From the Guidelines
A young adult with newly identified impaired renal function should be promptly referred to a nephrologist for comprehensive evaluation and management, as early intervention is critical to prevent long-term complications such as hypertension, cardiovascular disease, and potential progression to end-stage renal disease 1.
Initial Evaluation and Management
Initial steps include identifying and addressing reversible causes such as medication toxicity, dehydration, or urinary obstruction. A thorough workup should include:
- Comprehensive metabolic panel
- Complete blood count
- Urinalysis
- Urine protein-to-creatinine ratio
- Renal ultrasound
- Possibly additional testing based on clinical suspicion, such as estimating the glomerular filtration rate (GFR) and assessing the degree of albuminuria 1
Blood Pressure Control and Medications
Blood pressure control is essential, typically using ACE inhibitors (like enalapril 5-20 mg daily) or ARBs (such as losartan 25-100 mg daily) as first-line agents since they provide renoprotection beyond blood pressure control 1.
Dietary Modifications
Dietary modifications are crucial, including:
- Sodium restriction (<2.3g/day)
- Protein moderation (0.8g/kg/day)
- Potassium and phosphorus restriction if levels are elevated
Avoiding Nephrotoxic Medications
Nephrotoxic medications should be avoided, including NSAIDs, certain antibiotics, and contrast agents.
Regular Monitoring
Regular monitoring of renal function (every 3-6 months) is necessary to track disease progression, and referral to nephrology is recommended in case of uncertainty of etiology, worsening urinary albumin-to-creatinine ratio, or decrease in estimated GFR 1.
From the Research
Approach to Impaired Renal Function in a Young Adult
The patient's laboratory results indicate an estimated glomerular filtration rate (eGFR) of 70 mL/min/1.73m2, which is below the normal range, suggesting impaired renal function.
- The eGFR is calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, which is a widely accepted method for estimating renal function 2.
- A study published in the European Journal of Internal Medicine found that metabolic changes associated with renal impairment can occur at earlier stages of kidney disease than previously thought, emphasizing the importance of early detection and monitoring 2.
- Another study published in the Journal of Cardiac Failure found that even minor changes in renal function can be associated with adverse outcomes, highlighting the need for careful monitoring of patients with impaired renal function 3.
Diagnostic Approach
The diagnostic approach for impaired renal function typically involves a combination of laboratory tests, including serum creatinine, eGFR, and urinalysis.
- A study published in the Scottish Medical Journal found that the relationship between serum creatinine and eGFR is complex, and that different formulae for estimating eGFR can produce different results 4.
- A study published in the Journal of the American Medical Informatics Association found that machine-learning models can be used to detect chronic kidney disease using urine dipstick tests, which may be a useful tool for screening and monitoring patients with impaired renal function 5.
- A study published in Przeglad Lekarski found that serum creatinine level and eGFR are commonly used indices of renal function in clinical practice, but that there may be a need for greater awareness and education among physicians about the importance of early detection and monitoring of kidney disease 6.
Management and Monitoring
The management and monitoring of impaired renal function typically involve a combination of lifestyle modifications, medication, and regular monitoring of renal function.
- The patient's laboratory results should be monitored regularly to assess the progression of renal impairment and to adjust treatment as needed.
- Lifestyle modifications, such as a healthy diet and regular exercise, can help to slow the progression of kidney disease.
- Medication may be prescribed to control blood pressure, reduce proteinuria, and slow the progression of kidney disease.