Evaluation of acid-base disorders in dogs and cats presenting to an emergency room. Part 2: Comparison of anion gap, strong ion gap, and semiquantitative analysis

2014 ◽  
Vol 24 (5) ◽  
pp. 502-508 ◽  
Author(s):  
Kate Hopper ◽  
Steven E. Epstein ◽  
Philip H. Kass ◽  
Matthew S. Mellema
Keyword(s):  
Emergency Room ◽  
Anion Gap ◽  
Semiquantitative Analysis ◽  
Strong Ion Gap ◽  
Acid Base

scholarly journals Stability of the Strong Ion Gap versus the Anion Gap over Extremes of PCO2 and pH

2007 ◽  
Vol 35 (3) ◽  
pp. 370-373 ◽  
Author(s):  
T. J. Morgan ◽  
D. M. Cowley ◽  
S. L. Weier ◽  
B. Venkatesh
Keyword(s):  
Negative Charge ◽  
Respiratory Acidosis ◽  
Anion Gap ◽  
Normal Blood ◽  
Strong Ion Difference ◽  
Blood Gas ◽  
Strong Ion Gap ◽  
Acid Base ◽  
Buffer Base

The strong ion gap (SIG) is under evaluation as a scanning tool for unmeasured ions. SIG is calculated by subtracting [buffer base], which is ([A-]+[HCO3-]), from the apparent strong ion difference, which is ([Na+] + [K+]+[Ca++]+[Mg++]-[Cl-]-[L-lactate]). A- is the negative charge on albumin and phosphate. We compared the pH stability of the SIG with that of the anion gap (AG). In normal and hypoalbuminaemic hyperlactaemic blood, PCO2 was reduced stepwise in vitro from >200 mmHg to < 20 mmHg, with serial blood gas and electrolyte analyses, and [albumin] and [phosphate] measurement on completion. Respective [haemoglobin], [albumin], [phosphate] and [lactate] in normal blood were 156 (0.9) g/l, 44 (2) g/l, 1.14 (0.06) mmol/l and 1.7 (0.8) mEq/l, and in hypoalbuminaemic blood 116 (0.9) g/l, 24 (2) g/l, 0.78 (0.06) mmol/l and 8.5 (0.5) mEq/l. pH increased from <6.85 to >7.55, causing significant falls in [Na+] and elevations in [Cl-]. Initial and final SIG values did not differ, showing no correlation with pH. Mean SIG was 0.5±1.5 mEq/l. AG values were directly correlated with pH (normal: R2=0.51, hypoalbuminaemic: R2=0.65). Final AG values significantly exceeded initial values (normal blood: 15.9 (1.7) mEq/l versus 8.9 (1.8) mEq/l, P<0.01; hypoalbuminaemic blood: 16.5 (0.8) mEq/l versus 11.8 (2.0) mEq/l, P<0.05). We conclude that, unlike the AG, the SIG is not affected by severe respiratory acidosis and alkalosis, enhancing its utility in acid-base disturbances.

scholarly journals Effect of the Independent Acid Base Variables on Anion Gap Variation in Cardiac Surgical Patients: A Stewart-Figge Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Michalis Agrafiotis ◽  
Ilias Keklikoglou ◽  
Sofia Papoti ◽  
George Diminikos ◽  
Konstantinos Diplaris ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Retrospective Study ◽  
Linear Regression ◽  
Linear Regression Model ◽  
Multiple Linear Regression Model ◽  
Anion Gap ◽  
Surgical Patients ◽  
Strong Ion Difference ◽  
Strong Ion Gap ◽  
Acid Base

Purpose. To determine the effect of each of independent acid base variables on the anion gap (AG) value in cardiac surgical patients.Methods. This retrospective study involved 128 cardiac surgical patients admitted for postoperative care. The variation of AG (AGvar) between the day of admission and the first postoperative day was correlated via a multiple linear regression model with the respective variations of the independent acid base variables, that is, apparent strong ion difference (SIDa), strong ion gap (SIG), carbon dioxide (PCO2), and albumin and phosphate concentrations.Results. The variations of all the above variables contributed significantly to the prediction ofAGvar(adjustedR2=0.9999,F=201890.24, andP<0.001). According to the standardized coefficients (β),  SIGvar(β= 0.948,P<0.001),[Albumin]var(β= 0.260,P<0.001), and[Phosphate]var(β= 0.191,P<0.001) were the major determinants ofAGvarwith lesser contributions fromSIDa, var(β= 0.071,P<0.001) andPCO2, var(β= −0.067,P<0.001).Conclusions. All the independent acid base variables contribute to the prediction of the AG value. However, albumin and phosphate and SIG variations seem to be the most important predictors, while AG appears to be rather stable with changes in PCO2andSIDa.

