MNT Renal disorders

Question 1

Renal Disorders

Answer 1

1. Kidney Stones (nephrolithiasis)
2. Chronic kidney disease
3. ESRD
4. Nephrotic syndrome
5. Comorbid conditions and complications
   -secondary hyperparathyroisism
   -Anemia
   -CVD

Question 2

Nephrolithiasis (kidney stones)

Answer 2

Formation of kidney stones- due to abnormal crystaliization of calcium, oxalate, struvite, cysteine, hydroxyapatite or uric acid in the urine.
-Risk factors: gout, excess intake of vitamin D, urinary tract infection, urinary tract blockage, low urine volume and medical conditions (obesity, diabetes, and metabolic syndrome) associated with increased CA, oxalate and uric acid in circulation.

MNT:
-increase fluid intake by 3 L/day in divided doses- 12 cups to 16 cups to produce urine volume >2.5 L
-Limit oxalate intake to 50-60 mg/d (foods high in oxalate may prevent the formation of oxalate stones due to decreased absorption of oxalates in the gut). (less than 40 to 50 mg/day).
-Avoid foods that increase urinary oxalate (beets, chocolate, cola, coffee/tea, nuts, nut butters, berries, wheat bran, spinach, rhubarb)
-Limit Vitamin C intake to less than 2 grams if prone to oxalate stones (<100 mg/day)
-Avoid foods high in purine (animal protein, seafood, meat extract, consomme, gravies and organ meats) if the patient/client suffers from uric acid stones.
-protein- normalize intake .8 to 1 g/kg body weight. Not to exceed DRI
-calcium- 800 mg/day for men and 1200 mg/day for women, do not restrict and balance intake of calcium through out the day.
-sodium- lower intake to 2300 mg/day to 3450 mg/day.
-Wt control, normalize insulin response
- reduce fructose consumption

Question 3

Chronic Kidney disease

Answer 3

CKD is progressive loss of kidney function (slowly decreasing GFR) Glomerular Filtration rate:
-Is not reversible
-Progression to CKD stage 5
-Renal therapy of transplant
-Requires medication and specialized diet
-Diabetes, hypertension are leading risk factors.

Goal of MNT:
-Manage symptoms associated with syndrome (edema, hypoalbuminuria (low albumin protein), hyperlipidemia)
-decrease risk of progression to renal failure
-Maintain nutrition stores
-Maintain positive nitrogen balance

MNT:
-As the disease involves stages of progression, nutrition intervention need to be individualized according to stage and any comorbities.
-Protein -.8g/kg/day with 60 % HBV (high biological value)
-Look for drug and nutrient interaction and depletion
-Watch for hypocalcemia, hypermagnesemia
-potassium consumption should not exceed 60-70 mEq per day.

CKD-MNT:
stage 1 and 2
-Focus on comorbid consitions, diabetes, hypertension, hyperlipidemia, progression of CVD.
-No specific nutrition goals for this stage, but need to address nutritional needs of comorbid conditions.
-phosphorus restriction and oral phosphate binders
Stage 3 and 4
-Adequate kcal to prevent mal nutrition, adequate protein to maintain muscle mass and serum protein
-treat abnormal vitamin/mineral status (D, Ca+, P-, K+, Na+)
-address fluid imbalances
-Normalize blood lipids
Stage 5
-Meet nutritional requirement
-Minimize uremia and CKD
-Maintain blood pressure and fluid status
-Nutritents to monitor: protein, Kcal, fiber, Fluid, vitamins/minerals: D, Ca, P, K, Na

NFPE: Half and half nails (lindsey’s nails) -part of the nail closest to hand is white and the half closest to the finger tip is pink or brown.

