35 Nutritional Assessment and Undernutrition Flashcards
1
Q
Malnutrition
- Malnutrition
- optimized nutrition
A
-
Malnutrition
- includes extremes of both underweight and overweight states.
- affects > 50% of hospitalized patients (frequently with coexistent chronic illnesses)
- contributes to significantly longer hospital stays, higher morbidity, and higher mortality rates among both medical and surgical patients
-
optimized nutrition
- leads to improved clinical outcomes in patients with both medically- and surgically-treated conditions
2
Q
Protein-energy malnutrition (PEM)
- Protein-energy malnutrition (PEM)
- Other terms used interchangeably with PEM
- (PEM) and PCM are somewhat misleading terms implying that/
- malnutrition is a more general term that encompass
A
-
Protein-energy malnutrition (PEM)
- a form of malnutrition resulting from inadequate and/or inefficient nutrient availability in relation to tissue needs.
- Other terms used interchangeably with PEM are protein-calorie malnutrition (PCM), undernutrition, or simply, malnutrition.
-
(PEM) and PCM are somewhat misleading terms implying that the clinical signs and symptoms of malnutrition are due only to energy (calories) and protein deficiencies.
- deficiencies of vitamins, minerals and trace elements are equally important and often occur concurrently with macronutrient deficiencies (rarely with macronutrient excess).
- malnutrition is a more general term that encompass a mismatch of both macro- and/or micronutrient stores compared to physiological needs.
3
Q
Primary vs. Secondary Malnutrition
- Primary malnutrition:
- Secondary malnutrition:
A
-
Primary malnutrition:
- exists when the caloric, vitamin, or mineral content of ingested food is not sufficient to meet the minimum daily need as defined by the Recommended Daily Allowance (RDA).
-
Secondary malnutrition:
- occurs when an adequate diet is available and consumed, but the nutrients of the diet are unable to be digested, absorbed or assimilated because of illness.
- can occur in the context of illnesses that markedly increase nutrient requirements such that even “normal” intake becomes insufficient to meet needs.
- most common form in the United States, especially in acutely ill, hospitalized patients.
4
Q
Two major patterns of severe malnutrition
- Unstressed starvation
- Stressed starvation
A
-
Unstressed starvation
- generalized primary malnutrition resulting from slow, chronic semi-starvation (ingesting fewer nutrients than is required to meet daily needs) resulting in a severe total caloric deficiency that drives marked loss of body fat and protein stores.
-
Stressed starvation
- an acquired, maladaptive state with primary protein deficiency typically seen during severe metabolic stress.
- common in patients with both acute and chronic illnesses and leads to rapid muscle wasting, micronutrient deficiencies, decubitus ulcers, and life-threatening infections.
5
Q
Common Etiologies of Malnutrition
- Primary malnutrition
- Common causes of secondary undernutrition
- Digestion
- Absorption
- Metabolism
- excretion
- nutritional requirements
A
-
Primary malnutrition
- the most common form of malnutrition worldwide.
- common in impoverished children in Third World countries where the increased nutrient needs during growth and development often exceed supply.
- Other contributors to primary malnutrition include political unrest and displacement, famine, poverty, neglect, and lack of sanitation and infection.
- also occurs in the United States, often in the context of individuals with ongoing gastrointestinal symptoms (e.g. gastroparesis, dysphagia), impaired deglutition (gingivitis, poor dentition, stroke), cancer-induced anorexia, alcoholism/drug abuse, eating disorders, and those with severe mental illness or dementia
- _Common causes of secondary undernutrition (i.e. malnutrition that occurs despite adequate oral intake) _
- Digestion (cholestasis, disaccharidase deficiency, small bowel bacterial overgrowth, pancreatic insufficiency, cystic fibrosis, radiation enteritis, short bowel syndrome, AIDS, celiac disease, intestinal lymphoma)
- Absorption (enteritis, short bowel syndrome, tropical sprue, celiac, Whipple’s disease)
- Metabolism (AIDS, cancer, liver disease, renal disease, corticosteroid use, inborn errors of metabolism)
- Increased nutrient excretion (diarrhea, protein losing enteropathy)
- Increased nutritional requirements (burns, chronic infection, chronic lung disease, hyperthyroidism, major surgery, sepsis or trauma).
