From the Guidelines
A decline in estimated glomerular filtration rate (eGFR) from 83 to 47 mL/min/1.73m² over 1.5 months indicates a rapid and significant deterioration in kidney function, suggesting acute kidney injury or a sudden worsening of underlying conditions, which requires immediate medical evaluation and intervention. This drop from normal kidney function to moderate kidney disease (Stage 3b chronic kidney disease) is alarming because the average annual decline in eGFR for individuals with chronic kidney disease (CKD) is typically much slower, ranging from 1.03 to 4.9 mL/min/1.73m² per year, as seen in various studies 1. The rapidity of this decline, exceeding the mean annual decline rates reported in the literature, such as those found by Eriksen B 1 and Levin A 1, indicates a need for urgent assessment to identify and potentially reverse the cause. Possible causes include acute kidney injury from medications, dehydration, urinary obstruction, infection, or worsening of underlying conditions like diabetes or hypertension. The patient should seek immediate medical attention, which may involve comprehensive blood work, urinalysis, and imaging studies to determine the cause and appropriate treatment. While awaiting medical evaluation, it is crucial for the patient to stay hydrated, avoid nephrotoxic substances like NSAIDs, and monitor for symptoms of worsening kidney function, such as decreased urination, swelling, shortness of breath, or confusion. The significance of this decline is further underscored by the commentary that even a decline of less than 25% in eGFR can be associated with increased risk of all-cause mortality and end-stage renal disease (ESRD) 1, highlighting the importance of prompt intervention to prevent further kidney damage.
Key considerations in the management of this patient include:
- Immediate medical evaluation to identify the cause of the rapid decline in eGFR
- Comprehensive assessment including blood work, urinalysis, and possibly imaging studies
- Avoidance of nephrotoxic medications and substances
- Monitoring for signs of worsening kidney function
- Potential intervention to reverse or halt the progression of kidney disease, depending on the underlying cause.
Given the potential for significant morbidity and mortality associated with rapid declines in kidney function, prompt medical attention is essential to address the underlying cause and prevent further deterioration in kidney function.
From the Research
Decline in Estimated Glomerular Filtration Rate (eGFR)
A decline in eGFR from 83 to 47 in 1.5 months indicates a significant reduction in kidney function. This decline can be associated with various health risks, including:
- Increased risk of end-stage renal disease (ESRD) and mortality 2
- Higher risk of cardiovascular and kidney outcomes 3
- Association with comorbidities such as diabetes, heart failure, and hypertension 4
Association with Health Risks
The studies suggest that a decline in eGFR is strongly associated with the risk of ESRD and mortality. For example:
- A 30% decline in eGFR is associated with a higher risk of ESRD and mortality compared to a 0% decline 2
- A decline in eGFR is associated with an increased risk of diabetes, heart failure, and hypertension in elderly women 4
Clinical Implications
The clinical implications of a decline in eGFR include:
- Monitoring and management of kidney disease progression 5, 6
- Consideration of alternative end points for CKD progression, such as a 30% decline in eGFR 5, 6
- Association with cardiovascular and kidney outcomes, and consideration of continued use of sodium-glucose cotransporter-2 inhibitors (SGLT2i) despite eGFR dipping 3