Chronic Renal Failure for General Practice

Robin Jeffrey

Bradford Hospitals

Progressive and irreversible deterioration in glomerular +/- tubular function measured over

months and years

Pyramid of chronic renal disease

600/M

>5000/M

Measurement of renal function

• Glomerular function– Inulin clearance, radio-isotopic clearance– Creatinine clearance, Cockcroft-Gault– Serum creatinine, serum urea

• Tubular function– Serum K, PO4, urate, – Acid-base balance

• Endocrine function– Haemoglobin– Serum calcium, PO4, PTH

time

GFR

Cockcroft-Gault formula

• Calculated Crcl

= (140-age) x weight x 1.2

serum creatinine

example

• 70 year old woman• Weight 45kg• Crcl 25ml.min• Serum creatinine

132umol/l

• 25 year old male• Weight 85kg• Crcl 25ml/min• Serum creatinine

469umol/l

Urea as a marker of renal function

Elevated by• Dehydration• Increased dietary

protein inc. gut bleed• Catabolic states inc.

infection and steroids

Reduced by• Overhydration• Starvation• Liver disease• pregnancy

x x

xGFR

time

Who gets renal disease

• Elderly

• Males

• Ethnic minorities

Progression of CRF

• Continuation of primary disease process

• Factors associated with acute reversible deterioration

• Background irreversible progression

dehydrationand reduced renal perfusion obstruction

infection

toxins

hypercalcaemia

Acute insult

Background progression

• Adaptive hyperfiltration hypothesis

• Hypertension

• Proteinuria

• Tubulo-interstitial nephritis

• Hyperlipidaemia

• Cytokines

• Genetic factors

Glomerular maladaptation

Increased intraglomerular pressure

Glomerular hypertrophy

Glomerulosclerosis

Maintain GFR

GFR

time

Clinical factors associated with accelerated progression

• Hypertension

• Heavy proteinuria

• Type of renal disease

• Genetic markers

• ? Ethnic relationship

• Smokers

Management of chronic renal failure

• Reversal of underlying disease

• Avoid/treat acute insults

• Slow progression of nephropathy

• Minimise complications

• Prepare physically and mentally for renal replacement therapy

GFR

time

Slow disease progression

• Control of blood pressure

• Reduce proteinuria

• The special role of ACE inhibitors

• Low protein diet

Lewis slide from uptodate

METABOLICCOMPLICATIONS

Anaemia Left VentricularHypertrophy

AcceleratedAtherosclerosis

AcidosisRenal osteodystrophy

Catabolism

Hyperkalaemia

Management of complications

• Erythropoietin

• Sodium bicarbonate

• Calcium-based phosphate binders

• Vitamin D supplementation

• Statins

• Anti-hypertensives

Psychological and physical preparation for RRT

• Education about different forms of dialysis and transplantation

• Support and counselling of patient and family

• Surgical creation of dialysis access

• Discussion about potential living donor

CHRONICRENAL FAILURE

PRE-DIALYSIS

ESRF

RENALTRANSPLANT

LIVINGDONOR

CADAVERIC

Late referral to specialist care is associated with:

• Inferior biochemical control

• Malnourishment

• Poorer quality of life

• Longer hospitalisation

• Increased early morbidity and mortality

0

5

10

15

20

25

30

35

40

Early referral Late referral

Initiation of dialysis

• Ethics – ‘conservative care of CRF’

• Ideally smooth and programmed

• Emergency in 50%

• Absolute and relative indications