Definition
One of the following:
- ≥3 months with GFR <60cc/min/1.73m2.
- Kidney damage: abnormal pathology (from biopsy), imaging, or blood/urine markers (spot urine albumin:creatinine >30mg/g, or urine protein:creatinine ratio >0.2).
- Staging:
- Stage 1: GFR >90, with kidney damage.
- Stage 2: GFR 60-90, with kidney damage.
- Stage 3: GFR 30-60 (subgroup 3a = 45-60, 3b = 30-45).
- Stage 4: GFR 15-30.
- Stage 5: GFR <15 or on dialysis.
** Now modified by degree of proteinuria to predict progression to ESRD and mortality:
- A1 (<30mg albumin/g creatinine) – normal.
- A2 (30-299mg albumin/g creatinine) – formerly microalbuminuria.
- A3 (>300mg albumin/g creatinine) – macroalbuminuria.
Etiology
- DM and HTN are responsible for up to 2/3 of all cases.
- Other causes include glomerulonephritis, APKD, rheumatologic disease, repeated infections/stones.
Evaluation
- Need to rule out acute kidney injury and rapidly progressive glomerulonephritis.
- Workup should include: UA with microscopy, urine sediment exam, spot UProt/Cr, chem 10, CBC (for CKD-related anemia), and renal US.
- Ultrasound usually shows echogenic, small kidneys bilaterally (some exceptions are DM, myeloma, HIV, amyloid, PCKD).
Management
- History: ask about risk factors for CKD (e.g., DM and HTN). Check meds for nephrotoxic agents and drugs needing dose adjustment.
- Physical: blood pressure, complications of CKD/uremia (uremic encephalopathy, volume overload, pericarditis), signs of underlying cause of CKD.
- Screening for complications: chem 10, Fe studies, PTH, 25-OH Vit D, albumin. Patients with CKD stage 3b-5 are at much higher risk of calcium/phosphate metabolism derangements, chronic acidosis, and CKD related anemia which should be addressed in the hospital even if patient is not admitted on appropriate medications.
- Supplement vitamin D if insufficient and Ca <9.5, phosphate <5.
- Start phosphate binders: calcium acetate if Ca <9.5, phosphate >7 OR sevelamer if Ca >9.5, phosphate >7.
- Start bicitra PO if HCO3 <20.
- BP control.
- If age >50 with proteinuria or anemia, consider SPEP/UPEP/IFE (or serum free light chains instead of SPEP/UPEP/IFE).
Key Points
- When to consult nephrology:
- Any patient on HD or PD is admitted.
- Help for evaluation of AKI, CKD, proteinuria, glomerulonephritis, or renal stones.
- Management of electrolyte imbalances or difficult-to-control HTN.
- Management of patients with kidney transplant (KTU fellow) or neurogenic bladder.
- Choosing Wisely: please consult nephrology prior to placement of a PICC line in patients with advanced CKD (stages III-V) to prevent subclavian stenosis and to preserve sites for future AVG/AVF for hemodialysis.
- Reducing proteinuria reduces the progression of CKD. ACEI and ARBs are the medications of choice.
Drawz P, Rahman M. Chronic Kidney Disease. Ann Intern Med. 2015;162(11):ITC1.
Ifudu O. Current concepts: Care of patients undergoing hemodialysis. N Engl J Med 1998;339:1054-1062.
KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. http://kdigo.org/home/guidelines/ckd-evaluation-management/
Lederer E, Ouseph R. Chronic kidney disease. Am J Kidney Dis 2006;49:162-171.
Parmar MS. Chronic renal disease. BMJ 2002;325:85-90.