The utility of the transtubular potassium gradient in the. It adjusts the urinary potassium for the concentrating effects that occur in the collecting tubule, where water is removed from the urine. The dose gradient in the present study was defined as the change in the percentage of the prescription dose per millimeter. Potassium is positive, the cell at rest is negative. Serum and urine electrolyte levels, serum creatinine, renin, aldosterone, and cortisol levels were measured, and the transtubular potassium gradient was calculated. The standard for clinical calculations and analytics in medicine. Really simply put, the concentration of 3nas out and 2ks is maintained by the sodium potassium pump this requires atp, and anything associated with active transport usually means against the concentration gradient, from low to high. Physiology lecture 4 cell communication questions and study.
This causes a change in polarity and allows the voltage gated cells to open allowing further diffusion leading to a graded potential or an action potential. This resourceful tool with its user friendly interface allows you to experience real life based clinical scenarios on your device. Salt substitutes and dietary supplements are uncommon causes of hyperkalemia, but we propose that they are underrecognized and. The transtubular potassium gradient ttkg is a formula used to assess renal handling of potassium. Water would be forced out of the lumen of the malpighian tubules through an osmotic. A normal ttkg in normal subjects on normal diets is 89. The transtubular potassium gradient calculator evaluates the conservation of potassium in the collecting ducts of the kidney. A patient with severe hyponatremia and hypokalemia. Preterm neonates were divided into two groups according to their gestational age.
Transtubular potassium gradient how is transtubular. Purchase density gradient centrifugation, volume 6 1st edition. Density gradient centrifugation, volume 6 1st edition. E501 potassium carbonates i potassium carbonate ii potassium bicarbonate potassium hydrogen carbonate e515 potassium sulphates i potassium sulphate ii ttkg transtubular k concentration gradient. The transtubular potassium concentration in patients with.
Preparation of preformed iodixanol gradients thescientificworldjournal 2002 2, 5155 53 ideally, for particles that are to be separated at 04c, the gradient should be prepared in a cold cabinet or stored for at least 1 h at this temperature before use. Renal mechanism of trimethopriminduced hyperkalemia. Although access to this page is not restricted, the information found here is intended for use by medical providers. Transtubular potassium concentration gradient as a surrogate. In the face of hyperkalemia, a low ttkg ttkg calculator is based on the kidney index helping in the differential diagnosis of hyperkalemia and hypokalemia. Learn how urine potassium differentiates between causes of. Hendersonhasselbalch osmolal gap detect unmeasured osmoles, such as toxic alcohols transtubular k gradient workup hypokalemia and hyperkalemia water deficit in hypernatremia determine water replacement in hypernatremia volume of distribution of urea calcium correction for hypoalbuminemia adjust serum calcium in the setting of low albumin total. Diagnosis and treatment of hyperkalemia cleveland clinic. Answering your questions her renin level was transtubular potassium gradient was 17 high. Family practice notebook 2020, family practice notebook, llc. Transtubular potassium gradient definition of transtubular.
The transtubular potassium gradient in the cortical collecting duct is an index reflecting conservation of potassium. Transtubular potassium gradient how is transtubular potassium gradient abbreviated. As a result, the potassium concentration is higher in the lumen of the tubules than in hemolymph. It is advantageous to make an independent assessment of the potassium k secretory process and the luminal flow rate in the renal cortex to evaluate k handling by the kidney during hypokalemia or hyperkalemia. These pages are a collection of facts identities, approximations, inequalities, relations. The utility of the transtubular potassium gradient in the evaluation of hyperkalemia. The scd group was compared to a group of 15 healthy. Urinary acidification and concentration tests were performed using calcium chloride cacl2, after a 12h period of water and food deprivation. The one situation in which the transtubular potassium gradient may be of use is determining whether hyperkalemia is a result of low aldosterone levels as opposed to aldosterone resistance. A membrane preparation enriched in the basolateral segment of the plasma membrane was isolated from the rat renal cortex by a procedure that included separation of particulates on.
