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

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.

2020 ◽  
Author(s):  
Bulent Gucyetmez ◽  
Filiz Tuzuner ◽  
Hakan Korkut Atalan ◽  
Ugur Sezerman ◽  
Kaan Gucyetmez ◽  
...  

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Javier Enrique Cely ◽  
Oscar G. Rocha ◽  
María J. Vargas ◽  
Rafael M. Sanabria ◽  
Leyder Corzo ◽  
...  

Background. Acid-base disorders have been previously described in patients with chronic hemodialysis, with metabolic acidosis being the most important of them; however, little is known about the potential changes in acid-base status of patients on dialysis living at high altitudes. Methods. Cross-sectional study including 93 patients receiving chronic hemodialysis on alternate days and living in Bogotá, Colombia, at an elevation of 2,640 meters (8,661 feet) over sea level (m.o.s.l.). Measurements of pH, PaCO2, HCO3, PO2, and base excess were made on blood samples taken from the arteriovenous fistula (AVF) during the pre- and postdialysis periods in the midweek hemodialysis session. Normal values for the altitude of Bogotá were taken into consideration for the interpretation of the arterial blood gases. Results. 43% (n= 40) of patients showed predialysis normal acid-base status. The most common acid-base disorder in predialysis period was metabolic alkalosis with chronic hydrogen ion deficiency in 19,3% (n=18). Only 9,7% (n=9) had predialysis metabolic acidosis. When comparing pre- and postdialysis blood gas analysis, higher postdialysis levels of pH (7,41 versus 7,50, p<0,01), bicarbonate (21,7mmol/L versus 25,4mmol/L, p<0,01), and base excess (-2,8 versus 2,4, p<0,01) were reported, with lower levels of partial pressure of carbon dioxide (34,9 mmHg versus 32,5 mmHg, p<0,01). Conclusion. At an elevation of 2,640 m.o.s.l., a large percentage of patients are in normal acid-base status prior to the dialysis session (“predialysis period”). Metabolic alkalosis is more common than metabolic acidosis in the predialysis period when compared to previous studies. Paradoxically, despite postdialysis metabolic alkalosis, PaCO2 levels are lower than those found in the predialysis period.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250274
Author(s):  
Bulent Gucyetmez ◽  
Filiz Tuzuner ◽  
Hakan Korkut Atalan ◽  
Uğur Sezerman ◽  
Kaan Gucyetmez ◽  
...  

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.


2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Rita Jacobs ◽  
Patrick M. Honore ◽  
Marc Diltoer ◽  
Herbert D. Spapen

Abstract Background Citrate, the currently preferred anticoagulant for continuous veno-venous hemofiltration (CVVH), may influence acid-base equilibrium. Methods The effect of 2 different citrate solutions on acid-base status was assessed according to the Stewart-Figge approach in two consecutive cohorts of critically ill adult patients. The first group received Prismocitrate 10/2 (PC10/2; 10 mmol citrate/L). The next group was treated with Prismocitrate 18/0 (PC18; 18 mmol citrate/L). Both groups received bicarbonate-buffered fluids in post-dilution. Results At similar citrate flow, the metabolic acidosis present at baseline in both groups was significantly attenuated in PC18 patients but persisted in PC10/2 patients after 24 h of treatment (median pH 7,42 vs 7,28; p = 0.0001). Acidosis in the PC10/2 group was associated with a decreased strong ion difference and an increased strong ion gap (respectively 43 vs. 51 mmol/L and 17 vs. 12 mmol/L, PC10/2 vs. PC18; both p = 0.001). Chloride flow was higher in PC10/2 than in PC18 subjects (25.9 vs 14.3 mmol/L blood; p < 0.05). Conclusion Correction of acidosis was blunted in patients who received 10 mmol citrate/L as regional anticoagulation during CVVH. This could be explained by differences in chloride flow between the applied citrate solutions inducing hyperchloremic acidosis.


2009 ◽  
Vol 37 (3) ◽  
pp. 407-414 ◽  
Author(s):  
T. J. Morgan ◽  
M. Vellaichamy ◽  
D. M. Cowley ◽  
S. L. Weier ◽  
B. Venkatesh ◽  
...  

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.


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