Acid-base changes in blood and cerebrospinal fluid during altered ventilation

1961 ◽  
Vol 16 (6) ◽  
pp. 1016-1018 ◽  
Author(s):  
C. R. Merwarth ◽  
H. O. Sieker
Keyword(s):  
Carbon Dioxide ◽  
Cerebrospinal Fluid ◽  
Venous Blood ◽  
Clinical Importance ◽  
Carbon Dioxide Tension ◽  
Acid Base ◽  
Sagittal Sinus ◽  
Arterial Blood ◽  
Arterial Ph ◽  
The Central Nervous System

Functional abnormalities of the central nervous system are observed with hypo- and hyperventilation. This study correlates changes of pH, carbon dioxide tension and carbon dioxide content in arterial and cerebral venous blood and cerebrospinal fluid during altered ventilation. With the experimental design in which ventilation was controlled and the sagittal sinus, femoral artery, and cisterna magna were cannulated, a slight metabolic acidosis was found. With 10% CO2 inhalation acidosis occurred in both blood and spinal fluid and early in the period of inhalation, the usual cerebrospinal-arterial fluid pCO2 gradient was reversed. With hyperventilation, pH and pCO2 changes were more pronounced in the arterial blood but, as hyperventilation was continued, the arterial-cerebrospinal fluid difference decreased. It appeared likely that brain tissue acts as an important buffer, absorbing and releasing CO2 during states of altered ventilation. CO2 diffuses rapidly across cell boundaries, whereas bicarbonate crosses more slowly, thus providing an explanation for the differences noted between blood and cerebrospinal fluid. The particular clinical importance of these observations is that arterial pH, pCO2, and CO2 content may not accurately reflect changes within the cerebrospinal fluid or brain when ventilation is altered. Submitted on May 1, 1961

Hyperoxia of cerebral venous blood and cisternal cerebrospinal fluid following arterial air embolism

1972 ◽  
Vol 37 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Norval M. Simms ◽  
Don M. Long ◽  
James H. Matthews ◽  
Shelley N. Chou
Keyword(s):  
Cerebrospinal Fluid ◽  
Oxygen Tension ◽  
Venous Blood ◽  
Air Embolism ◽  
Carbon Dioxide Tension ◽  
Acid Base ◽  
Content Type ◽  
Arterial Blood ◽  
Base Parameters ◽  
The Right

✓ Oxygen tension and acid-base parameters of cerebral venous blood and cisternal cerebrospinal fluid, as well of femoral arterial blood, were studied in 14 dogs following injection of varying amounts of room air into the right vertebral artery. Acute elevations in oxygen tension were demonstrated in both cerebral venous blood and CSF, whereas hypoxemia occurred concomitantly in systemic arterial blood. Post-embolic increases in carbon dioxide tension with reciprocal diminutions in pH were evident in all sampling sites. The pathophysiological bases for these air-induced alterations are discussed.

scholarly journals Subdiaphragmatic venous stasis and tissular hypoperfusion as sources of metabolic acidosis during passive portal-jugular and caval-jugular bypasses in dogs

2000 ◽  
Vol 15 (2) ◽  
pp. 94-101 ◽  
Author(s):  
Antônio Roberto de Barros Coelho ◽  
Álvaro Antônio Bandeira Ferraz ◽  
Renato Dornelas Câmara Neto ◽  
Ayrton Ponce de Souza ◽  
Edmundo Machado Ferraz
Keyword(s):  
Carbon Dioxide ◽  
Liver Transplantation ◽  
Metabolic Acidosis ◽  
Venous Blood ◽  
Blood Stasis ◽  
Carbon Dioxide Tension ◽  
Base Deficit ◽  
Venous Stasis ◽  
Acid Base ◽  
Arterial Blood

Subdiafragmatic venous decompression during anhepatic stage of canine orthotopic liver transplantation attenuates portal and caval blood stasis and minimize hipoperfusion and metabolic acidosis observed with occlusion of portal and caval veins. During two hours, six dogs submitted to portal-jugular and caval-jugular passive shunts, with maintenance of arterial hepatic flow, were evaluated for pH, carbon dioxide tension (PCO2), base deficit (BD) and oxygen tension (PO2) in portal, caval and systemic arterial blood, as well as for increments of BD (DBD) in portal and caval blood. With a confidence level of 95%, the results showed that: 1. There were not changes of pH anDBD in portal and systemic arterial blood in the majority of studied times; 2. There was metabolic acidosis in caval blood; 3. The negative increments of BD (DBD) were higher in caval blood than in splancnic venous blood at T10, T30 and T105; and, 4. Deoxigenation of portal and caval blood were detected. Acid-base metabolism and oxigenation monitoring of subdiaphramatic venous blood can constitute an effective way to evaluate experimental passive portal-jugular and caval-jugular bypass in dogs.

