Effect of carbonic anhydrase inhibition on mixed venous CO2 tension in anesthetized dogs

1960 ◽  
Vol 15 (3) ◽  
pp. 390-392 ◽  
Author(s):  
Stephen M. Cain ◽  
Arthur B. Otis
Keyword(s):  
Carbonic Anhydrase ◽  
Venous Blood ◽  
Carbonic Anhydrase Inhibitor ◽  
Mixed Venous Blood ◽  
Bicarbonate Concentration ◽  
Significant Difference ◽  
Carbonic Anhydrase Inhibition ◽  
Anesthetized Dogs ◽  
The Difference ◽  
Mixed Venous

The ventilation of one lung in dogs was isolated and that lung continually rebreathed into a small rubber bag. The Pco2 of a sample of the gas in the rebreathing bag was compared with the Pco2 calculated from pH and bicarbonate concentration determined in a sample of mixed venous blood drawn simultaneously. Before the injection of a carbonic anhydrase inhibitor, acetazolamide, the difference between the two values for Pco2 was not significant. After acetazolamide, a highly significant difference (P < 0.001) was found. Apparently, when carbonic anhydrase was inhibited, the dissolved CO2 of mixed venous blood did not attain equilibrium with bicarbonate by the time the blood entered the lung. Submitted on December 18, 1959

Kinetics of CO2 excretion and intravascular pH disequilibria during carbonic anhydrase inhibition

1998 ◽  
Vol 84 (2) ◽  
pp. 683-694 ◽  
Author(s):  
Victor Cardenas ◽  
Thomas A. Heming ◽  
Akhil Bidani
Keyword(s):  
Mathematical Model ◽  
Gas Exchange ◽  
Carbonic Anhydrase ◽  
Blood Cells ◽  
Venous Blood ◽  
Hysteresis Loops ◽  
Mixed Venous Blood ◽  
Carbonic Anhydrase Inhibition ◽  
Kinetics Of ◽  
Mixed Venous

Cardenas, Victor, Jr., Thomas A. Heming, and Akhil Bidani.Kinetics of CO2 excretion and intravascular pH disequilibria during carbonic anhydrase inhibition. J. Appl. Physiol. 84(2): 683–694, 1998.—Inhibition of carbonic anhydrase (CA) activity (activity in red blood cells and activity available on capillary endothelium) results in decrements in CO2 excretion (V˙co 2) and plasma-erythrocyte CO2-[Formula: see text]-H+disequilibrium as blood travels around the circulation. To investigate the kinetics of changes in blood [Formula: see text]and pH during progressive CA inhibition, we used our previously detailed mathematical model of capillary gas exchange to analyze experimental data of V˙co 2and blood-gas/pH parameters obtained from anesthetized, paralyzed, and mechanically ventilated dogs after treatment with acetazolamide (Actz, 0–100 mg/kg iv). Arterial and mixed venous blood samples were collected via indwelling femoral and pulmonary arterial catheters, respectively. Cardiac output was measured by thermodilution. End-tidal[Formula: see text], as a measure of alveolar[Formula: see text], was obtained from continuous records of airway [Formula: see text] above the carina. Experimental results were analyzed with the aid of a mathematical model of lung and tissue-gas exchange. Progressive CA inhibition was associated with stepwise increments in the equilibrated mixed venous-alveolar [Formula: see text] gradient (9, 19, and 26 Torr at 5, 20, and 100 mg/kg Actz, respectively). The maximum decrements in V˙co 2were 10, 24, and 26% with 5, 20, and 100 mg/kg Actz, respectively, without full recovery ofV˙co 2 at 1 h postinfusion. Equilibrated arterial [Formula: see text]overestimated alveolar [Formula: see text], and tissue [Formula: see text] was underestimated by the measured equilibrated mixed venous blood[Formula: see text]. Mathematical model computations predicted hysteresis loops of the instantaneous CO2-[Formula: see text]-H+relationship and in vivo blood[Formula: see text]-pH relationship due to the finite reaction times for CO2-[Formula: see text]-H+reactions. The shape of the hysteresis loops was affected by the extent of Actz inhibition of CA in red blood cells and plasma.

