The typical range for serum creatinine is: For adult men, 0.74 to 1.35 mg/dL (65.4 to 119.3 micromoles/L) For adult women, 0.59 to 1.04 mg/dL (52.2 to 91. It increases with increased metabolism, and decreases with renal disease. Serum creatinine is reported as milligrams of creatinine to a deciliter of blood (mg/dL) or micromoles of creatinine to a liter of blood (micromoles/L). With an elevated BUN, one way to distinguish between renal disease and increased production of urea (such as is seen in GI bleeding) is the BUN:creatinine ratio. Learn BUN (Blood Urea Nitrogen) Lab Values - Lab Values - Physiology - Picmonic for Nursing RN faster and easier with Picmonics unforgettable videos.A higher than normal BUN level may be a sign that your kidneys are not working well. A more sensitive (but more complex) test of kidney function is the creatinine clearance. In general, about 7 - 20 mg/dL is a normal level.Big changes in BUN occur only in fairly extreme circumstances.Small changes in BUN may occur from medications, dietary changes, and hydration status, and have little significance.BUN is a fast way to evaluate kidney function, but has some limitations.Increased metabolism of proteins, as is seen with GI bleeding, a high protein meal, heart attack, diabetes, or infection.Kidney malfunction, as is seen in glomerulonephritis, pyelonephritis, and shock.In particular, prerenal disease should not be excluded by a normal ratio since diminished urea production (due to decreased protein intake or underlying liver disease) can prevent the expected rise in BUN due to increased tubular reabsorption.BUN (Blood Urea Nitrogen) Urea is a waste product, formed in the liver and excreted in the urine at a relatively constant rate.īUN (blood urea nitrogen) is a measurement of the nitrogen part of urea, and is therefore an indirect measurement of the urea in the bloodstream. In case of babies, younger than twelve months. Normally, BUN and creatinine should show a ratio of 10:1 to 20:1, if the age of the affected person is more than twelve months. In contrast to the potential utility of a high BUN/serum creatinine ratio, a normal ratio is of limited diagnostic utility. For an adult female, the normal creatinine levels in blood ranges from 0.5 to 1.1 mg/dl, or from 44 to 97 mol/L by the enzymatic method. However, this problem is chronic and cannot explain an acute rise in the BUN out of proportion to any change in the serum creatinine concentration. The BUN/serum creatinine ratio can exceed 20:1 when loss of muscle mass in a chronically ill or older patient lowers creatinine production and, therefore, the serum creatinine concentration, independent of the GFR. The BUN will rise out of proportion to the serum creatinine when urea production is increased due to GI bleed (upper somewhat more than lower), tissue breakdown, or glucocorticoid therapy. Thus, a high ratio is suggestive of prerenal disease as long as some other cause of a high ratio is not present. The BUN/Cr ratio is normal at 10 to 15:1 in ATN (intrarenal), but is often greater than 20:1 in prerenal disease due to the increase in the passive reabsorption of urea that follows the enhanced proximal reabsorption of sodium and water. *** A BUN/Cr ratio that is high when BUN and Creatinine are either low or at the lower range of normal is not going to be clinically significant. In ATN, the reabsorption of BUN or secretion of Cr is decreased making the ratio to be normal. As they pass through the renal tubule, BUN is reabsorbed from the PCT (proximal convoluted tubule) while Creatinine is not reabsorbed but instead, more is secreted into the tube in the DCT. In normal circumstances, Both BUN and Cr are filtered. Renal damage causes reduced reabsorption of BUN, therefore lowering the BUN:Cr ratio. Some sources say the normal range is 10-15:1. Dehydration or hypoperfusion is suspected. BUN is disproportionately elevated relative to creatinine in serum. Urea is made in the liver as a by-product of protein metabolism. *Note that BUN=Blood urea nitrogen which is essentially a measurement of urea. The ratio may be decreased with liver disease (due to a decrease in the formation of urea) and malnutrition. It may also be seen with increased protein, from BI bleed, or increased protein in the diet. An increased ratio may be due to a condition that causes a decrease in the flow of blood to the kidneys, such as CHF or dehydration. The ratio of BUN to creatinine is usually between 10:1 and 20:1. We may look at the BUN / Creatinine ratio to help determine the cause of renal failure.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |