What are the management strategies for a patient with impaired renal function?

Management of Kidney Decline

Blood Pressure Control and RAAS Blockade

Initiate ACE inhibitors or ARBs in patients with hypertension and albuminuria, titrating to the maximum approved tolerated dose, as this represents the most evidence-based intervention to slow kidney function decline. 1

• Target systolic blood pressure <120 mmHg using standardized office measurement in most adults with CKD 2
• For patients with albuminuria (albumin-creatinine ratio >30 mg/g), ACE inhibitors or ARBs are first-line therapy regardless of blood pressure 1, 2
• Monitor serum potassium and creatinine 1-2 weeks after initiating or adjusting ACE inhibitor/ARB doses 2, 3
• Do not discontinue ACE inhibitors/ARBs for modest, stable increases in serum creatinine up to 30% above baseline 2
• Avoid combination therapy with both ACE inhibitors and ARBs, as this is harmful 1

Common Pitfall

Clinicians frequently stop ACE inhibitors/ARBs prematurely when creatinine rises modestly during initiation. This acute hemodynamic effect reflects reduced intraglomerular pressure and predicts long-term kidney protection 1. Only discontinue if creatinine rises >30% or hyperkalemia becomes unmanageable 2.

SGLT2 Inhibitors for Diabetic and Non-Diabetic CKD

Use SGLT2 inhibitors in patients with eGFR ≥20 mL/min/1.73 m² who have diabetes and/or albuminuria, as they provide the most robust recent evidence for slowing CKD progression. 4, 5

• SGLT2 inhibitors reduce the composite renal outcome by 30% in patients with type 2 diabetes and eGFR 30 to <90 mL/min/1.73 m² 4
• These agents reduce cardiovascular death or heart failure hospitalization by 31% in advanced CKD 4
• Continue SGLT2 inhibitors even as eGFR declines to 20 mL/min/1.73 m², as kidney protective effects persist 4
• Expect a modest initial eGFR decline (similar to ACE inhibitors/ARBs) that does not indicate harm 1

Dietary Modifications

Restrict dietary sodium to <2.0 g/day (<90 mmol/day) for all patients with CKD. 2

• Target dietary protein intake of 0.8 g/kg/day—the same as the general population recommendation 1, 2
• Avoid high protein intake >1.3 g/kg/day, as this accelerates CKD progression 4
• Adopt diets high in vegetables, fruits, and whole grains but low in refined carbohydrates, sugar-sweetened beverages, red meat, and ultraprocessed foods 1, 6
• Mediterranean dietary patterns and plant-based diets show observational benefits for kidney outcomes 6

Evidence Nuance

While KDIGO found no conclusive evidence that protein restriction below 0.8 g/kg/day improves outcomes 1, the NKF KDOQI recommends 0.6-0.8 g/kg/day for diabetic CKD. Given the lack of strong trial evidence and potential for malnutrition, the consensus recommendation of 0.8 g/kg/day represents the safest approach 1, 2.

Glycemic Control in Diabetic CKD

Use GLP-1 receptor agonists in patients with type 2 diabetes and CKD when cardiovascular disease is a predominant concern. 4

• Liraglutide reduces new or worsening nephropathy by 22%; semaglutide reduces it by 36% 4
• GLP-1 RAs reduce cardiovascular events and hypoglycemia while slowing CKD progression 4
• Assess HbA1c twice yearly in stable patients; quarterly in those not meeting goals or with therapy changes 1
• Discontinue metformin when eGFR falls below 30 mL/min/1.73 m² 4
• Reassess metformin benefits versus risks when eGFR falls below 45 mL/min/1.73 m² 4

Mineralocorticoid Receptor Antagonists

Consider finerenone, a nonsteroidal mineralocorticoid receptor antagonist, in patients with diabetic CKD already on RAS blockade. 4

• Finerenone is currently the only nonsteroidal MRA with proven clinical kidney and cardiovascular benefits 4
• This agent reduces CKD progression and cardiovascular events when added to ACE inhibitors/ARBs 1
• Monitor serum potassium closely, as hyperkalemia risk increases with combination therapy 7

Physical Activity

Advise moderate to vigorous physical activity totaling ≥150 minutes per week. 1, 2

• Both observational studies and randomized trials demonstrate health benefits with increased physical activity in CKD 6
• Combine aerobic and resistance training for optimal results 4
• Avoid prolonged sedentary behavior 1

Medication Management and Avoidance of Nephrotoxins

Perform thorough medication review periodically and at care transitions to assess continued indication and potential drug interactions. 1

• Estimate creatinine clearance in all patients to guide medication dosing 2, 8
• Avoid NSAIDs and COX-2 inhibitors, as they worsen kidney function and interfere with sodium excretion 8, 5
• Use caution with proton-pump inhibitors and minimize iodinated contrast exposure 5
• For procedures requiring contrast, use isosmolar agents and maintain contrast volume <4 mL/kg 8

Perioperative Management

Consider planned discontinuation of metformin, ACE inhibitors, ARBs, and SGLT2 inhibitors 48-72 hours before elective surgery 1. However, establish a clear plan for restarting these medications postoperatively and document it prominently, as failure to restart leads to unintentional harm 1.

Metabolic Acidosis Correction

Correct metabolic acidosis in patients with CKD, as this slows kidney function decline. 5

• Metabolic acidosis accelerates CKD progression through multiple mechanisms 5
• Treatment typically involves oral sodium bicarbonate supplementation 5

Specialist Referral Criteria

Refer to nephrology when eGFR falls below 30 mL/min/1.73 m² or with sustained GFR decline >20-30% after starting hemodynamically active therapies. 2

• Also refer when the cause of CKD is uncertain, for hereditary kidney disease, or with recurrent nephrolithiasis 2
• Early nephrology involvement improves outcomes and facilitates timely preparation for kidney replacement therapy 1

Fluid Management in Advanced CKD

Use loop diuretics as first-line therapy for edema management, preferring twice-daily dosing. 2

• Combination therapy with loop plus thiazide diuretics is frequently necessary to overcome diuretic resistance 8, 4
• Monitor for hypokalemia, hyponatremia, impaired GFR, and volume depletion 2
• Do not withhold diuretics to preserve eGFR in congested patients, as worsening congestion causes greater harm 1

Lifestyle Modifications Beyond Diet and Exercise

Strongly advise smoking cessation, as tobacco use accelerates CKD progression. 1, 2

• Limit alcohol consumption; binge drinking increases CKD progression risk 9
• Maintain ideal body weight through diet, physical activity, and behavioral therapy in overweight/obese patients 1

Monitoring Strategy

Monitor kidney function through serum creatinine, eGFR, and assessment of proteinuria/albuminuria at regular intervals. 2

• Assess uremic symptoms (reduced appetite, nausea, fatigue) at each consultation using standardized tools in patients with progressive CKD 1
• Monitor serum potassium regularly, especially when using RAS inhibitors, SGLT2 inhibitors, or mineralocorticoid receptor antagonists 2, 7