Muehrcke’s lines (with hypoalbuminemia)- White arcuate lines (across the nail horizontally)

Mee’s lines(longitudinal white streaks from the cuticle to the nail edge)

Protein deficiency is common
Edema
Hypoalbuminemia
Hyperlipidemia
CKD increases the risk category for CVD and exacerbates any existing CVD
Growth in children with CKD is usually delayed

MNT FOR CHORNIC KIDNEY DISEASE

Protein 0.6 g/kg/day (50% high BV) and 35 kcal/kg/day for GFR <25 ml/min without dialysis
If unable to maintain adequate kcal intake, increase protein to 0.75 g/kg/day.
Control hypertension and blood pressure
Dash diet

Sodium—1500 mg to control edema
Potassium—Varies greatly, may need to be supplemented or may need to be restricted
Phosphorus—Early restriction (1000 mg/day) helpful in delaying hyperparathyroidism and preventing bone disease; phosphate binders
Lipids—Decrease saturated fat intake
Vitamins customized for renal disease

Question 4

End stage renal failure disease

Answer 4

ESRD is kidneys inability to excrete waste products, maintain fluid and electrolyte balance and produce hormones.

-Uremia- malaise, wekness, N/V, muscle cramps, itching, metallic taste in mouth, nephrologic impairment

-unacceptable levels of nitrogenous wastes

MNT:
-sodium restriction
-possible protein restriction
-monitor electrolyte
-phosphate biners
-decrease cardiac risk factors
-prevent nutrient deficiencies, control edema and serum electrolytes (sodium and potassium)
-prevent renal osteodystrophy (use of phosphate binders, low phosphorus diet and calcium supplementation.
-Provide a palatable and attractive diet
-Active Vitamin D
-Erythropoietin

Energy: 25 to 40 kcal/kg
HD: 1.2 g/kg (lose 15 g/dialysis treatment)
PD: 1.2 to 1.5 g/kg (lose 20 to 30 g over 24 hours)
50% high biological value protein
Uremia impact aversion to meats
Albumin indicator of inflammation not nutrition
Hypoalbuminemia associated with poor survival

Question 5

Nephrotic Syndrome

Answer 5

-condition marked by a deficiency of albumin in blood and its excretion in the urine due to altered glomerular function.
-Causes: infection, toxin exposure and another disease that leads to glomerular dysfunction (diabetic nephropathy)
-Aims of MNT:
-minimize the effects of edema, proteinuria, and hyperlipidemia
-replace nutrients lose in the urine
-reduce the risk of disease progression and atherosclerosis.

-Sodium restriction
-Protein recommendations-.8-1g/kg/day-soy or flaxseed based protein, avoid animal protein.
-manage comorbid conditions such as diabetes, hyperlipidemia
-Remove source of toxin exposure

Question 6

Hemodialysis

Answer 6

Prior to, restrict protein intake to .6 g/kg/day. May delay the need for dialysis. Replacement of some protein with alphaketo- analogues of essential amino acids may aid the preservation of body nitrogen stores when low total protein intakes are necessary.
-Individual receiving hemodialysis should receive 1.1 to 1.3 g protein/kg/daily, At least 50% should be High biological value.
-tends to remove trace elements, supplementation may be necessary to prevent symptoms of acute deficiencies.
-Loss of blood and dialysis membrane binding of iron during hemodialysis- supplement iron
-water soluble vitamin supplementation

Question 7

CVD in relation to CKD

Answer 7

CVD is associated with CKD. People with CKD more likely to die from CVD.
-Address lipoprotein metabolism, hyperparathyroidism, calciium and phosphate imbalance, elevate homocystein, vascular calcification, oxidative stress, inflammation and malnutrition
-Diet: <30% of total calories from fat
-<20% from saturated fat
<300 mg/day of cholesterol
-high proportion of complex carbs should replace dietary fat.
-Omega 3 fatty acids and L-carnitine may be used to reduce circulating triglyceride concentrations.

Question 8

MNT for secondary Hyperparathyroidisim

Answer 8

• Can progress to severe, intractable forms of bone disease
  -prolonged PTH exposure causes- osteitis fibrosa cystica- characterized by poor quality bone structure with increased likelihood of fractures
  -vascular soft tissue calcification
  -MNT
  -restrict dietary phosphorus
  -supplement with vitamin D
  -Monitor serum PTH, calcium and phosphorus levels closely.

