MNT in Renal Disorders

.

Medical Nutrition Therapy for Renal Disorders

.

Functions of the Kidney

Excretory Acid-base balance Endocrine Fluid and electrolyte balance

.

Excretory Functions

Removal of excess fluid and waste products 180 L of filtrate pass through the kidneys

each day producing 1-2 L of urine Wastes excreted from the body in urine

include urea (byproduct of protein metabolism); excess vitamins and minerals; metabolites of some drugs and poisons

.

Acid-Base Functions

Acid-base balance is maintained through a buffer system, which maintains blood at pH of 7.4

Bicarbonate carries hydrogen ions to the kidneys where they are removed from extracellular fluid in the tubules, returned to the bloodstream as needed

Phosphate buffers intracellular fluid

Source: Byham-Gray, Wiesen, eds. A Clinical Guide to Nutrition Care in Kidney Disease. ADA, 2004

.

Acid-Base Balance Functions

When fluid volume is low, anti-diuretic hormone (ADH) or vasopressin is released from the anterior pituitary; increases absorption of water in the collecting duct

When extracellular volume (ECV) decreases, the renin-angiotensin-aldosterone system is activated excretes less sodium chloride


.

Endocrine Functions

1,25-dihydroxy-vitamin D3 or calcitriol is produced in the kidney; enhances calcium absorption

Activation of Vitamin D and excretion of excess phosphate maintain healthy bones

Erythropoietin: acts on the bone marrow to increase production of red blood cells

Source: Byham-Gray, Wiesen, eds. A Clinical Guide to Nutrition Care in Kidney Disease. ADA, 2004Source: Byham-Gray, Wiesen, eds. A Clinical Guide to Nutrition Care in Kidney Disease. ADA, 2004

The NephronThe Nephron

.

The Most Common Kidney Diseases Diabetic Nephropathy damage to the nephrons in

the kidneys from unused sugar in the blood, usually due to Diabetes.

High Blood Pressure can damage the small blood vessels in the kidneys. The damaged vessels cannot filter poison from the blood as they are supposed to.

Polycystic Kidney Disease (PKD) is a hereditary kidney disease in which many cysts grow in the kidneys. These cysts may lead to kidney failure.

.

The Most Common Kidney Diseases

Acute Renal Failure - Sudden kidney failure caused by blood loss, drugs or poisons. If the kidneys are not seriously damaged, acute renal failure may be reversed.

Chronic Renal Failure - Gradual loss of kidney function is called Chronic Renal Failure or Chronic Renal Disease.

End-Stage Renal Disease - The condition of total or nearly total and permanent kidney failure.

.

Kidney DiseasesKidney Diseases Glomerular diseases

– Nephrotic syndrome– Nephritic syndrome—tubular or

interstitial Tubular defects

– Acute renal failure (ARF) Other

– End-stage renal disease (ESRD)– Kidney stones

Glomerular diseases– Nephrotic syndrome– Nephritic syndrome—tubular or

interstitial Tubular defects

– Acute renal failure (ARF) Other

– End-stage renal disease (ESRD)– Kidney stones

.

Nephrotic Syndrome Alterations of the glomerular basement

membrane allows persistent loss of large amounts of protein in the urine

Associated with diabetes, glomerulonephritis, amyloidosis, lupus

High risk for cardiovascular disease Hypercoagulability Abnormal bone metabolism

.

Nephrotic Syndrome

Albuminuria: more than 3 g/day urinary albumin losses, with proportionally lesser amounts for children

Hypoalbuminemia Hypertension Hyperlipidemia Edema

.

Medical Mgt of Nephrotic Syndrome

Corticosteroids Immunosuppressants ACE inhibitors/angiotensin receptor blockers

to reduce protein losses, control blood pressure and fluid balance

Coenzyme A reductase inhibitors to control hyperlipidemia

.

MNT in Nephrotic SyndromeMNT in Nephrotic Syndrome Protein 0.8 to 1 g/kg IBW 80% HBV Sodium based on fluid status Potassium and other minerals (calcium,

phosphorus) monitored and individualized

Fluid unrestricted Diet therapy probably not effective for

hyperlipidemia; may require medication

Protein 0.8 to 1 g/kg IBW 80% HBV Sodium based on fluid status Potassium and other minerals (calcium,

phosphorus) monitored and individualized

Fluid unrestricted Diet therapy probably not effective for

hyperlipidemia; may require medication

Byham-Gray L, Wiesen K. A clinical guide to nutrition care in kidney disease.ADA, 2004

.

