Laboratory Assessment of Protein and Hydration Status

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Laboratory Assessment of Protein and Hydration
Status

• Susan Tassinari, MS, RD, LD/N

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Assessment of Hydration Status
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Definition of Dehydration

• Excessive loss of water from the body tissues
• Accompanied by disturbance of essential
  electrolytes sodium, potassium and chloride

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Water in the Body

• Inside the cells (intracellular)
• 2/3 of body water
• Outside the cells (extracellular)
• Remaining 1/3 of body water
• Plasma
• Interstitial fluid
• Water moves between based on gradient created by
  solutes (mainly electrolytes)

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Effects of Dehydration

• Decreased blood volume leads to impaired physical
  functioning
• Inability to regulate body temperature
• Labored breathing and weakness
• Muscle spasms and delirium
• Renal failure
• Decreased circulation
• Loss of 20 of body water is fatal

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Dehydration in the Elderly

• Of special concern in long-term care
• Water content in elderly decreases from around
  60 of body weight to 45
• One of top ten most frequent diagnoses for
  hospital admission in patients 65 or over
• Approximately 50 of elderly diagnosed with
  dehydration die within one year

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Types of Dehydration

• Three types
• Hypertonic
• Isotonic
• Hypotonic
• All involve loss of fluid
• Defined by sodium losses

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Hypertonic Dehydration

• Body water loss gt sodium loss

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Hypertonic Dehydration

• Causes
• Reduced oral intake
• Excessive losses from fever or sweating
• Shifts in sodium concentrations at cellular level
• Common in elderly because of decreased appetite
  and decreased thirst mechanism
• ? Thirsty ?

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Hypertonic Dehydration
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Isotonic Dehydration

• Body water losses sodium losses

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Isotonic Dehydration

• Causes
• Extreme diarrhea
• Frequent vomiting
• Severe bleeding
• Must rehydrate with fluid and sodium
• 80 of cases usually missed
• ? Not Thirsty ?

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Isotonic Dehydration
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Hypotonic Dehydration

• Sodium losses gt body water losses

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Hypotonic Dehydration

• Hyponatremia
• Causes
• Diuretics
• Sodium-restricted diets
• Diarrhea, vomiting or excessive sweating
• Renal sodium-wasting syndrome
• Seen in severe CHF
• Requires water-electrolyte solution for
  rehydration

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Hypotonic Dehydration
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Recap Dehydration Labs
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Calculated Osmolality

• (2 X Na) (BUN/2.8) (Blood Glucose/18)

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Lab Values

• Need to compare to residents normal values
• BUN/Creatinine ratio may not be valid
• Decreased muscle mass or renal failure affects
  creatinine
• Lower sodium levels are normal in the elderly
• Body loses the ability to absorb sodium
• Elevated blood glucose levels give falsely low
  serum sodium values

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Diagnosis Dehydration

• Labs alone dont tell the story
• Must look at physical and clinical signs

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Weight Loss

• Acute weight loss over one week or less
• lt 5 of body weight mild dehydration
• 5-10 of body weight moderate dehydration
• gt 10 of body weight - severe dehydration

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Signs and Symptoms

• Poor skin turgor
• Fatigue
• Loss of appetite
• Confusion and irritability
• Common in Elderly - Must assess for changes

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Signs and Symptoms

• More useful measures
• Dry mucous membranes
• Rapid pulse and respirations
• Lowered blood pressure
• Decreased urine output
• Constipation/impaction
• No tearing or salivation
• Sunken eyeballs

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Identifying Dehydration Risks

• Conditions and Diseases
• COPD
• Fever/Infection
• Hyperglycemia
• Low urine output
• Vomiting/diarrhea/constipation
• GI bleed
• Cardiac disorders
• Reduced kidney function

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Identifying Dehydration Risks

• Nutrition and Medications
• Poor food and fluid intake
• Fluid restrictions
• Excessive protein intake
• Inability to access fluids
• Dysphagia
• Diuretics
• Laxatives