Treatment:
Calcium supplements
Active vitamin D (calcitriol)
Oral or IV drugs that bind to sites on parathyroid gland
Restrict dietary phosphate: <1200 mg
Phosphate binders
Surgery

Question 9

Anemia (related to kidney disease)

Answer 9

Due to low Hb from inadequate enogenous erythropoietin
-Treatment with rHuEPO and iron
-Complication of untreated:
malnutrition, impaired immunological response, cardiac and ventricular hypertrophy, congestive cardiac failure.

Question 10

Kidney function

Answer 10

Regulates water homeostasis: Vasopressin
Nitrogenous waste excretion: Uric acid, creatinine, ammonia, azotemia, renal failure-unable to excrete waste

Renin-angiotensin: Blood pressure control and Aldosterone
Erythropoietin (EPO)
Calcium-Phosphorus homeostasis (interactions of PTH, Calcitonin, active vitamin D) (Gut, Kidney, and bone)

Question 12

Kidney disease

Answer 12

Nephrolithiasis (kidney stones)
Acute Kidney injury (AKI)
Chronic Kidney disease (CKD)
End stage renal disease (ESRD)

Question 13

Kidney stone prevention

Answer 13

High prevalence and high health care costs
1. Risk assocaited with obesity, diabetes, HTN, metabolic syndrome,
2. Risk factor: low urine volume

Modifiable risk factors: BMI, fluid intake, DASH diet, dietary calcium intake, sugar sweetened beverage intake

Question 14

Kidney stones (Nephrolithiasis)

Answer 14

Calcium stones
1. calcium oxalate is most common.
2. calcium oxalate and calcium phosphate
3. Calcium phosphate

Uric acid
Struvite
Cystine
Melamine and indinavir

Question 15

Acute kidney injury

Answer 15

Sudden reduction in glomerular filtration rate (GFR) and altered ability to excrete metabolic waste

Associated with either oliguria or normal urine flow

Lasts for a few days to several weeks
causes prerenal, intrinsic and postrenal

RIFLE classification-severity and progression of kidney injury

-combination of uremia, acidosis, fluid and electrolyte imbalances, physiological stress\

Medical management: hemodialysis, peritoneal dialysis, CRRT (CVVH and CVVHD), prolonged intrinsic damage can cause acute tubular necrosis.

Question 16

MNT for AKI

Answer 16

Early dialysis and nutrition improve survival

-protein: .5 to .8 g/kg without dialysis; 1 to 2 g/kg with dialysis; 1.2 to 2.5 g/kg with CRRT.
-Energy: Indirect calorimetry or estimate at 25 to 40 kcal/kg
-Balance fluid and electrolytes with output: restrict in oliguria;
replace in diuresis.

Question 17

GFR FOR CHRONIC KIDNEY DISEASE

Answer 17

STAGE1
Kidney damage with normal kidney function
eGFR of 90 or higher
STAGE2
Mild loss of kidney function
eGFR of 60–89
STAGE3A
Mild to moderate loss of kidney function
eGFR of 45–59
STAGE3B
Moderate to severe loss of kidney function
eGFR of 30–44
STAGE4
Severe loss of kidney function
eGFR of 15–29
STAGE5- END
STAGE RENAL
DISEASE (ESRD)
Kidney failure or close to kidney failure
eGFR of less than 15

Question 18

Uremia

Answer 18

BUN >100 mg/dl and creatinine 10 to 12 mg/dl
Malaise
Weakness
Nausea and vomiting
Muscle cramps
Itching
Metallic taste (mouth)
Neurologic impairment

MNT:Nutrient
Recommendation
Goal
Protein
- ~0.6-0.8g/kg/IBW*
(*some variability depending on type of dialysis)
Uremia causes taste aberrations so patients often dislike the smell of meat. Eggs, tofu and white meat may be better tolerated and the use of spices and serving the animal meat cold can help.