Nephritic syndromeNephritic syndrome Acute glomerulonephritis (inflammation of

the glomerulus Sudden onset, often after streptococcus

infections Symptoms include hematuria, hypertension Usually resolve on their own or advance to

nephrotic syndrome or ESRD

Acute glomerulonephritis (inflammation of the glomerulus

Sudden onset, often after streptococcus infections

Symptoms include hematuria, hypertension Usually resolve on their own or advance to

nephrotic syndrome or ESRD

.

Nephritic syndrome: Nutritional ManagementNephritic syndrome: Nutritional Management Diet to treat underlying disease Restrict diet if necessary to control

symptoms Protein restricted in uremia Sodium restriction in hypertension Potassium restriction in hyperkalemia

Diet to treat underlying disease Restrict diet if necessary to control

symptoms Protein restricted in uremia Sodium restriction in hypertension Potassium restriction in hyperkalemia

.

Acute Renal Failure

Rapid, often reversible deterioration of renal function

GFR declines over hours to days Most commonly occurs during

hospitalization (5% of hospitalized pts; 30% of ICU pts)

Associated with major in-hospital morbidity and mortality (7 to 80%)


.

Causes of Acute Renal Failure

Pre-renal: caused by intravascular volume depletion, decreased cardiac output

Post-renal: benign prostatic hypertrophy, prostate cancer, cervical cancer, colorectal cancer, neurogenic bladder, urethral strictures

Intrinsic or parenchymal ARF: vascular disease, interstitial nephritis, glomerular disease, acute tubular necrosis


.

Causes of Acute Renal Failure Ischemic Injury (50% of all incidence) d/t loss of

blood supply to the kidneys secondary to surgical complications, thrombosis, hypotension, hypovolemia

Nephrotoxic injury: medications, contrast medium, chemotherapy, poisons (35%)

Multiorgan system failure, particularly liver failure Sepsis, especially bacterial Obstructive uropathy (trauma during surgery,

urolithiasis, enlarged prostate) Acute glomerular nephritis

.

Acute Tubular Necrosis

Most common cause of ARF Ischemia: due to major surgery,

hypotension, cardiogenic, septic, or hypovolemic shock

Nephrotoxicity: drugs, chemotherapeutic agents, organic solvents, heavy metals, cocaine

.


Initiating phase Period between onset and established renal

failure Usually reversible by treating the

underlying disorder or removing offending agent

Time frame: hours or days


.


Maintenance Phase Epithelial cell injury Urine output is at its lowest; complications

associated with uremia, fluid overload, electrolyte imbalance (decreased sodium, increased potassium levels)

Time frame: 10-16 days in oliguric patients; 5-8 days in nonoliguric patients

.


Recovery Phase Tubule cell regeneration and gradual return

of GFR BUN and creatinine return to near normal May be complicated by marked diuresis,

dehydration and fluid and electrolyte imbalance (increased sodium, decreased potassium)

Time frame: days to months

.

Renal Replacement Therapies in ARF

Recommended for patients with pronounced azotemia, electrolyte imbalance, fluid overload, severe acidosis

Used in 85% of patients with oliguric ARF and 30% of nonoliguric

Purpose is to correct imbalances as well as provide sufficient renal support to other organs

.


Hemodialysis: standard treatment if patient is hemodynamically stable– However, risk of hypotension and wide swings

in body weight in unstable patients

Continuous hemofiltration (CAVH, CVVH) provides slow, continuous filtration across a membrane, driven by arterial pressure (CAVH) or pump (CVVH)

.


Continuous hemodialysis (CAVHD, CVVHD) uses an ultrafiltrate fluid similar to plasma– Clearance occurs through diffusion from high

concentration (blood) to low concentration

Peritoneal dialysis: less often used in the US; not as effective when large volume or solute clearances needed.

.

CAVH

.

MNT for Adult ARF Energy: BEE X 1.2-1.3 or 25-35 kcal/kg Protein: .8-1.2 g/kg noncatabolic, without dialysis;

1.2-1.5 g/kg catabolic and/or initiation of dialysis Fluid: 24 hour urine output + 500 ml (750-1500

ml) Sodium: 2.0-3.0 grams Potassium: 2.0-3.0 grams Phosphorus: 8-15 mg/kg; may need binders; needs

may increase with dialysis, return of kidney function, anabolism


.

Nitrogen Balance in ARF

Standard nitrogen balance studies require a creatinine clearance of more than 50 mL/min/1.73m2

In ARF, urea nitrogen appearance (UNA) is a better method of determining nitrogen balance

UNA = UUN + change in the urea nitrogen pool

.

Calculation of Urea Nitrogen Appearance (UNA)UNA (g) = UUN + [BUN2 – BUN1) x .6 x BW1] +

[(BW2-BW1) x BUN2]Net protein breakdown = UNA x 6.25UUN = urinary urea nitrogen (g/24hr)BUN1 = initial collection of blood urea nitrogen,

postdialysis (g/L)BUN2 = final collection of blood urea nitrogen,

predialysis (g/L)BW1 = postdialysis wt (kg)BW2 = predialysis wt (kg)

.

