The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jeffrey A. Kraut - One of the best experts on this subject based on the ideXlab platform.
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treatment of acute non Anion Gap metabolic acidosis
Ndt Plus, 2015Co-Authors: Jeffrey A. Kraut, Ira KurtzAbstract:Acute non-Anion Gap metabolic acidosis, also termed hyperchloremic acidosis, is frequently detected in seriously ill patients. The most common mechanisms leading to this acid-base disorder include loss of large quantities of base secondary to diarrhea and administration of large quantities of chloride-containing solutions in the treatment of hypovolemia and various shock states. The resultant acidic milieu can cause cellular dysfunction and contribute to poor clinical outcomes. The associated change in the chloride concentration in the distal tubule lumen might also play a role in reducing the glomerular filtration rate. Administration of base is often recommended for the treatment of acute non-Anion Gap acidosis. Importantly, the blood pH and/or serum bicarbonate concentration to guide the initiation of treatment has not been established for this type of metabolic acidosis; and most clinicians use guidelines derived from studies of high Anion Gap metabolic acidosis. Therapeutic complications resulting from base administration such as volume overload, exacerbation of hypertension and reduction in ionized calcium are likely to be as common as with high Anion Gap metabolic acidosis. On the other hand, exacerbation of intracellular acidosis due to the excessive generation of carbon dioxide might be less frequent than in high Anion Gap metabolic acidosis because of better tissue perfusion and the ability to eliminate carbon dioxide. Further basic and clinical research is needed to facilitate development of evidence-based guidelines for therapy of this important and increasingly common acid-base disorder.
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the serum Anion Gap in the evaluation of acid base disorders what are its limitations and can its effectiveness be improved
Clinical Journal of The American Society of Nephrology, 2013Co-Authors: Jeffrey A. Kraut, Glenn T NagamiAbstract:The serum Anion Gap has been utilized to identify errors in the measurement of electrolytes, to detect paraproteins, and, most relevant to the nephrologist, to evaluate patients with suspected acid-base disorders. In regard to the latter purpose, traditionally an increased Anion Gap is identified when it exceeds the upper limit of normal for a particular clinical laboratory measurement. However, because there is a wide range of normal values (often 8-10 mEq/L), an increase in Anion concentration can be present in the absence of an increased Anion Gap. In addition, the type of retained Anion can affect the magnitude of the increase in Anion Gap relative to change in serum [HCO3(-)] being greater with lactic acidosis compared with ketoacidosis. This review examines the methods of calculation of the serum Anion Gap in textbooks and published literature, the effect of perturbations other than changes in acid-base balance, and its effectiveness in identifying mild and more severe disturbances in acid-base balance. Limitations of the present methods of determining the normal Anion Gap and change in the Anion Gap are highlighted. The possibility of identifying the baseline value for individuals to optimize the use of the calculation in the detection of metabolic acidosis is suggested.
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approach to the evaluation of a patient with an increased serum osmolal Gap and high Anion Gap metabolic acidosis
American Journal of Kidney Diseases, 2011Co-Authors: Jeffrey A. Kraut, Shelly Xiaolei XingAbstract:An increase in serum osmolality and serum osmolal Gap with or without high-Anion-Gap metabolic acidosis is an important clue to exposure to one of the toxic alcohols, which include methanol, ethylene glycol, diethylene glycol, propylene glycol, or isopropanol. However, the increase in serum osmolal Gap and metabolic acidosis can occur either together or alone depending on several factors, including baseline serum osmolal Gap, molecular weight of the alcohol, and stage of metabolism of the alcohol. In addition, other disorders, including diabetic or alcoholic ketoacidosis, acute kidney injury, chronic kidney disease, and lactic acidosis, can cause high-Anion-Gap metabolic acidosis associated with an increased serum osmolal Gap and therefore should be explored in the differential diagnosis. It is essential for clinicians to understand the value and limitations of osmolal Gap to assist in reaching the correct diagnosis and initiating appropriate treatment. In this teaching case, we present a systematic approach to diagnosing high serum osmolality and increased serum osmolal Gap with or without high-Anion-Gap metabolic acidosis.