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Identifying Dehydration Risks

• Other
• Warm Environments
• Early bed times
• Bed rest
• Urinary incontinence/Fear of incontinence
• Dementia

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Identifying Dehydration Risks

• Consider all other areas that affect ability to
  consume fluids
• Cognition
• Daily decision making skills
• Confusion
• May need assistance with obtaining and consuming
  fluids

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Identifying Dehydration Risks

• Communication/Hearing
• Unable to express needs
• Unable to understand
• Vision
• Unable to locate fluids
• Balance while sitting or standing
• Can have negative impact on ability to obtain and
  drink fluids
• Use of hands, arm, neck
• Mobility and ability to transfer

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Identifying Dehydration Risks

• Feeding tube
• Parenteral/IVF

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Fluid Needs

• Identify fluid needs
• 30 cc/kg for normal fluid needs
• 25 cc/kg with CHF
• 35 cc/kg with infections and Stage IV or draining
  wound
• 1500 cc minimum for all residents unless
  contraindicated

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Assessment of Protein Status
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Malnutrition

• State induced by nutrient deficiency that may be
  improved solely by administration of nutrients
• Kwashiorkor protein deficiency
• Hypoalbuminemia
• Muscle wasting
• Marasmus calorie deficiency
• Extreme weight loss
• Cachexia

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Malnutrition

• Stress-induced malnutrition
• Doesnt fit usual definition
• Occurs following traumatic event or acute illness
• Reflects bodys physiologic response to injury
  and infection
• Response to illness and injury is endogenous, not
  exogenous
• Does not respond to provision of protein and
  calories
• May affect appetite and GI motility, which can
  negatively impact nutritional status

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Malnutrition

• Two major paradigms
• Starvation pure caloric deficiency
• Organism adapts metabolically to conserve lean
  mass and increase fat metabolism
• Changes can be reversed by appropriate feeding
• Cachexia associated with neoplastic and
  inflammatory conditions
• Feeding does not reverse macronutrient changes
• May develop in elderly persons without obvious
  disease
• Hypermetabolism is cardinal feature

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Stress and the Long-term Care Resident

• Long-term care residents suffer from various
  forms of stress
• Physical
• Psychological
• Environmental
• Physiological response is the same for all forms
  of stress
• Response is regulated by degree and duration of
  stress

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Acute Phase Response

• Response to stress creates cascade of effects
• Increased WBC production
• Increased metabolic rate
• Decreased plasma iron levels with anemia
• Catabolism of skeletal muscle
• Negative nitrogen balance
• Anorexia
• Organisms way of surviving event that alters
  homeostasis
• Triggered by cytokines

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Acute Phase Response

• Loss of skeletal muscle
• Energy-intensive with high rates of hepatic
  protein synthesis requires large quantities of
  amino acids
• Survival mode
• Changes in fat metabolism
• Hypertriglyceridemia
• Increased hepatic secretion of VLDL
• Alterations in carbohydrate metabolism
• Peripheral insulin resistance
• Redirects glucose to the liver and other organs,
  away from skeletal muscle

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Acute Phase Response

• Chronic diseases (COPD, Diabetes, CHF)
• Inflammatory component triggered by cytokines
• Simmer
• Protein used for injury repair, not anabolism
• Over time, reduces lean body mass and prevents
  restoration
• New disease process or acute episode results in
  further erosion of nutritional status and lean
  body mass

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Cytokines Messengers of the Immune System

• Group of proteins and polypeptide molecules
• Signals with multiple cellular targets
• Can bring about widespread metabolic changes
• Mediators of the immune system
• Essential to healing process
• Excessive or prolonged production can lead to
  morbidity and mortality
• Process has been identified in development of
  many chronic diseases, including Alzheimers