Chronic Kidney Disease

.

Causes of Chronic Kidney Disease

Cause Incidence (%)

Diabetes 40

Hypertension 27

Glomerulonephritis 13

Interstitial disease 4

Renal cystic disease 3

Tumors 2

Other 10

.

Progression to End-Stage Renal Disease (ESRD)

First Decline in glomerular filtration rate (GFR)

Second Adaptations in renal function, i.e., increase in GFR

Third Adaptations improve renal function in short term

Fourth Long term loss of nephron units.

Fifth Slow, progressive decline in renal function

Sixth Eventually this decline leads to renal insufficiency, i.e., ESRD

.

Stages of Chronic Kidney DiseaseStage GFR Action

At increased risk CKD risk factors

Screening; CKD risk reduction

1. Kidney damage with normal or increased GFR

>90 Tx comorbid conditions. Slow progression. CVD risk reduction

2. Mild decrease in GFR 60-89 Estimating progression

3. Moderate decrease in GFR

30-59 Evaluating, treating complications

4. Severe decrease in GFR

15-29 Prepare for kidney replacement tx

5. Kidney failure <15 or dialysis

Replacement, if uremia present

National Kidney Foundation K/DOQI Clinical Practice Guidelines on CKD. Am J Kidney Dis 2002;39(suppl 1):46.

.

ESRD: Medical Management

Dialysis Immunosuppressant drugs Kidney transplant Psychological support

.

Uremia, a Clinical Syndrome—Signs and Symptoms

Malaise

Weakness

Nausea and vomiting

Muscle cramps

Itching

Metallic taste (mouth)

Neurologic impairment

.

Stages of CKD Nutrient RecommendationsPro

g/kg

Kcal Na+

g/day

K+ Phos Calcium

g/day

1 .75 Based on energy expenditure

1-4 g to NAS

No restriction

Unless high

Monitor and restrict if nec

1.2-1.5


1-4 g to NAS

No restriction

Unless high

Monitor and restrict if nec

1.2-1.5


1-4 g to NAS

No restriction

Unless high

800-1000 mg/day

1.2-1.5

4 .6 30-35 kcal/kg

1-4 g to NAS

No restriction

Unless high

800-1000 mg/day

<2000 mg/day

5 0.6-0.75

30-35 kcal/kg

1-4 g to NAS

No restriction

Unless high

800-1000 mg/day

<2000 mg/day

Fedje and Karalis. Nutrition mgt in early stages of CKD. Clin Guide Nutr Care Kidney Dis, ADA, 2004

.

Treatments: CKD, HD, CAPD Treatments: CKD, HD, CAPD

CKD Early Hemodialysis CAPD or CCPD

Treatment Diet and medications

Diet and medications Hemodialysis

Diet and medications Peritoneal dialysis

Modality Vascular access Peritoneal membrane

Duration Indefinite 3-5 h 2-3 d/wk

3-5 exchanges 7 d/wk

Concerns Glomerular hyperfiltration: BUN: bone disease: HTN: Glucose control in diabetes

AA loss; interdialytic electrolyte and fluid changes: Bone disease: HTN

Protein loss: glucose absorption: Bone disease: weight gain: hyperlipidemia: glucose control in diabetes

CKD Early Hemodialysis CAPD or CCPD

Treatment Diet and medications

Diet and medications Hemodialysis

Diet and medications Peritoneal dialysis

Modality Vascular access Peritoneal membrane

Duration Indefinite 3-5 h 2-3 d/wk

3-5 exchanges 7 d/wk

Concerns Glomerular hyperfiltration: BUN: bone disease: HTN: Glucose control in diabetes

AA loss; interdialytic electrolyte and fluid changes: Bone disease: HTN

Protein loss: glucose absorption: Bone disease: weight gain: hyperlipidemia: glucose control in diabetes

.

MNT for CKD, HD, PDMNT for CKD, HD, PDCKD Hemodialysis CAPD or CCPD

Protein 0.6-1.0 1.1-1.4 1.2-1.5g/kg/dayEnergy 30-35 30-35 30-35

(kcal/kg IBW)

Phosphorus 8-12 indiv <17 indiv <17 indiv

(mg/kg IBW)

Sodium 1000-3000 2000-3000 2000-4000

(mg/d)

Potassium Individualized ~ 40 Individualized

(mg/kg IBW)

Fluid Unrestricted 500-750 + Individualized

(ml/d) urine output

(1000 if anuric)