A nomogram to evaluate the arterial mixed venous oxygen saturation difference during cardiopulmonary bypass

Perfusion ◽  
1998 ◽  
Vol 13 (1) ◽  
pp. 45-51 ◽  
Author(s):  
F Cavaliere
Keyword(s):  
Cardiopulmonary Bypass ◽  
Muscle Relaxation ◽  
Venous Blood ◽  
Myocardial Revascularization ◽  
The Body ◽  
Mixed Venous Blood ◽  
Blood Haemoglobin ◽  
The Difference ◽  
Mixed Venous ◽  
Saturation Difference

A nomogram providing the arterial mixed venous haemoglobin saturation difference (Sa-vO2) corresponding to normal oxygen consumption (VO2) during cardiopulmonary bypass (CPB) was produced. Normal VO2 during CPB (95.8 ± 20.1 ml/min/m2 at 37°C) was obtained from the literature. The nomogram computes the Sa-vO2 from the body surface, pump flow, blood haemoglobin and patient temperature; a table is also presented which supplies the Sa-vO2 ranges corresponding to VO2 mean ±1 and ±2SD. The nomogram was tested on 10 subjects undergoing CPB for myocardial revascularization. Sa-vO2 was determined by arterial and mixed venous blood oximetry 5, 20, and 35 min after the start of CPB. The measured Sa-vO2 was 27.1 ± 7.2% while Sa-vO2 obtained from the nomogram was 24.9 ± 4.0%, the difference was not statistically significant. Eighteen values (60%) were within the range corresponding to VO2 mean ±1SD. One value was lower than the Sa-vO2 value corresponding to VO2 mean - 2SD and was associated with the lowest value of blood haemoglobin. Two values were higher than the Sa-vO2 value corresponding to VO2 mean + 2SD and were associated with inadequate muscle relaxation. By comparing measured Sa-vO2 values with those obtained by the nomogram and the table, anaesthesiologists and perfusionists can easily detect patients presenting abnormally low or high VO2 values.

Role of mixed venous blood Pco2 in respiratory control

1961 ◽  
Vol 16 (6) ◽  
pp. 1029-1033 ◽  
Author(s):  
Gerd J. A. Cropp ◽  
Julius H. Comroe
Keyword(s):  
Venous Blood ◽  
Vena Cava ◽  
Respiratory Control ◽  
Minute Volume ◽  
Regulation Of Respiration ◽  
Mixed Venous Blood ◽  
Physiological Regulation ◽  
Anesthetized Dogs ◽  
The Right ◽  
Mixed Venous

The Pco2 of mixed venous blood has been increased abruptly by 5—49 mm Hg, without altering the volume or pressure of blood returning to the right ventricle, by infusion of blood with 550—700 mm Hg Pco2 into the right atrium, and simultaneous withdrawal of equal volumes of blood from the inferior vena cava. Twenty-five such blood exchanges in four anesthetized cats, four anesthetized dogs, and three unanesthetized dogs failed, with one exception, to increase respiratory frequency or tidal volume if PaCOCO2 remained constant; respiration increased only when PaCOCO2 rose. Correlation of ventilatory minute volume with PvCOCO2 was poor ( r = 0.296; P > 0.1) but was good with PaCOCO2 ( r = 0.608; P < 0.001). Experiments on the innervated and denervated carotid body (dog) demonstrated that chemoreceptors can respond rapidly (0.5 sec) to changes in PaOO2 or PaCOCO2. The absence of demonstrable ventilatory response to increased PvCOCO2 over periods of 0.5–3.0 min in animals in whom increments in PaCOCO2 led promptly to increased ventilation indicates that there are no CO2 receptors in the precapillary pulmonary circulation of importance in the physiological regulation of respiration. Submitted on May 25, 1961

Perbedaan Penggunaan Antikoagulan K2EDTA DAN K3EDTA Terhadap Hasil Pemeriksaan Indeks Eritrosit

2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk
Keyword(s):  
Screening Test ◽  
Venous Blood ◽  
The Body ◽  
Ethylene Diamine ◽  
P Value ◽  
Cross Sectional ◽  
Significant Difference ◽  
Ethylene Diamine Tetra Acetate ◽  
The Difference ◽  
Index Value

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.

