Nutrition: Week Two

Chapter Two: Ingestion, Digestion, Absorption, Metabolism

Ingestion, Digestion, Absorption, Metabolism

Ingestion: the process of consuming food by the mouth, and moving it through the digestive system.
Digestion: a systemic process that includes the breakdown and absorption of nutrients.
Absorption: components of nutrients pass through the digestive system into the bloodstream and lymphatic system.
Metabolism: the sum of all chemical processes that occur on a cellular level to maintain homeostasis.

Energy nutrients are metabolized to provide carbon dioxide, water, and adenosine triphosphate (ATP). Excess energy nutrients are stored; glucose is converted to glycogen and stored in the liver and muscle tissue; surplus glucose is converted to fat; glycerol and fatty acids are reassembled into triglycerides and stored in adipose tissue; and amino acids make body proteins. The liver removes nitrogen from amino acids, and the remaining product is converted to glucose or fat for energy. Body cells first use available ATP for growth and repair, then use glycogen and stored fat.

Metabolic Rate

The speed at which food energy is burned.
Basal Metabolic Rate (BMR) – refers to the amount of energy used in 24 hr for involuntary activities of the body (maintaining body temp., heartbeat, circulation, and respirations). This rate is determined while at rest and following a 12-hr fast.
BMR is affected by lean body mass and hormones. Body surface area, age, and sex are also factors that contribute to BMR.
In general, males have a higher metabolic rate than females due to their higher amount of body muscle and decreased amount of fat.
Any catabolic illness (surgery, extensive burns) increases the body's requirement for calories to meet the demands of an increased BMR.
Disease and sepsis also increase demands and can lead to starvation/death.

Factors Affecting Metabolic Rate

Increased BMR

Lean, muscular body build
Exposure to extreme temperatures
Prolonged stress
Rapid growth periods (infancy, puberty)
Pregnancy
Lactation

Decreased BMR

Short, overweight body build
Starvation/malnutrition
Age-related loss of lean body mass

Conditions Increasing Metabolic Rate

Fever
Involuntary muscle tremors (shivering, Parkinson's)
Hyperthyroidism
Cancer
Cardiac failure
Burns
Surgery/wound healing
HIV/AIDS

Conditions Decreasing Metabolic Rate

Hypothyroidism

Medications Increasing Metabolic Rate

Epinephrine
Levothyroxine
Ephedrine sulfate

Medications Decreasing Metabolic Rate

Opioids
Muscle relaxants
Barbiturates

Nitrogen Balance

Nitrogen balance refers to the difference between the daily intake and excretion of nitrogen. It also is an indicator of tissue integrity. A healthy adult experiencing a stable weight is in nitrogen equilibrium, also known as neutral nitrogen balance.

Positive nitrogen balance indicates that the intake of nitrogen exceeds excretion. Specifically, the body builds more tissue than it breaks down. This normally occurs during periods of growth: infancy, childhood, adolescence, pregnancy, and lactation.
Negative nitrogen balance indicates that the excretion of nitrogen exceeds intake. The individual is receiving insufficient protein, and the body is breaking down more tissue than it is building, as seen during periods of illness, trauma, aging, and malnutrition.

ASSESSMENT/DATA COLLECTION

•Weight and history of recent weight patterns
•Medical history for diseases that affect metabolism and nitrogen balance
•Extent of traumatic injuries, as appropriate
•Fluid and electrolyte status
•Laboratory values: albumin, transferrin, glucose, creatinine
•Clinical findings of malnutrition: pitting edema, hair loss, wasted appearance
•Medication adverse effects that can affect nutrition
•Usual 24-hour dietary intake
•Use of nutritional supplements, herbal supplements, vitamins, and minerals
•Use of alcohol, caffeine, and nicotine

NURSING INTERVENTIONS

•Monitor food intake

•Monitor fluid intake and output

•Use client-centered approach to address disease-specific problems with ingestion, digestion, or medication regime.

•Collaborate with dietitian

•Provide adequate calories and high-quality protein

STRATEGIES TO INCREASE PROTEIN, CALORIC CONTENT

•Add skim milk powder to milk (double-strength milk)

•Use whole milk instead of water in recipes

•Add cheese, peanut butter, chopped hard-boiled eggs, or yogurt to foods

•Dip meats in eggs or milk and coat with bread crumbs before cooking

•Nuts and dried beans are significant sources of protein. These are good alternatives for a dairy allergy or lactose intolerance.