Anion gap physiology and faults of the correction formula

2021 ◽  
Author(s):  
Andrew K Posen ◽  
Frank P Paloucek ◽  
Renee Petzel Gimbar
Keyword(s):  
Clinical Trials ◽  
Human Physiology ◽  
Diagnostic Yield ◽  
Laboratory Parameter ◽  
Anion Gap ◽  
Acid Base ◽  
Final Version ◽  
Correction Formula ◽  
Final Article ◽  
Missed Diagnoses

Abstract Disclaimer In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose The anion gap is a calculated fundamental laboratory parameter used to identify and monitor acid-base disturbances. A recently popularized correction formula transforms the resulting integer to compensate for hypoalbuminemia and improve diagnostic yield. Clinical pharmacists should be aware of the underlying biochemistry, interpretation, and limitations of this formula to discern drug- and disease-related etiologies. Summary The anion gap is utilized in most care settings, ranging from outpatient monitoring to inpatient intensive care units. Supported by decades of experience, the original anion gap derives its value from its simplicity. Applying the anion gap in metabolic acidosis can help narrow differential diagnosis and detect concomitant acid-base disorders. To account for hypoalbuminemia and potential missed diagnoses, a correction formula was developed to improve sensitivity. Yet, the law of electroneutrality ensures that hypoalbuminemia is already accounted for in the original anion gap, and the proposed correction formula was derived from samples unrepresentative of human physiology. Evidence from clinical trials shows no benefit from applying the correction formula. Conclusion There is no advantage to correcting the anion gap, and such correction may increase the risk of misinterpretation or error. Clinicians should understand these limitations when diagnosing or trending acid-base disturbances.

Anion Gap and Strong Ion Gap

2009 ◽  
pp. 611-614
Author(s):  
John A. Kellum ◽  
Raghavan Murugan
Keyword(s):  
Anion Gap ◽  
Strong Ion Gap

scholarly journals Acid-Base Disturbances in Patients with Asthma: A Literature Review and Comments on Their Pathophysiology

2019 ◽  
Vol 8 (4) ◽  
pp. 563 ◽  
Author(s):  
Ioannis Vasileiadis ◽  
Emmanouil Alevrakis ◽  
Sevasti Ampelioti ◽  
Dimitrios Vagionas ◽  
Nikoletta Rovina ◽  
...  
Keyword(s):  
Severe Asthma ◽  
Anaerobic Metabolism ◽  
Respiratory Muscles ◽  
Anion Gap ◽  
Acute Severe Asthma ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Energy Needs ◽  
Respiratory Gases ◽  
Underlying Pathophysiology

Asthma is a common illness throughout the world that affects the respiratory system function, i.e., a system whose operational adequacy determines the respiratory gases exchange. It is therefore expected that acute severe asthma will be associated with respiratory acid-base disorders. In addition, the resulting hypoxemia along with the circulatory compromise due to heart–lung interactions can reduce tissue oxygenation, with a particular impact on respiratory muscles that have increased energy needs due to the increased workload. Thus, anaerobic metabolism may ensue, leading to lactic acidosis. Additionally, chronic hypocapnia in asthma can cause a compensatory drop in plasma bicarbonate concentration, resulting in non-anion gap acidosis. Indeed, studies have shown that in acute severe asthma, metabolic acid-base disorders may occur, i.e., high anion gap or non-anion gap metabolic acidosis. This review briefly presents studies that have investigated acid-base disorders in asthma, with comments on their underlying pathophysiology.

The use of elements of the Stewart model (Strong Ion Approach) for the diagnostics of respiratory acidosis on the basis of the calculation of a value of a modified anion gap (AGm) in brachycephalic dogs

2015 ◽  
Vol 18 (1) ◽  
pp. 217-222 ◽  
Author(s):  
P. Sławuta ◽  
K. Glińska-Suchocka ◽  
A. Cekiera
Keyword(s):  
Reference Values ◽  
Soft Palate ◽  
Respiratory Acidosis ◽  
Anion Gap ◽  
Correction Procedure ◽  
Acid Base Balance ◽  
Acid Base ◽  
Apparent Lack ◽  
Before And After ◽  
Base Balance

AbstractApart from the HH equation, the acid-base balance of an organism is also described by the Stewart model, which assumes that the proper insight into the ABB of the organism is given by an analysis of: pCO2, the difference of concentrations of strong cations and anions in the blood serum – SID, and the total concentration of nonvolatile weak acids – Acid total. The notion of an anion gap (AG), or the apparent lack of ions, is closely related to the acid-base balance described according to the HH equation. Its value mainly consists of negatively charged proteins, phosphates, and sulphates in blood. In the human medicine, a modified anion gap is used, which, including the concentration of the protein buffer of blood, is, in fact, the combination of the apparent lack of ions derived from the classic model and the Stewart model. In brachycephalic dogs, respiratory acidosis often occurs, which is caused by an overgrowth of the soft palate, making it impossible for a free air flow and causing an increase in pCO2– carbonic acid anhydride The aim of the present paper was an attempt to answer the question whether, in the case of systemic respiratory acidosis, changes in the concentration of buffering ions can also be seen. The study was carried out on 60 adult dogs of boxer breed in which, on the basis of the results of endoscopic examination, a strong overgrowth of the soft palate requiring a surgical correction was found. For each dog, the value of the anion gap before and after the palate correction procedure was calculated according to the following equation: AG = ([Na+mmol/l] + [K+mmol/l]) – ([Cl−mmol/l]+[HCO3−mmol/l]) as well as the value of the modified AG – according to the following equation: AGm= calculated AG + 2.5 × (albuminsr– albuminsd). The values of AG calculated for the dogs before and after the procedure fell within the limits of the reference values and did not differ significantly whereas the values of AGmcalculated for the dogs before and after the procedure differed from each other significantly. Conclusions: 1) On the basis of the values of AGmobtained it should be stated that in spite of finding respiratory acidosis in the examined dogs, changes in ion concentration can also be seen, which, according to the Stewart theory, compensate metabolic ABB disorders 2) In spite of the fact that all the values used for calculation of AGmwere within the limits of reference values, the values of AGmin dogs before and after the soft palate correction procedure differed from each other significantly, which proves high sensitivity and usefulness of the AGmcalculation as a diagnostic method.

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