoration of euhydration. Helps maintain proper fluid and electrolyte balance among fluid compartments. Supports cardiovascular function during exercise via better maintenance of plasma volume. Promotes whole body rehydration by stimulating renal fluid retention (decreased urine loss). Hydration Status Body mass loss Body mass gain Sweat Drinking Urine Eating Respiration (fuel oxidation, water vapor) What is Dehydration? Dehydration is condition caused by the loss of too much fluid from the body. It happens when loss of fluids is greater than fluids that are taken in, and the body does not have enough fluids to work properly. There are 2 types of dehydration; water loss dehydration (hyperosmolar, due either to increased sodium or glucose) salt and water loss dehydration (hyponatremia). 19 Feeling thirsty Dry mouth, tongue or skin Poor skin turgor Muscle cramps Signs and Constipation Headache Symptoms Tiredness or lethargy Irritability Decreased urine output or dark, concentrated urine Dizziness or fainting Sweating less than usual Rapid heartbeat or breathing Confusion or disorientation Low blood pressure (orthostatic hypotension) 20 Causes of Dehydration Diarrhea. Vomiting. Sweating too much. Fever. Not drinking enough. Urinating too much (Can be caused by certain medications and illnesses). 21 Biochemical markers for assessment: 1. Serum osmolality. 2. Blood urea nitrogen (BUN). 3. Creatinine. Dehydration 4. Electrolytes (primarily sodium and potassium). Complementary methods: assessment Physical signs (skin turgor, mucous membrane moisture). Urine colour and specific gravity. 22 Nutritional anemia assessment Definition: Insufficient healthy red blood cells due to nutrient deficiencies. Impact: Reduced oxygen-carrying capacity of blood, leading to fatigue and other symptoms. Common types of nutritional anemia: 1. Iron deficiency anemia (most common). 2. Vitamin B12 deficiency anemia. 3. Folate deficiency anemia. Importance of differential diagnosis: Different types require specific treatments. May indicate underlying health conditions. Nutritional anemia assessment CBC- complete blood count The CBC interpretation are useful in the diagnosis of various types of anemias. It can reflect acute or chronic infection, allergies, and problems with clotting. A (CBC) gives important information about the kinds and numbers of cells in the blood, especially red blood cells, white blood cells, and platelets. A CBC helps in checking any symptoms, such as weakness, fatigue you may have. A CBC also helps in diagnose conditions, such as anemia , infection, and many other disorders. Red blood cell (RBC) count Red blood cells carry oxygen from the lungs to the rest of the body. They also carry carbon dioxide back to the lungs so it can be exhaled. If the RBC count is low (anemia), the body may not be getting the oxygen it needs. If the count is too high (a condition called polycythemia), there is a chance that the red blood cells will clump together and block tiny blood vessels (capillaries). This also makes it hard for red blood cells to carry oxygen. Hematocrit (HCT, packed cell volume) This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. For example, a hematocrit of 38 means that 38% of the blood's volume is made of red blood cells. Hematocrit and hemoglobin values are the two major tests that show if anemia or polycythemia is present. Normal hematocrit levels vary based on age and race In adults, normal levels for men range from 41%-50%. For women, the normal range is slightly lower: 36%-44%. A hematocrit level below the normal range, meaning the person has too few red blood cells, is called anemia. A hematocrit level above the normal range, meaning too many red blood cells, may indicate polycythemia or erythrocytosis. Hemoglobin (Hgb) The hemoglobin molecule fills up the red blood cells. It carries oxygen and gives the blood cell its red color. The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body. Normal range (adults): Men: 13.5-17.5 g/dL Women: 12.0-15.5 g/dL Red blood & other cell indices There are three red blood cell indices: mean corpuscular volume (MCV), shows the size of the red blood cells mean corpuscular hemoglobin (MCH), the amount of hemoglobin in an average red blood cell mean corpuscular hemoglobin concentration (MCHC) the concentration of hemoglobin in an average red blood cells They are measured by a machine, and their values come from other measurements in a CBC. These numbers help in the diagnosis of different types of anemia. Serum Ferritin Reflects iron stores in the body Normal range: 15-300 ng/mL Interpretation: 300 ng/mL may suggest iron overload Advantages: Highly sensitive for iron deficiency Limitations: Acute-phase reactant (increases with inflammation) Vitamin B12 Deficiency Assessment Serum vitamin B12 levels: Direct measure of vitamin B12 in blood Normal range: 200-900 pg/mL Interpretation: