Acid-base analysis during experimental anemia in rats

2000 ◽  
Vol 78 (10) ◽  
pp. 774-780 ◽  
Author(s):  
J Pesquero ◽  
V Alfaro ◽  
L Palacios
Keyword(s):  
Base Excess ◽  
Respiratory Alkalosis ◽  
Physicochemical Analysis ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Experimental Conditions ◽  
Physiological Relevance ◽  
Base Analysis ◽  
Acid Base Status

The present study evaluated the acid-base status of anemic rats by using two approaches of acid-base analysis: one based on the base excess (BE) calculation and the other based on Stewart's physicochemical analysis. Two sets of experimental data, derived from two different methods of inducing anemia, were used: repetitive doses of phenylhydrazine (PHZ) and bleeding (BL). A significant uncompensated respiratory alkalosis was found in both groups of anemic rats. BE increased slightly, whereas strong ion difference ([SID]) and weak acid buffers ([ATOT]) remained unchanged in anemic rats. The reasons for the absence of compensation for hypocapnia and the differences in the behaviour of acid-base variables are discussed. BE increase was considered paradoxical; its calculation was affected by the experimental conditions and BE had little physiological relevance during anemia. The absence of metabolic renal compensation in anemic rats could be due to a lower pH in the kidney due to anemic hypoxia. Finally, the changes in buffer strength related to low Hb and low Pc02 might influence plasma [SID] through counteracted shifts of strong ions between erythrocytes and plasma, finally resulting in unchanged [SID] during anemia.Key words: anemia, phenylhydrazine, bleeding, base excess, strong ion difference, non-carbonic buffers.

scholarly journals Base-excess chloride; the best approach to evaluate the effect of chloride on the acid-base status: A retrospective study

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250274
Author(s):  
Bulent Gucyetmez ◽  
Filiz Tuzuner ◽  
Hakan Korkut Atalan ◽  
Uğur Sezerman ◽  
Kaan Gucyetmez ◽  
...  
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Base Excess ◽  
Tertiary Care ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Entire Cohort ◽  
Acid Base Status ◽  
Evaluation Approaches

To practically determine the effect of chloride (Cl) on the acid-base status, four approaches are currently used: accepted ranges of serum Cl values; Cl corrections; the serum Cl/Na ratio; and the serum Na-Cl difference. However, these approaches are governed by different concepts. Our aim is to investigate which approach to the evaluation of the effect of Cl is the best. In this retrospective cohort study, 2529 critically ill patients who were admitted to the tertiary care unit between 2011 and 2018 were retrospectively evaluated. The effects of Cl on the acid-base status according to each evaluative approach were validated by the standard base excess (SBE) and apparent strong ion difference (SIDa). To clearly demonstrate only the effects of Cl on the acid-base status, a subgroup that included patients with normal lactate, albumin and SIG values was created. To compare approaches, kappa and a linear regression model for all patients and Bland-Altman test for a subgroup were used. In both the entire cohort and the subgroup, correlations among BECl, SIDa and SBE were stronger than those for other approaches (r = 0.94 r = 0.98 and r = 0.96 respectively). Only BECl had acceptable limits of agreement with SBE in the subgroup (bias: 0.5 mmol L-1) In the linear regression model, only BECl in all the Cl evaluation approaches was significantly related to the SBE. For the evaluation of the effect of chloride on the acid-base status, BECl is a better approach than accepted ranges of serum Cl values, Cl corrections and the Cl/Na ratio.

scholarly journals Hypoproteinemia, strong-ion difference, and acid-base status in critically ill patients

1998 ◽  
Vol 84 (5) ◽  
pp. 1740-1748 ◽  
Author(s):  
Peter Wilkes
Keyword(s):  
Total Protein ◽  
Protein Concentration ◽  
Total Concentration ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Acid Base Status ◽  
The Relationship

The present study was a prospective, nonrandomized, observational examination of the relationship among hypoproteinemia and electrolyte and acid-base status in a critical care population of patients. A total of 219 arterial blood samples reviewed from 91 patients was analyzed for arterial blood gas, electrolytes, lactate, and total protein. Plasma strong-ion difference ([SID]) was calculated from [Na+] + [K+] − [Cl−] − [La−]. Total protein concentration was used to derive the total concentration of weak acid ([A]tot). [A]tot encompassed a range of 18.7 to 9.0 meq/l, whereas [SID] varied from 48.1 to 26.6 meq/l and was directly correlated with [A]tot. The decline in [SID] was primarily attributable to an increase in [Cl−]. A direct correlation was also noted between[Formula: see text] and [SID], but not between [Formula: see text] and [A]tot. The decrease in [SID] and [Formula: see text] was such that neither [H+] nor [[Formula: see text]] changed significantly with [A]tot.

Equivalent Metabolic Acidosis with Four Colloids and Saline on Ex Vivo Haemodilution

2009 ◽  
Vol 37 (3) ◽  
pp. 407-414 ◽  
Author(s):  
T. J. Morgan ◽  
M. Vellaichamy ◽  
D. M. Cowley ◽  
S. L. Weier ◽  
B. Venkatesh ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Base Excess ◽  
Ex Vivo ◽  
Venous Blood ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Strong Ion Gap ◽  
Acid Base ◽  
Acid Properties

Colloid infusions can cause metabolic acidosis. Mechanisms and relative severity with different colloids are incompletely understood. We compared haemodilution acid-base effects of 4% albumin, 3.5% polygeline, 4% succinylated gelatin (all weak acid colloids, strong ion difference 12 mEq/l, 17.6 mEq/l and 34 mEq/l respectively), 6% hetastarch (non-weak acid colloid, strong ion difference zero) and 0.9% saline (crystalloid, strong ion difference zero). Gelatin weak acid properties were tracked via the strong ion gap. Four-step ex vivo dilutions of pre-oxygenated human venous blood were performed to a final [Hb] near 50% baseline. With each fluid, base excess fell to approximately −13 mEq/l. Base excess/[Hb] relationships across dilution were linear and direct (R2 ≥0.96), slopes and intercepts closely resembling saline. Baseline strong ion gap was −0.3 (2.1) mEq/l. Post-dilution increases occurred in three groups: small with saline, hetastarch and albumin (to 3.5 (02) mEq/l, 4.3 (0.3) mEq/l, 3.3 (1.4) mEq/l respectively), intermediate with polygeline (to 12.2 (0.9) mEq/l) and greatest with succinylated gelatin (to 20.8 (1.4) mEq/l). We conclude that, despite colloid weak acid activity ranging from zero (hydroxyethyl starch) to greater than that of albumin with both gelatin preparations, ex vivo dilution causes a metabolic acidosis of identical severity to saline in each case. This uniformity reflects modifications to the albumin and gelatin saline vehicles, in part aimed at pH correction. By proportionally increasing the strong ion difference, these modifications counter deviations from pure saline effects caused by colloid weak acid activity. Extrapolation in vivo requires further investigation.

Physicochemical analysis of acid–base status during recovery from high-intensity exercise in Standardbred racehorses

2005 ◽  
Vol 2 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Amanda Waller ◽  
Michael I Lindinger
Keyword(s):  
High Intensity ◽  
Venous Blood ◽  
Physicochemical Analysis ◽  
High Intensity Exercise ◽  
Ion Concentration ◽  
Strong Ion Difference ◽  
Acid Base Balance ◽  
Acid Base ◽  
Acid Base Status ◽  
Standardbred Racehorses

AbstractThe present study used the physicochemical approach to characterize the changes in acid–base status that occur in Standardbred racehorses during recovery from high-intensity exercise. Jugular venous blood was sampled from nine Standardbreds in racing condition, at rest and for 2 h following a high-intensity training workout. Plasma [H+] increased from 39.1±1.0 neq l−1 at rest to 44.8±2.7 neq l−1 at 1 min of recovery. A decreased strong ion difference ([SID]) was the primary contributor to the increased [H+] immediately at the end of exercise, while increased plasma weak ion concentration ([Atot]) was a minor contributor to the acidosis. A decreased partial pressure of carbon dioxide (PCO2) at 1 min of recovery had a slight alkalinizing effect. The decreased [SID] at 1 min of recovery was a result of a 15.1±3.1 meq l−1 increase in [lactate−], as [Na+] and [K+] were also increased by 6.5±0.7 and 1.14±0.06 meq l−1, respectively, at 1 min of recovery. It is concluded that high-intensity exercise and recovery is associated with significant changes in acid–base balance, and that full recovery of many parameters that determine acid–base status requires 60–120 min.

