An update on chronic An update on chronic renal failure: follow-up renal failure: follow-up

and when to refer ?and when to refer ?

Assoc Prof Johan RosmanAssoc Prof Johan Rosman

Renal Department Waitemata Renal Department Waitemata DHBDHB

johan.rosman@waitematadhb.gojohan.rosman@waitematadhb.govt.nzvt.nz

Apollo Health Centre, AlbanyApollo Health Centre, Albany

www.bloodpressure.org.nzwww.bloodpressure.org.nz

Chronic renal failureChronic renal failure

DiagnosisDiagnosis Presentations and stages of CRF in Presentations and stages of CRF in

generalgeneral Causes of CRFCauses of CRF Monitoring CRFMonitoring CRF Consequences of CRFConsequences of CRF Progression of CRFProgression of CRF Principles of treatmentPrinciples of treatment

Differentiation acute-chronic renal Differentiation acute-chronic renal failurefailure

Short History (ds-Short History (ds-wks)wks)

Normal HbNormal Hb Normal renal sizeNormal renal size No osteodystrophyNo osteodystrophy Periph neuropathy Periph neuropathy

-- Normal Ca and PNormal Ca and P Normal PTHNormal PTH

Long history (mo-Long history (mo-yrs)yrs)

Low HbLow Hb Reduced renal sizeReduced renal size Often Often

osteodystrophyosteodystrophy Periph neuropathy Periph neuropathy

++ Low Ca / elevated PLow Ca / elevated P Increased PTHIncreased PTH

Acute on chronic renal Acute on chronic renal failurefailure

Recrudescence of primary diseaseRecrudescence of primary disease Complication of primary diseaseComplication of primary disease Accelerated hypertensionAccelerated hypertension Volume depletionVolume depletion Cardiac failureCardiac failure SepsisSepsis Nephrotoxins (radiocontrast, drugs)Nephrotoxins (radiocontrast, drugs) Renal artery occlusionRenal artery occlusion Urinary tract obstructionUrinary tract obstruction Dietary protein loadDietary protein load

Presentation of CRFPresentation of CRF

Asymptomatic serum biochemical Asymptomatic serum biochemical abnormalityabnormality

Asymptomatic Asymptomatic proteinuria/haematuriaproteinuria/haematuria

HypertensionHypertension Symptomatic primary diseaseSymptomatic primary disease Symptomatic uraemiaSymptomatic uraemia Complications of renal failureComplications of renal failure

Commonest causes of Commonest causes of ESRFESRF

GlomerulonephritisGlomerulonephritis 30%30% DiabetesDiabetes 25%25% HypertensionHypertension 10%10% Polycystic kidney diseasePolycystic kidney disease 5%5% Vesicoureteral refluxVesicoureteral reflux 5%5% Analgesic nephropathyAnalgesic nephropathy 5%5% UnknownUnknown 10%10% OthersOthers 10%10%

(ANZData)

GFR (glomerular GFR (glomerular filtration rate) equals filtration rate) equals

creatinine clearance ??creatinine clearance ?? The accurate assessment of GFR is The accurate assessment of GFR is desirabledesirable Planning for the treatment of end stage Planning for the treatment of end stage

renal diseaserenal disease Referral to nephrologyReferral to nephrology Trace the course of progression of Trace the course of progression of

chronic renal disease or response to chronic renal disease or response to therapytherapy

What is the best, most practical way What is the best, most practical way to assess GFR?to assess GFR?

Creatinine: an imperfect Creatinine: an imperfect markermarker

Afferent arteriole

Efferent arteriole

Glomerulus

Filtered

ReabsorbedSecreted

[Cre

ati

nin

e] s

m

icro

mo

le/L

GFR ml/min/1.73m2 BSA

20 40 60 80 100 120

20

04

00

60

08

00

10

00

““Normal” GFR by AgeNormal” GFR by Age

Age (years)Age (years) Average eGFRAverage eGFR

20 - 2920 - 29 116 ml/min/1.73m116 ml/min/1.73m22 BSA BSA

30 - 3930 - 39 107 ml/min/1.73m107 ml/min/1.73m22 BSA BSA

40 - 4940 - 49 99 ml/min/1.73m99 ml/min/1.73m22 BSA BSA

50 - 5950 - 59 93 ml/min/1.73m93 ml/min/1.73m22 BSA BSA

60 - 6960 - 69 85 ml/min/1.73m85 ml/min/1.73m22 BSA BSA

> 70 years> 70 years 75 ml/min/1.73m75 ml/min/1.73m22 BSA BSA

Measuring glom. Measuring glom. filtration ratefiltration rate

Many formulas have attempted to predict Many formulas have attempted to predict GFR from a serum creatinine measurement GFR from a serum creatinine measurement only, most factoring in age, weight/height, only, most factoring in age, weight/height, and gender, which are all independent of and gender, which are all independent of serum creatinine in influencing GFR. serum creatinine in influencing GFR.

This would be the easiest approach This would be the easiest approach clinicallyclinically

a serum creatinine of 130 umol/l is normal a serum creatinine of 130 umol/l is normal in an athlete, but can mean dialysis in an athlete, but can mean dialysis dependency in a 80 year old !dependency in a 80 year old !

