Peritoneal Dialysis

Nutritional Considerations in PD

Peritoneal Dialysis

Objectives

1. Discuss risks and importance of poor nutrition

2. How to assess nutritional state

3. How to achieve good nutrition

Peritoneal Dialysis

Nutrition

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Alternatives to Avoid

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Nutrition in Patients with CRF

Classes of nutrients - carbohydrates - fats - proteins - vitamins - minerals - water

Essential nutrients - amino-acids - essential fatty

acids - vitamins, elements

•Without these, an individualcannot function

•Dietary protein provide amino acids - body proteins

•Without sufficient dietaryprotein and energy, no growthor repair

Peritoneal Dialysis

Recommended Protein & Energy Intakes

# safe for 97.5 % of the population (WHO 1985) CRF patients with GFR 30-20 ml/min reduce protein and energy intake (MDRD study) Protein and energy intake lower than recommended in a large proportion (20-60%?) of HD and CAPD patients

Protein Energy (g/kg BW/day) (kcal/kg BW/day)

Healthy adults > 0.75# >35

CRF patients (non-dialyzed) ? 0.60 (high quality) >35

HD patients > 1.2 >35

CAPD patients > 1.2 >35

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Protein-Energy Malnutrition

A state of deficiency resulting from inadequate intake of protein and/or energy relative to physiological needs leading to progressive changes in body composition and function and nutrition

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B O D YS T O R E

IN T A K E L O S S E S

S U P P L Y D E M A N D

Nutrition is a balance between supply and demand

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Negative Feedback Loop

Loss of renal function

Low protein andenergy intake

Anorexa nauseavomiting

Accumulation of uremic toxins

Low serumurea

MALNUTRITiON

J Bergström ASN -94

Peritoneal Dialysis

Major Metabolic Steps in Nutritional Deficiency Disease

Mortality

Morbid ity

Clin ical sym ptom s

Deterioration in capacityto function norm ally

Altered b io logical and physiologicalFunctions

Depletion of T issueLevels and Body Stores

Inadequate in takeIm paired absorption

Increased nutrient loss from body

Well nourishedindividual

Individual at risk

Malnourishedindividual

Dietary surveyNutrient intake

Biochem and physiol studies

Signs & symptoms

Vital statistic

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Patients at Risk of Developing Malnutrition

Elderly Socially isolated Diabetes mellitus Recurrent peritonitis Active comorbid conditions Loss of RRF Inadequate solute removal

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Risk Factors for Poor Nutrition

Late start of dialysis - Use of low protein diet

Poor appetite Social factors Protein loss through peritoneum

- Increased with peritonitis Catabolic state

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Effects of Renal Insufficiency

Protein and Amino Acid Metabolism• Altered metabolism of proteins & amino acids• Intravascular alb pool may be reduced, even

though serum albumin is normal• Transferrin levels low• Increased catabolism (higher levels of

glucagon, PTH, toxins, acidosis)• Changes in amino-acid profiles• Increased risk of developing protein

malnutrition• Major cause of morbidity and mortality

DPI also diminishes with declining GFR

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Protein-Calorie Malnutrition in CRF

Catabolic Factors Comorbid illness Physical inactivity Infections Metabolic acidosis Abnormal energy metabolism

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Protein intake and GFR

>50 25-50 24-10 <100.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

GFR

DPI

10ml / minGFR = 4.4g in DPI

Ikizler, JASN 1995

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Protein Intake in Pre-dialysis

GFR (mls / min)

N = 1687

70 45 25 90.0

0.2

0.4

0.6

0.8

1.0

1.2

DPI

MDRD study ; JASN 1994

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CAPD HD

Loss of amino acids

2-4 g/day

14-28 g/week

9-13 g/dialysis

27-39 g/week

Loss of glucose uptake ~25 g/dialysis(glucose free dialysate)

Loss of protein 5-15 g/day(higher with peritonitis)

0

Inflammatory stimuli

Low grade inflammation (particles chemicals)