scholarly journals Base-excess chloride; the best approach to evaluating the effect of chloride on the acid- base status: a retrospective study

2020 ◽  
Author(s):  
Bulent Gucyetmez ◽  
Filiz Tuzuner ◽  
Hakan Korkut Atalan ◽  
Ugur Sezerman ◽  
Kaan Gucyetmez ◽  
...  
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Base Excess ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Standard Base Excess ◽  
Serum Chloride ◽  
Acid Base Status ◽  
Standard Base

Abstract Background: To determine the effect of chloride on the acid-base status, four approaches are currently used: 1) accepted ranges of serum chloride values; 2) chloride corrections, such as chloride deficiency/excess and chloride modification; 3) the Cl/Na ratio; and 4) the sodium- chloride difference, such as base-excess chloride. However, these approaches are governed by different concepts, and they can evaluate the effects of chloride on the acid-base status differently. Our aim is to investigate which approach to the evaluation of the effect of chloride is the best.Methods: In this retrospective cohort study, 2529 critically ill patients who were admitted to the tertiary care unit were evaluated between 2011 and 2018. Patient characteristics and blood gas parameters at the ICU admission and outcomes were recorded. The effects of chloride on the acid-base status according to each evaluative approach were validated by the standard base excess and apparent strong ion difference. To compare approaches, kappa and Bland-Altman tests and a linear regression model were used. Results: In the linear regression model for all patients, only base-excess chloride in all the chloride evaluation approaches was significantly related to the standard base excess. In the subgroup, the correlation and limits of agreement between base-excess chloride and the standard base excess were the strongest (r2=0.92 p<0.001 bias: 0.5mmol/L). Conclusions: For the evaluation of the effect of chloride on the acid-base status, base-excess chloride is a better approach than accepted ranges of serum chloride values, chloride corrections and the Cl/Na ratio.

scholarly journals Acid-Base Effects of a Bicarbonate-Balanced Priming Fluid during Cardiopulmonary Bypass: Comparison with Plasma-Lyte 148. A Randomised Single-Blinded Study

2008 ◽  
Vol 36 (6) ◽  
pp. 822-829 ◽  
Author(s):  
T. J. Morgan ◽  
G Power ◽  
B. Venkatesh ◽  
M. A. Jones
Keyword(s):  
Metabolic Acidosis ◽  
Cardiopulmonary Bypass ◽  
Base Excess ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Elective Cardiac Surgery ◽  
Standard Base Excess ◽  
Acid Base Status ◽  
Standard Base ◽  
Normal Acid

Fluid-induced metabolic acidosis can be harmful and can complicate cardiopulmonary bypass. In an attempt to prevent this disturbance, we designed a bicarbonate-based crystalloid circuit prime balanced on physico-chemical principles with a strong ion difference of 24 mEq/l and compared its acid-base effects with those of Plasma-Lyte 148, a multiple electrolyte replacement solution containing acetate plus gluconate totalling 50 mEq/l. Twenty patients with normal acid-base status undergoing elective cardiac surgery were randomised 1:1 to a 2 litre prime of either bicarbonate-balanced fluid or Plasma-Lyte 148. With the trial fluid, metabolic acid-base status was normal following bypass initiation (standard base excess 0.1 (1.3) mEq/l, mean, SD), whereas Plasma-Lyte 148 produced a slight metabolic acidosis (standard base excess -2.2 (2.1) mEq/l). Estimated group difference after baseline adjustment was 3.6 mEq/l (95% confidence interval 2.1 to 5.1 mEq/l, P=0.0001). By late bypass, mean standard base excess in both groups was normal (0.8 (2.2) mEq/l vs. -0.8 (1.3) mEq/l, P=0.5). Strong ion gap values were unaltered with the trial fluid, but with Plasma-Lyte 148 increased significantly on bypass initiation (15.2 (2.5) mEq/l vs. 2.5 (1.5) mEq/l, P <0.0001), remaining elevated in late bypass (8.4 (3.4) mEq/l vs. 5.8 (2.4) mEq/l, P <0.05). We conclude that a bicarbonate-based crystalloid with a strong ion difference of 24 mEq/l is balanced for cardiopulmonary bypass in patients with normal acid-base status, whereas Plasma-Lyte 148 triggers a surge of unmeasured anions, persisting throughout bypass. These are likely to be gluconate and/or acetate. Whether surges of exogenous anions during bypass can be harmful requires further study.

