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GFR Calculator

Estimate your GFR and view your stage of CKD

Virtus Vita suggests an easy and simple way to calculate your GFR. We have incorporated the Cockcroft-Gault formula into the Virtus Vita GFR calculator so that you can estimate your GFR with just a few clicks. Just fill in the required fields in the GFR calculator and find out your estimated GFR.

What is the Glomerular Filtration Rate (GFR)?

The glomerular filtration rate (GFR) is a good indicator of renal function assessment and measures the ability of the kidney to filter and excrete all the useless waste products of metabolism from human body. It is probably the best indicator for assessing the functional mass of the kidneys and their filtration ability. GFR measurements or estimates are used to detect the stages of CKD or any renal disease, to assess its severity and monitor progress. This way, a clear picture of the patients’ renal condition is obtained so that treatment methods can be decided.

How is GFR estimated?

The calculation of glomerular filtration rate is done by various methods such as measurement of creatinine in plasma or determination of creatinine clearance after measurements of 24-hour urine collection and appropriate calculations or most accurately by radionucleotide methods. In everyday practice, the level of GFR can also be estimated by equations, taking account the creatinine in blood (SCr) and some other variables, such as age, gender, body size and race.

Here is an example:

Creatine clearance by Cockcroft-Gault formula:
CrCl(mi/min)= (140-age in years)x (body weight in kg)/(SCr,mg/dlx 72)
Multiplie by 0.85 if female.

More recently the modification of diet in renal disease (MDRD) study proposed the following equation:
GFR (mL/min/1.73m2) = 186 (SCr in µmol/l ? 0.011312) -1.154 ? (age)-0.203 ? (0.742 if female) ? (1.212 if African/American Black)

Stages of Chronic Kidney disease based on estimated GFR

Stage
GFR
Kidney Function
Stage 1
More than 90
Normal kidney function or known kidney disease or damage (abnormalities in blood , urine tests, imaging studies). View More
Stage 2
60 to 89
Function of kidney mildly reduced, patient diagnosed with CKD View More
Stage 3
30 to 59
Function of kidney moderately reduced. View More
Stage 4
15 to 29
Function of kidney severely reduced. View More
Stage 5
Less than 15 or idalysis
End-stage renal failure. View More

Stage 1 CKD

In the early stages of CKD (1-2) the patient is asymptomatic, SCr  is normal or near normal and fluid, acid-base and electrolyte balance are maintained through adaptive increase of function in the remaining nephrons. In stage 1, where there is normal GFR but there is kidney damage, like albuminuria, it is crucial to diagnose and proceed to treatment in order to slow or even regress the progression of CKD and even more to assess the cardiovascular risk, because proteinuria is a marker and a major risk factor of cardiovascular disease.

Stage 2 CKD

Similar to Stage 1. What is also important thing in this stage is the assessment of the progression of CKD, as the disease might give no symptoms since the remaining nephrons can still preserve the homeostasis of the human body. In this stage we should assess the rate of decline of GFR, for example a rate of 4ml/min/year means that if we cannot delay the progression, the patient will have reached the stage of kidney failure in 11 years i.e. the stage of renal replacement therapy.

Stage 3 CKD

In stage 3 of moderate kidney impairment patients usually have no symptoms, but the levels of SCr, erythropoetin, calcitriol and parathyroid hormones are abnormal. In this stage equilibration of the human homeostasis is starting to be lost, so it is crucial to evaluate and treat complications, such as hypertension, anaemia, possible bone disease, and also the decrease of quality of life. The most essential features of Stage 3 management are:

  • Tight control of blood pressure with target level: 130 mmhg systolic and 80mmhg diastolic. ACE inhibitors for all diabetics with CKD and for patients with albuminuria are the antihypertensive drugs of choice. As it is found in large trials, this drug category can delay the progression of CKD in these special groups of patients. Most patients will require more than two drugs to reach this target level of blood pressure, most importantly a diuretic and also a calcium channel blocker.
  • Tight glycemic control for diabetics.
  • Dietary protein restriction.
  • Smoking cessation.
  • Lipid lowering therapy.

Stage 4 CKD

In stage 4 of severe kidney impairment patients may have symptoms like anaemia, bone disease, hypertension, cardiovascular complications, hypocalcaemia, neuropathy, malnutrition, hyperphosphatemia, hyperkalemia, anorexia, acidosis. At this stage you are advised to see a nephrologist, start considering dialysis and get ready for the process. Click here to view the information you need about patient’s first steps to dialysis,

Stage 5 CKD

In stage 5 of GFR renal replacement therapy is required i.e. hemodialysis, peritoneal dialysis or kidney transplantation, as renal function has failed. Possible symptoms are cardiovascular issues, anorexia, nausea or vomiting, resistant hyperkalemia, etc. After your screening, your nephrologist will discuss with you the ideal and most effective therapy for you. Click here to view the information you need about dialysis.

It is important to note that -whatever the cause of CKD- the symptoms of the disease in every stage are similar, as well as all the needed measures to slow the progression of the disease.

What doctors recommend for patients in any stage of CKD:
  • Tight control of blood pressure with target level: 130 mmhg systolic and 80mmhg diastolic
  • Tight glycemic control for diabetics
  • Smoking cessation
  • Lipid lowering therapy
  • Regular exercise
  • Weight loss in case of obesity
  • Visiting your nephrologist regularly
  • Take medications and do blood tests as advised