Low non-carbonic buffer power amplifies acute respiratory acid-base disorders in septic patients: an in-vitro study

2021 ◽  
Author(s):  
Thomas Langer ◽  
Serena Brusatori ◽  
Eleonora Carlesso ◽  
Francesco Zadek ◽  
Paolo Brambilla ◽  
...  
Keyword(s):  
Whole Blood ◽  
In Vitro Study ◽  
Blood Gases ◽  
Hemoglobin Concentration ◽  
Strong Ion Difference ◽  
Strongly Correlated ◽  
Acid Base ◽  
Buffer Power ◽  
Ph Variations

Rationale: Septic patients have typically reduced concentrations of hemoglobin and albumin, the major components of non-carbonic buffer power(β). This could expose patients to high pH variations during acid-base disorders. Objectives: To compare, in-vitro, non-carbonic β of septic patients with that of healthy volunteers, and evaluate its distinct components. Methods: Whole blood and isolated plasma of 18 septic patients and 18 controls were equilibrated with different CO2 mixtures. Blood gases, pH and electrolytes were measured. Non-carbonic β and non-carbonic β due to variations in Strong Ion Difference (βSID) were calculated for whole blood. Non-carbonic β and non-carbonic β normalized for albumin concentrations (βNORM) were calculated for isolated plasma. Representative values at pH=7.40 were compared. Albumin proteoforms were evaluated via two-dimensional electrophoresis. Measurements and Main Results: Hemoglobin and albumin concentrations were significantly lower in septic patients. Septic patients had lower non-carbonic β both of whole blood (22.0±1.9 vs. 31.6±2.1 mmol/L, p<0.01) and plasma (0.5±1.0 vs. 3.7±0.8 mmol/L, p<0.01). Non-carbonic βSID was lower in patients (16.8±1.9 vs. 24.4±1.9 mmol/L, p<0.01) and strongly correlated with hemoglobin concentration (r=0.94, p<0.01). Non-carbonic βNORM was lower in patients (0.01 [-0.01 - 0.04] vs. 0.08 [0.06 - 0.09] mmol/g, p<0.01). Septic patients and controls showed different amounts of albumin proteoforms. Conclusions: Septic patients are exposed to higher pH variations for any given change in CO2 due to lower concentrations of non-carbonic buffers and, possibly, an altered buffering function of albumin. In both septic patients and healthy controls, electrolyte shifts are the major buffering mechanism during respiratory acid-base disorders.

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.

A simplified strong ion model for acid-base equilibria: application to horse plasma

1997 ◽  
Vol 83 (1) ◽  
pp. 297-311 ◽  
Author(s):  
Peter D. Constable
Keyword(s):  
Human Plasma ◽  
Practical Method ◽  
Published Data ◽  
Strong Ion Difference ◽  
Weak Acids ◽  
Acid Base ◽  
Plasma Protein Concentration ◽  
Horse Plasma ◽  
Hasselbalch Equation

Constable, Peter D. A simplified strong ion model for acid-base equilibria: application to horse plasma. J. Appl. Physiol. 83(1): 297–311, 1997.—The Henderson-Hasselbalch equation and Stewart’s strong ion model are currently used to describe mammalian acid-base equilibria. Anomalies exist when the Henderson-Hasselbalch equation is applied to plasma, whereas the strong ion model does not provide a practical method for determining the total plasma concentration of nonvolatile weak acids ([Atot]) and the effective dissociation constant for plasma weak acids ( K a). A simplified strong ion model, which was developed from the assumption that plasma ions act as strong ions, volatile buffer ions ([Formula: see text]), or nonvolatile buffer ions, indicates that plasma pH is determined by five independent variables:[Formula: see text], strong ion difference, concentration of individual nonvolatile plasma buffers (albumin, globulin, and phosphate), ionic strength, and temperature. The simplified strong ion model conveys on a fundamental level the mechanism for change in acid-base status, explains many of the anomalies when the Henderson-Hasselbalch equation is applied to plasma, is conceptually and algebraically simpler than Stewart’s strong ion model, and provides a practical in vitro method for determining [Atot] and K a of plasma. Application of the simplified strong ion model to CO2-tonometered horse plasma produced values for [Atot] (15.0 ± 3.1 meq/l) and K a(2.22 ± 0.32 × 10−7 eq/l) that were significantly different from the values commonly assumed for human plasma ([Atot] = 20.0 meq/l, K a = 3.0 × 10−7 eq/l). Moreover, application of the experimentally determined values for [Atot] and K a to published data for the horse (known [Formula: see text], strong ion difference, and plasma protein concentration) predicted plasma pH more accurately than the values for [Atot] and K a commonly assumed for human plasma. Species-specific values for [Atot] and K a should be experimentally determined when the simplified strong ion model (or strong ion model) is used to describe acid-base equilibria.