Daily variation in plasma electrolyte and acid–base status in fasted horses over a 25 h period of rest

2006 ◽  
Vol 3 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Amanda Waller ◽  
Kerri Jo Smithurst ◽  
Gayle L Ecker ◽  
Ray Geor ◽  
Michael I Lindinger
Keyword(s):  
Time Course ◽  
Daily Variation ◽  
Venous Blood ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Night Time ◽  
Plasma Protein Concentration ◽  
Plasma Electrolyte ◽  
Acid Base Status

AbstractMeasurement and interpretation of acid–base status are important in clinical practice and among racing jurisdictions to determine if horses have been administered alkalinizing substances for the purpose of enhancing performance. The present study used the physicochemical approach to characterize the daily variation in plasma electrolytes and acid–base state that occurs in horses in the absence of feeding and exercise. Jugular venous blood was sampled every 1–2 h from two groups (n=4 and n=5) of Standardbred horses over a 25 h period where food and exercise were withheld. One group of horses was studied in October and one in December. The time course and magnitude of circadian responses differed between the two groups, suggesting that subtle differences in environment may manifest in acid–base status. Significant daily variation occurred in plasma weak acid concentration ([Atot]) and strong ion difference ([SID]), [Cl−], [K+], [Na+] and [lactate−], which contributed to significant changes in [H+] and TCO2. The night-time period was associated with a mild acidosis, marked by increases in plasma [H+] and decreases in TCO2, compared with the morning hours. The night-time acidosis resulted from an increased plasma [Atot] due to an increased plasma protein concentration ([PP]), and a decreased [SID] due to increases in [Cl−] and decreases in [Na+]. An increased plasma [K+] during the night-time had a mild alkalotic effect. There were no differences in pCO2. It was concluded that many equine plasma electrolyte and acid–base parameters exhibit fluctuations in the absence of feeding and exercise, and it is likely that some of these changes are due to daily variation.

scholarly journals Responses of a Stenohaline Freshwater Teleost (Catostomus Commersoni) to Hypersaline Exposure: I. The Dependence of Plasma pH and Bicarbonate Concentration on Electrolyte Regulation

1986 ◽  
Vol 121 (1) ◽  
pp. 77-94 ◽  
Author(s):  
P. R. H. WILKES ◽  
B. R. MCMAHON
Keyword(s):  
Plasma Concentrations ◽  
Haemoglobin Concentration ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Catostomus Commersoni ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Bicarbonate Buffer ◽  
Plasma Electrolyte ◽  
Acid Base Status

The effects of exposure to 0.94% (300 mosmol1−1) sodium chloride on plasma electrolyte and acid-base status were examined in the freshwater stenohaline teleost Catostomus commersoni (Lacépède), the white sucker. Four days' exposure to this maximum sublethal salinity resulted in an increase in plasma concentrations of both sodium and chloride but a decrease in the Na+/Cl− ratio. Since the plasma concentrations of free amino acids and other strong ions - Ca2+, Mg2+ and K+ - remained unchanged, plasma strong ion difference (SID) decreased. Additionally, plasma pH and bicarbonate concentration decreased at constant Pcoco2 The changes in electrolyte and acid-base status that occurred after the 96 h were not appreciably altered after a further 2–3 weeks of saline exposure. The ambient calcium concentration had no influence on these results. Haemolymph non-bicarbonate buffer capacity (β) calculated as Δ[HCO3−]/ ΔpH, increased in saline-exposed fish. Consequently ΔH+, the apparent proton load, was zero despite the apparent change in acid-base status. Although β was directly proportional to the haemoglobin concentration in both control and experimental fish, this could not account for the increase in β since haemoglobin remained at control values. These results can be explained solely by the change in plasma SID and serve to illustrate the dependence of plasma acid-base status on the prevailing electrolyte characteristics, weak acid concentration and Pcoco2.