6
Q
Subjective Nutritional Assessment
A
- Typical diet, with attention to any medical restriction or self-imposed limits (i.e. low sodium, diabetic diet, vegan, Atkins, Kosher, lactose intolerance, etc.)
- Food allergies
- Use of vitamins/minerals and over-the-counter supplements
- Appetite changes
- Difficulties/barriers to normal intake (i.e. poor fitting dentures, tooth pain, etc.)
- Gastrointestinal symptoms such as dysphagia, abdominal pain, bloating, early satiety, nausea, vomiting or diarrhea
-
Living situation / activities of daily living
- elderly patients living alone are at high risk for malnutrition due to loss of independence with restricted mobility, driving, or access to shopping.
- Nursing home residents with dementia or mental retardation may not be able to communicate or recognize hunger or thirst.
7
Q
Objective Nutritional Assessment
- In the clinical nutritional assessment,
- important to identify/
- undernutrition can be expected if a patient develops/
- nutritional risk
A
-
In the clinical nutritional assessment,
- important to identify recent changes in dietary intake and/or body weight, new or chronic gastrointestinal symptoms, levels of functional activity and diseases that may affect nutritional status.
- undernutrition can be expected if a patient develops an unintentional weight loss of > 10% IBW (ideal body weight) within the preceding 3 months, if the patient’s body weight is < 90% of IBW or if the body mass index (BMI = Weight (kilograms) / Height (meters squared)) is < 18.5.
- patients can be placed at high, moderate or low nutritional risk based on either the current % of ideal body weight (IBW), or by using the body mass index (BMI).
8
Q
Objective Nutritional Assessment
- In clinical practice,
- ideal body weight
- Women
- Men
- Undernutrition: Severity
- Low
- Moderate
- High
- Incompatible with life
- Weight Categories
- Underweight
- Normal
- Overweight
- Class I obese
- Class II obese
- Class III obese
A
-
In clinical practice,
- ideal body weight of an adult is often estimated using a simple calculation that considers only a person’s height and gender:
- Women: 100 lbs + (# of inches greater than 5 feet in height) x 5 lbs = IBW
- Men: 110 lbs + (# of inches greater than 5 feet in height) x 6 lbs = IBW
-
Undernutrition: Severity
- Low: BW< 90% IBW for HT
- Moderate: BW< 85% IBW for HT
- High: BW< 70% IBW for HT
- Incompatible with life: BW< 60% IBW for HT
-
Weight Categories
- Underweight: BMI< 18.5 kg/m²
- Normal: BMI 18.5 – 24.9 kg/m²
- Overweight: BMI 25 – 29.9 kg/m²
- Class I obese: BMI 30 – 34.9 kg/m²
- Class II obese: BMI 35 – 39.9 kg/m²
- Class III obese: BMI ≥40 kg/m²
9
Q
Objective Nutritional Assessment (p.5-7+24)
- Physical signs of malnutrition include:
- General
- Mouth
- Head/neck
- Hands
- Abdomen
- Skin
- Classic signs of micronutrient deficiency:
- Glossitis
- Cheilosis/Angular Stomatitis
- Pellagra (Dermatitis)
- Koilonychia (Spoon Nails)
A
-
Physical signs of malnutrition include:
- General: obesity (with attention to distribution to thighs/buttocks vs. abdominal), cachexia, or anasarca
- Mouth: condition of teeth, lips, gums, tongue
- Head/neck: temporal wasting, visible bony prominences, hair changes
- Hands: interosseus/thenar/hypothenar muscle wasting, nail bed deformities
- Abdomen: ascites, adiposity, presence of a gastrostomy/jejunostomy tube
- Skin: xanthomas, rash, edema
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Classic signs of micronutrient deficiency:
- Glossitis – Thiamine, Niacin, or B12 Deficiency
- Cheilosis/Angular Stomatitis – Riboflavin and/or Folic Acid Deficiency
- Pellagra (Dermatitis) - Niacin Deficiency
- Koilonychia (Spoon Nails) –Severe Iron Deficiency
10
Q
Laboratory data
- Measurement of plasma proteins levels
- The measurement of visceral proteins needs to be taken in a physiological context.
