Estimated GFR

Estimated Glomerular Filtration Rate (eGFR) is a measure used to assess the level of kidney function and determine the stage of kidney disease. It is calculated based on a blood test for creatinine, along with other factors such as age, sex, and body size. The eGFR is a critical indicator in the diagnosis, management, and treatment planning for patients with chronic kidney disease (CKD).

Overview

The glomerulus is a network of tiny blood vessels in the kidney that filters waste from the blood. The Glomerular Filtration Rate (GFR) is the rate at which this filtration occurs. However, directly measuring GFR is complicated and requires specific procedures that are not practical for routine clinical use. Therefore, the eGFR is used as a surrogate to estimate the filtering capacity of the kidneys.

Calculation

Several formulas exist for calculating eGFR, with the most commonly used being the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) and the MDRD (Modification of Diet in Renal Disease) study equation. These formulas take into account the serum creatinine levels, age, sex, and sometimes race, as these factors can influence creatinine levels in the blood.

Clinical Significance

The eGFR is used to:

• Screen for and monitor the progression of chronic kidney disease.
• Help decide when to start treatment for CKD and monitor the effectiveness of therapy.
• Determine the dosage of medications that are excreted by the kidneys to avoid drug toxicity.

Stages of Chronic Kidney Disease

Based on the eGFR, CKD is classified into five stages:

• Stage 1: eGFR ≥90 mL/min/1.73 m^2 with other signs of kidney damage
• Stage 2: eGFR of 60-89 mL/min/1.73 m^2 with other signs of kidney damage
• Stage 3: eGFR of 30-59 mL/min/1.73 m^2
• Stage 4: eGFR of 15-29 mL/min/1.73 m^2
• Stage 5: eGFR <15 mL/min/1.73 m^2 or on dialysis

Limitations

While eGFR is a useful tool, it has limitations. It may not be accurate in certain populations, such as those with extreme body types, very young or elderly individuals, pregnant women, and people with rapidly changing kidney function. Additionally, the eGFR assumes that the serum creatinine level is stable, which may not always be the case.

Conclusion

The estimated Glomerular Filtration Rate is a vital measure in the management of patients with kidney disease. It provides a non-invasive way to assess kidney function and guide clinical decisions. However, healthcare providers should be aware of its limitations and consider other diagnostic tools and clinical information when necessary.

‎

---

Translate: - East Asian 中文, 日本, 한국어, South Asian हिन्दी, தமிழ், తెలుగు, Urdu, ಕನ್ನಡ, Southeast Asian Indonesian, Vietnamese, Thai, မြန်မာဘာသာ, বাংলা
European español, Deutsch, français, Greek, português do Brasil, polski, română, русский, Nederlands, norsk, svenska, suomi, Italian
Middle Eastern & African عربى, Turkish, Persian, Hebrew, Afrikaans, isiZulu, Kiswahili,
Other Bulgarian, Hungarian, Czech, Swedish, മലയാളം, मराठी, ਪੰਜਾਬੀ, ગુજરાતી, Portuguese, Ukrainian