Total weak acid concentration and effective dissociation constant of nonvolatile buffers in human plasma

2001 ◽  
Vol 91 (3) ◽  
pp. 1364-1371 ◽  
Author(s):  
Peter D. Constable
Keyword(s):  
Dissociation Constant ◽  
Human Plasma ◽  
Total Concentration ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Horse Plasma ◽  
Using Data ◽  
Species Specific

The strong ion approach provides a quantitative physicochemical method for describing the mechanism for an acid-base disturbance. The approach requires species-specific values for the total concentration of plasma nonvolatile buffers (Atot) and the effective dissociation constant for plasma nonvolatile buffers ( K a), but these values have not been determined for human plasma. Accordingly, the purpose of this study was to calculate accurate Atot and K a values using data obtained from in vitro strong ion titration and CO2tonometry. The calculated values for Atot (24.1 mmol/l) and K a (1.05 × 10−7) were significantly ( P < 0.05) different from the experimentally determined values for horse plasma and differed from the empirically assumed values for human plasma (Atot = 19.0 meq/l and K a = 3.0 × 10−7). The derivatives of pH with respect to the three independent variables [strong ion difference (SID), Pco 2, and Atot] of the strong ion approach were calculated as follows: [Formula: see text] [Formula: see text], [Formula: see text]where S is solubility of CO2 in plasma. The derivatives provide a useful method for calculating the effect of independent changes in SID+, Pco 2, and Atot on plasma pH. The calculated values for Atot and K a should facilitate application of the strong ion approach to acid-base disturbances in humans.

Physicochemical analysis of phasic menstrual cycle effects on acid-base balance

2001 ◽  
Vol 280 (2) ◽  
pp. R481-R487 ◽  
Author(s):  
Robert J. Preston ◽  
Aaron P. Heenan ◽  
Larry A. Wolfe
Keyword(s):  
Menstrual Cycle ◽  
Ventilatory Threshold ◽  
Physicochemical Analysis ◽  
Carbon Dioxide Tension ◽  
Weak Acid ◽  
Ion Concentration ◽  
Strong Ion Difference ◽  
Acid Base Balance ◽  
Hydrogen Ion Concentration ◽  
Base Balance

In accordance with Stewart's physicochemical approach, the three independent determinants of plasma hydrogen ion concentration ([H+]) were measured at rest and during exercise in the follicular (FP) and luteal phase (LP) of the human menstrual cycle. Healthy, physically active women with similar physical characteristics were tested during either the FP ( n = 14) or LP ( n = 14). Arterialized blood samples were obtained at rest and after 5 min of upright cycling at both 70 and 110% of the ventilatory threshold (TVent). Measurements included plasma [H+], arterial carbon dioxide tension (PaCO2 ), total weak acid ([ATot]) as reflected by total protein, and the strong-ion difference ([SID]). The transition from rest to exercise in both groups resulted in a significant increase in [H+] at 70% TVentversus rest and at 110% TVent versus both rest and 70% TVent. No significant between-group differences were observed for [H+] at rest or in response to exercise. At rest in the LP, [ATot] and PaCO2 were significantly lower (acts to decrease [H+]) compared with the FP. This effect was offset by a reduction in [SID] (acts to increase [H+]). After the transition from rest to exercise, significantly lower [ATot] during the LP was again observed. Although the [SID] and PaCO2 were not significantly different between groups, trends for changes in these two variables were similar to changes in the resting state. In conclusion, mechanisms regulating [H+] exhibit phase-related differences to ensure [H+] is relatively constant regardless of progesterone-mediated ventilatory changes during the LP.

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