Carbon Dioxide Equilibration in Canine Lungs during Rebreathing and Acute Alkalosis

1979 ◽  
Vol 57 (5) ◽  
pp. 385-388 ◽  
Author(s):  
R. D. Latimer ◽  
G. Laszlo
Keyword(s):  
Whole Blood ◽  
Base Excess ◽  
Venous Blood ◽  
Main Pulmonary Artery ◽  
Mixed Venous Blood ◽  
Arterial Blood ◽  
Significant Difference ◽  
Venous Pco2 ◽  
Pulmonary Arterial ◽  
Gas Pressures

1. The left lower lobe of the lungs of six anaesthetized dogs were isolated by the introduction of a bronchial cannula at thoracotomy. Catheters were introduced into the main pulmonary artery and a vein draining the isolated lobe. 2. Blood-gas pressures and pH were measured across the isolated lobe and compared with gas pressures in alveolar samples from the lobe. 3. When the isolated lobe was allowed to reach gaseous equilibrium with pulmonary arterial blood for 30 min, there was no significant difference between alveolar and pulmonary venous Pco2. Mean values of whole-blood base excess were similar in pulmonary arterial and pulmonary venous blood. 4. After injection of 20 ml of 8·4% sodium bicarbonate solution into a peripheral vein, Pco2, pH and plasma bicarbonate concentrations rose in the mixed venous blood. There was no change of whole-blood base excess across the lung, indicating that HCO−3, as distinct from dissolved CO2, did not enter lung tissue in measurable amounts. 5. No systematic alveolar—pulmonary venous Pco2 differences were demonstrated in this preparation other than those explicable by maldistribution of lobar blood flow.

Effects of cocaine on incremental treadmill exercise in horses

1993 ◽  
Vol 75 (6) ◽  
pp. 2727-2733 ◽  
Author(s):  
K. H. McKeever ◽  
K. W. Hinchcliff ◽  
D. F. Gerken ◽  
R. A. Sams
Keyword(s):  
Right Ventricular ◽  
Blood Lactate ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Ventricular Pressure ◽  
Mixed Venous Blood ◽  
Work Intensity ◽  
Venous Blood Lactate ◽  
Mixed Venous

Four mature horses were used to test the effects of two doses (50 and 200 mg) of intravenously administered cocaine on hemodynamics and selected indexes of performance [maximal heart rate (HRmax), treadmill velocity at HRmax, treadmill velocity needed to produce a blood lactate concentration of 4 mmol/l, maximal mixed venous blood lactate concentration, maximal treadmill work intensity, and test duration] measured during an incremental treadmill test. Both doses of cocaine increased HRmax approximately 7% (P < 0.05). Mean arterial pressure was 30 mmHg greater (P < 0.05) during the 4- to 7-m/s steps of the exercise test in the 200-mg trial. Neither dose of cocaine had an effect on the responses to exertion of right atrial pressure, right ventricular pressure, or maximal change in right ventricular pressure over time. Maximal mixed venous blood lactate concentration increased 41% (P < 0.05) with the 50-mg dose and 75% (P < 0.05) with the 200-mg dose during exercise. Administration of cocaine resulted in decreases (P < 0.05) in the treadmill velocity needed to produce a blood lactate concentration of 4 mmol/l from 6.9 +/- 0.5 and 6.8 +/- 0.9 m/s during the control trials to 4.4 +/- 0.1 m/s during the 200-mg cocaine trial. Cocaine did not alter maximal treadmill work intensity (P > 0.05); however, time to exhaustion increased by approximately 92 s (15%; P < 0.05) during the 200-mg trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary diffusion in the dog lung

1962 ◽  
Vol 17 (6) ◽  
pp. 885-892 ◽  
Author(s):  
Albert H. Niden ◽  
Charles Mittman ◽  
Benjamin Burrows
Keyword(s):  
Carbon Monoxide ◽  
Pulmonary Artery ◽  
Experimental Animal ◽  
Venous Blood ◽  
Whole Body ◽  
Mixed Venous Blood ◽  
Pulmonary Diffusion ◽  
Perfused Lung ◽  
Pulmonary Arterial ◽  
Mixed Venous