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Chapter Three: Nutrition Assessment and Data Collection

Nurses play a key role in assessing the nutritional needs of clients. Nurses monitor and intervene with clients requiring acute and chronic nutritional care. Nurses should consider and incorporate the family’s nutritional habits into a client’s individual plan of care. Nurses should take an active role in assessing and teaching community groups regarding nutrition.

A collaborative, interprofessional approach provides the best outcomes for the client. Providers and nurses collect physical assessment data, as well as serving as liaison between the health care team and the dietitian. Registered dietitians complete comprehensive nutritional assessments. Nurses monitor and evaluate interventions provided to clients.

A client’s physical appearance can be deceiving. A client who has a healthy weight and appearance can be malnourished, Cultural, social, and physical norms must be part of a client’s assessment. Even with adequate client education, personal preferences can be an overriding factor to successful nutritional balance.

A diet history is an assessment of the usual foods, fluids, and supplements. The diet history is part of the nutrition screening performed using various settings to determine malnutrition issues. Components of the diet history include the following:

Time, type, and amount of food eaten for breakfast, lunch, dinner, and snacks.
Time, type, and amount of fluids consumed throughout the day, including water, health drinks, coffee/tea, carbonated beverages, and beverages with caffeine.
Type, amount, and frequency of “special foods” (celebration foods, movie foods).
Typical preparations of foods and fluids (coffee with sugar, fried foods).
Number of meals eaten away from home (at work or school).
Type of preferred or prescribed diet (ovo-lacto vegetarian, 2 g sodium/low-fat diet).
Foods avoided due to allergies or preference.
Frequency and dose/amount of meds or supplements taken.
Satisfaction with diet over a specified time frame (last 3 months, 1 year)

Dietary History

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Tools to Determine Nutritional Status

A physical assessment is performed by the provider or nurse to identify indicators of adequate nutrition. However, other diseases or conditions can cause these clinical findings.

MANIFESTATIONS

Hair that is dry or brittle, or skin that has dry patches
Poor wound healing
Lack of subcutaneous fat or muscle wasting
Irregular cardiovascular measurements (heart rate and rhythm, blood pressure)
Enlarged spleen or liver
General weakness or impaired coordination.

Anthropometric Tools

WEIGHT

Weigh at same time of day wearing similar clothing to ensure accurate readings.
Daily fluctuations are usually due to water weight changes.
Calculate percentage weight change: % weight change = ((usual weight -present weight))⁄(usual weight) x 100
Ideal body weight based on the Hamwi method using height/weight calculation. - MALES: 48 kg (106 lbs) for the first 152 cm (5 ft) of height, and 2.7 kg (6 lbs) for each additional 2.5 cm (1 in). FEMALES: 45 kg (100 lbs) for the first 152 cm (5 ft) of height, and 2.3 kg (5 lb) for each additional 2.5 cm (1 In).

During illness, weight loss is monitored to prevent or detect malnutrition.

- with starvation or chronic disease, weight loss indicating severe malnutrition greater than 5%/month, greater than 7.5%/3 months, greater tha 10%/6 months, greater than 20%/year.

- with acute disease or injury, weight loss indicating severe malnutrition: greater than 2%/week, greater than 5%/month, greater than 7.5%/3 months.

HEIGHT

Measure on a vertical, flat surface. Ask the client to remove shoes and head coverings and stand straight with heels together looking straight ahead. Read the measurements to the nearest 0.1 cm or 1/8 inch.
Obtain a recumbent measurement (lying on a firm, flat surface) for infants and young children.

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BODY MASS INDEX (BMI)

BMI measurements compare the weight to height to estimate the effect of the individual’s body weight. Client factors should be considered when determining the value of BMI measurement. For example, a client who has a large muscle mass compared to height can have an increased BMI, since weight can be influenced by both fat and muscle, or a client with a normal BMI might have excess body fat.
Healthy weight is indicated by a BMI of 18.5 to 24.9
Underweight is indicated by a BMI less than 18.5
Overweight is defined as an increased BMI of 25-29.9, and are about 20% above desirable levels.
Obesity is indicated by a BMI greater than or equal to 30

BMI = weight (kg) ÷ height (m^2)

Clinical Values

Fluid I & O

Adults: 2,000 to 3,000 mL per day
Total average output: 1,750 to 3,000 mL/day

Protein Levels are usually measured by albumin levels, although total protein is sometimes used.

