FENa Test:
Why FENa Test ?
CLINICAL INFORMATION
Acute kidney injury is also known as acute renal failure - is a medical emergency condition. AKI or ARF is characterized by rapid deterioration of kidney function. The causes for AKI or ARF may be due to pre-renal causes (reduced blood volume flow to the kidneys), intrinsic renal causes (Acute tubular necrosis – ATN, renal emboli, interstitial nephritis etc) and post-renal conditions (blockage in ureters, bladder, urethra due to stones, haemorrhage, tumours, trauma etc). FENa is Fractional Excretion of SODIUM(Na), i.e the quantity of salt that leaves the body through urine is actually calculated to compare with the amount of sodium filtered and reabsorbed by the kidneys. Hence, this test is a direct measure of the sodium and water from the glomerular filtrate. This test reflects the ratio between the sodium filtration rates to that of the filtration rate of the functional glomeruli. This test helps to investigate if the reduction in urine is due to the decreased blood flow to the kidneys or due to the damaged kidneys themselves. Thus the test results were evaluated by calculating the retention of sodium in response to the depleted volume of flow. Therefore the test results are helpful in patients with sudden kidney mal-functions due to any cause, that reflects acute oligo-uric injury of the kidneys in the absence of any prolonged kidney illness like Chronic kidney disease (CKD), Acute Kidney Disease (ATN), Metabolic alkalosis or any such chronic ailments of the kidneys. Low fractional excretion indicates sodium retention by kidneys due to any other extrinsic pathologies other than kidneys (urinary system), such as any pre-renal conditions like, decreased circulating blood volume in case of low blood pressure etc. Whereas a high FENa is reflected in patients with chronic kidney conditions with prolonged underlying pathologies like chronic glomerulonephritis etc. This test is a very helpful tool to screen in differential diagnosis for ATN (Acute Tubular Necrosis: ATN – characterized by inappropriate loss of sodium due to tubular damage caused in the nephrons – functional unit of a kidney) with superimposed similar clinical manifestations, to rule them out for an authentic definitive diagnosis. Thus the test report aids in initiating appropriate and effective treatment to eradicate the cause of the renal/kidney pathology. Clinical manifestations include severe pain, discomfort, greatly diminished urine flow etc. Additional tests are essential to tract the root cause of underlying pathophysiology like creatinine, urea, uric acid etc, in the urine and blood chemistry tests such as BUN etc. Other tests like imaging studies: X-rays, CT Scans, MRI, Ultrasound, angiography etc.
General Instructions:
Sample Requirement: Specimen - Urine sample. Test Preparation: None.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
