Blood Gas Analysis

2011 ◽  
Author(s):  
Patrick Magee ◽  
Mark Tooley
Keyword(s):  
Electrical Potential ◽  
Physical Principle ◽  
Gas Analysis ◽  
The Other ◽  
Potential Difference ◽  
Ion Concentration ◽  
Blood Gas ◽  
Glass Membrane ◽  
Current Flows ◽  
Ph Electrode

A blood gas machine has electrodes to measure pH, pCO2 and pO2 and often measures Hb and some biochemistry as well [King et al. 2000]. Derived values from such a device include O2 saturation, O2 content, bicarbonate, base excess and total CO2. This is the Clarke electrode described in the previous section on gas analysers and is suitable for both respiratory and blood O2 analysis. A pH unit has been defined in Chapter 1 as. In words, this can be described as ‘the negative logarithm, to base ten, of the hydrogen ion concentration’. The physical principle on which the pH electrode is based depends on the fact that when a membrane separates two solutions of different [H+], a potential difference exists across the membrane. In a pH electrode, such a membrane is usually made of glass and the development of a potential difference between the two solutions is thought to be due to the migration of H+ into the glass matrix. If one solution consists of a standard [H+], the pH of the other solution can be estimated by measurement of the potential difference between them. The glass membrane used is selectively permeable to H+. No current flows in this device, which does not wear out, in contrast to the Clark electrode, in which current does flow and that does need periodic replacement. The pH measurement system is shown diagrammatically in Figure 17.1. It consists of two half cells. In one half it has an Ag/AgCl electrode and in the other a Hg/HgCl2 (calomel) electrode. Each electrode maintains a fixed electrical potential. The Ag/AgCl electrode is surrounded by a buffer solution of known pH, surrounded by the pH sensitive glass. Outside the glass membrane is the test solution, usually blood, whose pH is to be measured. It is the potential difference across the glass, between these two solutions, which is variable. The blood or other solution is separated from the calomel electrode by a porous plug and a potassium chloride salt bridge to minimise KCl diffusion. The potential difference across the system is about 60 mV per unit of pH change at 37◦C.

scholarly journals Blood Gas Analysis (Astrup) in Children suffering from Gastroenteritis dehydration with Acidosis

2017 ◽  
Vol 15 (9-10) ◽  
pp. 229
Author(s):  
Sutoto Sutoto ◽  
Sunoto Sunoto ◽  
Bambang M. ◽  
Sutejo Sutejo
Keyword(s):  
Blood Gas Analysis ◽  
Gas Analysis ◽  
The Other ◽  
Blood Gas ◽  
Blood Ph ◽  
Severe Gastroenteritis ◽  
Half Strength

Blood gas analysis and blood pH examinations have been carried out on 20 children suffering from severe gastroenteritis and dehydration. Ten patients were treated singly with half strength Darrow’s solution in 2.5% glucose containing potassium 17 mEq/L and lactate 26 mEq/ L as base corrector. The other 10 patients were given 3A solution (without potassium), containing lactate as base corrector as much as 53 mEq/L in the first 8 hours, followed by Darrow-Glucose (1:2) solution (with potassium).

scholarly journals Electrical Potential Difference Measurements in Perfused Single Proximal Tubules of Necturus Kidney

1961 ◽  
Vol 44 (4) ◽  
pp. 679-687 ◽  
Author(s):  
Guillermo Whittembury ◽  
Erich E. Windhager
Keyword(s):  
Electrical Potential ◽  
Proximal Tubules ◽  
The Other ◽  
Potential Difference ◽  
Stopped Flow ◽  
Electrical Potential Difference ◽  
Necturus Maculosus ◽  
Other Hand ◽  
Glomerular Filtrate

Transtubular and peritubular face electrical potential differences (P.D.) of the proximal tubules of the kidney of the amphibian Necturus maculosus have been measured in situ. These measurements have been carried out both under normal conditions, when the tubular fluid originates in the glomerular filtrate, and under conditions when the composition of the tubular fluid has been altered using the stopped flow microperfusion technique. Under normal conditions the transtubular potential difference is 20 mv. (lumen-negative) and the P.D. across the peritubular face is 74 mv. (cell-negative). The P.D. across the luminal face is thus 54 mv. (cell-negative). This electrical asymmetry is not influenced by replacing the normal tubular fluid by NaCl, NaCl + mannitol, or by alteration in the intraluminal pH from 7 to 4. On the other hand, replacement of Na by K or choline and the addition of small amounts of DNP to the perfusate diminish this asymmetry.

