An update on chronic renal failure: follow-up and when to refer ? Assoc Prof Johan Rosman Renal Department Waitemata DHB Apollo Health Centre, Albany

Chronic renal failure Diagnosis Diagnosis Presentations and stages of CRF in general Presentations and stages of CRF in general Causes of CRF Causes of CRF Monitoring CRF Monitoring CRF Consequences of CRF Consequences of CRF Progression of CRF Progression of CRF Principles of treatment Principles of treatment

Differentiation acute-chronic renal failure Short History (ds-wks) Short History (ds-wks) Normal Hb Normal Hb Normal renal size Normal renal size No osteodystrophy No osteodystrophy Periph neuropathy - Periph neuropathy - Normal Ca and P Normal Ca and P Normal PTH Normal PTH Long history (mo-yrs) Low Hb Reduced renal size Often osteodystrophy Periph neuropathy + Low Ca / elevated P Increased PTH

Acute on chronic renal failure Recrudescence of primary disease Recrudescence of primary disease Complication of primary disease Complication of primary disease Accelerated hypertension Accelerated hypertension Volume depletion Volume depletion Cardiac failure Cardiac failure Sepsis Sepsis Nephrotoxins (radiocontrast, drugs) Nephrotoxins (radiocontrast, drugs) Renal artery occlusion Renal artery occlusion Urinary tract obstruction Urinary tract obstruction Dietary protein load Dietary protein load

Presentation of CRF Asymptomatic serum biochemical abnormality Asymptomatic serum biochemical abnormality Asymptomatic proteinuria/haematuria Asymptomatic proteinuria/haematuria Hypertension Hypertension Symptomatic primary disease Symptomatic primary disease Symptomatic uraemia Symptomatic uraemia Complications of renal failure Complications of renal failure

Commonest causes of ESRF Glomerulonephritis30% Glomerulonephritis30% Diabetes25% Diabetes25% Hypertension10% Hypertension10% Polycystic kidney disease5% Polycystic kidney disease5% Vesicoureteral reflux5% Vesicoureteral reflux5% Analgesic nephropathy5% Analgesic nephropathy5% Unknown10% Unknown10% Others10% Others10% (ANZData)

GFR (glomerular filtration rate) equals creatinine clearance ?? The accurate assessment of GFR is desirable The accurate assessment of GFR is desirable Planning for the treatment of end stage renal disease Planning for the treatment of end stage renal disease Referral to nephrology Referral to nephrology Trace the course of progression of chronic renal disease or response to therapy Trace the course of progression of chronic renal disease or response to therapy What is the best, most practical way to assess GFR? What is the best, most practical way to assess GFR?

Creatinine: an imperfect marker Afferent arteriole Efferent arteriole Glomerulus Filtered Reabsorbed Secreted

[Creatinine] s micromole/L GFR ml/min/1.73m 2 BSA

“Normal” GFR by Age Age (years) Average eGFR ml/min/1.73m 2 BSA ml/min/1.73m 2 BSA ml/min/1.73m 2 BSA ml/min/1.73m 2 BSA ml/min/1.73m 2 BSA > 70 years 75 ml/min/1.73m 2 BSA

Measuring glom. filtration rate Many formulas have attempted to predict GFR from a serum creatinine measurement only, most factoring in age, weight/height, and gender, which are all independent of serum creatinine in influencing GFR. Many formulas have attempted to predict GFR from a serum creatinine measurement only, most factoring in age, weight/height, and gender, which are all independent of serum creatinine in influencing GFR. This would be the easiest approach clinically This would be the easiest approach clinically a serum creatinine of 130 umol/l is normal in an athlete, but can mean dialysis dependency in a 80 year old ! a serum creatinine of 130 umol/l is normal in an athlete, but can mean dialysis dependency in a 80 year old !

