Everything you wanted to know about CKD SUE GILDERSLEVE RENAL NURSE SPECISLIST

eGFR

CKD NSF ► Part 1 launched January 2004  Dialysis and transplantation ► Part 2 launched February 2005  Chronic kidney disease  Acute renal failure  End of life care

eGFR Good things about NSF  Raised profile of chronic kidney disease  Opportunity for education of primary care teams  Promotes the use of eGFR  Improve management particularly blood pressure control  Reduce morbidity and mortality  Promote appropriate referrals

eGFR Problems since NSF  Confusion re eGFR results  Concern at high prevalence  Confusion re use of ACE-I and ARB  Confusion over urinary albumincreatinine results  Increase in inappropriate referrals  Raised patient anxiety

eGFR  Known CKD  <1% of population  Unrecognised CKD  10% of population

eGFR ► 0.05% of UK population on dialysis or with a kidney transplant (1 in 2000) ► 1-2% of NHS budget ► £25-30,000 per dialysis patient per year  Preventing 33 cases of established renal failure per year saves ~£1m per annum

eGFR Incident Counts & Adjusted Rates, By Primary Diagnosis

eGFR GMS Contract ► ChKD 1: The practice can produce a register of patients aged 18 years and over with ChKD (US NKF Stage 3-5) 6 points ► ChKD 2: The percentage of patients on the ChKD register whose notes have a record of blood pressure in the past 15 months (40-90%) 6 points

eGFR ► ChKD 3: The % of patients on the ChKD register in whom the last blood pressure reading, measured in the previous 15 months is 140/85 or less (40-70%) 11 points ► ChKD4: The % of patients on the ChKD register who are treated with an ACEi or ARB (unless contra-indication or side effects are recorded) (40-80%) 4 points

eGFR Assessment chronic kidney disease ► Assessment of severity of CKD is more accurate when based on eGFR rather than plasma creatinine (Renal NSF 2005) ► eGFR takes into account creatinine, age and sex using the MDRD equation(Modification of Diet in Renal Disease study)

eGFR Estimating the GFR (the MDRD ‘eGFR’ equation) Only requires age, sex and blood creatinine level to automatically calculate eGFR Can be automatically generated by pathology laboratories, online or spreadsheet calculators, or by using reference tables Allows direct lab reporting to clinicians of estimated GFR Estimated GFR (eGFR) = 186 x (creatinine plasma ) x (age) x if female x 1.21 if Afro-Caribbean

eGFR Glomerular Filtration Rate ► Sum of all nephron filtration rates ► Best index of overall function ► Reduction implies a problem ► Translatable concept ► Equates to percentage Kidney function

eGFR Problems with plasma creatinine Plasma creatinine determined by muscle mass as well as renal function Normal plasma creatinine higher in:  Males vs Females  Younger vs Older  Afro-Caribbeans vs Others

eGFR Creatinine 200umol/L  eGFR 55ml/min  eGFR 5ml/min

eGFR Influencing factors on eGFR ► Obesity no effect ► Big muscle mass  creat  eGFR ► Muscle wasting  creat  eGFR ► Large meat intake  creat  eGFR ► Vegetarian  creat  eGFR ► Drugs Trimethoprin & Cimetidine  creat  eGFR

eGFR Chronic Kidney Disease Stages: Stage 1 – GFR > 90 ml/min. No kidney damage Stage 2 – GFR 60 – 90 ml/min. Evidence of kidney damage Stage 3a– GFR 45 – 60 ml/min Stage 3b – GFR ml/min Stage 4 – GFR 15 – 30 ml/min Stage 5 – Established renal failure (GFR <15)

eGFR Stage 3 is now divided into 2 groups 3A and 3B 3A lower risk eGFR B higher risk eGFR occasions over minimum 3 month period

eGFR Feb 2007 Improving classification Dipstick test for proteinuria If positive then quantify using PCR Protien Creatinine Ratio Those with Proteinuria have higher risk and are classified with the addition of suffix “p” ie 2p 3Ap 4p

eGFR Microalbuminuria ► Is the first marker of diabetic nephropathy ► Early detection and treatment can delay or prevent progression to ESRD ► Valuable marker of CV risk in T2DM ► All patients with diabetes should be screened annually

eGFR ► Ratio of albumin to creatinine in single urine sample (Early morning) ► Test only in absence of urinary tract infection ► 2 out of 3 +ve tests indicate need for treatment

eGFR Meaning of results +ve > 2.5 mg/mmol in men +ve > 3.5 mg/mmol in women

eGFR ► Unable to calculate result with urine microalbuminuria <3 means negative ► Unable to calculate with urine microalbuminuria >100mg/l, comments will be:- suggestive of proteinuria. Protein level to follow ► Results can be high in people who exercise heavily, avoid testing after heavy exercise if you suspect this may be the case

eGFR Microalbuminuria  Then monitor yearly for regression or progression  Microalbuminuria is likely progress to proteinuria, unless well managed  Microalbuminuria is reversible  Established Proteinuria is NOT reversible  If a person has proteinuria then testing for microalbuminuria is of NO VALUE

