Introduction[edit | edit source] Show
Renal function tests (RFT) are a group of tests that may be performed together to evaluate kidney (renal) function. The tests measure levels of various substances, including several minerals, electrolytes, proteins, and glucose (sugar), in the blood to determine the current health of the kidneys. If the kidneys are not functioning properly, waste products can accumulate in the blood and fluid levels can increase to dangerous volumes, causing damage to the body or a potentially life-threatening situation. Numerous conditions and diseases can result in damage to the kidneys. The most common causes of and main risk factors for kidney disease are diabetes and hypertension. [1] Image: Kidney structure [2] This 15 minute video goes into details of RFT [3] Indication[edit | edit source]Indications for the assessment of renal function are varied and range from acute emergency to chronic settings.
Components of RFT[edit | edit source]Clinically, the most practical tests to assess renal function is to get an estimate of the glomerular filtration rate (GFR) and to check for proteinuria (albuminuria).[4] Glomerular Function- Clearance test[edit | edit source]Within the kidneys are about a million tiny blood filtering units called nephrons. In each nephron, blood is continually filtered through a cluster of looping blood vessels, called a glomerulus, which allows the passage of water and small molecules but retains blood cells, proteins such as albumin, and larger molecules. The best test to assess glomerular function is Glomerular filtration rate (GFR), which is the rate in milliliters per minute at which substances in plasma are filtered through the glomerulus; in other words, the clearance of a substance from the blood. The normal GFR for an adult male is 90 to 120 mL per minute. Testing for GFR can be a complicated and lengthy procedure, which is why doctors use a formula to estimate GFR or eGFR. The standard way to estimate GFR is with a simple blood test that measures creatinine levels. Creatinine is a waste product from the digestion of dietary protein and the normal breakdown of muscle tissue. Aside from chronic kidney disease, creatinine levels can be affected by other factors, including diet, muscle mass, malnutrition, and other chronic illnesses.[5] According to the Kidney Disease Improving Global Outcomes (KDIGO), The stages of chronic kidney disease (CKD):
Albuminuria[edit | edit source]Albuminuria refers to the abnormal presence of albumin in the urine
Urine albumin may be measured in 24-hour urine collections or early morning/random specimens as an albumin/creatinine ratio. The presence of albuminuria on two occasions with the exclusion of a urinary tract infection indicates glomerular dysfunction. The presence of albuminuria for three or more months is indicative of chronic kidney disease[4]. Typical Tests[edit | edit source]The individual tests included in a kidney function panel can vary by laboratory, but the tests typically performed include:
2. Minerals
3. Protein
4. Waste products
5. Energy Source
Clinical Significance[edit | edit source]
Physiotherapy[edit | edit source]Chronic Kidney Disease requires a multidisciplinary treatment approach. A Physiotherapist will be involved in Renal rehabilitation.[6] References[edit | edit source]
Which aspect of a patient renal function is most important for the nurse to assess?Clinically, the most practical tests to assess renal function is to get an estimate of the glomerular filtration rate (GFR) and to check for proteinuria (albuminuria). The best overall indicator of the glomerular function is the glomerular filtration rate (GFR).
What is the most important indicator of kidney function?Glomerular filtration rate is the best overall indicator of kidney function. It is superior to the serum creatinine level, which varies with age, sex, and race and often does not reflect kidney function accurately.
What is the most accurate assessment of kidney function?The GFR is considered the best overall measure of the kidney's ability to carry out these various functions, and therefore estimation of the GFR is used clinically to assess the degree of kidney impairment and to follow the course of the disease.
What should you assess for a patient with renal failure?Pulse oximetry, blood pressure, pulse, respirations and temperature should all be assessed and recorded. Ask if the patient has been diagnosed with renal failure.
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