- In a steady state
- systemic inflammatory states
- during states of acute systemic inflammatory illness
A
-
Measurement of plasma proteins levels
- an objective method of nutritional assessment of macronutrient status.
- Serum albumin, prealbumin, transferrin, and retinol binding protein are the most commonly used “visceral” proteins used in nutritional assessment.
- equally important to assess the status of micronutrients when suspected by the history and/or physical examination.
-
The measurement of visceral proteins needs to be taken in a physiological context.
- In a steady state (without significantly active systemic disease), the levels of these proteins can be a useful readout of actual nutritional status.
-
systemic inflammatory states associated with acute illness or trauma rapidly reorient the hepatic synthesis of core visceral proteins due to the impact of circulating inflammatory cytokines.
- Although true malnutrition clearly can occur simultaneously with acute illness, it becomes more difficult to use the absolute value of any one of the circulating visceral proteins as a direct measure of current nutritional state during systemic inflammatory states.
- measurement of C-reactive protein (CRP) levels is typically integrated into the nutritional assessment as a measure of systemic inflammation.
-
during states of acute systemic inflammatory illness, there is a significant inverse correlation between albumin/prealbumin and CRP levels.
- The trend of these measurements serves as an invaluable tool in assessing both the progression of clinical disease and the underlying nutritional state.
11
Q
Visceral Proteins in Nutritional Assessment:
For each: normal values, half-life, increased in, and decreased in
- Albumin
- Prealbumin (transthyretin)
- Retinol Binding Protein
- Transferrin
A
-
Albumin
- Normal values: 3.5-5.2 g/dl
- Half-life: 3 weeks
- Increased: Dehydration
- Decreased: Chronic malnutrition, Nephrotic syndrome, Severe liver disease, Inflammation/Malignancy, Fluid overload, Pregnancy
-
Prealbumin (transthyretin)
- Normal values: 19-43 mg/dl
- Half-life: 3 days
- Increased: Dehydration, Renal failure
- Decreased: Acute and chronic malnutrition, Cancer/Inflammatory response, Fluid overload, Hyperthyroidism, Severe liver injury, Pregnancy
-
Retinol Binding Protein
- Normal values: 2.1-6.4 mg/dl
- Half-life: 12 hours
- Increased: Renal Failure, Alcoholism
- Decreased: Acute and Chronic malnutrition, Chronic Liver disorders, Hyperthyroidism, Vitamin A deficiency, Zinc deficiency
-
Transferrin
- Normal values: 200-400 mg/dl
- Half-life: 1 week
- Increased: Iron deficiency, Estrogens/oral contraceptives, Acute hepatitis, Pregnancy
- Decreased: Malnutrition, Inflammatory response, Nephrotic syndrome, Marked liver disease
12
Q
Laboratory data
- Serum Albumin:
- Normal levels
- synthesized by
- Half-life
- Negative acute phase reactant
- Prealbumin (transthyretin):
- Normal levels
- Synthesized in
- Half-life
- Negative acute-phase reactant
- Useful in monitoring
- Other indirect measures of nutritional status:
- BUN
- Normal
- Reflects
- Can be elevated in
- Can be decreased in
- Creatinine
- Normal
- In a steady state (euvolemia) and with normal renal function
- Hemoglobin / Hematocrit:
- BUN
A
-
Serum Albumin:
- Normal levels 3.5 – 5.2 g/dl
- synthesized by the liver, and is the most abundant plasma protein, providing 80% of the oncotic pressure
- Half-life 21 days; therefore albumin is a lagging indicator of poor nutritional status
- Negative acute phase reactant (decreases rapidly with inflammation)
-
Prealbumin (transthyretin):
- Normal levels 19-43 mg/dl
- Synthesized in the liver
- Half-life: 2 days; therefore it is generally a good indicator of recent changes in nutritional status (typically measured weekly)
- Negative acute-phase reactant
- Useful in monitoring improvements in protein-energy status especially when a baseline value is obtained; increasing values correlate with improved nutritional status
-
Other indirect measures of nutritional status:
-
BUN:
- Normal 7 – 20 mg/dl
- Reflects protein breakdown
- Can be elevated in catabolic state or with high protein intake
- Can be decreased in low metabolic states or with very low protein intake
-
Creatinine:
- Normal 0.5 – 1.1 mg/dl
- In a steady state (euvolemia) and with normal renal function, creatinine levels reflect lean muscle mass (higher creatinine with greater lean body mass; creatinine can be nearly undetectable in those with severe cachexia).
