Plasma creatinine

Excretion Virtually entirely in urine. Lithium clearance about 20% of creatinine. Plasma half-life about 20 hours. 

Urine mmol/mol creatinine Plasma pmol/l Urine mmol/mol creatinine Plasma pmol/l... 

The absorption of dietary Mn by humans is low, about 6,0%, and can range frorn 1 to 16%. About 99% of the body s losses of Mn ate fecal, with about 0.7% lost via the skin and 0.1 % via the urine. The primary route of excretion of the body s Mn is the bile, which cemtributes to the fecal rnanganese. Plasma Mn levels vary from 0.015 to 0.030 pM. Plasma Mn can vary within this range from day to day in an individual. Ked blood cell manganese is about 20 ng/ml of packed cells. Urinary Mn is fairly constant at about 7.0 nmol/g of creatinine. Plasma and urinary Mn levels seem not to be closely correlated with Mn intake. 

Trough whole blood j lacrolimus and rapamycin concentrations Serum creatinine, plasma,... 

Administration of cimetidine has also resulted in improved performance of CG to predict GFR. Ixkes and associates gave patients three 800-mg doses of cimetidine in 24 hours, and measured creatinine plasma levels from 3 to 7 hours following the final dose. During this 4-hour period, the CL iothalamate was used to measure the GFR. The CG calculations were performed with the plasma creatinine measurement 3 hours after the last dose of cimetidine. The ratio of the CG-estimated CLcriCL iothalamate decreased from 1.28 0.21 to 0.98 0.11 in the presence of cimetidine. 

Mayersohn M, Conrad KA, Achari R. The influence of a cooked meat meal on creatinine plasma concentration and creatinine clearance. Br J Clin Pharmacol 1983 15 227-230. 

For example, at low and high rates of urine flow, the minimal and maximal values of the may vary from 30% to 60% of the glomerular filtration rate. This occurs because various tubular segments are permeable to urea and allow passive reabsorption to occur under conditions of antidiuresis. The fractional excretion of urea (FE ,pa) is calculated as [(urine urea/ plasma urea)/(urine creatinine/plasma creatinine) x... 

Because its rate of production is influenced by changes in protein metabolism and its excretion by the rate of urine flow, the level of urea in plasma varies more widely than that of creatinine. Although it is therefore a less reliable indicator of glomerular function than is plasma creatinine, plasma urea is frequently used to follow changes in GFR. Note that blood and plasma or serum urea are used interchangeably because this solute freely diffuses into and out of blood cells. 

Figure 1. Frequency distributions of urinary iodine and creatinine, plasma T4 and TSH, height and weight percentiles of 156 schoolchildren from Las Hurdes (villages of Table 1), and of 354 from Madrid. 86 % of the children from Las Hurdes had goiter, vs. 1 % for the reference population. All curves for children from Las Hurdes are shifted significantly ( ) towards lower values. Drawn from data by Escobar del Rey et al.l7.

Figure 2.- Frequency distributions for urinary iodine and creatinine, plasma T4, weight and height percentiles, corresponding to 6-12 yrs.-old children from Las Hurdes (Casares, Cabezo, Aceitunillo) and from Miranda del Castaf1ar+ Cepeda, tested by Bleichrodt et al.. Goiter rates were 66 % and 23 %, respectively. indicates P<.001 n.s., P>.05.

Creatinine Plasma or serum Human, dog, rat Extrarenal influences (age, muscle mass), poor sensitivity, can be secreted by proximal tubule in rats... 

Urine (mmol/mol Creatinine)/Plasma or Serum Organic Acids (Gas Chromatography/Mass Spectrometry, GC/MS)... 

Garcia-Nieto V, Navarro JF, Sanchez-Almeida E et al (1997) Standards for ultrasound guidance of suprapubic bladder aspiration. Pediatr Nephrol 11 607-609 Guignard JP, Gouyon JB, John EG (1991) Vasoactive factors in the immature kidney. Pediatr Nephrol 5 443-446 Guignard JP, Drukker A (1999a) Why do newborn infants have elevated creatinine plasma levels Pediatrics 103 49... 

While some clinical and laboratory findings assist in the general diagnosis of ARF, others are used to differentiate between prerenal, intrinsic, and postrenal ARF. For example, patients with prerenal ARF typically demonstrate enhanced sodium reabsorption, which is reflected by a low urine sodium concentration and a low fractional excretion of sodium. Urine is typically more concentrated with prerenal ARF and there is a higher urine osmolality and urine plasma creatinine ratio compared to intrinsic and postrenal ARF. 