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serum Anion Gap its uses and limitations in clinical medicine
Clinical Journal of The American Society of Nephrology, 2006Co-Authors: Jeffrey A. Kraut, Nicolaos E MadiasAbstract:The serum Anion Gap, calculated from the electrolytes measured in the chemical laboratory, is defined as the sum of serum chloride and bicarbonate concentrations subtracted from the serum sodium concentration. This entity is used in the detection and analysis of acid-base disorders, assessment of quality control in the chemical laboratory, and detection of such disorders as multiple myeloma, bromide intoxication, and lithium intoxication. The normal value can vary widely, reflecting both differences in the methods that are used to measure its constituents and substantial interindividual variability. Low values most commonly indicate laboratory error or hypoalbuminemia but can denote the presence of a paraproteinemia or intoxication with lithium, bromide, or iodide. Elevated values most commonly indicate metabolic acidosis but can reflect laboratory error, metabolic alkalosis, hyperphosphatemia, or paraproteinemia. Metabolic acidosis can be divided into high Anion and normal Anion Gap varieties, which can be present alone or concurrently. A presumed 1:1 stoichiometry between change in the serum Anion Gap (DeltaAG) and change in the serum bicarbonate concentration (DeltaHCO(3)(-)) has been used to uncover the concurrence of mixed metabolic acid-base disorders in patients with high Anion Gap acidosis. However, recent studies indicate variability in the DeltaAG/DeltaHCO(3)(-) in this disorder. This observation undercuts the ability to use this ratio alone to detect complex acid-base disorders, thus emphasizing the need to consider additional information to obtain the appropriate diagnosis. Despite these caveats, calculation of the serum Anion Gap remains an inexpensive and effective tool that aids detection of various acid-base disorders, hematologic malignancies, and intoxications.
James Mcmillan - One of the best experts on this subject based on the ideXlab platform.
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ion selective electrode and Anion Gap range what should the Anion Gap be
International Journal of Nephrology and Renovascular Disease, 2013Co-Authors: Sayedali Sadjadi, Rendell Manalo, Navin Jaipaul, James McmillanAbstract:Background Using flame photometry technique in the 1970s, the normal value of Anion Gap (AG) was determined to be 12 ± 4 meq/L. However, with introduction of the autoanalyzers using an ion-selective electrode (ISE), the Anion Gap value has fallen to lower levels.
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ion selective electrode and Anion Gap range what should the Anion Gap be
International Journal of Nephrology and Renovascular Disease, 2013Co-Authors: Sayedali Sadjadi, Rendell Manalo, Navin Jaipaul, James McmillanAbstract:BACKGROUND Using flame photometry technique in the 1970s, the normal value of Anion Gap (AG) was determined to be 12 ± 4 meq/L. However, with introduction of the autoanalyzers using an ion-selective electrode (ISE), the Anion Gap value has fallen to lower levels. METHODS A retrospective study of US veterans from a single medical center was performed to determine the value of the Anion Gap in subjects with normal renal function and normal serum albumin and in patients with lactic acidosis and end-stage renal disease on dialysis. RESULTS In 409 patients with an estimated glomerular filtration rate ≥60 mL/min/1.73 m(2) body surface area and serum albumin ≥4 g/dL, the mean AG was 7.2 ± 2 (range 3-11) meq/L. In 299 patients with lactic acidosis (lactate level ≥4 meq/L) and 68 patients with endstage renal disease on dialysis, the mean AG was 12.5 meq/L and 12.4 meq/L, respectively. A value <2 meq/L should be considered a low Anion Gap and a possible clue to drug intoxication and paraproteinemic disorders. CONCLUSION With the advent of ISE for measurement of analytes, the value of the Anion Gap has fallen. Physicians need to be aware of the normal AG value in their respective institutions, and laboratories need to have an established value for AG based on the type of instrument they are using.