Calcium Individualized Individualized Individualized

(mg/d) based on serum level ~1000 mg/day ~1000 mg/day

Use adjusted IBW if obese

CKD Hemodialysis CAPD or CCPD

Protein 0.6-1.0 1.1-1.4 1.2-1.5g/kg/dayEnergy 30-35 30-35 30-35

(kcal/kg IBW)

Phosphorus 8-12 indiv <17 indiv <17 indiv

(mg/kg IBW)

Sodium 1000-3000 2000-3000 2000-4000

(mg/d)

Potassium Individualized ~ 40 Individualized

(mg/kg IBW)

Fluid Unrestricted 500-750 + Individualized

(ml/d) urine output

(1000 if anuric)

Calcium Individualized Individualized Individualized

(mg/d) based on serum level ~1000 mg/day ~1000 mg/day

Use adjusted IBW if obese

National Renal Diet Professional Guide 2nd edition, ADA 2002

.

Nutrition Assessment and Monitoring in the CKD Pt

.

Anthropometric Measurements

% usual body weight (%UBW) % standard body weight (%SBW) Height Skeletal frame size BMI Skinfold thickness Mid-arm muscle area, circumference, or

diameter

.

Body Weight Assessment in CKD

Use dry weight or edema-free body weight– In HD: post-dialysis weight– In PD: weight after drainage of dialysate with

peritoneum empty In obese or very underweight people, use

adjusted edema-free body weightAdjusted EFBW=

BWef + [SBW*-BWef x .25]*Use NHANES II data for standard body weight (SBW)

National Kidney Foundation. K/DOQI clinical practice guidelines for nutrition in chronic renal failure. Am J Kidney Dis 2000;35(suppl);S27-S86.

.

Blood Urea Nitrogen (BUN)

Measure of the nitrogenous waste products of protein

High BUN in CKD may reflect high protein intake, GI bleeding or inadequate dialysis, increased catabolism due to infection, surgery, poor nutrition

Decreased BUN may mean protein anabolism, overhydration, protein loss, low dietary protein


.

Creatinine (nl 0.5-1.4 mg/dL) Nitrogenous waste product of muscle metabolism Produced proportionate to muscle mass Unrelated to dietary protein intake (DPI) Sensitive marker of renal function: the higher the

serum creatinine, the greater the loss of renal function; may reflect inadequate dialysis or muscle catabolism

A decrease in creatinine over time may reflect loss of lean body mass


.

Causes of Hyperkalemia (K+) Goal 3.5-5.5 mEq/L

>6 mEq/L – abnormal, potentially dangerous

Renal failure (kidney is primary filter)

Excessive nutritional intake

Chronic constipation Infection GI bleeding Insulin deficiency (high BG)

Metabolic acidosis Drug interactions Catabolism of

malnutrition or cell damage caused by injury or surgery

Decreased urinary output Chewing tobacco

.

Causes of Hypokalemia (↓ K+)

Vomiting, diarrhea Diuresis Potassium binder K+ too low in dialysate

Urine output >1000 mL/day or serum NL, do not need to restrict K+

.

Phosphorus (normal 3.5-5.5 mg/dL) As renal function decreases, phos accumulates in

the blood phos triggers release of PTH that releases

calcium from bone Phos binders prevent phosphorus from being

absorbed in the gut; form insoluble compound so phos is excreted in stool

Phos clearance poor in HD and CAPD ↓ phos may mean excess phos binder or poor p.o.

.

Calcium (8.4-9.5 mg/dL) Most abundant mineral in human body Nearly half of calcium is bound to albumin; if

serum calcium is low, evaluate albumin level; can correct for low albumin

Calcium-Phosphorus Product: multiply serum calcium x serum phos: if >55-75, calcification can occur

<2000 mg/day elemental calcium from diet + binders stage 3-4

High ca+: calcification, nausea, vomiting, muscle twitching may mean too much Ca+ from meds or diet

.

Serum Sodium (nl 133-145 mEq/L)

Not a reliable indicator of sodium intake in CKD

Fluid retention due to decreased urine production can dilute an elevated level

Serum levels must be evaluated in conjunction with fluid status

.

Lipids

Cardiovascular disease is the most common cause of death in people with CKD

Kidney disease is considered the equivalent of a risk factor, like diabetes

HD: often have normal LDL, TC, ↑ triglycerides, ↓ HDL

PD: have ↑ LDL/TC + ↑ TG Renal Tx: ↑ LDL/TC/TG, normal HDL,

often due to medications

.

Cholesterol in CKD

High • High risk TC 200-300 mg/dl (non-fasting)

• LDL goal < 100 mg/dl

Low • <150 -180, evaluate for pro-energy malnutrition

• Increased mortality

.

Hematological Indicators

Hemoglobin: ↓ due to lack of erythropoetin, produced by the kidney; pts receive synthetic EPO tx (Epogen)

May have anemia of chronic disease Ferritin: may be indicator of iron overload;

↑ ferritin may mean EPO resistance

.

