A new principle to normalize plasma concentrations allowing single-sample clearance determinations in both children and adults

Bubeck, B.; Piepenburg, R.; Grethe, Ulrich; Ehrig, Burghard; Hahn, Klaus

doi:10.1007/bf00185857

Cited by 44 publications

(24 citation statements)

References 13 publications

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“…The clearance of 99m Tc-mercaptoacetyltriglycine ( 99m Tc-MAG3), also known as tubular extraction rate, is calculated using both the Russell algorithm (11) and the Bubeck algorithm (12 The distribution volume (in L) at time t is defined as:…”

Section: Tubular Extraction Ratementioning

confidence: 99%

Development of a Comprehensive Software Application for Calculations in Nuclear Medicine and Radiopharmacy

Perales

Mendoza²

2010

Journal of Nuclear Medicine Technology

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In the daily practice of in-hospital or centralized radiopharmacies, there is a need to perform reliable numeric calculations. Furthermore, several nuclear medicine diagnostic tests also involve carrying out calculations. In both cases, these calculations are sometimes complex or tedious and prone to error. We report the development of a computer software program that performs a comprehensive range of calculations required in radiopharmacy and nuclear medicine diagnostic tests. Methods: This software was developed and compiled in the Visual Basic programming language using algorithms and methods reflected in the scientific literature. Results: We developed 2 versions of the software program, which we call Nucleolab. It automatically performs calculations relating to radiopharmacy practice as well as 9 diagnostic nuclear medicine tests. The 0.1 version performs all these calculations, and the 1.2 version also has a database that enables the user to save and recover diagnostic test results and issue custom reports. The software can be downloaded at www.radiofarmacia.org/ nucleolab-english.Conclusion: To our knowledge, ours is the first attempt to develop a comprehensive software application that facilitates calculations in nuclear medicine and radiopharmacy, reducing errors and improving efficiency and accuracy.Key Words: nuclear medicine software; radiopharmacy software; pediatric dosage of radiopharmaceuticals; 99m Tc generator; red cell volume; plasma volume; red cell kinetic; platelet kinetic; renal plasma flow; glomerular filtration rate Cal culations-such as the appropriate pediatric dose of radiopharmaceuticals or the theoretic activity of a 99m Tc generator at any specified time point-are required in radiopharmacy but can be cumbersome and prone to error. There are also several diagnostic techniques in nuclear medicine, such as studies of red cell and platelet kinetics, blood volume, or renal function, that require complex or time-consuming calculations. All such calculations can be performed using scientific calculators or spreadsheets. The purpose of this work was to develop a software application, which we call Nucleolab, to perform the most important calculations relating to the practice of radiopharmacy and several important diagnostic techniques of nuclear medicine. In addition, we set out to link this software with a database to store test data and results and to enable the issuance of custom reports of these tests at any time. MATERIALS AND METHODSThe first stage in the design of the application was the analysis, in our respective radiopharmacies and nuclear medicine departments, of those processes involving calculations that are of some complexity or are time-consuming. After identifying these processes, we reviewed the scientific literature to find the best ways to perform the calculations. When multiple formulas were described, we tried to choose those most widely agreed upon. These algorithms and methods were used to program the calculations in the software. The computer application was develop...

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Section: Tubular Extraction Ratementioning

confidence: 99%

Development of a Comprehensive Software Application for Calculations in Nuclear Medicine and Radiopharmacy

Perales

Mendoza²

2010

Journal of Nuclear Medicine Technology

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“…Blood pressure was measured three times on every hospital visit by the digital oscillometric blood pressure monitor (Omuron HEM-907, Mie), and expressed as M ± SD. GFR was estimated by 24-hour creatinine clearance (24CCr), and effective renal plasma flow (ERPF) was calculated by Tc99m-mercaptoacetyltriglycine (MAG3) scintigram [16] at the start and end of the study. 24UP and 24-hour accumulated urine volume (24UV) were measured simultaneously.…”

Section: Study Protocolmentioning

confidence: 99%

Change of Glomerular Hemodynamics in Patients with Advanced Chronic Kidney Disease after Cilnidipine Therapy