scholarly journals Hyperlactacemia in critically ill children: comparison of traditional and Fencl-Stewart methods

2007 ◽  
Vol 47 (1) ◽  
pp. 35
Author(s):  
Hari Kushartono ◽  
Antonius H. Pudjiadi ◽  
Susetyo Harry Purwanto ◽  
Imral Chair ◽  
Darlan Darwis ◽  
...  
Keyword(s):  
Base Excess ◽  
Pediatric Intensive Care ◽  
Blood Gases ◽  
Critically Ill Children ◽  
Strongly Correlated ◽  
Acid Base ◽  
Arterial Blood ◽  
Acid Base Status ◽  
Lactate Levels ◽  
Elevated Lactate

Background Base excess is a single variable used to quantifymetabolic component of acid base status. Several researches havecombined the traditional base excess method with the Stewartmethod for acid base physiology called as Fencl-Stewart method.Objective The purpose of the study was to compare two differentmethods in identifying hyperlactacemia in pediatric patients withcritical illness.Methods The study was performed on 43 patients admitted tothe pediatric intensive care unit of Cipto MangunkusumoHospital, Jakarta. Sodium, potassium, chloride, albumin, lactateand arterial blood gases were measured. All samples were takenfrom artery of all patients. Lactate level of >2 mEq/L was definedas abnormal. Standard base excess (SBE) was calculated fromthe standard bicarbonate derived from Henderson-Hasselbalchequation and reported on the blood gas analyzer. Base excessunmeasured anions (BE UA ) was calculated using the Fencl-Stewartmethod simplified by Story (2003). Correlation between lactatelevels in traditional and Fencl-Stewart methods were measuredby Pearson’s correlation coefficient .Results Elevated lactate levels were found in 24 (55.8%) patients.Lactate levels was more strongly correlated with BE UA (r = - 0.742,P<0.01) than with SBE (r = - 0.516, P<0.01).Conclusion Fencl-Stewart method is better than traditionalmethod in identifying patients with elevated lactate levels, so theFencl-Stewart method is suggested to use in clinical practice.

Carbon dioxide removal using low bicarbonate dialysis in rodents

Perfusion ◽  
2019 ◽  
Vol 34 (7) ◽  
pp. 578-583 ◽  
Author(s):  
Lien H Vu ◽  
John A Kellum ◽  
William J Federspiel ◽  
Matthew E Cove
Keyword(s):  
Carbon Dioxide ◽  
In Vitro Study ◽  
Blood Gases ◽  
Carbon Dioxide Removal ◽  
Low Flow ◽  
Sprague Dawley ◽  
Bicarbonate Concentration ◽  
Extracorporeal Carbon Dioxide Removal ◽  
Arterial Ph