Glomerular Filtration Rate (GFR)

Best index of kidney function Used to establish stage of CKD GFR is the amount of filtrate formed per minute

based on total surface area available for filtration (number of functioning glomeruli)

Can be determined using injected isotope (inulin) measurement in urine

Can be calculated from serum creatinine using standard equations

.

.

Cockroft-Gault Equation to Calculate GFR MICROMOL: [(140-age) x weight x 1.23 x

(0.85 if female)]/Creat[micromol/l] MG: [(140-age) x wt/kg x .85 if

female]/(72*serum creatinine mg/dL)

http://renux.dmed.ed.ac.uk/EdREN/Handbookbits/HDBKgfrest.html

.

Interdialytic Weight Gain

Pts on dialysis gain several kg of fluid between HD treatments

If pts gain >5%, may reflect excessive fluid intake, leading to hypertension, edema, ascites, pleural effusion

Fluid gains of <2% reflect minimal fluid and food intake, may be losing body mass

.

Measures of Dialysis Adequacy

Urea Reduction Rate (URR) Refers to change in urea concentration between

pre and post-dialysis blood tests Statistically significant predictor of mortality CMS goal is >65%

Kt/V The fractional clearance of urea as a function of its

distribution volume Goal is 1.2 or more

.

Monitoring Nutrition Status in CKD with GFR<12mL/min/1.73m2Recommended measure Frequency

Serum albumin levels Every 3 months

Edema-free actual body weight, % std wt, SGA

Every 1-3 months

nPNA or dietary interviews and diaries

Every 3-4 months

Fedje and Karalis. Nutrition mgt in early stages of CKD. Clin Guide Nutr Care Kidney Dis, ADA, 2004

.

0 2 5 11-23 13-25 15-27

O nsetD iabetes

Functional C hanges Increased G FR R eversib le a lbum inuria Increased kidney size

Structura l Changes Increased g lom erular m em brane

th ickening "G lom eru larsclerosis"

Time (years)

O nsetProte inuria

R isingC reatin ine

EndStageR enal

D isease

Predictors

H yperfiltra tion M icroa lbum inuria H igh B lood P ressure Poor G lycem ic C ontro l

Incipient Nephropathy

The Natural History of Diabetic Nephropathy

.

Pre-ESRD (DM)

Primary Prevention– Glycemic control (DCCT)

• Aim for Euglycemia

• Watch for low B.S.

– B.P. control• 130/80

• Na+ restrict– Base on comorbidities (~2-3 g.)

– Medications may increase or decrease K+; monitor

• Wt. loss (gradual)/exercise

– Meds: ACE inhibitors and ARB’s

.

Pre-ESRD

Secondary Prevention (overt nephropathy; GFR ~ 25)– Protein normalization– 0.6 g/kg - RDA 0.8 g/kg ( minimum for DM) – Delay need for dialysis, control uremic

symptoms, reduce acidosis

Stage 4 CKD: monitor labs, may need to limit K+, Phos., Ca++, Mg++

.

MNT in Patients on Hemodialysis

.

Hemodialysis

Removes concentrated molecules and excess fluid from pts blood through diffusion and ultrafiltration

Three parts of the system are the dialyzer (artificial kidney), the dialysis machine, and the dialysate

Requires vascular access, usually through an AV (arteriovenous) fistula

.

AV (arteriovenous) Fistula

.

ESRD: Nutritional Management

Prevent deficiencies Control edema and serum electrolytes Prevent renal osteodystrophy Provide an attractive and palatable diet

.

MNT in HD: Protein 10-12 g free amino acids lost per treatment

during dialysis Greater amino acid losses with glucose-free

dialysate and high flux dialyzers 1.2 g protein/kg standard body weight

(SBW) with 50% high biological value (meat, poultry, fish, eggs, soy, dairy)

Most HD patients take in less than 1 g/day

NKF K/DOQI practice guidelines. Am J Kid Dis 2000;35(suppl):S40-S41, Cited in Byham-Gray, p. 45-46

.

MNT in HD: Energy

Adults <60 years: 35 kcal/kg SBW Adults > 60 or obese: 30-35 kcals/kg body

weight Actual intakes of HD patients in studies are

lower than that (mean 23 kcals/kg in HEMO study)

NKF K/DOQI practice guidelines. Am J Kid Dis 2000;35(suppl):S40-S41, Cited in Byham-Gray, p. 46

.

MNT in HD: Lipids

HD patients at risk for lipid disorders Recommended fat intake<30% of calories

and saturated fat<10%; cholesterol <300 mg/day

Optimum fiber intake 20-25 g/day These restrictions are difficult to achieve

along with other restrictions of HD diet

.

