Acid–base and respiratory properties of a buffered bovine erythrocyte perfusion medium

1986 ◽  
Vol 64 (5) ◽  
pp. 550-555 ◽  
Author(s):  
Michael I. Lindinger ◽  
George J. F. Heigenhauser ◽  
Norman L. Jones
Keyword(s):  
Oxygen Saturation ◽  
Base Excess ◽  
Hemoglobin Concentration ◽  
Mammalian Skeletal Muscle ◽  
Dissociation Curve ◽  
Perfusion Medium ◽  
Acid Base ◽  
Oxygen Dissociation ◽  
Carbon Dioxide Dissociation Curve

Current research in organ physiology often utilizes in situ or isolated perfused tissues. We have characterized a perfusion medium associated with excellent performance characteristics in perfused mammalian skeletal muscle. The perfusion medium consisting of Krebs–Henseleit buffer, bovine serum albumin, and fresh bovine erythrocytes was studied with respect to its gas-carrying relationships and its response to manipulation of acid–base state. Equilibration of the perfusion medium at base excess of −10, −5, 0, 5, and 10 mmol∙L−1 to humidified gas mixtures varying in their CO2 and O2 content was followed by measurements of perfusate hematocrit, hemoglobin concentration, pH, [Formula: see text], [Formula: see text], [Formula: see text], and percent oxygen saturation. The oxygen dissociation curve was similar to that of mammalian bloods, having a P50 of 32 Torr (1 Torr = 133.3 Pa), Hill's constant n of 2.87 ± 0.15, and a Bohr factor of −0.47, showing the typical Bohr shifts with respect to CO2 and pH. The oxygen capacity was calculated to be 190 mL∙L−1 blood. The carbon dioxide dissociation curve was also similar to that of mammalian blood. The in vitro nonbicarbonate buffer capacity (Δ[HCO3−] × ΔpH−1) at zero base excess was −24.6 and −29.9 mmol∙L−1∙pH−1 for the perfusate and buffer, respectively. The effects of reduced oxygen saturation on base excess and pH of the medium were quantified. The data were used to construct an acid–base alignment diagram for the medium, which may be used to quantify the flux of nonvolatile acid or base added to the venous effluent during tissue perfusions.

The Lack of Effects of Phototherapy on Neonatal Oxygen Dissociation Curves and Hemoglobin Concentration in Vivo

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 1027-1031
Author(s):  
Barry D. Chandler ◽  
William J. Cashore ◽  
Pierre J. P. Monin ◽  
William Oh
Keyword(s):  
Serum Bilirubin ◽  
Hemoglobin Concentration ◽  
Control Group ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
The Right ◽  
Dissociation Curves ◽  
2,3 Dpg

Phototherapy has been shown to cause hemolysis of fetal red cells and a shift to the right in the neonatal oxygen dissociation curve (ΔP50) in vitro. To determine if these parameters act similarly in vivo, we have studied 16 icteric infants before and after phototherapy and compared them with eight control infants studied at birth and at 3 days of age, measuring the change in P50, 2,3-diphosphoglycerate (2,3-DPG), serum bilirubin, the percent of bilirubin/albumin saturation, and the hemoglobin concentration in the two groups. Following phototherapy, in the icteric infants there was a shift to the right in the O2 dissociation curve of + 1.7 mm Hg, a rise in 2,3-DPG of 2.26 µmol/gm Hb, a fall in serum bilirubin of 4.3 mg/100 ml, a decrease in percent bilirubin/albumin saturation of 12.4%, and a drop in hemoglobin of 1.1 gm/100 ml. The control group showed a ΔP50 of + 2.0 mm Hg, a rise in 2,3-DPG of 3.67 µmol/gm Hb, an increase in serum bilirubin of 3.2 mg/100 ml, an increase in percent bilirubin/albumin saturation of 9.3%, and a fall in hemoglobin of 0.3 gm/100 ml. Significant differences between the groups were seen only in the changes in bilirubin concentration and percent bilirubin/albunmin saturation. The magnitude of changes in P50, 2,3-DPG, and hemoglobin concentration was similar in the phototherapy and control groups and was related to the expected changes with reference to postnatal age. These results suggest that phototherapy in vivo neither affects fetal erythrocytic affinity for oxygen nor causes hemolysis.

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.

Bohr effect and slope of the oxygen dissociation curve after physical training

1982 ◽  
Vol 52 (6) ◽  
pp. 1524-1529 ◽  
Author(s):  
K. M. Braumann ◽  
D. Boning ◽  
F. Trost
Keyword(s):  
Venous Blood ◽  
Training Period ◽  
Dissociation Curve ◽  
Period Increase ◽  
Oxygen Dissociation ◽  
Small Rise ◽  
Dissociation Curves ◽  
O2 Dissociation

Three O2 dissociation curves from venous blood [taken at rest (A), after in vitro acidification with lactic acid (B), and after exhaustive exercise (C)] were determined in eight athletes twice in a year in detrained and fully trained state. The steepness of the standard O2 dissociation curve becomes greater during the training period (increase in Hill's n from 2.68 +/- 0.10 to 2.96 +/- 0.15). There was a concomitant small rise in the intraerythrocytic organic phosphate concentrations. Bohr coefficients (BC) were calculated for blood O2 saturations ranging from 10 to 80% by comparing the dissociation curves A and B (“in vitro” BC) and curves A and C (“in vivo” BC). In detrained and trained state the in vivo BC show their maximal values at low saturation levels, in contrast the in vitro BC exhibit maximal values at middle saturations. During the training period there was an increase in the in vivo BC as well as in the in vitro BC at low saturations. These alterations may lead to augmented O2 extraction from a given volume of blood by up to 15% during heavy work in trained state. The reason for these observations could be an altered erythrocyte population.