eGFR Proteinuria ► 24 hr protein estimations are no longer required ► Protein creatinine ratio can be measured in an early morning urine sample ► This x 10 gives daily protein excretion ► I.e. PCR = 100mg/mmol x 10 = 1000mg= 1g

eGFR ► It is anticipated that most patients with an eGFR less than 30 ml/min will be managed primarily by secondary care in collaboration with primary care colleagues. Lesser degrees of renal impairment will be managed in primary care with guidance and protocols from secondary care. Web address for eGFR calculator:

eGFR Why is CKD Stage 3 important: Stage 3A eGFR ml/min indicates only slight increased CV risk Stage 3B eGFR is associated with x5 increase in CV risk This is very similar to patients with a previous history of myocardial infarction. p=proteinuria further doubles current risk ie stage 3Bp

eGFR

Patients with CKD are more likely to die than require dialysis Stage GFR (ml/min) RRTDeath %19.5% %24.3% %45.7% 27,998 CKD patients followed for 5 years: Keith DS, AIM 2004;164:

eGFR

Why is hypertension important? ► Control of Hypertension  Reduces or halts eGFR decline  Control reduces risk of cardiovascular disease  Just as effective in the elderly  Most of the projected increase in dialysis is amongst the elderly

eGFR Practical guidance: ► Refer all patients with CKD Stage 4 and 5 ► Consider referral of Stage 3 if:

eGFR Stage 3 Practical management: After excluding acute cause of decline, refer if:  Younger (<55 years)  Protein 2+ or more (dipstick; PCR.100mg/mmol)  GFR has fallen by more than 10 ml/min in 1 year  Haematuria – refer urology

eGFR Acute deterioration of renal function Consider possible causes for deterioration: ► Prescribed and non prescribed drugs are responsible for up to 30% of acute renal failure ► Recent introduction of ACE/ARB allow rise of up to 30% creatinine or fall of up to 20% eGFR ► NSAID’s or other nephrotoxic drugs including penicillin (gentamycin) and chinese herbal remedies

eGFR ► Bladder outflow obstruction (any urinary symptoms?) may need renal US ► Check diuretic dose. Consider reducing or stopping diuretic if no longer needed (check ankles, JVP, postural hypotension and any other symptoms of overload or dehydration) Has diabetes been poorly controlled lately? ► Recent angiogram? Nephrotoxic dye/contrast

eGFR Stage 3 Practical Management (if not referred)  Repeat dipstick or PCR - 3A annually and 3B 6monthly  Repeat creatinine, potassium, Ca/PO 4, Hb annually  Monitor BP annually if stable (aim <130/80 or 120/70 mmHg? if progressive proteinuria)  Recent data suggests optimal BP is around 132/70 as low BP can reduce perfusion of major organs

eGFR  Vaccinations  Smoking cessation, weight reduction, low salt diet  USS renal tract only if: ► Fall in eGFR ► Haematuria ► Resistant hypertension ► Bladder outflow symptoms

eGFR Stage 3 and DIABETES  As before plus  Microalbuminuria / ACR  ACEi or ARB – creatinine can rise up to 30%  ACEi/ARB need NOT be stopped unless potassium rises >6.0 ( could try low K+ diet before stopping)  Consider stopping potassium sparing diuretics BEFORE introducing ACEi/ARB

eGFR Primary prevention of nephropathy in diabetics ► Control BP aiming for <130/70 ► Improve glycaemic control aim for Hba1c % recent data also indicates too low can be as bad as too high

eGFR Type 1 Diabetes ► 1/3 rd all Type 1 DM develop diabetic renal disease ► Reach stage 3 approx 10yrs after diagnosis ► After 20yrs they will have progressed to overt diabetic nephropathy

eGFR Type 2 Diabetes ► Type 2 DM follow a similar pattern though are not generally diagnosed until middle age ► Type 2 diabetics with diabetic nephropathy often present with microalbuminuria and hypertension

eGFR Diabetic Nephropathy ► Diabetic nephropathy is progressive ► Good BP control reduces the decline in eGFR from 12ml/min per year to 5ml/min per year ► ACEi/ARB may reduce this further to as little as 0.3ml/min per year ► Correct dyslipidaemia

eGFR WHY ACEi or ARB? ► Management of nephropathy centres on aggressive treatment of BP ► Inhibition of renin-angiotensin system ► Studies show that they reduce intraglomerular pressure over and above their effect on systemic BP ► They have been shown to reverse microalbuminuria, reduce proteinuria and reduce the rate of decline in eGFR

eGFR DUAL BLOCKADE COMBINING ACEi AND ARB ► Can be used for further control of Hypertension if other options exhausted ► Used to reduce high levels of proteinuria ► Angiotensin II can be produced by non ACE pathways ► This has been described as the ‘ACE escape’ ► ARB blocks the ‘ACE escape’

eGFR ► Cooperate study looked at dual blockade in non diabetic patients, this showed a significant benefit in dual therapy ► Combination may have additive effects in slowing progression ► More study is required in DM

eGFR Difficult to treat hypertension ► Non compliance ► White coat hypertension ► Fluid imbalance ► High salt diet ► Renal artery stenosis

eGFR Early Treatment Makes a Difference