Replace K+ 1 0 mEq/hour when plasma K+ less than 5.5 mEq/L, ECG normal, urine flow and normal creatinine documented administer 40-80 mEq/hour when plasma K+ less than 3.5 mEq/L or if bicarbonate is given. 

Plasma blood urea nitrogen (BUN) and serum creatinine may be increased as a result of long-standing bladder outlet obstruction. 

Although the measurement of GFR with inulin is quite accurate, it is inconvenient because it requires the continuous infusion of this exogenous substance for several hours. More often, in clinical situations, the plasma clearance of creatinine is used to estimate GFR. Creatinine, an end-product of muscle metabolism, is released into the blood at a fairly constant rate. Consequently, only a single blood sample and a 24-h urine collection are needed. Measurement of the plasma clearance of creatinine provides only an estimate of GFR in fact, this measurement slightly overestimates it. A small amount of creatinine is secreted into the urine (about 10% on average). In other words, the concentration of creatinine in the urine is the result of the amount filtered (as determined by GFR) plus the amount secreted. 

After 48 h, marked increase in blood glucose, depressed plasma insulin level, marked depletion of liver glycogen, significant increase in plasma creatinine phosphokinase and glutamic oxaloacetic transaminase activity (Giri etal. 1979)... 

Renal Effects. Renal function tests (serum creatinine and urate, urinary hemoglobin, protein and glucose) completed in 11 hexachloroethane workers were within the normal range (Selden et al. 1994). Plasma hexachloroethane levels in these workers, who wore protective equipment, were 7.3 + 6.04 pg/L at the time of the tests (Selden et al. 1993). Mild skin and mucous membrane irritation were reported in the exposed group, suggesting that exposure may have been through either the inhalation or dermal routes of exposure. 

Serum creatinine is not a good measure of renal function in elderly because muscle mass is reduced and the production of creatinine is thus reduced. Estimation of GFR based on serum creatinine is therefore not accurate enough in the elderly (Baracskay et al. 1997). Creatinine clearance should be used instead. Another possibility is measurement of cystatin C in plasma. The rate of production of cystatin C is relatively constant so it seems to be a more reliable estimation of GFR also in older adults. 

Chemistry Plasma urea Plasma sodium Plasma potassium Plasma creatinine... 

Alan Smith was a 58 year old who suffered chemical bums to 35% of his body following exposure to a phenol-containing industrial solvent. He was admitted to hospital for treatment of the burns and observation. Concerns arose, when despite intravenous fluids, he failed to pass urine and plasma concentrations of urea and creatinine began to rise. 

Relative kidney weight was increased on exposure to the individual compounds at their LONEL and, to about the same extent, on combined exposure at the NONEL or the LONEL/3. The other endpoints studied (histopathology, concentrating abihty, urinary excretion of glucose, protein and marker enzymes, and plasma creatinine and urea) were not or only scarcely affected upon combined exposure at the NONEL or LONEL/3. As assessed by the effect on kidney weight, the renal toxicity of the mixtures corresponded to the effect expected on the basis of the additivity assumption (Feron et al. 1995a, Jonker et al. 1996). 

For a drug that is to be developed for a disease that occurs mainly in the elderly, it is often advisable to evaluate tolerability and pharmacokinetics in healthy elderly volunteers before clinical trials in the patient population. Dosage may need to be reduced and particular care taken when the kidney is the major organ of elimination, which should be established in the healthy young before administration to the elderly. It should be remembered that the GFR in the healthy elderly with normal plasma creatinine and urea is generally much lower than that in the young. One reason why healthy elderl/ studies have... 

Brydon and Roberts- added hemolyzed blood to unhemolyzed plasma, analyzed the specimens for a variety of constituents and then compared the values with those in the unhemolyzed plasma (B28). The following procedures were considered unaffected by hemolysis (up to 1 g/100 ml hemoglobin) urea (diacetyl monoxime) carbon dioxide content (phe-nolphthalein complex) iron binding capacity cholesterol (ferric chloride) creatinine (alkaline picrate) uric acid (phosphotungstate reduction) alkaline phosphatase (4-nitrophenyl phosphate) 5 -nucleotidase (adenosine monophosphate-nickel) and tartrate-labile acid phosphatase (phenyl phosphate). In Table 2 are shown those assays where increases were observed. The hemolysis used in these studies was equivalent to that produced by the breakdown of about 15 X 10 erythrocytes. In the bromocresol green albumin method it has been reported that for every 100 mg of hemoglobin/100 ml serum, the apparent albumin concentration is increased by 100 mg/100 ml (D12). Hemolysis releases some amino acids, such as histidine, into the plasma (Alb). 

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