Background: Extracorporeal carbon dioxide removal may be used to manage hypercapnia, but compared to dialysis, it’s not widely available. A recent in vitro study showed that dialysis with low bicarbonate dialysates removes CO2. Objective: To show that bicarbonate dialysis removes CO2 in an animal model to validate in-vitro findings and quantify the effect on arterial pH. Methods: Male Sprague-Dawley hypercapnic rats were dialyzed with either a conventional dialysate (PrismasolTM) or a bicarbonate-free dialysate (Bicarb0). The effect of dialysis on standard blood gases and electrolytes was measured. Results: Partial pressure of CO2 and bicarbonate concentration in blood decreased significantly after exposure to Bicarb0 compared to PrismasolTM (filter outflow values 12.8 vs 81.1 mmHg; p < 0.01 for CO2 and 3.5 vs 22.0 mmol/L; p < 0.01 for bicarbonate). Total CO2 content of blood was reduced by 459 mL/L during dialysis with Bicarb0 (filter inflow 546 ± 91 vs filter outflow 87 ± 52 mL/L; p < 0.01), but was not significantly reduced with PrismasolTM. Conclusions: Bicarbonate dialysis removes CO2 at rates comparable to existing low-flow ECCO2R.

In Vitro Study of Photodynamic Therapy for Treatment of Bacteremia in Whole Blood

2018 ◽  
Vol 6 (9) ◽  
Author(s):  
Jennifer Machado Soares ◽  
Thaila Quatrini Corrêa ◽  
Natalia Mayumi Inada ◽  
Vanderlei Salvador Bagnato ◽  
Kate Cristina Blanco
Keyword(s):  
Photodynamic Therapy ◽  
Whole Blood ◽  
In Vitro Study ◽  
Vitro Study

Changes in uterine fluid composition and acid-base status during shell formation in the chicken

1989 ◽  
Vol 257 (4) ◽  
pp. R732-R737 ◽  
Author(s):  
Z. Arad ◽  
U. Eylath ◽  
M. Ginsburg ◽  
H. Eyal-Giladi
Keyword(s):  
Sharp Increase ◽  
Blood Gases ◽  
Future Application ◽  
Epithelial Tissue ◽  
Fluid Composition ◽  
Acid Base ◽  
Co2 Partial Pressure ◽  
Uterine Fluid ◽  
Acid Base Status

The aim of this study was to characterize the dynamic changes in uterine fluid composition and acid-base status during shell calcification in the chicken. Uterine eggs at timed intervals were manually aborted and the accompanying fluid collected and analyzed for composition of osmolytes, enzymes, and acid-base parameters. Blood samples were analyzed for comparison. No considerable change in blood gases took place in relation to residence time of the calcifying egg in the uterus. A significant acidosis occurred at latter stages. Only minor changes were revealed in plasma osmotic and biochemical composition throughout egg calcification. In contrast, major changes were revealed in uterine fluid composition and acid-base status during calcification. The most prominent phenomenon was the sharp increase in CO2 partial pressure, from 82.2 Torr at 0 h to 132.8 Torr at 10 h. As bicarbonate concentration remained almost stable, fluid pH dropped from 7.412 to 7.250 within this stage. Uterine fluid sodium and chloride concentrations and osmolality dropped significantly in the course of calcification, whereas potassium concentration significantly increased. A sharp increase in glucose, calcium, and magnesium concentrations was measured in the early stages of calcification. These findings are discussed in relation to existing models for transport mechanisms of the uterine epithelial tissue. The comprehensive picture that emerges from the present study should enable future application in establishing a self-contained culturing system in vitro for studies of embryonic development.

In vitro study of thimerosal reactions in human whole blood and plasma surrogate samples

2014 ◽  
Vol 28 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Stefan Trümpler ◽  
Björn Meermann ◽  
Sascha Nowak ◽  
Wolfgang Buscher ◽  
Uwe Karst ◽  
...  
Keyword(s):  
Whole Blood ◽  
In Vitro Study ◽  
Vitro Study ◽  
Human Whole Blood

The in vitro respiratory and acid–base properties of blood and tissue from the Kemp's ridley sea turtle, Lepidochelys kempi

1994 ◽  
Vol 72 (8) ◽  
pp. 1403-1408 ◽  
Author(s):  
Erich K. Stabenau ◽  
Thomas A. Heming
Keyword(s):  
Temperature Sensitivity ◽  
Whole Blood ◽  
Sea Turtles ◽  
Hill Coefficient ◽  
Acid Base ◽  
Kemp's Ridley Sea Turtles ◽  
Dissociation Curves ◽  
Kemp's Ridley ◽  
Base Properties

