An update on chronic renal failure:
follow-up and when to refer ?
Assoc Prof Johan Rosman
Renal Department Waitemata DHB
johan.rosman@waitematadhb.govt.nz
Apollo Health Centre, Albany
www.bloodpressure.org.nz
Chronic renal failure
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Diagnosis
Presentations and stages of CRF in general
Causes of CRF
Monitoring CRF
Consequences of CRF
Progression of CRF
Principles of treatment
Differentiation acute-chronic renal failure
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Short History (ds-wks)
Normal Hb
Normal renal size
No osteodystrophy
Periph neuropathy Normal Ca and P
Normal PTH
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Long history (mo-yrs)
Low Hb
Reduced renal size
Often osteodystrophy
Periph neuropathy +
Low Ca / elevated P
Increased PTH
Acute on chronic renal failure
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Recrudescence of primary disease
Complication of primary disease
Accelerated hypertension
Volume depletion
Cardiac failure
Sepsis
Nephrotoxins (radiocontrast, drugs)
Renal artery occlusion
Urinary tract obstruction
Dietary protein load
Presentation of CRF
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Asymptomatic serum biochemical abnormality
Asymptomatic proteinuria/haematuria
Hypertension
Symptomatic primary disease
Symptomatic uraemia
Complications of renal failure
Commonest causes of ESRF
(ANZData)
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Glomerulonephritis
Diabetes
Hypertension
Polycystic kidney disease
Vesicoureteral reflux
Analgesic nephropathy
Unknown
Others
30%
25%
10%
5%
5%
5%
10%
10%
GFR (glomerular filtration rate)
equals creatinine clearance ??
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The accurate assessment of GFR is desirable
Planning for the treatment of end stage renal disease
 Referral to nephrology
 Trace the course of progression of chronic renal
disease or response to therapy
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What is the best, most practical way to assess
GFR?
Creatinine: an imperfect marker
Afferent
arteriole
Efferent
arteriole
Glomerulus
Filtered
Secreted
Reabsorbed
20
40 60 80 100 120
GFR ml/min/1.73m2 BSA
[Creatinine]s micromole/L
200 400 600 800 1000
“Normal” GFR by Age
Age (years)
Average eGFR
20 - 29
116 ml/min/1.73m2 BSA
30 - 39
107 ml/min/1.73m2 BSA
40 - 49
99 ml/min/1.73m2 BSA
50 - 59
93 ml/min/1.73m2 BSA
60 - 69
85 ml/min/1.73m2 BSA
> 70 years
75 ml/min/1.73m2 BSA
Measuring glom. filtration rate
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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
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)
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Use the Cockroft Gault equation
Use the MDRD equation
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)
Use 1/creatinine in individual patients to see
whether a rise in creatinine represent an acute
on chronic event
Renal Screen
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BP
MSU
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RBC morphology; ACR; 24-hour proteinuria
Serum urea, creatinine, Na+, K+
Ultrasound scan renal tract
Albumin, calcium, phosphate
PTH
 eGFR
Why do 24-hour urine collection?
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Extremes of age / body size
Malnutrition or obesity
Catabolic states
Amputees / paraplegia / mm. wasting
Vegetarians / vegans
Pregnancy
Medication-dosing
Rapidly changing renal function
Problems of ESRD
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Cardiovascular disease
Anaemia
Renal Bone Disease
Metabolic acidosis
Malnutrition
Sodium and water
Potassium
Bleeding Diathesis
Dermatologic manifestations
Neurologic manifestations
Endocrine abnormalities
Immunity
Psychological manifestations
Factors causing progression of CRF
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Cont activity of primary disease
Systemic hypertension
Intraglomerular hypertension
Proteinuria
Nephrocalcinosis (dystr and metast)
Dyslipidaemia
Imbalance renal energy demands and supply
Cardiovascular Morbidity
and Proteinuria
Proteinuria
Cumulative incidence (%)
of CV morbidity
40
30
p < 0.001
20
No Proteinuria
10
0
0
1
2
3
4
5
Years
Adapted from Samuelsson et al. J Hypertens 1985;3:72
6
7
8
9
RPLM Hoogma
10
Relationship between BP and
progression of CRF
MAP (mm Hg)
GFR (mL/min per year)
98
100
102
104
106
108
110
0
–2
r = 0.66; P<0.05
–4
–6
–8
–10
Clinical trials of >3–years duration
Adapted with permission from Bakris. Diabetes Res Clin Pract 1998;39:S35
RPLM Hoogma
Principles of treatment of pat with CRF
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Differentiate from ARF on CRF
Establish aetiology
Establish severity
Seek and treat reversible factors
Seek and treat complications
Lifestyle improvements
Seek and treat factors that promote progression
Planned and timely refer to nephrologist
When to refer to renal physician?
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eGFR < 30 ml/min/1.73m2 BSA
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Proteinuria > 1G per 24 hours
Glomerular haematuria
Difficult to control hypertension
Rapidly declining GFR
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<45 in diabetics; anaemia (Hb < 100g/L)
>15% in 3 months (Australia)
Electrolytes, vascular disease, etc.
Early detection is paramount
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CKD
Preventable
 Growing @ 6%pa
 Delayed progression
 Renal abnormality is prevalent!
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16% of Australians (AusDIAB)
 15% NZers (Simmonds)
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20 x more likely to die than get RRT
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Asymptomatic
Keith et al. Arch Int Med 164:659; 2004
The key to good care
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Communication
Communication
Communication
021- KIDNEY
(021-543639)