Cytokine release

Blood membrane contact

Cytokine release

Catabolic Effects of Dialysis

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Causes of Anorexia

Underdialysis particularly with loss of residual renal function

Sensation of abdominal fullness- Poor gastric emptying particularly in diabetics

Hyperglycaemia and glucose absorption from excessive use of hypertonic dextrose

Depression

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Risk Factors for Obesity

Use of hypertonic dialysate, particularly 3.86% dextrose, to maintain fluid balance

High caloric intake, but low protein intake

Lack of physical activity

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Causes of Low Plasma Albumin (Malnutrition vs. Malnourished)

True malnutrition Co-morbid conditions

- Infection

- Generalised vascular disease

- Chronic inflammation

- Proteinuria

- Malignancy

Old age Dietary preference

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Assessment of Nutritional Status

History and physical examination looking for loss of weight and muscle wasting

Dietary history Plasma creatinine, urea, albumin, transferrin

- creatinine can mean muscle mass and not dialysis clearance

- creatinine can mean muscle mass and not dialysis clearance

Anthropometry SGA (Subjective Global Assessment) Biochemical / laboratory tests

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Anthropometry

Mainly used as research tool

Wolfson 1984

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Subjective Global Assessment

Four items assessed over 7 point scale

Weight change - What was weight change over last 6 months?

Anorexia- Has dietary intake changed?

Subcutaneous tissue- Fat and muscle wasting e.g., under eyes or shoulders- Muscle mass and wasting- Examining temporalis muscle, prominence of clavicles,

contour of shoulders etc

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Subjective Global Assessment

1. Weight Change - in last 6 mths

- % (<5, 5-10,>10)

- in last 2 weeks

2. Dietary Intake - overall

- pattern

- duration

- type

3. GIT Symptoms - > 6weeks

4. Functional Capacity - overall +change

1. Loss of subcutaneous fat

2. Loss of muscle mass

3. Oedema

History

PE

Peritoneal Dialysis

Subjective Global Assessment

Severe malnutrition - ‘1 or 2’ ratings in most categories

Mild to moderate - ‘3, 4 or 5’ ratings in most categories

Mild to Well Nourished - ‘6 or 7’ ratings in most categories or continued improvement

A - Well nourished

B - Mild-Mod malnourished

C - Severely malnourished

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There is No Single Magic Nutritional Index

Each has limitations

Use of combinations gives corroborating information

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Non-Nutritional Factors Affecting Albumin

Fluid balance

Infection/inflammation

Urinary losses

High dialysate losses

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Non-Nutritional Factors Affecting Albumin

Analytical method Gender Age Pregnancy Fluid balance

Infection/inflammation Cardiac disease Malignancy Protein losses

(urine, dialysate)

•Infection/inflammation related albumin is like an ‘negative’ acute phase protein•Association between cardiac disease and hypoalbuminaemia (Foley 1996)

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Albumin as a Negative Acute Phase Reactant

Qureshi et al., 1995

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Albumin as a Predictor

Strong predictor of morbidity and mortality (CANUSA study)

Albumin may be affected by protein intake

Albumin is affected by non-nutritional factors

Albumin may not increase in response to nutritional intervention

However,

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Serum albumin alone is neither necessary nor sufficient to indicate

malnutrition

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<=2.5 2.5-3.0 3.0-3.5 3.5-4.0 4.0-4.5 >4.50

10

20

Serum Albumin (mg/dl)

Rel

ativ

e D

eath

Ris

k

Lowrie et al, 1990

Serum Albumin and Death RiskHaemodialysis Patients

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Target Protein Intake for PD

Nitrogen balance is the reference method for determining adequacy of protein intake

N Balance studies by Blumenkrantz and Bergstrom indicate that at 1.2 g protein/kg/day no patients were in negative nitrogen balance

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Malnutrition in ESRDTarget Intake for PD

Blumenkrantz et al, KI 1982

4

5

3

2

1

1

0

2

0.9 1.0 1.1 1.2 1.3 1.4 1.5

Protein intake, g/kg body wt/day

Nit

roge

n b

alan

ce, g

/day

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How Can This Target Be Achieved?