scholarly journals Relating oxygen partial pressure, saturation and content: the haemoglobin–oxygen dissociation curve

Breathe ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 194-201 ◽  
Author(s):  
Julie-Ann Collins ◽  
Aram Rudenski ◽  
John Gibson ◽  
Luke Howard ◽  
Ronan O’Driscoll
Keyword(s):  
Oxygen Saturation ◽  
Partial Pressure ◽  
Pulse Oximetry ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Oxygen Dissociation Curve ◽  
Blood Gas ◽  
Dissociation Curve ◽  
Oxygen Dissociation ◽  
The Relationship

Key PointsIn clinical practice, the level of arterial oxygenation can be measured either directly by blood gas sampling to measure partial pressure (PaO2) and percentage saturation (SaO2) or indirectly by pulse oximetry (SpO2).This review addresses the strengths and weaknesses of each of these tests and gives advice on their clinical use.The haemoglobin–oxygen dissociation curve describing the relationship between oxygen partial pressure and saturation can be modelled mathematically and routinely obtained clinical data support the accuracy of a historical equation used to describe this relationship.Educational AimsTo understand how oxygen is delivered to the tissues.To understand the relationships between oxygen saturation, partial pressure, content and tissue delivery.The clinical relevance of the haemoglobin–oxygen dissociation curve will be reviewed and we will show how a mathematical model of the curve, derived in the 1960s from limited laboratory data, accurately describes the relationship between oxygen saturation and partial pressure in a large number of routinely obtained clinical samples.To understand the role of pulse oximetry in clinical practice.To understand the differences between arterial, capillary and venous blood gas samples and the role of their measurement in clinical practice.The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (SO2) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin–oxygen dissociation curve, a graphical representation of the relationship between oxygen satur­ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the SO2 in blood from patients with normal pH and SO2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (SpO2) is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (SaO2) as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable SpO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

Capillary Po2 in Neonates

PEDIATRICS ◽  
1969 ◽  
Vol 43 (4) ◽  
pp. 637-638
Author(s):  
L. Stefan ◽  
A. Leschin ◽  
K. Gray
Keyword(s):  
Oxygen Saturation ◽  
Rectal Temperature ◽  
Full Term ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Oxygen Dissociation

Capillary samples were obtained from warmed heel punctures of 30 full-term, healthy neonates 3 to 23 hours after birth (3 samples between 3-4 hours, 15 samples between 5-12 hours, and 12 samples between 12-23 hours). The blood was processed promptly, observing usual precautions, using London-Astrup equipment. Corrections were made to 37°C,assuming a rectal temperature of 36°C.After ternperatune correction, oxygen saturation was calculated from pH using Nelson's oxygen dissociation curve and Helleger's and Schruefer's pH corrections.

scholarly journals Continuous Determination of the Oxygen Dissociation Curve for Whole Blood

1975 ◽  
Vol 21 (12) ◽  
pp. 1747-1753 ◽  
Author(s):  
Luigi Rossi-Bernardi ◽  
Massimo Luzzana ◽  
Michele Samaja ◽  
Mario Davi ◽  
Daniela DaRiva-Ricci ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Whole Blood ◽  
Circulatory System ◽  
Oxygen Electrode ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
Total Oxygen ◽  
Oxygen Dissociation ◽  
Continuous Determination

Abstract We report here the development of a new method that allows continuous determination of the oxygen dissociation curve for microsamples (600 µl) of whole blood under conditions of pH, pco2, methemoglobin concentration, and 2,3-diphosphoglycerate content closely approaching those found in the circulatory system. The method consists of gradually oxygenating a blood sample by adding H2O2 in the presence of catalase (EC 1.11.1.6), to produce the reaction H2O2 → H2O + ½ O2. Because the total oxygen content of blood can be derived from the known rate of H2O2 addition and the po2 is determined in the liquid phase by an oxygen electrode, the two functions (total O2 content) and (% oxygen saturation) vs. po2 are simple to calculate. pco2 and pH are controlled by adding base simultaneously with the gradual oxygenation of blood. The method described thus avoids the direct measurement of oxygen saturation of whole blood.

Letter to the Editor

PEDIATRICS ◽  
1982 ◽  
Vol 70 (3) ◽  
pp. 501-501
Author(s):  
Michel A. Bureau
Keyword(s):  
Maternal Smoking ◽  
Hemoglobin Concentration ◽  
Dissociation Curve ◽  
Preliminary Results ◽  
Left Shift ◽  
Letter To The Editor ◽  
Oxygen Dissociation ◽  
Dissociation Curves ◽  
O2 Dissociation Curve ◽  
O2 Dissociation

The valuable comments of Christoffel are much appreciated. It is said that newborns do adapt to carboxyhemoglobin poisoning (from smoking) by increasing their hemoglobin concentration in blood. Recently, we have further explored the adaptability of newborns to maternal smoking by a study of oxygen dissociation curves in newborns of smoking mothers. Our preliminary results showed that the newborn adapts to maternal and fetal increases in HbCO by a very small left shift in the Hb-O2 dissociation curve and by an increase in hemoglobin.1

Sign in / Sign up

Export Citation Format

Share Document