We determined the in vitro respiratory and acid–base properties of blood and tissue from Kemp's ridley sea turtles (Lepidochelys kempi). Blood O2 dissociation curves of ridley turtles were sigmoid, with a P50 of 31.2 ± 0.3 (mean ± SD) torr at 25 °C and pH 7.51. Increments in temperature or [Formula: see text] were associated with a shift of the O2 dissociation curves to the right and, hence, a reduction in haemoglobin–O2 binding affinity. The apparent heat of oxygenation, which is a measure of the temperature sensitivity of haemoglobin–O2 affinity, was −10.5 kcal/mol O2. The degree of cooperativity of O2 for hemoglobin binding sites, as measured by the Hill coefficient, increased at higher temperatures (20–30 °C at a [Formula: see text] of 37 torr), but was unaffected by changes in [Formula: see text] (37–52 torr at 25 °C). The CO2-Bohr effect was −0.34 torr/pH unit. The CO2 capacitance coefficient of whole blood and plasma declined as a function of increased [Formula: see text] (22 °C). Non-bicarbonate buffer capacities (22 °C) were 19.7, 18.5, and 6.4 slykes for whole blood, true plasma, and separated plasma, respectively. The skeletal muscle myoglobin content was 3.1 ± 0.84 mg∙g−1 of tissue. The respiratory and acid–base properties of blood and tissue from Kemp's ridley sea turtles are consistent with those of species that utilize lung O2 stores during long-term aerobic dives. The enhanced haemoglobin–O2 temperature sensitivity exhibited by the ridley turtle could be a physiological adaptation for life in coastal environments that typically undergo substantial fluctuations in temperature.

Mobile phone exposure influences some erythrocytes parameters in vitro. A novel source of preanalytical variability?

Diagnosis ◽  
2016 ◽  
Vol 3 (2) ◽  
pp. 75-79
Author(s):  
Elisa Danese ◽  
Giuseppe Lippi ◽  
Giorgio Brocco ◽  
Martina Montagnana ◽  
Gian Luca Salvagno
Keyword(s):  
Mobile Phone ◽  
Whole Blood ◽  
Hemoglobin Concentration ◽  
Phone Call ◽  
Mean Corpuscular Hemoglobin ◽  
Corpuscular Hemoglobin ◽  
Distribution Width ◽  
Preanalytical Variability ◽  
Rbc Count

AbstractThe effect of radiofrequency exposure on human health and health care equipment is a matter of ongoing debate. This study was planned to investigate the influence of radiofrequency (RF) waves emitted by a commercial mobile phone on red blood cells (RBC) in vitro.The study population consisted of 16 ostensibly healthy volunteers. Two whole blood specimens were collected from each volunteer. One sample was placed in a plastic rack, 1 cm distant from the chassis of a commercial mobile phone which was activated by a remote phone call lasting 30 min. The other blood sample was placed in another plastic rack, but was kept distant from any type of RF source. The main RBC parameters including RBC count, hematocrit (Ht), hemoglobin, mean corpuscular platelet volume (MPV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and RBC distribution width (RDW-CV) were assessed with an Advia 2120.The exposure of whole blood to the mobile phone call significantly increased Ht, hemoglobin, MCV and MCH, whereas the RBC count, MCHC and RDW-CV remained unchanged. A significant correlation was observed between variation of Ht and those of hemoglobin (p=0.008), MCV (p=0.009) or MCH (p=0.037), as well as between hemoglobin and MCV (p=0.048). Increased values were found in 13/16 (81%) samples for both Ht and hemoglobin, 14/16 (88%) samples for MCH and 16/16 (100%) samples for MCV.These results suggest that close mobile phone exposure may be an unappreciated and possibly underestimated cause of preanalytical bias in RBC testing.

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