Many non-nutritional factors (injury, kidney disease), interfere with this measure for protein malnutrition.
Expected reference range for albumin: 3.5 to 5 g/dL.
Prealbumin (thyroxine-binding protein) is a sensitive measure used to assess critically ill clients who are at risk for malnutrition. This test reflects acute changes rather than gradual changes. However, it is more expensive and often unavailable. This is not part of routine assessment.
•Prealbumin levels can decrease with an inflammatory process resulting in an inaccurate measurement.
•Prealbumin levels are used to measure effectiveness of total parenteral nutrition.
•Expected reference range is 15 to 36 mg/dL (less than 10.7 mg/dL indicates severe nutritional deficiency).
Nitrogen Balance refers to the relationship between protein breakdown (catabolism) and protein synthesis (anabolism).
To measure nitrogen balance:
-record protein intake (g) over 24 hr and divide by 6.25.
- record nitrogen excretion in urine over 24 hr and add 4 g.
-subtract nitrogen output from nitrogen intake
-24 hr protein intake divided by 6.25 = nitrogen intake (g)
-24 hr urinary urea nitrogen + 4 g = total nitrogen output
Nitrogen balance = intake - output
A neutral nitrogen balance indicates adequate nutritional intake.
A positive nitrogen balance indicates protein synthesis is greater than protein breakdown as during growth, pregnancy, or during recovery.
A negative nitrogen balance indicates protein is used at a greater rate than it is synthesized as in starvation or a catabolic state following injury or disease.

Obesity

Approximately 36.5% of American adults have obesity, and an estimated 68.5% have obesity or are overweight.

Obesity is a chronic condition caused by calorie intake in excess of energy expenditure. It can be affected by numerous factors (culture, metabolism, environment, socioeconomics, individual behaviors).
Obesity might be linked to protective measures within the body to prevent weight loss during calorie restriction, which cause it to secrete hormones that stimulate the appetite to maintain a specific weight. As weight increases, the body accepts a higher weight as the expected weight and seeks to maintain it.

RISK FACTORS

•Genetic predisposition
•Hormones (leptin, ghrelin)
•Behavioral factors (sedendary lifestyle, diet choices)

Obesity: Assessment

EXPECTED FINDINGS

Clients report of depression, low self-esteem, avoidance of health-related appointments, and no desire to exercise as a result of feeling stigmatized by their excessive weight.

Body Mass Index

Overweight: 25 to 29.9
Obesity: 30 or greater

Waist circumference

Females: greater than 88.9 cm (35 inches)
Males: greater than 101.6 cm (40 inches)

Waist to hip ratio (WHR)

Measurement of difference between peripheral lower body obesity and central obesity
Can be used as a predictor of coronary artery disease
Indicates excess fat at the waist and abdomen: males 0.95 or greater. Females 0.8 or greater.

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Obesity: Laboratory Tests

Screening to evaluate for cardiovascular disease, diabetes mellitus, fatty liver disease, or thyroid disorders.
Total cholesterol.
Triglycerides.
Fasting blood glucose.
Glycosylated hemoglobin.
Aspartate aminotransferase (AST)
Alanine aminotransferase (ALT)

Obesity: Patient Centered Care

MEDICATIONS

Clients who do not lose weight during weight loss programs can benefit from pharmacological therapy.
Anorectic medications suppress appetite and reduce food intake, When combined with an exercise program, they can result in weight loss.
Orlistat: prevents digestion of fats. Adverse effects include oily discharge, reduced food and vitamin absorption, decreased bile flow, loose oily stools, abdominal cramps, fecal incontinence.
Lorcaserin: stimulates serotonin receptors in the hypothalamus in the brain to curb appetite. Adverse effects include headache, dry mouth, fatigue, nausea.
Phentermine-topiramate: suppresses the appetite and induces a feeling of satiety. Adverse effects include dry mouth, constipation, nausea, change in taste, dizziness, insomnia, numbness and tingling of extremities. Contraindications include hyperthyroidism, glaucoma, taking an MAO inhibitor.

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