Aids in monitoring GFR (creat Aids in monitoring GFR (creat

clearanceclearance)) Use the Cockroft Gault equationUse the Cockroft Gault equation Use the MDRD equationUse the MDRD equation But: in the follow up of a patient stick to But: in the follow up of a patient stick to

the same way of estimating GFRthe same way of estimating GFR Formula’s for free available on the web Formula’s for free available on the web

(spreadsheet) or free for Palmtop (spreadsheet) or free for Palmtop (Medcalc)(Medcalc)

Use 1/creatinine in individual patients to Use 1/creatinine in individual patients to see whether a rise in creatinine represent see whether a rise in creatinine represent an acute on chronic eventan acute on chronic event

Renal ScreenRenal Screen

BPBP MSUMSU

RBC morphology; ACR; 24-hour RBC morphology; ACR; 24-hour proteinuriaproteinuria

Serum urea, creatinine, NaSerum urea, creatinine, Na++, K, K++

Ultrasound scan renal tractUltrasound scan renal tract Albumin, calcium, phosphateAlbumin, calcium, phosphate PTHPTH eGFReGFR

Why do 24-hour urine Why do 24-hour urine collection?collection?

Extremes of age / body sizeExtremes of age / body size Malnutrition or obesityMalnutrition or obesity Catabolic statesCatabolic states Amputees / paraplegia / mm. wastingAmputees / paraplegia / mm. wasting Vegetarians / vegansVegetarians / vegans PregnancyPregnancy Medication-dosingMedication-dosing Rapidly changing renal functionRapidly changing renal function

Problems of ESRDProblems of ESRD Cardiovascular diseaseCardiovascular disease AnaemiaAnaemia Renal Bone DiseaseRenal Bone Disease Metabolic acidosisMetabolic acidosis MalnutritionMalnutrition Sodium and waterSodium and water PotassiumPotassium Bleeding DiathesisBleeding Diathesis Dermatologic manifestationsDermatologic manifestations Neurologic manifestationsNeurologic manifestations Endocrine abnormalitiesEndocrine abnormalities ImmunityImmunity Psychological manifestationsPsychological manifestations

Factors causing Factors causing progression of CRFprogression of CRF

Cont activity of primary diseaseCont activity of primary disease Systemic hypertensionSystemic hypertension Intraglomerular hypertensionIntraglomerular hypertension ProteinuriaProteinuria Nephrocalcinosis (dystr and metast)Nephrocalcinosis (dystr and metast) DyslipidaemiaDyslipidaemia Imbalance renal energy demands Imbalance renal energy demands

and supplyand supply

40

Cardiovascular Cardiovascular Morbidity Morbidity

and Proteinuriaand Proteinuria

30

20

10

0

Adapted from Samuelsson et al. J Hypertens 1985;3:72

No Proteinuria

Years0 1 2 3 4 5 6 7 8 9 10

Cu

mu

lati

ve in

cid

enc

e (%

)o

f C

V m

orb

idit

y

Proteinuria

p < 0.001

RPLM Hoogma

Relationship between Relationship between BP andBP and

progression of CRF progression of CRF

Adapted with permission from Bakris. Diabetes Res Clin Pract 1998;39:S35

GF

R (

mL

/min

per

yea

r)

MAP (mm Hg)

r = 0.66; P<0.05

––1010

––88

––66

––44

––22

009898 100100 102102 104104 106106 108108 110110

Clinical trials of >3–years duration

RPLM Hoogma

Principles of treatment of pat Principles of treatment of pat with CRFwith CRF

Differentiate from ARF on CRFDifferentiate from ARF on CRF Establish aetiologyEstablish aetiology Establish severityEstablish severity Seek and treat reversible factorsSeek and treat reversible factors Seek and treat complicationsSeek and treat complications Lifestyle improvementsLifestyle improvements Seek and treat factors that promote Seek and treat factors that promote

progressionprogression Planned and timely refer to nephrologistPlanned and timely refer to nephrologist

When to refer to renal When to refer to renal physician?physician?

eGFR < 30 ml/min/1.73meGFR < 30 ml/min/1.73m22 BSA BSA <45 in diabetics; anaemia (Hb < <45 in diabetics; anaemia (Hb <

100g/L)100g/L) Proteinuria > 1G per 24 hoursProteinuria > 1G per 24 hours Glomerular haematuriaGlomerular haematuria Difficult to control hypertensionDifficult to control hypertension Rapidly declining GFRRapidly declining GFR

>15% in 3 months (Australia)>15% in 3 months (Australia) Electrolytes, vascular disease, etc.Electrolytes, vascular disease, etc.

Early detection is Early detection is paramountparamount

CKDCKD PreventablePreventable Growing @ 6%paGrowing @ 6%pa Delayed progressionDelayed progression Renal abnormality is prevalent!Renal abnormality is prevalent!

16% of Australians (AusDIAB)16% of Australians (AusDIAB) 15% NZers (Simmonds)15% NZers (Simmonds)

20 x more likely to die than get RRT20 x more likely to die than get RRT Keith et al. Arch Int Med 164:659; 2004Keith et al. Arch Int Med 164:659; 2004

AsymptomaticAsymptomatic

The key to good careThe key to good care

CommunicationCommunication CommunicationCommunication CommunicationCommunication

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