Clinical evaluation of an instrument to measure carbon dioxide tension at the oxygenator gas outlet in cardiopulmonary bypass

Perfusion ◽  
2006 ◽  
Vol 21 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Frode Kristiansen ◽  
Jan Olav Høgetveit ◽  
Thore H Pedersen
Keyword(s):  
Carbon Dioxide ◽  
Cardiopulmonary Bypass ◽  
Venous Blood ◽  
Carbon Dioxide Tension ◽  
Circuit Board ◽  
Separate Analysis ◽  
Blood Gas ◽  
Arterial Blood ◽  
Gas Measurement ◽  
Venous Blood Gas

This paper presents the clinical testing of a new capno-graph designed to measure the carbon dioxide tension at the oxygenator exhaust outlet in cardiopulmonary bypass (CPB). During CPB, there is a need for reliable, accurate and instant estimates of the arterial blood CO2 tension (PaCO2) in the patient. Currently, the standard practice for measuring PaCO2 involves the manual collection of intermittent blood samples, followed by a separate analysis performed by a blood gas analyser. Probes for inline blood gas measurement exist, but they are expensive and, thus, unsuitable for routine use. A well-known method is to measure PexCO2, ie, the partial pressure of CO2 in the exhaust gas output from the oxygenator and use this as an indirect estimate for PaCO2. Based on a commercially available CO2 sensor circuit board, a laminar flow capnograph was developed. A standard sample line with integrated water trap was connected to the oxygenator exhaust port. Fifty patients were divided into six different groups with respect to oxygenator type and temperature range. Both arterial and venous blood gas samples were drawn from the CPB circuit at various temperatures. Alfa-stat corrected pCO2 values were obtained by running a linear regression for each group based on the arterial temperature and then correcting the PexCO2 accordingly. The accuracy of the six groups was found to be (±SD): ±4.3, ±4.8, ±5.7, ±1.0, ±3.7 and ±2.1%. These results suggest that oxygenator exhaust capnography is a simple, inexpensive and reliable method of estimating the PaCO2 in both adult and pediatric patients at all relevant temperatures.

Relative effects of carbonic anhydrase infusion or inhibition on carbon dioxide transport and acid-base status in the sea lamprey Petromyzon marinus following exercise

1996 ◽  
Vol 199 (4) ◽  
pp. 933-940
Author(s):  
B Tufts ◽  
S Currie ◽  
J Kieffer
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Venous Blood ◽  
Extracellular Fluid ◽  
Respiratory Acidosis ◽  
Acid Base ◽  
Carbon Dioxide Transport ◽  
Co2 Transport ◽  
Arterial Blood ◽  
Acid Base Status

In vivo experiments were carried out to determine the relative effects of carbonic anhydrase (CA) infusion or inhibition on carbon dioxide (CO2) transport and acid-base status in the arterial and venous blood of sea lampreys recovering from exhaustive exercise. Infusion of CA into the extracellular fluid did not significantly affect CO2 transport or acid-base status in exercised lampreys. In contrast, infusion of the CA inhibitor acetazolamide resulted in a respiratory acidosis in the blood of recovering lampreys. In acetazolamide-treated lampreys, the post-exercise extracellular pH (pHe) of arterial blood was significantly lower than that in the saline-infused (control) lampreys. The calculated arterial and venous partial pressure of carbon dioxide (PCO2) and the total CO2 concentration in whole blood (CCO2wb) and red blood cells (CCO2rbc) during recovery in the acetazolamide-infused lampreys were also significantly greater than those values in the saline-infused control lampreys. These results suggest that the CO2 reactions in the extracellular compartment of lampreys may already be in equilibrium and that the access of plasma bicarbonate to CA is probably not the sole factor limiting CO2 transport in these animals. Furthermore, endogenous red blood cell CA clearly has an important role in CO2 transport in exercising lampreys.