Aids in monitoring GFR (creat clearance ) Use the Cockroft Gault equation Use the Cockroft Gault equation Use the MDRD equation Use the MDRD equation But: in the follow up of a patient stick to the same way of estimating GFR But: in the follow up of a patient stick to the same way of estimating GFR Formula’s for free available on the web (spreadsheet) or free for Palmtop (Medcalc) Formula’s for free available on the web (spreadsheet) or free for Palmtop (Medcalc) Use 1/creatinine in individual patients to see whether a rise in creatinine represent an acute on chronic event Use 1/creatinine in individual patients to see whether a rise in creatinine represent an acute on chronic event

Renal Screen BP BP MSU MSU RBC morphology; ACR; 24-hour proteinuria RBC morphology; ACR; 24-hour proteinuria Serum urea, creatinine, Na +, K + Serum urea, creatinine, Na +, K + Ultrasound scan renal tract Ultrasound scan renal tract Albumin, calcium, phosphate Albumin, calcium, phosphate PTH PTH eGFR eGFR

Why do 24-hour urine collection? Extremes of age / body size Extremes of age / body size Malnutrition or obesity Malnutrition or obesity Catabolic states Catabolic states Amputees / paraplegia / mm. wasting Amputees / paraplegia / mm. wasting Vegetarians / vegans Vegetarians / vegans Pregnancy Pregnancy Medication-dosing Medication-dosing Rapidly changing renal function Rapidly changing renal function

Problems of ESRD Cardiovascular disease Cardiovascular disease Anaemia Anaemia Renal Bone Disease Renal Bone Disease Metabolic acidosis Metabolic acidosis Malnutrition Malnutrition Sodium and water Sodium and water Potassium Potassium Bleeding Diathesis Bleeding Diathesis Dermatologic manifestations Dermatologic manifestations Neurologic manifestations Neurologic manifestations Endocrine abnormalities Endocrine abnormalities Immunity Immunity Psychological manifestations Psychological manifestations

Factors causing progression of CRF Cont activity of primary disease Cont activity of primary disease Systemic hypertension Systemic hypertension Intraglomerular hypertension Intraglomerular hypertension Proteinuria Proteinuria Nephrocalcinosis (dystr and metast) Nephrocalcinosis (dystr and metast) Dyslipidaemia Dyslipidaemia Imbalance renal energy demands and supply Imbalance renal energy demands and supply

40 Cardiovascular Morbidity and Proteinuria Adapted from Samuelsson et al. J Hypertens 1985;3:72 No Proteinuria Years Cumulative incidence (%) of CV morbidity Proteinuria p < RPLM Hoogma

Relationship between BP and progression of CRF Adapted with permission from Bakris. Diabetes Res Clin Pract 1998;39:S35 GFR (mL/min per year) MAP (mm Hg) r = 0.66; P<0.05 –10 –8 –6 –4 – Clinical trials of >3–years duration RPLM Hoogma

Principles of treatment of pat with CRF Differentiate from ARF on CRF Differentiate from ARF on CRF Establish aetiology Establish aetiology Establish severity Establish severity Seek and treat reversible factors Seek and treat reversible factors Seek and treat complications Seek and treat complications Lifestyle improvements Lifestyle improvements Seek and treat factors that promote progression Seek and treat factors that promote progression Planned and timely refer to nephrologist Planned and timely refer to nephrologist

When to refer to renal physician? eGFR < 30 ml/min/1.73m 2 BSA eGFR < 30 ml/min/1.73m 2 BSA <45 in diabetics; anaemia (Hb < 100g/L) <45 in diabetics; anaemia (Hb < 100g/L) Proteinuria > 1G per 24 hours Proteinuria > 1G per 24 hours Glomerular haematuria Glomerular haematuria Difficult to control hypertension Difficult to control hypertension Rapidly declining GFR Rapidly declining GFR >15% in 3 months (Australia) >15% in 3 months (Australia) Electrolytes, vascular disease, etc. Electrolytes, vascular disease, etc.

Early detection is paramount CKD CKD Preventable Preventable 6%pa 6%pa Delayed progression Delayed 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 RRT 20 x more likely to die than get RRT Keith et al. Arch Int Med 164:659; 2004 Keith et al. Arch Int Med 164:659; 2004 Asymptomatic Asymptomatic

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