Click on the image or right click to open the source website in a new browser window. Pdf a potential density gradient dependent analysis scheme. Defined expected values for ttkg in hypokalemia and hyperkalemia. Patients should address specific medical concerns with their physicians. It is useful in diagnosing the causes of hyperkalemia or hypokalemia. The use of selected urine chemistries in the diagnosis of. Patients with comorbodities such as heart failure and diabetes are predisposed to electrolyte problems. These images are a random sampling from a bing search on the term transtubular potassium gradient. It is useful in diagnosing the cause of hyperkalemia. Over the next six days, the patient received high doses of intravenous and oral potassium chloride, with slow progressive correction, and further studies were performed in order to exclude other potential causes. Download fulltext pdf a potential density gradient dependent analysis scheme for ocean multiscale data assimilation article pdf available in advances in meteorology 2017. The transtubular potassium gradient calculation and interpretation. Ttkg is sometimes criticized for being inaccurate, particularly in the evaluation of hyperkalemia. New clinical approach to evaluate disorders of potassium excretion.
The effects of trimethoprim infusion on urinary sodium, chloride, and potassium. The transtubular potassium concentration in patients with hypokalemia and hyperkalemia. A study of tubular potassium secretory capacity in older patients with hyperkalaemia. The transtubular potassium concentration in patients with hypokalemia and hyperkalemia jean h. Structural biochemistrymembrane proteinsmembrane gradients. It involves mechanical homogenization of cells in isotonic sucrose, followed by velocity centrifugation of nuclei through a denser layer of sucrose. Glasgow software free download glasgow top 4 download offers free software downloads for windows, mac, ios and android computers and mobile devices. We measured ttkg at discharge in 100 adhf patients. Ttkg transtubular potassium gradient acronymfinder. Transtubular potassium gradient ttkg is an index reflecting the conservation of potassium in the cortical collecting ducts of the kidneys. The transtubular potassium gradient ttkg is used to gauge renal potassium secretion by the cortical collecting duct, indirectly assessing mineralocorticoid bioactivity in patients who have hypo or hyperkalemia. Chapter 2 interpretation of urine electrolytes and. Treatment of hyponatremia requires indepth understanding of the mechanisms leading to these metabolic disorders, especially the role of hypokalemia in the development of hyponatremia.
The formula estimates the ratio of potassium in the lumen of the cortical collecting duct to that in the peritubular capillaries at a point where tubular fluid is. The transtubular potassium concentration gradient ttkg is a semiquantitative index of the activity of the k secretory process. Please visit the project page for details or ask questions at wikipedia talk. The ttkg estimates the ratio of potassium in the lumen of the ccd to that in the peritubular capillaries. Halperin, md it is advantageous to make an independent assessment of the potassium k secretory process and the luminal flow rate in the renal cortex to evaluate k handling by the kidney during hypokalemia. Thanks to vaibhav for presenting a case of a middleaged man with postoperative hyperkalemia, found to have a type 4 rta. You can find more information on the ttkg index results and the variables involved in the text placed under the form. Dose gradient near targetnormal structure interface for. This transtubular potassium gradient ttkg calculator is based on the kidney index helping in the differential diagnosis of hyperkalemia and hypokalemia. Ttkg urine k plasmaosm plasma k urineosm where, ttkg transtubular potassium gradient urine k urine potassium in meql or. Regulation of potassium homeostasis in ckd advances in. A potassium ion gradient is set up in the malpighian tubules through an active transport process. To determine the postnatal changes in mineralocorticoid action on the cortical distal nephron in preterm neonates, we evaluated the transtubular potassium gradient ttkg and its relationship to other renal and nonrenal parameters in 16 preterm neonates during the first 5 weeks of life. Fractional excretion of sodium fena, transtubular potassium gradient ttkg and solute free water reabsorption tch2o were calculated.
One can compare the transtubular potassium gradient before and after a physiologic dose 0. It is represented mathematically as the urinary potassium concentrationplasma potassium concentration, all divided by the. By comparing the k concentration in the kidney ducts with that from the peritubular capillaries, ttkg can help with the differential diagnosis of hyperkalemia and hypokalemia. This protocol describes a modified version of a widely used method to isolate nuclei from tissue culture cells. Mc greevy c, horan j, jones d, biswas k, omeara ym, mulkerrin ec. Results fortythree patients with hypokalemia and paralysis were identified. The purpose of this study was to define expected values. This study tested the hypothesis that ttkg can be a surrogate of arterial underfilling in patients with adhf.
