Nutrition in dialysis patients

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Nutrition in dialysis patients

• Shiva Seyrafian
• Nephrologist

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Nutrition in dialysis patients
Causes of Malnutrition

• one third of hemodialysis peritoneal dialysis
  patients have malnutrition.
• There is decreased energy intake at GFRlt25-35
  ml/min.
• Malnutrition leads to increased mortality and
  hospitalization, impaired wound healing,
  increased susceptibility to infection, malaise,
  fatigue, and poor rehabilitation.

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Nutrition in dialysis patients
Causes of Malnutrition

• Decreased nutritional intake
• ?Overzealous dietary restrictions,? delayed
  gastric emptying and diarrhea, ? other medical
  comorbidities, ? intercurrent illnesses and
  hospitalizations, ? decreased in food intake on
  hemodialysis days, ? medication causes dyspepsia
• (phosphate binders, iron preparations), ?
  suppression of oral intake by peritoneal
  dialysate glucose load, ? inadequate dialysis, ?
  monetary restrictions, ? depression, ? altered
  sense of taste ?? serum leptin ? ? Interleukin
  1,6,TNF-? .

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Nutrition in dialysis patients
Causes of Malnutrition

• Increased losses
• ?gastrointestinal blood losses, ( 100 ml
  blood losses 14- 17 g protein) ? intradialytic
  nitrogen losses( HD 6-8 g amino acid/ procedure,
  PD 8-10 g /d)
• Increase in protein catabolism
• ? intercurrent illnesses and hospitalizations
  ?other medical comorbidities ?metabolic acidosis
  (promote protein catabolism) ? dysfunction of
  growth hormone / insulin growth factor endocrine
  axis ? catabolic effects of other hormones (PTH,
  cortisol, glucagon)

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Nutrition in dialysis patients
Nutritional Assessment

• ?Patient Interview
• Nausea, Vomiting, Anorexia, Severe
• congestive heart failure, Diabetes,
• Gastrointestinal diseases, and Depression.
• Assessment of food intake
• Food intake on dialysis days is 20 lower
• than nondialysis days ( interruption of
  
• patients routine and dialysis side effects ).

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Nutrition in dialysis patients Nutritional
Assessment

• ?Medication Intake
• ? Dyspepsia due to aluminum-containing
  antacids or oral iron supplements.
• ? Protein catabolism due to prednisolone and
  tetracyclines.
• ?Physical Examination
• ?Anthropometry ( assessment of body fat
  protein stores).
• ? Skin fold thickness (at the biceps and
  triceps), an estimate of body fat.
• ? Mid arm circumference (estimate of muscle
  mass). values below the 25 th for skin mid arm
  are at risk for malnutrition.

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Nutrition in dialysis patients
Nutritional Assessment

• ?Laboratory Tests
• Serum albumin
• Predialysis serum urea nitrogen (SUN)
• Urea nitrogen appearance (UNA)
• Protein equivalent of total nitrogen appearance
  (PNA)
• Serum prealbumin (transthyretin)
• Serum creatinine
• Serum cholesterol
• Serum transferrin

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Nutrition in dialysis patients
Nutritional Assessment

• ?Laboratory Tests
• ? Serum Albumin low SA is a strong predictor of
  mortality and hospitalization in chronic HD and
  PD patients. The risk of mortality rises
  dramatically as serum Albumin decline to less
  than 4 g/dl (bromocresol greenBCG method).
• Serum albumin is a valid and clinically
  useful measure of protein-energy nutritional
  status. SA may fall with ? in dietary protein and
  energy intake and may rise with? in dietary
  protein and energy intake.

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Nutrition in dialysis patients
Nutritional Assessment

• ?Laboratory Tests
• SA influenced by hepatic synthesis, peritoneal
  or urinary excretion, change in plasma volume,
  infection, inflammation, or acute or chronic
  stress, and acidemia.
• S Albumin is a negative acute-phase protein,
  whereas C-reactive protein, alpha 1-acid
  glycoprotein, ferritin, and ceruloplasmin are not
  nutritional factors but are positive acute-phase
  proteins.
• Measurement of S Al is inexpensive, easy to
  perform, and widely available.

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Nutrition in dialysis patients
Nutritional Assessment

• Serum urea nitrogen (SUN)
• ? A predialysis low SUN level is an important
  clue to inadequate protein intake.
• ? Unless patient has a substantial renal
  function (gt2-3 ml/min) or receiving an unusual
  amount of dialysis, a predialysis SUN level less
  than 50 mg/dl is often due to inadequate protein
  intake.
• ?However SUN can rise to 50-80 mg/dl in a poor
  protein intake due to inadequate dialysis.

