What additional follow-up is recommended for a patient with impaired renal function (eGFR of 55)?

Follow-Up for a 61-Year-Old with eGFR 55

For a 61-year-old patient with eGFR 55 (CKD Stage G3a), you should assess albuminuria immediately if not already done, monitor eGFR and albuminuria at least annually (or every 6 months if albuminuria is present), review and adjust all medications for renal dosing, optimize blood pressure control, and consider nephrology referral if there is significant albuminuria (≥300 mg/g), rapid progression (>5 mL/min/1.73 m² per year), or other concerning features. 1, 2, 3

Initial Assessment and Risk Stratification

• Measure urinary albumin-creatinine ratio (UACR) immediately if not already done, as the combination of eGFR and UACR provides critical risk stratification for both CKD progression and cardiovascular events. 1, 3

• Obtain a second eGFR measurement to confirm the diagnosis of CKD, as small fluctuations in GFR are common and a single value may not represent true kidney function. 1

• Review the patient's medical history for CKD risk factors including diabetes, hypertension, cardiovascular disease, family history of kidney disease, and use of nephrotoxic medications. 3, 4

Monitoring Frequency

• Monitor eGFR and albuminuria at least annually for patients with eGFR 45-59 mL/min/1.73 m² (Stage G3a) without significant albuminuria. 1

• Increase monitoring frequency to every 6 months if UACR is ≥30 mg/g or if there are other high-risk features such as diabetes, hypertension, or cardiovascular disease. 1, 3

• Monitor more frequently (every 3 months) if evidence of rapid progression is detected, defined as sustained decline in eGFR >5 mL/min/1.73 m² per year. 1, 2

Medication Review and Adjustment

• Review all medications for appropriate renal dosing at eGFR 55, as many drugs require dose adjustment even at this level of kidney function. 2, 3

• If the patient is on metformin, continue current dosing but check renal function more frequently; metformin should be used with caution when eGFR is between 30-60 mL/min/1.73 m² and temporarily discontinued before contrast procedures. 1, 3

• Avoid NSAIDs completely, including over-the-counter ibuprofen and naproxen, as they can precipitate acute kidney injury and accelerate CKD progression. 1, 3, 5

• If the patient has diabetes and albuminuria ≥30 mg/g, ensure they are on an ACE inhibitor or ARB for renoprotection, and strongly consider adding an SGLT2 inhibitor for additional kidney and cardiovascular protection. 3, 5

Blood Pressure Management

• Target blood pressure <140/90 mm Hg for most patients with CKD Stage G3a without significant albuminuria. 1, 2

• If albuminuria is ≥30 mg/g, target blood pressure ≤130/80 mm Hg and use an ACE inhibitor or ARB as the foundation of antihypertensive therapy. 1, 3, 5

• Monitor serum potassium when using ACE inhibitors or ARBs, especially if eGFR continues to decline. 3, 6

Cardiovascular Risk Reduction

• Initiate statin therapy if not already prescribed, as cardiovascular disease is the leading cause of morbidity and mortality in patients with CKD, and most patients with CKD die of heart disease before progressing to end-stage renal disease. 2, 4

• Address other cardiovascular risk factors including smoking cessation, weight management, and glycemic control if diabetic. 1, 3

Nephrology Referral Criteria

• Refer to nephrology if any of the following develop: eGFR <30 mL/min/1.73 m² (absolute indication), UACR ≥300 mg/g, rapid progression (sustained decline >5 mL/min/1.73 m² per year), drop in eGFR category accompanied by ≥25% decline from baseline, or unexplained eGFR decline. 1, 2, 3

• Additional referral indications include refractory hypertension requiring ≥4 antihypertensive agents, persistent electrolyte abnormalities, urinary abnormalities (red cell casts, RBC >20 per high power field), or hereditary kidney disease. 3

Common Pitfalls to Avoid

• Do not rely solely on serum creatinine to assess kidney function; always use eGFR, as creatinine levels can be misleading, especially in elderly patients with reduced muscle mass. 2, 7

• Do not delay albuminuria testing—the combination of eGFR and UACR is essential for accurate risk stratification and cannot be determined by eGFR alone. 1, 3

• Recognize that "normal" creatinine does not equal normal kidney function; eGFR 55 represents moderate kidney disease (Stage G3a) and requires active management even if the patient is asymptomatic. 2, 4

• When initiating or titrating ACE inhibitors or ARBs, expect a transient eGFR decline of up to 25%; this is hemodynamic and not harmful unless the decline exceeds this threshold or potassium rises above 5.5 mmol/L. 1, 3, 6