MNT in HD: sodium and fluid

≥ 1 L fluid output: 2-4 g Na and 2 L fluid

≤ 1 L fluid output: 2 g Na and 1-1.5 L fluid

Anuria: 2 g Na and 1 L fluid

Restrict Na+ if ↑ interdialytic wt gain, CHF, edema, HTN, low serum sodium

.

MNT in HD: Potassium

Potassium needs related to urinary output Most patients on HD can tolerate 2.5 g of

K+ Stricter diet may be indicated for pts w/

insulin deficiency, metabolic acidosis, treated with beta blockers or aldosterone antagonists, hypercatabolic

Individuals: 40 mg/kg edema-free IBW or SBW

.

MNT in HD: Phosphorus

Maintain s. phos 3.5-5.5 mg/dL Usually ok until GFR ↓ to 20-30 mL/min Dialysis removes 500-1000 mg/treatment Use phosphorus binders with meals: absorb

50% of dietary phosphorus Dietary intake: 800 to 1000 mg/day or <17

mg/kg IBW or SBW Identify high protein, low phos food sources

.

MNT in HD: Calcium

High from excess Ca++ type binders, vitamin D analogs, Ca++ fortification

Goal 8.4-9.5 mg/dl Always use corrected Ca++ (adjusted Ca+

+)[ (4-alb.) x 0.8] + Ca++]

CaXPhos product: goal <55

.

Phosphate Binders(Taken with meals to prevent phos absorption)

Calcium acetate PhosLo

Mg/Ca++ carbonate MagneBind

Sevelamer hydrochloride Renagel

Aluminum carbonate

Aluminum hydrozide Alucap, Amphogel

Calcium carbonate TUMS, Os-Cal, calci-Chew, Calci-Mix

.

MNT in HD: Vitamins

H2O soluble vitamins Dialyzable – take after H.D. B vitamins and vitamin C in renal vitamin

↑ Vit. C → ↑ oxalate → calcification of soft tissues and stones

Individualize need for:– Fe++ (IV most common), Vitamin D, Ca++, Zinc.

.

MNT in HD: Vitamin D

Vitamin D is activated in the kidney to calcitriol, or vitamin D3

As D3 levels fall, calcium absorption ↓ and phos excretion ↓

Vitamin D3 therapy helps prevent renal bone disease but may cause hypercalcemia

Renal pts should use calcitriol supplements under the supervision of a physician

.

Hemodialysis

Typical diet order– 2000 calorie, 80 g protein, 2 g Na+, 3 g K+,

low phosphorus, 1500 cc fluid restriction

.

Skeletal Effects of Chronic Renal Failure

Hyperphosphatemia Hypocalcemia Hyperparathyroidism Low bone mass and density Osteitis fibrosa cystica—hyperplastic

demineralized bone

.

Monitor Patient Status

1. BP >140/90

2. Edema

3. Weight changes

4. Urine output

5. Urine analysis:—Albumin—Protein

.

Monitor Patient Status (cont)Monitor Patient Status (cont)6. Kidney function

Creatinine clearanceGlomerular filtration rate (GFR)

7. Blood valuesBUN 10 to 20 mg/dl (<100 mg/dl)Creatinine 0.7 to 1.5 mg/dl (10-15 mg/dl)Potassium 3.5 to 5.5 mEq/LPhosphorus 3.0 to 4.5 mg/dlAlbumin 3.5-5.5 g/dlCalcium 9-11 mg/dl

6. Kidney function

Creatinine clearanceGlomerular filtration rate (GFR)

7. Blood valuesBUN 10 to 20 mg/dl (<100 mg/dl)Creatinine 0.7 to 1.5 mg/dl (10-15 mg/dl)Potassium 3.5 to 5.5 mEq/LPhosphorus 3.0 to 4.5 mg/dlAlbumin 3.5-5.5 g/dlCalcium 9-11 mg/dl

.

Peritoneal Dialysis

.

CAPD (continuous ambulatory peritoneal dialysis) Most patients do 4-5 exchanges per day A specific volume of dialysate (1500-3000 ml) is

infused into the peritoneal cavity via a catheter The dialysate dwells for 4 hours as excess fluid

and toxins diffuse through peritoneal membrane Dialysate and wastes are drained from the body

and the process repeated. Dialysate is present in the body 24 hours per day APD (automated peritoneal dialysis therapy)

speeds the process

.

Peritoneal Dialysis (home dialysis)

Blood cleansed by passive movement from capillaries to dialysate (diffusion)

Ultra-filtration (UF): fluid removed by osmosis due to high osmolality of dextrose in dialysate

Better control of labs, fluid balance and B.P. Advantages for those with heart failure, access

problems. Diet liberal, independence. Disadvantages:, anorexia, a.a. losses in dialysate,

peritionitis→ catabolism, anorexia, long- term wasting, high B.S., wt. gain, lack of socialization

.

