Workup for GFR 30 ml/min/1.73 m²
A patient with GFR 30 ml/min/1.73 m² has Stage 3b-4 chronic kidney disease and requires comprehensive laboratory monitoring every 3 months, immediate nephrology referral, complete anemia workup, mineral-bone disorder assessment, cardiovascular risk evaluation, and preparation for potential renal replacement therapy. 1, 2
Initial Laboratory Assessment
Hematologic Workup
- Check hemoglobin and complete anemia workup including iron studies (serum iron, TIBC, ferritin, transferrin saturation) if hemoglobin is <12 g/dl in women or <13 g/dl in men 1, 2
- Anemia evaluation is critical at this GFR threshold as erythropoietin deficiency becomes prevalent 1
Mineral-Bone Disorder Assessment
- Measure serum calcium, phosphorus, and intact parathyroid hormone (iPTH) at baseline 1, 2
- Check 25(OH) vitamin D levels if iPTH >100 pg/ml (or >1.5 times upper limit of normal) 1, 2
- Phosphorus levels ≥4.5 mg/dl or elevated iPTH indicate need for dietary intervention and potential phosphate binders 1
Metabolic Assessment
- Check serum bicarbonate concentration to detect metabolic acidosis 2
- Target serum bicarbonate ≥22 mmol/L to prevent bone disease and muscle wasting 2
Cardiovascular Risk Evaluation
- Obtain complete lipid panel including triglycerides, LDL, HDL, and total cholesterol 1, 2
- Evaluate for secondary causes of dyslipidemia including comorbid conditions and medications 1
- Target LDL <100 mg/dl and non-HDL cholesterol <130 mg/dl 1
Nutritional Status
- Measure serum albumin and document body weight 1, 2
- Albumin <4.0 g/dl (Bromo-Cresol-Green assay) or <3.7 g/dl (Bromo-Cresol-Purple assay) warrants nutritional evaluation 1
Monitoring Schedule
Establish quarterly monitoring (every 3 months) for: 1, 2
- GFR and albuminuria to track disease progression
- Hemoglobin levels
- Serum calcium and phosphorus
- iPTH levels (if abnormal calcium/phosphorus)
- Serum albumin and body weight
- Blood pressure at every clinic visit
Blood Pressure Management
- Check blood pressure at every clinic visit, minimum every 3 months 1, 2
- Target blood pressure <130/80 mmHg 1, 2
- Use ACE inhibitor or ARB as first-line antihypertensive agent with appropriate dose adjustment for renal function 1, 2
Medication Review
Critical medication adjustments at GFR 30: 2
- Review all medications for appropriate renal dosing
- Consider discontinuing metformin when GFR approaches <30 ml/min/1.73 m²
- Avoid nephrotoxic agents including NSAIDs
- Temporarily discontinue potentially nephrotoxic medications during acute illness
- Avoid iodinated contrast when possible 2
Nephrology Referral and RRT Planning
- Immediate referral to nephrology services is mandatory at GFR <30 ml/min/1.73 m² 2
- Begin discussions about renal replacement therapy modalities (hemodialysis, peritoneal dialysis, transplantation) 1, 2
- Initiate transplant evaluation if patient is willing and medically appropriate 1, 2
- Consider vascular access planning for future dialysis needs 2
Common Pitfalls to Avoid
- Failing to refer to nephrology when GFR falls below 30 is a critical error that delays preparation for renal replacement therapy 2
- Continuing full doses of renally excreted medications without adjustment leads to toxicity 2
- Using iodinated contrast without considering alternatives risks acute kidney injury 2
- Neglecting anemia and mineral-bone disorder screening allows preventable complications to develop 2
- Assuming elderly patients don't benefit from interventions—they still require appropriate management 2
Special Considerations
This GFR level (30 ml/min/1.73 m²) represents the boundary between Stage 3b and Stage 4 CKD, indicating loss of >70% of normal kidney function and significantly increased risk for progression to end-stage renal disease, cardiovascular complications, and mortality 2. Patients with diabetes require particularly careful monitoring of both conditions 2. An interdisciplinary care approach optimizes management of complex comorbidities 2.