Application of a CO2 Electrode as a Microtonometer for the Study of pH Kinetics in the Blood1

2015 ◽  
pp. 187-192
Author(s):  
H. R. Ahmad ◽  
A. Luttmann ◽  
H. H. Loeschcke
Keyword(s):  
Co2 Electrode

Electrode and cuvette for rapid continuous CO2 tension and pH measurement in blood

1985 ◽  
Vol 59 (5) ◽  
pp. 1660-1664
Author(s):  
S. A. Katz ◽  
A. C. Roth ◽  
E. O. Feigl
Keyword(s):  
Carbonic Anhydrase ◽  
Response Time ◽  
Electrode Surface ◽  
Porous Ceramic ◽  
Reference Electrode ◽  
Silicone Membrane ◽  
Dimethyl Silicone ◽  
Glass Ph Electrode ◽  
Co2 Electrode ◽  
Ph Electrode

An electrode and cuvette system has been developed for the continuous and rapid measurement of either blood CO2 tension or pH. The CO2 electrode consists of a 1.5-mm-diameter flat-tip glass pH electrode covered by a film of carbonic anhydrase solution, over which a 25-micron-thick dimethyl silicone membrane is attached. Porous ceramic filled with 20% polyacrylamide, equilibrated with a salt solution, serves as a salt bridge between a Ag-AgCl reference electrode and the pH electrode surface. The electrode is housed in a four-port cuvette assembly. Blood from a vessel of interest is delivered to the cuvette by means of an occlusive roller pump. The cuvette maintains the electrode and blood at a constant temperature and directs a continuous jet of blood against the electrode surface. The cuvette also allows for easy and frequent calibration of the electrode with either gas or liquid standards. The 90% response time of the CO2 electrode is 3.0 s for liquids and 1.3 s for gases. Removal of the dimethyl silicone membrane and carbonic anhydrase film yields a pH electrode that can continuously measure blood pH with a 90% response time of 1.6 s.

Effect of temperature on rate of CO2 uptake by human red cell suspensions

1975 ◽  
Vol 228 (5) ◽  
pp. 1589-1596 ◽  
Author(s):  
RA Holland ◽  
Forster RE
Keyword(s):  
Time Course ◽  
Effect Of Temperature ◽  
Hydration Reaction ◽  
Co2 Uptake ◽  
Cell Water ◽  
Uptake Curve ◽  
Carbon Dioxide Uptake ◽  
Capillary Bed ◽  
To Come ◽  
Co2 Electrode

The time course of carbon dioxide uptake by oxygenated supensions of human red cells was followed using a CO2 electrode in a Hartridge-Roughton continuous-flow rapid-reaction apparatus. Measurements were made at several temperatures from 1i to 42 degrees C, with the initial PCO2 in the reacting mixture from 40 to 60 mmHg. The initial part of the uptake curve is presumably rate limited by the intracellular hydration of CO2 with reaction-velocity constants in cell water from 280 to 960 S-1 at 42 degrees C and an activation energy of 2.4 kcal mol-1. The later stages of CO2 uptake were much slower, with half-times from greater than 1.5 s at 12 degrees C to 0.7 s at 42 degrees C, and were presumably rate limited by the chloride-bicarbonate shift and H+ interchanges. The results indicate that despite the acceleration of the hydration reaction in cell water by a factor of 5,000 at 37 degrees C and 3,800 at 42 degrees C, the later part of the exchange is too slow to permit blood to come intoC02, equilibrium with actively exercising muscles during its passage through the capillary bed.

Measurement of blood O2 and CO2 concentrations using PO2 and PCO2 electrodes

1978 ◽  
Vol 44 (5) ◽  
pp. 818-820 ◽  
Author(s):  
A. L. Harabin ◽  
L. E. Farhi
Keyword(s):  
Carbon Monoxide ◽  
Blood Volume ◽  
Whole Blood ◽  
Co2 Concentration ◽  
Saturated Solution ◽  
Additional Step ◽  
Co2 Concentrations ◽  
O2 Concentration ◽  
Co2 Electrode ◽  
Small Blood Volume

Accurate dilution of a small blood volume with a carbon monoxide-saturated solution allows measurement of the whole blood O2 concentration as an increase in O2 tension in the solution. We have improved the method by simplifying both equipment and procedure. We also suggest an additional step in which the mixture is acidified, thereby allowing the measurement of CO2 concentration in the same solution with a CO2 electrode. The accuracy of both the O2 and CO2 determinations compares favorably with that obtained with other micromethods.