PERITONEAL DIALYSIS Dialysis solutions

– Pt. chooses depending on fluid status1.5%, 2.5% or 4.25% glucose

CAPD– ~4 – 2L. Exchanges/day– Dwells ~6 hours (dialysis) and drain– ~60% glucose absorbed (3.7 kcal/g)

CCPD– ~10 L exchanged throughout night– 40% glucose absorbed 2nd to rapid exchanges

.

MNT for PD: Energy

Energy: 35 kcals/kg/day SBW or adjusted body weight for pts<60 years; 30 kcals/kg for those >60

Calories provided in the dialysate should be included in total intake (may absorb as much as 1/3 of daily energy needs)

PERITONEAL DIALYSISSAMPLE GLUCOSE ABSORPTION

g glucose per liter x volume = total g of glucose

Example: one – 2 L. exchange of 1.5% solution = 30 g glucose

Total g of glucose x absorption rate (~60%) = g glucose absorbed

Example: 30 g glucose x 60% = 18 g glucose absorbed

g glucose absorbed x kcal per g glucose (3.7)= calories absorbed

Example: 18 x 3.7=66.6 calories/2 L. exchange

Patient does 4 exchanges/d

67 x 4 = 268 calories/d from diaysate

.

MNT for PD: Protein

PD patients lose 5-15 grams of protein a day, primarily as albumin

Goal 1.2-1.3 g/kg SBW or ABW/day

.

MNT for PD: Sodium

PD clears sodium very well, so sodium can be fairly liberal

However, high salt diets increase thirst and may make adherence to fluid limits more difficult

General recommendation is 2-4 grams sodium

.

MNT for PD

Potassium: is easily cleared by PD; some patients may need K+ supplementation

Calcium: limit to 2000 mg elemental calcium– Generally pts get ~1500 mg from calcium-

based phosphate binders– Serum calcium should be maintained in low

normal range (8.4-9.5 mg/dl)

.

MNT for PD

Phosphorus: limited to 800-1000 mg/day which is difficult with high protein diet– Use phosphate binders

Fluid: can be adjusted by varying the dextrose concentrations of the dialysate– May need to be restricted if pts cannot achieve

fluid balance without frequent hypertonic exchanges

.

PD: weight gain, hypertriglyceridemia, hyperglycemia

Increase exercise as allowed by MD Limit sodium and fluid to minimize

hypertonic exchanges Use solutions with alternate hypertonic

agents such as Icodextrin Modify energy intake to facilitate wt loss Modify intake of sugars and fats, especially

saturated fats

.

PD: Protein Losses, Malnutrition

Patient education regarding protein goals and ways to meet them

Suggest pt eat protein foods first and limit fluids at mealtime

Frequent smaller portions of protein and easy to eat proteins such as egg white, cottage cheese, etc

Education on sterile technique to avoid peritonitis

.

Food Groups Kcal CHO g. PRO g. FAT g. Na mg. K+ mg. PO4 mg.

Milk ( ½ c.) 85 6 4 5 80 185 110

Meat 65 0 7 4 25 100 65

Starch 80 15 2 1 80 35 35

Vegetable 25 5 1 0 15 150 20

Fruit 60 15 0.5 0 5 150 15

Fat (1TB.) 100 0 0 11 150 0 5

Calorie Boosters

60 15 0 0 15 20 5

Beverages:Coffee (1c.) tea (1 bag) wine (4 oz.) beer (12 oz.)

0 0 0 0 0 100 0

RENAL EXCHANGES FOR MEAL PLANNING

.

Protein Foods (65 kcals, 7 grams protein, 25 mg Na, 100 mg K+, 65 mg phos)

Meat 1 ounce Egg 1 Fish 1 ounce Shellfish 1 ounce Poultry 1 ounce Egg substitutes ¼ c

Bacon 4 slices Cheese 1 oz Milk 1 cup Nut butters 2 T Tofu ¼ cup Cottage cheese ¼ cup Lunchmeat 1 oz

.

Milk Servings (2% milk) 85 kcals, 6 g CHO, 4 g pro, 5 g fat, 80 mg Na+, 185 mg K+, 110 mg Phos

½ cup milk ½ cup plain ice cream ½ cup yogurt

.

Starch Servings80 kcal, 15 g CHO, 2 g pro, 1 g fat, 80 mg Na+, 35 mg K+, 35 mg PO4

Bread, white or rye 1 slice Cake 2 in sq or cupcake Plain cake donut 1 Cold cereal 1 cup Dinner roll 1 small Macaroni, noodles, rice ½ cup Popcorn, unsalted, 1 cup

.

