a. – eGFR < 60 ml/min/1.73m2
eGFR derived by the MDRD equation has become the standard to assess kidney function in most adult outpatients with stable CKD. eGFR outperforms 24 hour urine collection and/or measured GFR in diagnosis and prognostication.
Manitoba Renal Program Recommendations:
- If eGFR is reported as < 60 ml/min/1.73m2, it should be repeated to ensure it is not declining rapidly, and again after 3 months to determine if persistent, or chronic. This should also be accompanied by a urinalysis and estimation of protein excretion rate to calculate each individual’s risk of CKD progression.
- Patients are deemed to have CKD if there are abnormalities of kidney imaging, urinalysis, or function (eGFR < 60 ml/min/1.73m2) for greater than 3 months.
- Routine urinalysis and an estimate of protein excretion rate should be done to help guide diagnosis, management, and predict risk of progression of CKD.
- eGFR only provides information about the degree but not the cause of kidney impairment; further assessment of urinary sediment, protein excretion rate, and imaging, is required. Determining whether a patient has CKD should not be based on eGFR in isolation.
- eGFR should be used with caution in the very elderly, and those with extreme body composition (i.e. amputations, very obese or lean) and pregnancy. eGFR may under- or overestimate the true GFR with any of these variables.
- eGFR requires a correction/conjugation for African American ethnicity. In these patients, eGFR should be multiplied by 1.21.
- Drugs that inhibit the tubular secretion of creatinine (i.e. trimethoprim, fibric acid derivatives other than gemfibrozil) can affect the accuracy of eGFR
- eGFR should not be used in patients with acute kidney injury.
- Nephrology referral should be considered for eGFR < 60/ml/min or/and proteinuria per criteria outlined in the MRP Kidney Disease Referral Pathway.