Rinaldo Bellomo - One of the best experts on this subject based on the ideXlab platform.
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Quantitative relationships among plasma lactate, inorganic phosphorus, albumin, unmeasured Anions and the Anion Gap in lactic acidosis.
Journal of critical care, 2017Co-Authors: James J. Figge, Rinaldo Bellomo, Moritoki EgiAbstract:Abstract Background Quantitative relationships among plasma [Lactate], [Pi], [Albumin], unmeasured Anions ([UA]) and the Anion Gap (AG K ) in lactic acidosis (LA) are not well defined. Methods A mathematical model featuring compensatory potassium and chloride shifts and respiratory changes in LA demonstrated: (1) AG K = [Lactate] + Zp × [Pi] + 2.4 × [Albumin] + constant1 + e , where Zp is a function of pH, and e reflects unmeasured Anions and cations plus pH-related variations. Eq. (1) can be algebraically rearranged to incorporate the albumin-corrected Anion Gap, cAG K : (2) cAG K = [Lactate] + Zp × [Pi] + constant2 + e . Eq. (1) was tested against 948 data sets from critically ill patients with [Lactate] 4.0 mEq/L or greater. AG K and cAG K were evaluated against 12,341 data sets for their ability to detect [Lactate] > 4.0 mEq/L. Results Analysis of Eq. (1) revealed r 2 = 0.5950, p k > 15 mEq/L exhibited a sensitivity of 93.0% [95% CI: 91.3–94.5] in detecting [Lactate] > 4.0 mEq/L, whereas AG K > 15 mEq/L exhibited a sensitivity of only 70.4% [67.5–73.2]. Additionally, [Lactate] > 4.0 mEq/L and cAG K > 20 mEq/L were each strongly associated with intensive care unit mortality (χ 2 > 200, p Conclusions In LA, cAG K is more sensitive than AG K in predicting [Lactate] > 4.0 mEq/L.
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comparison of point of care versus central laboratory measurement of electrolyte concentrations on calculations of the Anion Gap and the strong ion difference
Anesthesiology, 2003Co-Authors: Hiroshi Morimatsu, Rinaldo Bellomo, Jens Rocktaschel, Shigehiko Uchino, Donna Goldsmith, Geoffrey A GutteridgeAbstract:BackgroundClinicians calculate the Anion Gap (AG) and the strong ion difference (SID) to make acid-base diagnoses. The technology used is assumed to have limited impact. The authors hypothesized that different measurement technologies markedly affect AG and SID values.MethodsSID and AG were calculat
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estimating unmeasured Anions in critically ill patients Anion Gap base deficit and strong ion Gap
Anaesthesia, 2002Co-Authors: David A Story, S Poustie, Rinaldo BellomoAbstract:We used 100 routine blood samples from critically ill patients to establish whether correcting the Anion-Gap and base-deficit for decreased plasma albumin improves agreement with the strong-ion-Gap for estimating unmeasured Anions and whether the modifications increase the proportion of samples with levels of Anion-Gap or base-deficit above the reference ranges. We used Bland-Altman analyses to compare the methods of estimating unmeasured ions. Compared with the strong-ion-Gap, modification reduced the limits of agreement for both the Anion-Gap and the base-deficit. The bias for the base-deficit was also reduced but the bias for the Anion-Gap was increased. The proportion of samples with an Anion-Gap > 22 meq.l(-1) increased from 4 to 29% (p 5 meq.l(-1) increased from 8 to 42% (p < 0.001). Consequently, metabolic acidosis from unmeasured ions in critically ill patients maybe more frequent than often recognised.
James Helstrom - One of the best experts on this subject based on the ideXlab platform.