-
Hemoglobin / Hematocrit:
- Anemia and mean corpuscular volume (MCV) can be indicative of iron (low MCV), or B12 / folate deficiencies (high MCV)
-
BUN:
13
Q
Pathophysiology of Malnutrition / Undernutrition (p.17)
- People lose weight when:
- Body Composition
- The human body stores
- The remaining fat-free mass (FFM)
- In addition to body fat, energy reserves are provided by
- The BCM
A
-
People lose weight when:
- the intake or gastrointestinal assimilation of dietary calories is insufficient to meet normal energy expenditure
- the expenditure of body energy stores is greater than the energy normally consumed or assimilated
- the metabolism of energy, protein, and other nutrients is impaired by a disease process
-
Body Composition
- The human body stores between 15 and 25% of its energy as fat (generally greater in women than men), which becomes available for metabolism of endogenous fatty acids (FAs) during starvation.
- The remaining fat-free mass (FFM) is composed of extracellular and intracellular water, the bony skeleton, glycogen and cellular visceral proteins.
- In addition to body fat, energy reserves are provided by intracellular glycogen and protein, which together with intracellular water constitute the body cell mass (BCM).
- The BCM, particularly from muscle stores, provides reserve protein for energy production via gluconeogenesis during metabolic stress.
14
Q
Metabolic Responses to Starvation and Stress
- The rate of changes in various fluid compartments and body stores of energy
- unstressed starvation
- stressed starvation
A
- The rate of changes in various fluid compartments and body stores of energy (fat, glycogen, protein) differs during unstressed starvation and stressed starvation.
- General unstressed starvation slowly decreases the size of all body compartments,
- stressed starvation more specifically reduces BCM (mostly via rapid muscle protein catabolism), increases extracellular water, and has variable effects on body fat.
15
Q
Unstressed Starvation:
Metabolic adaptations to unstressed starvation
- Early starvation (<24 hours):
- Medium-term starvation (days to less than 3 weeks):
- Late starvation (> 3 weeks):
A
-
Early starvation (<24 hours):
- Glycogen stores are used to provide circulating glucose;
- insulin concentrations decrease as glycogen is depleted;
- glucagon concentrations increase;
- amino acids (AAs) are released from muscle for gluconeogenesis;
- fatty acids (FAs) are released from adipose tissue for additional energy.
-
Medium-term starvation (days to less than 3 weeks):
- Glycogen is depleted,
- glucose is derived solely from gluconeogenesis.
- Protein breakdown occurs at a high rate to provide substrate for gluconeogenesis.
- Lipolysis provides the primary energy source (via ketone bodies from FA metabolism).
- After about one week, the brain can adapt to use both glucose and ketones for energy.
-
Late starvation (> 3 weeks):
- Ketone body production (from lipid metabolism) accelerates
- blood levels of ketone bodies rise, facilitating transfer into brain (which has adapted to use ketones for energy).
- less need for gluconeogenesis,
- reduction in the rate of protein breakdown.
- Hormonal adaptations include: increased levels of growth hormone, TSH, free cortisol, renin, aldosterone, and ADH; decreased levels of glucagon, insulin, LH, FSH, T4, T3, prolactin, IGF-1 (somatomedin C).