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Methods for Nutritional Support in PD

Nutritional counseling Pharmacologic appetite stimulation Oral supplements Enteral formulas (nasogastric, PEG) Intravenous Intraperitoneal (nutritional dialysis)

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Prevalence of Malnutrition is Similar in HD and PD*

Mode #Studies #Pts % Malnourished

HD 3 502 21-53 (28%)

PD 3 401 26-56 (36%)

* Evaluated by the same method

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Nutrition: Guidelines 2002

All patients should undergo regular screening for undernutrition using as a minimum SGA, height weight and albumin

Diagnosis of undernutrition should be considered if any of following are met:- BMI < 18.5

- unintentional loss of oedema free weight of > 10% in last 6 mths

- plasma albumin below normal (value depends on assay)

- Low SGA scores

Peritoneal Dialysis

Nutrition: Guidelines 2002

If undernutrition suspected- refer to dietitian to assess dietary intake- measure CRP, plasma bicarbonate, dialysis adequacy

and residual renal function

Correct low dietary intake

If intake adequate, look for infection if CRP high, and other catabolic factors such as acidosis, thyrotoxicosis and poorly controlled diabetes

Peritoneal Dialysis

What is Nutrineal™?

Nutrineal™ is a peritoneal dialysis solution with

amino acids instead of glucose which integrates

dialysis and nutritional supplementation

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Nutrineal™ Characteristics

Amino acids as osmotic agent

No glucose

No change in dialysis procedures

More physiologic pH

Osmolality equivalent to 1.5% glucose

Clearance equivalent to 1.5% glucose

40 mEq/L lactate

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Amino Acid Content of Nutrineal™ (2.0 L)

Essential Nonessential

Histidine AlanineIsoleucine ArginineLeucine GlycineLysine ProlineMethionine SerinePhenylalanine TyrosineThreonineTryptophanValine

14.1g (64%) 7.9 g (36%)

Conditionally essential in renal patients

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Bioavailability and Utilization Nutrineal™

• How much is absorbed?

• How is it utilized (Anabolic?)- Nitrogen balance- IGF-1

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In just one exchange Nutrineal can deliver 25% of the target Daily Protein Intake*

Delivering 25% of daily protein intake

Jones MR, et al., PDI, 1998;18(2):210-216

With an absorption rate of 70-80% over 4-6 hours, one exchange of 2L Nutrineal provides approximately 18g of AAs to an average, stable, 60kg patient: that is 0.3 g/kg body weight/day, which represents 25% of the 1.2 g/kg body weight/day target intake1

* Recommended dosage for adults: one 2L or 2.5L bag/day

25%

Target DPI

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0.16g/kg 0.3 g/kg

Bioavailability

AAsFor 60 kg

patient

Day 1 Protein and AA Losses

Day 2 AA gains

Jones et al, PDI 1998;18:210-216

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The Therapy

Before Prescription:

1. Check adequacy (Kt/V > 2; Cr.Cl. > 50 L./week)

2. Correct possible acidosis (bicarbonate > 23 mmol/L.)

3. Verify protein intake

4. Review comorbid conditions

5. Assess nutritional status

Therapeutic Target:

Protein intake of around 1.2 g/kg/day

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Nutrineal® : an efficient and compliant way of delivering AA’s whilst providing dialysis

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Managing Protein Needs with Nutrineal

Target protein intake* = 1.2 g/kg/day

One exchange with Nutrineal contributes the equivalent of 0.3 g/kg in an average patient (20-25% of daily target)

*Kopple, 1997

Peritoneal Dialysis

Conclusion

Poor nutrition common in PD patients and is adverse risk factor

Important to assess nutritional status In malnourished patients

- correct identifiable comorbidities - assess dialysis adequacy and increase dose if near or

below target- maximise oral intake

Nutrineal