What is the best approach to manage a patient with impaired renal function, considering their overall health, medical history, and underlying cause of kidney damage?

Management of Renal Failure

Manage renal failure using a stage-based approach that prioritizes blood pressure control with ACE inhibitors/ARBs for patients with albuminuria, SGLT2 inhibitors for disease modification, early nephrology referral when eGFR falls below 30 mL/min/1.73m², and timely preparation for kidney replacement therapy when eGFR approaches 15 mL/min/1.73m². 1

Initial Assessment and Diagnosis

Establish Diagnosis and Chronicity

• Confirm CKD by demonstrating kidney damage or dysfunction persisting for at least 3 months using repeated measurements of eGFR and urinary albumin-to-creatinine ratio (ACR). 2
• Use serum creatinine with eGFRcr for initial GFR assessment, and when available, combine creatinine and cystatin C (eGFRcr-cys) for more accurate estimation when clinical decisions are significantly impacted. 2
• Establish chronicity by reviewing past GFR measurements, albuminuria/proteinuria results, imaging showing reduced kidney size or cortical thickness, or pathological findings of fibrosis and atrophy. 2

Determine Underlying Cause

• Establish the cause using clinical context, personal and family history, medications, physical examination, laboratory measures, imaging, and consider kidney biopsy when clinically appropriate to guide treatment decisions. 2
• Look specifically for diabetes, hypertension, glomerulonephritis (dysmorphic RBCs or RBC casts), hereditary kidney disease, or obstructive uropathy. 1, 2

Stage-Based Management Strategy

CKD Stages 1-2 (eGFR ≥60 mL/min/1.73m²)

Primary prevention and early intervention:

• Achieve strict glycemic control (HbA1c ≤7%) in diabetic patients and blood pressure control with target <140/90 mm Hg (or <130/85 mm Hg for higher-risk patients). 1, 3
• Initiate ACE inhibitor or ARB in patients with albuminuria ≥30 mg/g (A2-A3 categories), regardless of blood pressure, and titrate to maximum tolerated dose. 1, 2
• Monitor serum potassium and creatinine within 2-4 weeks of ACE inhibitor/ARB initiation or dose changes; continue therapy unless creatinine increases >30% or uncontrolled hyperkalemia develops. 1
• Evaluate and control dyslipidemia and other cardiovascular risk factors. 1

CKD Stage 3 (eGFR 30-59 mL/min/1.73m²)

Secondary prevention with complication management:

• Continue all interventions from earlier stages. 1
• Initiate SGLT2 inhibitor in patients with eGFR ≥20 mL/min/1.73m² who have diabetes, ACR ≥200 mg/g, or heart failure for disease modification. 2
• Prescribe statin therapy for all patients ≥50 years with CKD, or younger patients with diabetes, prior cardiovascular events, or 10-year cardiovascular risk >10%. 2
• Evaluate and treat anemia when hemoglobin falls below 10 g/dL; initiate erythropoietin at 50-100 Units/kg three times weekly intravenously or subcutaneously, targeting hemoglobin 10-11 g/dL (never >11 g/dL due to increased cardiovascular risks). 1, 4
• Assess and manage bone metabolism abnormalities including secondary hyperparathyroidism, vitamin D deficiency, hyperphosphatemia, and metabolic acidosis. 1
• Ensure iron supplementation when serum ferritin <100 mcg/L or transferrin saturation <20%. 4

CKD Stage 4 (eGFR 15-29 mL/min/1.73m²)

Preparation for kidney replacement therapy:

• Refer to nephrology for co-management and preparation for kidney replacement therapy. 1, 5
• Discuss treatment options including hemodialysis, peritoneal dialysis, kidney transplantation (including preemptive living donor transplantation), and comprehensive conservative management. 1
• Create vascular access for hemodialysis when creatinine >4.0 mg/dL or eGFR <20 mL/min/1.73m² to allow maturation before dialysis initiation. 1, 3
• Monitor nutritional status closely to avoid protein malnutrition; recommend protein intake of 0.8 g/kg/day and avoid high protein intake >1.3 g/kg/day. 2
• Advise sodium restriction to <2 g/day. 2