Validation of a maskless CO2-response test for sleep and infant studies

1988 ◽  
Vol 64 (1) ◽  
pp. 391-396 ◽  
Author(s):  
K. H. Naifeh ◽  
J. W. Severinghaus
Keyword(s):  
Steady State ◽  
Co2 Response ◽  
Arterial Pco2 ◽  
Response Test ◽  
Response Slope ◽  
Fractional Increase ◽  
The Subject ◽  
End Tidal ◽  
Co2 Electrode ◽  
Co2 Excretion

The Hazinski method is an indirect, noninvasive, and maskless CO2-response test useful in infants or during sleep. It measures the classic CO2-response slope (i.e., delta VI/delta PCO2) divided by resting ventilation Sr = (VI''--VI')/(VI'.delta PCO2) between low (')- and high ('')-inspired CO2 as the fractional increase of alveolar ventilation per Torr rise of PCO2. In steady states when CO2 excretion (VCO2') = VCO2'', Hazinski CO2-response slope (Sr) may be computed from the alveolar exchange equation as Sr = (PACO2'--PICO2')/(PACO2'--PICO2'') where PICO2 is inspired PCO2. To avoid use of a mask or mouthpiece, the subject breathes from a hood in which CO2 is mixed with inspired air and a transcutaneous CO2 electrode is used to estimate alveolar PCO2 (PACO2). To test the validity of this method, we compared the slopes measured simultaneously by the Hazinski and standard steady-state methods using a pneumotachograph, mask, and end-tidal, arterial, and four transcutaneous PCO2 samples in 15-min steady-state challenges at PICO2 23.5 +/- 4.5 and 37 +/- 4.1 Torr. Sr was computed using PACO2 and arterial PCO2 (PaCO2) as well as with the four skin PCO2 (PSCO2) values. After correction for apparatus dead space, the standard method was normalized to resting VI = 1, and its CO2 slope was designated directly measured normalized CO2 slope (Sx), permitting error to be calculated as Sr/Sx.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of oxalate by continuons analysis using photochemical oxidation by iron(III) and a CO2 electrode detector

1978 ◽  
Vol 56 (18) ◽  
pp. 2452-2458 ◽  
Author(s):  
Jean Margaret Cooley ◽  
Byron Kratochvil
Keyword(s):  
Carbon Dioxide ◽  
Calibration Curve ◽  
Theoretical Study ◽  
Ionic Species ◽  
Photochemical Oxidation ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Ion Concentrations ◽  
Co2 Electrode

Oxalate concentrations were measured by photochemical oxidation with iron(III) to carbon dioxide. Technicon AutoAnalyzer components were used to automate the sampling and mixing steps, and the carbon dioxide produced in the radiation step was measured with a CO2 electrode. Variables in the System were evaluated and the optimum conditions identified. A theoretical study was made of the effect on ionic species concentrations of variations in iron(III), acid, and counter ion concentrations. A linear calibration curve could be obtained for oxalate concentrations in the range of 2 × 10−4 to 0.02 M; by modifying conditions linearity could be achieved at both higher and lower concentration ranges. Several other acids are partially oxidized under optimum conditions for oxalate. Tartrate, citrate, and malonate introduce errors of 2% or less at concentrations equivalent to oxalate; malate and pyruvate cause errors on the order of 10%. Several small carboxylic acids were found to interfere with the CO2 electrode.

EVALUATION OF A NEW TRANSCUTANEOUS O2 AND CO2 ELECTRODE

1981 ◽  
Vol 9 (3) ◽  
pp. 169
Author(s):  
Michael J. Banner ◽  
T. James Gallagher ◽  
Tina E. Caruthers
Keyword(s):  
Co2 Electrode

In vivo response times for a heated skin surface CO2 electrode during rest and exercise

1986 ◽  
Vol 2 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Bruce G. Nickerson ◽  
Christopher Patterson ◽  
Ray McCrea ◽  
Frank Monaco
Keyword(s):  
Response Times ◽  
Skin Surface ◽  
Co2 Electrode ◽  
Rest And Exercise
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