Stages 4-5 CKD
Stage 4 CKD is severely reduced kidney function, 15-30% (eGFR 15-29ml/min/1.73m2)
Stage 5 CKD is very severely reduced kidney function (endstage or ESRF/ESRD), less than 15% (eGFR less than 15 ml/min).
Creatinine and eGFR in an individual are usually quite stable. Deteriorating renal function needs rapid assessment. Note that CKD staging and management outlined below are only applicable to stable renal function.
Assessment and management of stable Stages 4 and 5 CKD.
Initial assessment is identical to Stage 3 CKD, but in contrast to Stage 3, referral to or discussion with a specialist service will be usual. Exceptions to 'always refer or discuss' may include patients in whom:
- severe renal impairment is part of another terminal illness
- those in whom all appropriate investigations have been performed and there is an agreed and understood care pathway
- those in whom further investigation and management is clearly inappropriate.
Initial assessment of stages 4 and 5 CKD
- Is the patient well? Is there a history of significant associated disease?
- If assessment is precipitated by a first discovery of elevated creatinine, it is important to be certain that the value is stable. Maybe there are previously recorded values? If not, and the patient is well, repeat test within 14 days. Ideally this sample should be taken after a period of at least 12h without meat consumption, and the sample must get to the lab or be separated the same day. Deteriorating renal function needs rapid assessment.
- Clinical assessment - especially for sepsis, heart failure, hypovolaemia, examination for bladder enlargement (imaging indicated if obstruction suspected from symptoms or examination), cardiovascular system.
- Medication review - any potentially nephrotoxic drugs, or drugs that need dose alterations when GFR reduced?
- Urine tests: dipstick for blood and quantitation of proteinuria by ACR/PCR. Presence of haematuria or proteinuria may suggest progressive renal disease.
- Blood tests: Ca, PO4, Hb.
- Imaging - exclusion of obstruction is indicated in patients with singnificant urinary symptoms or other things to suggest obstruction.
- As above, referral or discussion is usual. Referral by urgency
Management of stable Stages 4 and 5 CKD
Typically 3 monthly estimation of
- Creatinine and K - hyperkalaemia that is severe or not responsive to changes in therapy should lead to discussion or referral.
- Hb - if low, exclude non-renal cause. More on anaemia.
- Ca and phosphate - Oral phosphate binders will often be necessary. More on Ca and phosphate.
- Urinary protein for ACR or PCR. Note thresholds; ACR 30 or PCR 50 for more stringent blood pressure targets (and suffix 'p' on CKD stage), and ACR 70 or PCR 100 for specialist referral/discussion. More on proteinuria
- Blood pressure - 140/90 max (130-139/90), or 130/80 max (120-129/80) for patients with proteinuria: urinary ACR>30 or PCR>50. More on hypertension
- Cardiovascular risk - advice on smoking, exercise and lifestyle. Consider cholesterol lowering therapy if already have macrovascular disease, or if estimated 10 year risk of cardiovascular events =/>20%. More on CV risk in CKD
- Immunization - influenza and pneumococcal, plus hepatitis B immunization if renal replacement therapy contemplated.
- Medication review - regular review of medication to minimise nephrotoxic drugs (particularly NSAIDs) and ensure doses of others are appropriate to renal function.
- In osteoporosis/ low bone density, do not use bisphosphonates or other agents that reduce bone turnover without detailed assessment of possibility of renal osteodystrophy. Specialist discussion required.