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diagnosing metabolic acidosis in the critically ill bridging the Anion Gap stewart and base excess methods
Canadian Journal of Anaesthesia-journal Canadien D Anesthesie, 2009Co-Authors: Christina W Fidkowski, James HelstromAbstract:Metabolic acid–base disorders are common in critically ill patients. Clinicians may have difficulty recognizing their presence when multiple metabolic acid–base derangements are present in a single patient. Clinicians should be able to identify the components of complex metabolic acid–base disorders since metabolic acidoses due to unmeasured Anions are associated with increased mortality in critically ill patients. This review presents the derivation of three commonly used methods of acid–base analysis, which include the Anion Gap, Stewart physiochemical, and modified base excess. Clinical examples are also provided to demonstrate the subtleties of the different methods and to demonstrate their application to real patient data. A comparison of these methods shows that each one is equally adept at identifying a metabolic acidosis due to unmeasured Anions; however, the Stewart physiochemical and the modified base excess methods better evaluate complex metabolic acid–base disorders. While all three methods correctly identify metabolic acidosis due to unmeasured Anions, which is a predictor of mortality, it remains unclear if further delineation of complex metabolic acid–base disorders using the Stewart physiochemical or the modified base excess methods is clinically beneficial.
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diagnosing metabolic acidosis in the critically ill bridging the Anion Gap stewart and base excess methods
Canadian Journal of Anaesthesia-journal Canadien D Anesthesie, 2009Co-Authors: Christina W Fidkowski, James HelstromAbstract:Purpose Metabolic acid–base disorders are common in critically ill patients. Clinicians may have difficulty recognizing their presence when multiple metabolic acid–base derangements are present in a single patient. Clinicians should be able to identify the components of complex metabolic acid–base disorders since metabolic acidoses due to unmeasured Anions are associated with increased mortality in critically ill patients. This review presents the derivation of three commonly used methods of acid–base analysis, which include the Anion Gap, Stewart physiochemical, and modified base excess. Clinical examples are also provided to demonstrate the subtleties of the different methods and to demonstrate their application to real patient data.
Glenn T Nagami - One of the best experts on this subject based on the ideXlab platform.
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non Anion Gap metabolic acidosis a clinical approach to evaluation
American Journal of Kidney Diseases, 2017Co-Authors: Mandana Rastegar, Glenn T NagamiAbstract:Acid-base disturbances can result from kidney or nonkidney disorders. We present a case of high-volume ileostomy output causing large bicarbonate losses and resulting in a non–Anion Gap metabolic acidosis. Non–Anion Gap metabolic acidosis can present as a form of either acute or chronic metabolic acidosis. A complete clinical history and physical examination are critical initial steps to begin the evaluation process, followed by measuring serum electrolytes with a focus on potassium level, blood gas, urine pH, and either direct or indirect urine ammonium concentration. The present case was selected to highlight the differential diagnosis of a non–Anion Gap metabolic acidosis and illustrate a systematic approach to this problem.
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the serum Anion Gap in the evaluation of acid base disorders what are its limitations and can its effectiveness be improved
Clinical Journal of The American Society of Nephrology, 2013Co-Authors: Jeffrey A. Kraut, Glenn T NagamiAbstract:The serum Anion Gap has been utilized to identify errors in the measurement of electrolytes, to detect paraproteins, and, most relevant to the nephrologist, to evaluate patients with suspected acid-base disorders. In regard to the latter purpose, traditionally an increased Anion Gap is identified when it exceeds the upper limit of normal for a particular clinical laboratory measurement. However, because there is a wide range of normal values (often 8-10 mEq/L), an increase in Anion concentration can be present in the absence of an increased Anion Gap. In addition, the type of retained Anion can affect the magnitude of the increase in Anion Gap relative to change in serum [HCO3(-)] being greater with lactic acidosis compared with ketoacidosis. This review examines the methods of calculation of the serum Anion Gap in textbooks and published literature, the effect of perturbations other than changes in acid-base balance, and its effectiveness in identifying mild and more severe disturbances in acid-base balance. Limitations of the present methods of determining the normal Anion Gap and change in the Anion Gap are highlighted. The possibility of identifying the baseline value for individuals to optimize the use of the calculation in the detection of metabolic acidosis is suggested.