Satomura¹,

Fujita²,

Fuke³

et al. 2009

TOCCHEMJ

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Cilnidipine, a dual calcium channel antagonist, is assumed to regulate hypertension via N-and L-type calcium channel. The N-type calcium channel is associated with sympathetic nerve activation. This effect may improve the glomerular hemodynamics in the injured nephron, and may mitigate the progression of renal injury. To clarify the effect of cilnidipine in instances of already existing decreased renal blood flow, we examined the alteration of renal hemodynamics before and after cilnidipine therapy in patients with advanced chronic kidney disease (CKD). Cilnidipine was administrated daily to 17 CKD patients with hypertension for 12 months. Another 16 patients were similarly administered amlodipine during this study, a long-acting L-type calcium channel antagonist has also been shown to be renoprotective. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and protein excretion in 24-hour accumulated urine were measured at the start and end of the study. The parameters of renal hemodynamics were calculated by Gomez's estimation equation. Systolic blood pressure decreased to 80 % of the level at the beginning of the study, and ERPF increased to 127 % of the level at baseline. Glomerular capillary pressure on single nephron was reduced to 90 %, although total GFR decreased within the non-statistical change. Especially, renal vascular resistance ratio (RA/RE) on single nephron improved to 120 %. Cilnidipine improves ERPF and glomerular hypertension without worsening total renal function. N-and L-type calcium channel antagonist is effective and safe for patients with advanced CKD as a result of improvement of glomerular capillary resistance.

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“…The plasma clearance of iohexol was determined by two different one-compartment models: (I) the iohexol clearance was determined using the single-sample technique of Jacobsson [11] with Brôchner-Mortensen [14] corrections for nonimmediate mixing and the gra dient between total extracellular concentration and plasma concen tration of iohexol during its renal excretion, and (2) the method of Bubeck et al [10], originally developed for the determination of renal plasma flow, was modified so that it could be used to determine the GFR. With this technique, a reference line was constructed which compared normalized plasma iohexol clearances with iothalamate clearances.…”

Section: Calculation O F Iohexol Clearancementioning

confidence: 99%

“…With the simplified HPLC method, the serum sample is injected directly onto the column [7], in lieu of sample preparation via precipitation with either trichloroacetic acid [8] or perchloric acid [9]. The coefficient of variation for this technique is 3.1 % for serum samples with a iohexol concentration in the range between 25 and 1.000 mg/i [7], The new one-compart ment model was originally developed by Bubeck et al [ 10] for the determination of renal blood flow. We have modi fied this model so that it can be used to calculate the GFR.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Glomerular Filtration Rate Using Nonradioactive lohexol: Comparison of Two One-Compartment Models

Rocco

Buckalew²,

Moore³

et al. 1996

Am J Nephrol

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Radioisotopic methods for the determination of the glomerular filtration rate (GFR) are highly accurate but require the collection of multiple blood and urine samples and are costly to perform due to personnel, material, and analysis costs. Nonradioactive methods of GFR determination have the potential of minimizing procedure costs while preserving accuracy. We determined the GFR simultaneously by ¹²⁵I-iothalamate and nonradioactive iohexol clearance methods in 41 adults. The study group consisted of 54% males, with a mean age of 50.7 (range 28-79) years and a mean GFR by ¹²⁵I-iothalamate clearance of 66.5 ± 28.3 (range 10-118) ml/min. The iohexol concentrations were measured by a simplified high-performance liquid chromatography method that did not require sample preparation. The iohexol plasma clearance was calculated by both a new one-compartment model as well as by Jacobsson’s one-compartment model. Using Jacobsson’s single-sample model and data from the 240-min point, there was an excellent correlation between ¹²⁵I-iothalamate and nonradioactive iohexol clearance values: r² = 0.95, standard error of the estimate = 11.4 ml/min, and intrapatient coefficient of variation = 16.9%. However, this formula tended to overestimate GFRs < 30 ml/min and to underestimate GFRs > 80 ml/min. The new one-compartment model is a modification of Bubeck’s model, originally used for the determination of renal plasma blood flow. Using this modified model, there was an excellent correlation between ¹²⁵I-iothalamate and nonradioactive iohexol clearance values at all levels of GFR tested: r² = 0.95, standard error of the estimate = 9.2 ml/min, and intrapatient coefficient of variation = 13.7%. In conclusion, the determination of the plasma clearance of iohexol by a nonradioactive technique and a monoexponential model is a simple and accurate method of determining the GFR in patients with varying degrees of renal impairment.

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A new principle to normalize plasma concentrations allowing single-sample clearance determinations in both children and adults

Cited by 44 publications

References 13 publications

Development of a Comprehensive Software Application for Calculations in Nuclear Medicine and Radiopharmacy

Development of a Comprehensive Software Application for Calculations in Nuclear Medicine and Radiopharmacy

Change of Glomerular Hemodynamics in Patients with Advanced Chronic Kidney Disease after Cilnidipine Therapy

Measurement of Glomerular Filtration Rate Using Nonradioactive lohexol: Comparison of Two One-Compartment Models

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