Lactate and Pyruvate Levels in Brain and Skeletal Muscle During Hyperthermia in Dogs

1971 ◽  
Vol 49 (6) ◽  
pp. 520-524 ◽  
Author(s):  
Robert B. Dunn ◽  
Franco Lioy
Keyword(s):  
Cerebrospinal Fluid ◽  
Cerebral Metabolism ◽  
Free Breathing ◽  
Respiratory Alkalosis ◽  
Tissue Hypoxia ◽  
Sagittal Sinus ◽  
Arterial Blood ◽  
Arterial Ph ◽  
Anesthetized Dogs ◽  
Lactate And Pyruvate

Tissue hypoxia, as shown by an increase of the arterial concentration of lactate and of the lactate–pyruvate (L/P) ratio, has been observed during hyperthermia in free-breathing animals with high arterial [Formula: see text]. The effect of raising body temperature to 41.9 °C for 2 h on lactate and pyruvate concentrations in arterial, muscle venous, and sagittal sinus blood and cerebrospinal fluid was studied in anesthetized dogs. The animals were paralyzed with gallamine, and arterial pH and [Formula: see text] maintained at normal levels by artificial ventilation with 50% O2[Formula: see text]. A slight increase in lactate and pyruvate took place in the arterial blood and parallel changes were observed both in the muscle venous and sagittal sinus blood. The L/P ratio did not change. Lactate and pyruvate increased markedly in the CSF, without a change in the L/P ratio. Therefore hyperthermia, in the absence of respiratory alkalosis, does not appear to induce tissue hypoxia associated with an increase in L/P ratio. The lack of correlation between lactate and pyruvate concentrations in sagittal sinus blood and cerebrospinal fluid confirms the fact that the A–V differences of these substrates across the brain are not a good index of cerebral metabolism.

Effect of Diamox (Acetazoleamide) on the Carbon Dioxide Tension of the Urine

1957 ◽  
Vol 191 (1) ◽  
pp. 55-58 ◽  
Author(s):  
Nicholas E. Capeci ◽  
Oscar R. Kruesi ◽  
Davis C. Weaver ◽  
James G. Hilton
Keyword(s):  
Carbon Dioxide ◽  
Intravenous Administration ◽  
Venous Blood ◽  
Carbon Dioxide Tension ◽  
Urine Flow ◽  
Arterial Blood ◽  
Before And After

In the anesthetized dog the pCO2 of the urine, arterial blood, and renal venous blood was measured before and after the intravenous administration of Diamox (acetazoleamide). The pCO2 of the urine always rose to a much greater degree than did the pCO2 of the arterial or renal venous blood This rise in urinary pCO2 could be explained satisfactorily neither by a rise in intracellular pCO2 nor by an increase in the rate of urine flow, but seemed best explained by the fact that Diamox itself acted as a urinary buffer.

A New Open-Circuit Method for Estimating Carbon Dioxide Tension in Mixed Venous Blood

1977 ◽  
Vol 52 (4) ◽  
pp. 377-382 ◽  
Author(s):  
Reiah Al-Dulymi ◽  
R. Hainsworth
Keyword(s):  
Carbon Dioxide ◽  
Venous Blood ◽  
Carbon Dioxide Tension ◽  
Open Circuit ◽  
Mixed Venous Blood ◽  
Arterial Blood ◽  
Venous Pco2 ◽  
Rebreathing Methods ◽  
Mixed Venous ◽  
Good Agreement

1. A new open-circuit respiratory method was developed to estimate mixed venous Pco2 more rapidly and accurately than is possible with rebreathing techniques. 2. The subject breathes a mixture of CO2 in air from an open circuit. Carbon dioxide is added to the air flowing through the circuit at a rate such that the Pco2 in the inspired and expired gases (recorded continuously with a CO2 analyser) are almost identical. 3. Results from respiratory and cardiac patients showed that equilibrium occurred in less than 10 s. There was good agreement between the tensions of CO2 in the respiratory plateaux and in mixed venous and arterial blood withdrawn during equilibrium. 4. During exercise, the tensions of CO2 of the plateaux and arterial blood at equilibrium also showed good agreement. 5. It is suggested that the new method represents an improvement over rebreathing methods as equilibrium is achieved rapidly before the mixed venous tension rises from recirculation.

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