The ttkg is used clinically to determine the cause of high serum potassium levels. Transtubular potassium gradient at ccd the merck manuals. We defined inadequate renal response to hyperkalemia as the combination of hyperkalemia and ttkg below the normal range established for the age of the subject. The matrix cookbook kaare brandt petersen michael syskind pedersen version. Although the consequences of acute and chronic hyperkalemia and treatment of these conditions in ckd have been widely appreciated by nephrologists, more recent information has focused attention on the consequences of chronic hypokalemia. This article is within the scope of wikiproject medicine, which recommends that medicinerelated articles follow the manual of style for medicinerelated articles and that biomedical information in any article use highquality medical sources.
Laboratory tests to determine the cause of hypokalemia and. Hyperkalemia is a common electrolyte problem in patients with chronic kidney disease. May 15, 1981 sodium gradient and sodium plus potassium gradient dependent lglutamate uptake in renal basolateral membrane vesicles. Transtubular potassium gradient ttkg is controversial but may be used for evaluation of hyperkalemia etiology ie. Another index that has been proposed for the evaluation of urine potassium loss is the transtubular potassium gradient ttkg. Halperin, md the purpose of these investigations was to describe the mechanisms responsible for the change in the plasma k during the development and maintenance of hyperchloremic metabolic acidosis. Glasgow software free download glasgow top 4 download. A normal ttkg in normal subjects on normal diets is 89 with a potassium load the ttkg may rise to 11 in the face of hyperkalemia, a low ttkg transtubular potassium gradient ttkg is used to gauge renal potassium secretion by the cortical collecting duct, indirectly assessing mineralocorticoid bioactivity in patients who have hypo.
Severe hyponatremia is a rare, but important, complication of thiazide diuretics. We recommend medical users try the free calculate by qxmd first. Calculate is a nextgeneration clinical calculator and decision support tool freely available to the medical community. Aug 21, 2017 for the love of physics walter lewin may 16, 2011 duration. Sodium gradient and sodium plus potassium gradientdependent.
Creatinine clearance transtubular potassium gradient ttkg 2. The transtubular potassium concentration gradient ttkg has been reported to be a marker of renal aldosterone bioactivity. The matrix cookbook university of california, irvine. A urine sample analysis showed urinary sodium of 50 mmoll and potassium of 65 mmoll, with a transtubular potassium gradient of 16. Transtubular potassium concentration gradient as a. How would the potassium gradient affect water movement. This is a health tool that offers information regarding the conservation.
Ttkg values 2 during hypokalemia point to renal loss. It is typically caused by medications in patients with poor kidney function. Hypokalemia report free download as powerpoint presentation. The plasma potassium concentration in metabolic acidosis. Transtubular potassium concentration gradient in preterm. The transtubular potassium gradient ttkg is a method designed to overcome the limitations of a random urine potassium concentration in the evaluation of a patient with dyskalemia. The calx are linked to the dynamic tables for visually efficient point.
Formation of continuous gradients in gradient master from 5 ml. Answering your questions 5 miul low, aldosterone was 2 234 pmoll high and her transtubular potassium gradient was 17 high. Finally, potassium excess is removed by loop or thiazidetype diuretics or by cationexchanging resins kayexalate. In patients with hypokalemia, an fek potassium loss can also be evaluated by calculating the transtubular potassium gradient ttkg using the following formula. The transtubular potassium gradient ttkg is an index reflecting the conservation of potassium in the cortical collecting ducts ccd of the kidneys. Transtubular potassium gradient ttkg calculator medical. This often is associated with hypokalemia and other metabolic abnormalities, including hypophosphatemia and metabolic alkalosis. To calculate the dose gradient or falloff rate in terms of distance, the target contours were expanded 30 mm anteriorly and posteriorly and 50 mm uniformly in all directions for all patient cases for the ck and imrt planning systems. Disturbances of potassium homeostasis can cause either hyperkalemia or hypokalemia and result in serious consequences.
1033 303 718 88 237 1276 866 1460 233 984 1007 478 606 1315 944 284 261 291 859 935 371 330 102 1460 17 314 319 3 1172 1454 303 475 742 987 876 75 1494 1147 1281 1393 467 1209