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Nutritional Cytokines

• Pro-inflammatory cytokines that influence
  appetite and acute phase response

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Nutritional Cytokines

• Tumor-Necrosis Factor-alpha (TNF-a)
• Interleukin-1 (IL-1) and Interleukin-6 (IL-6)
• Interferons
• Initiate hypermetabolic response
• Breakdown of skeletal muscle, lipolysis and
  production of acute phase proteins
• Induces fever, anorexia, weight loss, cachexia
• Significantly increase REE
• Increases hepatic glucose output and
  gluconeogenesis
• Increases synthesis of acute phase reactants
• Primarily responsible for most catabolic states
• Interact together to depress appetite

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Hypoalbuminemia

• Hepatic Proteins Albumin, Prealbumin,
  Transferrin
• Historically linked in clinical practice to
  nutritional status
• Published evidence suggests serum levels of
  hepatic proteins are impacted more significantly
  by factors other than nutrition
• However, serum levels continue to be used to
  evaluate nutritional status

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Hypoalbuminemia

• Stress-induced hypoalbuminemia
• Reflects bodys physiologic response to injury or
  illness
• Decreases in response to infection, injury,
  trauma
• Increases with recovery from same conditions
• Does not increase in response to provision of
  protein and energy

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Hypoalbuminemia

• Mediators of inflammation exert most significant
  effects on hepatic proteins
• IL-6
• Most potent stimulator of positive acute-phase
  protein synthesis in the liver
• Alters normal hepatic protein metabolism
• TNF
• Causes capillary membrane leak
• Serum hepatic proteins move into extravascular
  compartment

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Hypoalbuminemia

• Net effect of reduced synthesis and dilution is
  lower serum levels independent of nutritional
  status
• Resolution of inflammation, not exogenous
  substrate from nutrition support, restores normal
  hepatic protein metabolism, and eventually, serum
  levels

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Hypoalbuminemia

• Indirect relationship with nutritional status
• Hepatic protein levels can be indicators of
  inflammatory processes that will accelerate
  nutritional depletion.

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Implications for Nutritional Assessment

• Can help identify individuals likely to become
  malnourished
• Hypoalbuminemia should alert clinician to search
  for underlying cachexia syndromes
• Less likely to meet nutritional requirements
  volitionally will probably require aggressive
  medical nutrition therapies.
• More likely to be clinically unstable and require
  more frequent monitoring and adjustment of
  nutritional interventions.

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Implications for Nutritional Assessment

• Document possible causes for abnormal protein
  values
• Survey guidelines note that some abnormal lab
  values can be expected in some disease processes
• Make sure nutritional interventions are in place
  to meet normal needs
• Nutrition needs are the same for all individuals
  in catabolic state

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Other Laboratory Values

• Changes occur with metabolic response to stress
• Lab values during stress are point in time
  measurements
• Valid during period of stress but not after
  resolution of stress
• Recommendations should not be made based on labs
  drawn during period of stress

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Other Laboratory Values

• Glucose
• Elevated due to increased insulin resistance
• Protects brain function
• Zinc
• Decreased due to use in immune function
• Iron
• Decreased due to sequestration acts as oxidant
• Copper
• Increased due to use as antioxidant

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Other Laboratory Values

• BUN
• Increased due to breakdown of protein
• Sodium
• Increased
• Antidiuretic hormone effect
• May disguise actual tissue loss

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Implications for Nutrition Assessment

• Lab values can be used for decision making
  purposes as stress moderates
• Clue to moderation of stress is return of blood
  glucose toward normal levels.
• If disease is chronic, lab values remain altered
• Anemia of chronic disease
• Document possible reasons for abnormal labs
• Use to support low albumin, weight loss
• Many of the altered labs are used by surveyors to
  assess nutritional status

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Summary

• Identifying dehydration and malnutrition is a
  more complex process than just looking at labs.
• Careful analysis of labs in relation to the
  clients environment and disease state is
  necessary to correctly assess hydration and
  protein status.
• Documentation must be based on the current
  knowledge and medical diagnoses cannot be made by
  dietitians.