scholarly journals Chloride-ion stimulation of the tonoplast H+-translocating ATPase from Hevea brasiliensis (rubber tree) latex. A dual mechanism

1985 ◽  
Vol 226 (1) ◽  
pp. 85-94 ◽  
Author(s):  
B P Marin ◽  
X Gidrol
Keyword(s):  
Membrane Potential ◽  
Atpase Activity ◽  
Hevea Brasiliensis ◽  
Rubber Tree ◽  
Electrical Potential ◽  
Chloride Ion ◽  
The Other ◽  
Potential Difference ◽  
Dual Mechanism ◽  
Stimulation Of

The effect of Cl- and other anions on the tonoplast H+-translocating ATPase (H+-ATPase) from Hevea brasiliensis (rubber tree) latex was investigated. Cl- and other anions stimulated the ATPase activity of tightly sealed vesicles prepared from Hevea tonoplast, with the following decreasing order of effectiveness: Cl- greater than Br- greater than SO4(2-) greater than NO3-. As indicated by the changes of the protonmotive potential difference, anion stimulation of tonoplast H+-ATPase was caused in part by the ability of these anions to dissipate the electrical potential. This interpretation assumes not a channelling of these anions against a membrane potential, negative-inside, but a modification of the permeability of these ions through the tonoplast membrane. In addition, Cl- and the other anions stimulated the ATPase activity solubilized from the tonoplast membrane. Consequently, the tonoplast H+-pumping ATPase can be considered as an anion-stimulated enzyme. These results are discussed in relation to various models described in the literature for the microsomal H+-ATPase systems claimed as tonoplast entities.

Blood gas analysis in newborns with low cardiac output syndrome after cardiac surgery.

2018 ◽  
Vol 19 (5) ◽  
pp. 676-687
Author(s):  
G.G. Khubulava ◽  
A.B. Naumov ◽  
S.P. Marchenko ◽  
O.Yu. Chupaeva ◽  
A.A. Seliverstova ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Cardiac Surgery ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Low Cardiac Output Syndrome ◽  
Low Cardiac Output

scholarly journals The effect of clamped and unclamped umbilical cord samples on blood gas analysis

2021 ◽  
Author(s):  
Elisabetta Colciago ◽  
Simona Fumagalli ◽  
Elena Ciarmoli ◽  
Laura Antolini ◽  
Antonella Nespoli ◽  
...  
Keyword(s):  
Blood Gas Analysis ◽  
Cross Sectional Study ◽  
Gas Analysis ◽  
Blood Collection ◽  
Large Sample Size ◽  
Blood Gas ◽  
Delayed Cord Clamping ◽  
Cross Sectional ◽  
High Risk Women ◽  
Significant Difference

Abstract Purpose Delayed cord clamping for at least 60 s is recommended to improve neonatal outcomes. The aim of this study is to evaluate whether there are differences in cord BGA between samples collected after double clamping the cord or without clamping the cord, when blood collection occurs within 60 s from birth in both groups. Methods A cross-sectional study was carried out, collecting data from 6884 high-risk women who were divided into two groups based on the method of cord sampling (clamped vs unclamped). Results There were significant decrease in pH and BE values into unclamped group compared with the clamped group. This difference remained significant when considering pathological blood gas analysis parameters, with a higher percentage of pathological pH or BE values in the unclamped group. Conclusion Samples from the unclamped cord alter the acid–base parameters compared to collection from the clamped cord; however, this difference does not appear to be of clinical relevance. Findings could be due to the large sample size, which allowed to achieve a high power and to investigate very small numerical changes between groups, leading to a statistically significant difference in pH and BE between samples even when we could not appreciate any clinical relevant difference of pH or BE between groups. When blood gas analysis is indicated, the priority should be given to the timing of blood collection to allow reliable results, to assess newborns status at birth and intervene when needed.

scholarly journals AN IMPROVEMENT IN THE VAN SLYKE METHOD FOR BLOOD GAS ANALYSIS

1934 ◽  
Vol 104 (1) ◽  
pp. 29-31
Author(s):  
Friedrich Rappaport ◽  
Klara Köck-Molnar
Keyword(s):  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas
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