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Nutrition in dialysis patients
Nutritional Assessment

• Urea nitrogen appearance (UNA)
• UNA should be equal to urea nitrogen intake,
  if the patient is in nitrogen balance.
• Nitrogen imbalance caused by either by
  catabolism or anabolism, then the relationship is
  not valid. UNA is a synonymous of protein
  catabolic rate.
• UNAurinary UN dailysate UN (g/d)

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Nutrition in dialysis patients
Nutritional Assessment

• Protein equivalent of total nitrogen appearance
  (PNA)
• When nitrogen balance is zero in the steady
  state, the difference between nitrogen intake and
  total nitrogen losses is zero or only slightly
  positive (ie, up to about 0.5 g nitrogen/d
  because of unmeasured nitrogen losses). Hence in
  the clinically stable patient, PNA provides a
  valid estimate of protein intake.
• The protein equivalent of total nitrogen
  appearance (PNA) can be estimated from
  interdialytic changes in urea nitrogen
  concentration in serum and the urea nitrogen
  content of urine and dialysate.
• PNA20.17.5 UNA (g/d)

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Nutrition in dialysis patients
Nutritional Assessment

• Serum prealbumin
• is a valid and clinically useful measure of
  protein-energy nutritional status in maintenance
  dialysis (MD) patients.
• serum prealbumin less than 30 mg/dL should be
  evaluated for protein-energy malnutrition.
• The presence of acute or chronic inflammation
  limits the specificity of serum prealbumin as a
  nutritional marker.

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Nutrition in dialysis patients
Nutritional Assessment

• Serum Creatinine
• The predialysis or stabilized serum creatinine
  reflect the sum of dietary intake of foods rich
  in creatine and creatinine (eg, skeletal muscle)
  and endogenous (skeletal muscle) creatinine
  production minus the urinary excretion, dialytic
  removal, and the endogenous degradation of
  creatinine.
• Individuals with low predialysis or stabilized
  serum creatinine (less than approximately 10
  mg/dL) should be evaluated for protein-energy
  malnutrition and wasting of skeletal muscle.

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Nutrition in dialysis patients
Nutritional Assessment

• Serum Cholesterol
• ? Low or declining serum cholesterol
  concentrations are predictive of increased
  mortality risk.
•   ?  Hypocholesterolemia is associated with
  chronic protein-energy deficits and/or the
  presence of comorbid conditions, including
  inflammation.
• ? Serum cholesterol gt200-300mg/dl also
  increases the risk of mortality.
• ?  Individuals with low, low-normal (less than
  approximately 150 to 180 mg/dL), or declining
  serum cholesterol levels should be investigated
  for possible nutritional deficits.

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Nutrition in dialysis patients
Nutritional Assessment

• SerumTransferrin and prealbumin influenced by
  non-nutritional factors such as infection,
  inflammation, changes in volume status, .
• Transferrin influenced by iron stores.
• Transferrin is ngative acute-phase protein.

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Nutrition in dialysis patients
Nutritional Assessment

• Dual energy x-ray absorptiometry (DXA)
• Whole body dual energy x-ray absorptiometry (DXA)
  is a reliable, noninvasive method to assess the
  three main components of body composition (fat
  mass, fat-free mass, and bone mineral density).
  The accuracy of DXA is less influenced by the
  variations in hydration that commonly occur in
  ESRD patients.
• DXA is a valid and clinically useful technique
  for assessing protein-energy nutritional status.
• The main limitations to DXA are the substantial
  cost of acquiring the instrument, the requirement
  for dedicated space to house it, the costs for
  the DXA measurement, and the fact that
  individuals may need to travel to the DXA
  facility for the measurements.

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Nutrition in dialysis patients Nutritional
Assessment

• ? Bioimpedance
• used to predict total body free water from
  resistance and, total body mass from the ratio
  resistance/ rectance, phase angle.

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Daily dietary recommendations in dialysis patients
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Daily dietary recommendations in dialysis patients
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Daily dietary recommendations in dialysis patients
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Nutrition in dialysis patients Nutritional
Assessment

• Average rather than actual body weight
• protein and caloric recommendations should be
  based on the average body weight for healthy
  subjects of the same sex, height, age, and body
  size. For ex. If a patient whose BW is now 50 kg
  instead of the usual 90 kg,with 180 cm tall,
  average BW80kg, 1.2 g/kg protein ? 50/800.75
  g/kg!

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Classification of selected foods by potassium
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