Limit drain of protein from dialysis
-maintain plasma albumin to 4g/dL
-monitor for protein sufficiency with anthropometrics, good blood pressure control and blood glucose control
Energy
35kcal/kg body weight
To spare protein for tissue repair and maintenance
-Use SGA (Subjective Global Assessment) to monitor nutritional status
Fluid and Sodium
To level that allows weight gain of 4-5 lb between dialyses
Fluid restriction to ~750mL/d(fluids liquid at room temperature included – not liquids in solid foods)
Suck on ice chips, cold sliced fruit or sour lozenges
Sodium 1500 mg/day
No salt in cooking or at the table, no salted snacks, canned soup or convenience foods with salt and no salted, smoked or cured meat or fish

To maintain oncotic pressure and prevent hypertension
-monitor bp
-monitor edema
Potassium
Restriction to 2.3-3.1g per day (levels depend on type of dialysis and stage of kidney disease)
-Note that many low-sodium foods use potassium chloride instead
-evaluate medications that may ¯potassium (diuretics)
-monitor serum potassium
Phosphorus
Difficult to achieve because of the need for high protein
<1200mg of phosphates per day
Phosphate binder with meals/snacks (can lead to severe constipation)

-Delay hyperparathyroidism & bone disease
-Monitor phosphorus levels
Calcium and PTH
Keep the calcium X phosphorus product <55
(via controlling phosphate levels)
-Supplement, as needed, with calcitriol to raise ­calcium and ¯PTH
Monitor with labs
Lipids
Cholesterol-lowering diet
Lipid-lowering medications
Prevent atherosclerosis
Iron and Erythropoeitin
Recombinant EPO
Intravenous or intramuscular iron supplementation
Prevent/correct anemia
Monitor serum ferritin (<100 ng/mL, IV iron is needed)
Monitor % transferrin saturation (aim for 25-30%)
Vitamins
Supplement to counterbalance losses in dialysis (B vitamins and vitamin C) and as a result of potassium and phosphorus-restricted diet
-Folate 1 mg/d
-Uremic toxins may interfere with activity of some vitamins (inhibit phosphorylation, etc.) give activated forms of vitamins
-Niacin to help in lowering phosphate levels – once per day dosing

Maintain adequate nutrient status
-OTC (over-the-counter) supplements may be appropriate, but additional folate and pyridoxine may be needed

Question 19

Fluid and sodium balance in ESRD

Answer 19

Modify
Modify sodium and fluid intake according to blood pressure, edema, fluid weight gain, serum sodium, and dietary intake.
Restrict
Most dialysis patients need to restrict sodium; a small number may require sodium supplementation.
Allow
Allow weight gain of 4 to 5 lb between dialyses.
Limit
Limit fluid to 750 ml + urine output.

Question 20

Calcium, vitamin D, PTSH in ESRD

Answer 20

Decreased ability of kidney to activate vitamin D decreases calcium absorption
Increased phosphorus increases need for calcium.
Increased PTH to increase resorption of bone
Metabolic bone disease or renal osteodystrophy
Osteomalacia (bone demineralization)
Osteitis fibrosa cystica (hyperparathyroidism)
Metastatic calcification of joints and soft tissues
Adynamic bone disease

Limit potassium

Atherosclerosis CVD associated with diabetes, HTN, and nephrotic syndrome

Replace unhealthy (saturated) fats with healthy (MUFA) fats
Dash diet

Monitor iron using serum ferritin

Water soluble vitamins lost during dialysis.

Question 21

MNT for kidney transplant

Answer 21

Metabolic effects of immunosuppressive therapy
Increase protein first 6 weeks.
Limit sodium to 2 to 3 g/day.
Adequate calcium, phosphorus, and vitamin D
Encourage fluid.
Treat dyslipidemia.
Monitor for weight gain.
Food safety

Question 22

Enteral nutrition vs. parental

Answer 22

Enteral nutrition: Provision of nutrients into the GIT through a tube or catheter when oral intake is inadequate. (may include formulas as oral supplements or meal replacements)

Parental nutrition:Parenteral nutrition: Provision of nutrients intravenously

benefits of enteral vs. parental :Better GI barrier function
Preserved GI immunity
Attenuate catabolic response
Better blood glucose control
Decreased rates of infection