This is the updated guideline from NICE which looks at CKD. There is some stuff that as similar in this to previous guidelines, but a fair bit that is different. I have highlighted the main differences and why they have been made, then included a flow chart which covers the main features of management, then summarised some of the other important bits to be aware of.
Cystatin C is a protein that is filtered out through the kidney. Traditionally eGFR has been estimated using creatinine clearance (eGFRcreatinine), but this isn't very accurate in mild CKD and doesn't distinguish CKD from normal ageing processes. It is also highly variable with muscle mass and protein intake. Cystatin C gets around these issues - but is more expensive. Therefore the new guideline advises using eGFRcystatinC to confirm a diagnosis of CKD when the eGFRcreatinine is 45-59 and there are no other markers of renal disease (see the flowchart below). For the rest of this summary, where I use eGFR, I mean eGFRcreatinine. It is worth noting that hypothyroidism or hyperthyroidism can give an inaccurate eGFRcystatinC.
Use ACR rather than PCR or reagent strips (unless they are capable of giving an 'ACR' reading and can measure albumin at low levels).
Classification of CKD
This now includes two elements, ie CKDG4A2. The 'G' refers to the GFR bracket and the 'A' to the ACR. The reason for this is that it has become clear that the risk of progression is determined both by the ACR and by the GFR. If someone has either proteinuria or a low GFR, their risk is increased. If they have both, their risk is increased exponentially (ie not just in an additive way). Therefore expressing both gives a much clearer idea of the risk that patient is at, as demonstrated by this table from NICE.
Frequency of Monitoring
This chart from NICE gives advice on the number of times a year that a patient should be monitored. This applies to minimum frequency and you may want to increase it (eg if you are changing medication / they are unwell / their co-morbidities etc):
All patients with CKD should have a statin (atorvastatin 20mg) as it is a marker of CVD.
Flowchart outlining the main elements of management:
Now for a bit more detail on some of the elements
If you find a GFR of < 60 for the first time, repeat it in 2 weeks (to ensure it is not dropping quickly). To diagnose CKD, you need 3 readings over 90 days. NB - if the eGFR is > 90, but there is a 20% increase in creatinine, this also suggest a significant reduction in renal function.
Markers of kidney disease - these are important as even if the patient has an eGFR of > 60, they may still have CKD if they have any of these markers:
- ACR > 3
- Urine sediment abnormalities
- Electrolyte and other abnormalities due to tubular disorders
- Abnormalities detected on histology
- Structural abnormalities detected on imaging
- History of kidney transplantation
Do NOT diagnose CKD if
- eGFRcreatinine of 45-59 AND
- eGFRcystatinC of > 60 AND
- no other marker of kidney disease.
Who should be tested for renal function?
- Acute Kidney Injury ( AKI - need following up for 2 - 3 yrs, even if everything has returned to normal)
- Structural renal disease (including recurrent renal calculi or prostatic hypertrophy)
- Multisystem disease (eg SLE)
- FHx end stage renal disease or hereditary kidney disease
- Opportunistic detection of haematuria
- Drugs known to affect renal function (eg ciclosporin / tacrolimus / lithium / NSAIDS)
Who is at increased risk of progression to End Stage Renal Failure (ESRF)?
Anyone with rapid worsening of CKD as defined by:
- Sustained decrease in GFR of 25% or more AND a change in GFR category within 12m OR
- Sustained decrease in GFR of 15% per year
It is worth looking at people's rate of change and seeing if their GFR is likely to drop below 15 in their lifespan.
Other conditions increase someone's risk of progression too
- African / Afro-Caribbean / Asian in family origin
- Chronic NSAID use
- Untreated urinary outflow tract obstruction
What advice should be given to patients?
What CKD is and what it means.
Lifestyle advice (eg exercise, weight, smoking, dietary, medications)
Renal PatientView - an NHS website designed to let people access their own results etc.
How should you manage microscopic/non-visible haematuria?
- Use reagent strips to monitor - NOT microscopy
- 1+ or more of blood counts as significant
- Regard 2 out of 3 positive dipstix (on separate samples) as confirmation
- They will then need further investigation, depending on their age and situation
NB - NICE advises 50 as a cut-off for urgent referral, with those under 50 being referred non-urgently. If there is proteinuria OR raised creatinine as well, then consider nephrology referral instead. In Portsmouth, there is a haematuria clinic, with referral criteria and guidelines on PIP.
Follow-up: patients need annual follow-up with ACR / GFR / BP and dipstix, for as long as the haematuria lasts.