Methods have been presented for assessing pulmonary diffusion by the “equilibration technique” in the experimental intact dog and perfused lung while controlling ventilation with a whole body respirator. No significant change in diffusion of carbon monoxide was noted between open and closed chest anesthetized animals, with duration of anesthesia in the intact dog, or with duration of perfusion of the isolated dog's lung. There was no demonstrable difference in diffusion when arterialized blood was used as the perfusate in place of mixed venous blood in the lung perfusions suggesting that within the range studied the Po2, Pco2, and pH of pulmonary artery blood does not directly affect the diffusion of carbon monoxide. Retrograde perfusions of dogs' lungs did not significantly alter diffusion, suggesting that pulmonary venous resistance was not significantly lower than pulmonary arterial resistance in the perfused dog lung at the flows and pressures studied. The equilibration technique for measuring pulmonary diffusion and assessing the uniformity of diffusion was well suited to the study of pulmonary diffusing characteristics in the experimental animal. Submitted on January 8, 1962

An electrical analyzer for carbon dioxide in respiratory gases

1962 ◽  
Vol 17 (1) ◽  
pp. 126-130
Author(s):  
Leon Bernstein ◽  
Chiyoshi Yoshimoto
Keyword(s):  
Carbon Dioxide ◽  
Thermal Conductivity ◽  
Medical Students ◽  
Venous Blood ◽  
Mixed Venous Blood ◽  
The Subject ◽  
Respiratory Gases ◽  
Rebreathing Method ◽  
Mixed Venous

The analyzer described was de signed for measuring the concentration of carbon dioxide in the bag of gas from which the subject rebreathes in the “rebreathing method” for estimating the tension of carbon dioxide in mixed venous blood. Its merits are that it is cheap, robust, simple to construct and to service, easy to operate, and accurate when used by untrained operators. (Medical students, unacquainted with the instrument, and working with written instructions only, obtained at their first attempt results accurate to within ±0.36% [sd] of carbon dioxide.) The instrument is suitable for use by nurse or physician at the bedside, and also for classes in experimental physiology. Some discussion is presented of the theoretical principles underlying the design of analyzers employing thermal conductivity cells. Submitted on July 13, 1961

Respiratory measurements of cardiac output: from elegant idea to useful test

2004 ◽  
Vol 96 (2) ◽  
pp. 428-437 ◽  
Author(s):  
Gabriel Laszlo
Keyword(s):  
Cardiac Output ◽  
Human Subjects ◽  
Venous Blood ◽  
The Body ◽  
Mixed Venous Blood ◽  
Indirect Determination ◽  
Arterial Blood ◽  
Pulmonary Capillary ◽  
Pulmonary Arterial ◽  
Mixed Venous

The measurement of cardiac output was first proposed by Fick, who published his equation in 1870. Fick's calculation called for the measurement of the contents of oxygen or CO2 in pulmonary arterial and systemic arterial blood. These values could not be determined directly in human subjects until the acceptance of cardiac catheterization as a clinical procedure in 1940. In the meanwhile, several attempts were made to perfect respiratory methods for the indirect determination of blood-gas contents by respiratory techniques that yielded estimates of the mixed venous and pulmonary capillary gas pressures. The immediate uptake of nonresident gases can be used in a similar way to calculate cardiac output, with the added advantage that they are absent from the mixed venous blood. The fact that these procedures are safe and relatively nonintrusive makes them attractive to physiologists, pharmacologists, and sports scientists as well as to clinicians concerned with the physiopathology of the heart and lung. This paper outlines the development of these techniques, with a discussion of some of the ways in which they stimulated research into the transport of gases in the body through the alveolar membrane.

Influence of changes in cardiac output on the acid-base status of arterial and mixed venous blood

1987 ◽  
Vol 410 (3) ◽  
pp. 257-262 ◽  
Author(s):  
Y. L. Hoogeveen ◽  
J. P. Zock ◽  
P. Rispens ◽  
W. G. Zijlstra
Keyword(s):  
Cardiac Output ◽  
Venous Blood ◽  
Mixed Venous Blood ◽  
Acid Base ◽  
Acid Base Status ◽  
Mixed Venous
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