CKD Stage 5 (eGFR <15 mL/min/1.73m² or on dialysis)

Tertiary prevention with kidney replacement therapy:

• Initiate dialysis when uremic symptoms develop (altered mental status, pericarditis, bleeding), BUN >100 mg/dL, severe metabolic acidosis, refractory hyperkalemia, or volume overload unresponsive to diuretics. 1, 6
• For severe uremia with hyperammonemia and altered mental status, initiate urgent hemodialysis as first-line treatment. 6
• Monitor dialysis adequacy, bone metabolism, anemia, cardiovascular disease, and nutrition according to established guidelines. 1
• Continue evaluation for kidney transplantation, with preemptive transplantation (eGFR 5-15 mL/min/1.73m²) as the preferred option when available. 1

Medication Management and Safety

Dose Adjustments

• Adjust all medication doses based on eGFR to prevent toxicity and adverse events. 1
• Avoid nephrotoxins including NSAIDs, aminoglycosides, and unnecessary contrast agents. 1, 5
• Use iodinated contrast cautiously when eGFR <30 mL/min/1.73m²; implement adequate hydration with isotonic saline before contrast administration and use low-osmolar or iso-osmolar agents at the lowest diagnostic volume. 7
• For MRI requiring gadolinium in patients with eGFR <30 mL/min/1.73m², use macrocyclic Group II agents at the lowest diagnostic dose to minimize nephrogenic systemic fibrosis risk. 7

Monitoring During RAS Inhibitor Therapy

• Monitor serum potassium and creatinine within 2-4 weeks of initiation or dose adjustment. 1
• Accept creatinine increases up to 30% from baseline; this does not represent acute kidney injury and should not prompt discontinuation. 1
• For hyperkalemia, implement potassium restriction, initiate diuretics, use sodium bicarbonate if metabolic acidosis present, and consider gastrointestinal cation exchangers before discontinuing RAS inhibitors. 1

Multidisciplinary Care and Monitoring

Team Composition

• Establish multidisciplinary care teams including nephrologists, primary care physicians, nurses, dietitians, pharmacists, and social workers, with team composition driven by local resources and patient complexity. 1
• Utilize patient navigators for patients with social challenges or low health literacy to assist with appointments, language translation, and care coordination. 1

Monitoring Frequency

• Monitor eGFR and albuminuria annually for CKD stages 1-2 (green zone), at least once yearly for stage 3a (yellow zone), twice yearly for stage 3b (orange zone), three times yearly for stage 4 (red zone), and four times yearly for stage 5 (dark red zone). 1
• Measure blood pressure at every clinical encounter using standardized technique. 2
• Monitor for hyperkalemia especially in patients on RAS inhibitors or with eGFR <30 mL/min/1.73m². 2

Lifestyle Modifications

• Encourage 150 minutes weekly of moderate-intensity physical activity adjusted to cardiovascular tolerance. 2
• Advise tobacco cessation for all patients who use tobacco products. 1
• Recommend optimal body weight maintenance through diet and exercise. 1

Common Pitfalls to Avoid

• Do not target hemoglobin >11 g/dL with erythropoietin therapy, as this increases risks of death, serious cardiovascular reactions, and stroke. 1, 4
• Do not combine ACE inhibitors with ARBs, as combination therapy is harmful in patients with diabetes and CKD. 1
• Do not delay nephrology referral until eGFR <15 mL/min/1.73m²; refer when eGFR <30 mL/min/1.73m² or when 5-year kidney failure risk is 3-5%. 1, 2
• Do not assume chronicity based on a single abnormal eGFR or ACR measurement, as this could represent acute kidney injury requiring different management. 2
• Do not rely on serum creatinine alone without calculating eGFR, as this leads to missed diagnoses, particularly in elderly patients or those with reduced muscle mass. 2
• Do not withhold necessary contrast studies solely based on eGFR values; balance the risk of contrast-induced nephropathy against the clinical necessity of diagnostic information. 7