Vegetable Servings25 kcal, 5 g CHO, 1 g pro, 15 g Na+, 150 mg K+, 20 mg PO4

Asparagus ½ cup Green beans ½ cup Cabbage ½ cup Carrots ½ cup Cauliflower ½ cup Corn ½ cup

.

Fruit Servings ↓ K+60 kcals, 15 g CHO, .5 g protein, 150 mg K+, 15 mg phos

Apple Apple juice ½ c Applesauce ½ c Apricot nectar ½ c Blackberries ½ c Blueberries ½ c Fruit cocktail ½ c Grapes ½ c Lemon Lime

Peach Pear Pineapple Plums (1) Raspberries Watermelon

.

Fruit Servings (High potassium)60 kcals, 15 g CHO, .5 g protein, >250 mg K+, 15 mg phos

Apricots Bananas Dates Honeydew melon Kiwifruit Nectarine Orange Orange Juice Prune juice

Prunes (5) Raisins

.

Fat Choice100 kcals, 11 g fat, 150 mg Na+, 5 mg PO4

Margarine/butter 1 T Cream cheese 2 T Mayonnaise 11/2 T Non-dairy topping ½ cup Sour cream ¼ cup Vegetable oil 1 T Tartar sauce 2 T

.

Calorie Boosters60 kcals, 15 g CHO, 15 mg Na+, 20 mg K+, 5 mg PO4

Hard candy 4 pieces Jam or jelly 2 T Jelly beans 15 Honey 2 T Sugar brown or white 2 T Marshmallows 5 large Fruit snacks and candies 1 oz

.

Beverages100 mg K+ (also counts as fluid)

Coffee 1 cup Tea 1 bag Wine 4 oz Beer 12 oz

.

Medicare Rules for MNT in Renal Disease As of January, 2002, Medicare covers MNT

for pre-dialysis renal disease Includes nutritional, diagnostic, therapy and

counseling services Restricted to patients with GFR 15 to 50

mL/min/1.73m2 (stages 3-4-5 not on dialysis)

.

Kidney TransplantKidney Transplant1. Types: related donor or cadaver2. Posttransplant management:

CorticosteroidsCyclosporine

3. Diet while on high-dose steroids:1.3 to 2 g/kg BW protein30 to 35 kcal/kg BW energy80 to 100 mEq Na

4. Diet after steroids:1 g/kg BW proteinKcal to achieve IBWIndividualize Na level

1. Types: related donor or cadaver2. Posttransplant management:

CorticosteroidsCyclosporine

3. Diet while on high-dose steroids:1.3 to 2 g/kg BW protein30 to 35 kcal/kg BW energy80 to 100 mEq Na

4. Diet after steroids:1 g/kg BW proteinKcal to achieve IBWIndividualize Na level

.

Well Mr. Osborne, it may not be kidney stones after all.

.

Kidney StonesKidney Stones1. Particulate matter crystallizes

Ca salts (Ca oxalate or Ca phosphate)Uric acidCystine

Struvite (NH4, magnesium and phosphate)2. Ca salts in stones—Rx: high fluid; evaluate

calcium from diet; may need more!3. Treat metabolic problem; low-oxalate diet

may be needed; acid-ash diet is sometimes useful but not proven totally effective

1. Particulate matter crystallizesCa salts (Ca oxalate or Ca phosphate)Uric acidCystine

Struvite (NH4, magnesium and phosphate)2. Ca salts in stones—Rx: high fluid; evaluate

calcium from diet; may need more!3. Treat metabolic problem; low-oxalate diet

may be needed; acid-ash diet is sometimes useful but not proven totally effective

.

Kidney Stones—cont’dKidney Stones—cont’d

4. Uric acid stones

Alter pH of urine to more alkaline

Use high-alkaline-ash diet

Food list in Krause text

5. Cystine stones (rare)

6. Struvite (infection stones) antibiotics and/or surgery

4. Uric acid stones

Alter pH of urine to more alkaline

Use high-alkaline-ash diet

Food list in Krause text

5. Cystine stones (rare)

6. Struvite (infection stones) antibiotics and/or surgery

.

Acid-Ash Diet

Increases acidity of urine (contains chloride, phosphorus, and sulfur)

Meats, cheese, grains emphasized Fruits and vegetables limited (exceptions

are corn, lentils, cranberries, plums, prunes)

.

Alkaline-Ash Diet

Increases alkalinity of urine (contains sodium, potassium, calcium, and magnesium)

Fruits and vegetables emphasized (exceptions are corn, lentils, cranberries, plums, prunes)

Meats and grains limited

.

Summary

Renal diseases—delicate balance of nutrients

Regular monitoring of lab values, with altered dietary interventions accordingly

Documents

MNT in Renal Disorders