Association of the Arteriovenous Difference in Carbon Dioxide and Its Relation to the Difference in Arteriovenous Oxygen Content With the Occurrence of Postoperative Complication

2019 ◽  
Author(s):  
Keyword(s):  
Carbon Dioxide ◽  
Postoperative Complication ◽  
Oxygen Content ◽  
The Difference ◽  
Arteriovenous Difference

Continuous, transcutaneous carbon-dioxide monitoring to avoid hypercapnia in complex catheter ablations under conscious sedation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Weinmann ◽  
A Lenz ◽  
R Heudorfer ◽  
D Aktolga ◽  
M Rattka ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Conscious Sedation ◽  
Venous Blood ◽  
Patient Comfort ◽  
Carbon Dioxide Partial Pressure ◽  
Close Monitoring ◽  
Blood Gas ◽  
Transcutaneous Carbon Dioxide ◽  
The Difference ◽  
Venous Blood Gas

Abstract Background Ablation of complex cardiac arrhythmias requires an immobilized patient. For a successful and safe intervention and for patient comfort, this can be achieved by conscious sedation. Administered sedatives and analgesics have respiratory depressant side effects and require close monitoring. Purpose We investigated the feasibility and accuracy of an additional, continuous transcutaneous carbon-dioxide partial pressure (tpCO2) measurement during conscious sedation in complex electrophysiological catheter ablation procedures. Methods We evaluated the accuracy and additional value of tpCO2 detection by application of a Severinghaus electrode in comparison to arterial and venous blood gas analyses. Results We included 110 patients in this prospective observational study. Arterial pCO2 (paCO2) and tpCO2 showed good correlation throughout the procedures (r=0.60–0.87, p<0.005). Venous pCO2 (pvCO2) were also well correlated to transcutaneous values (r=0.65–0.85, p<0.0001). Analyses of the difference of pvCO2 and tpCO2 measurements showed a tolerance within <10mmHg in up to 96–98% of patients. Hypercapnia (pCO2<70mmHg) was detected more likely and earlier by continuous tpCO2 monitoring compared to half-hourly pvCO2 measurements. Conclusion Continuous tpCO2 monitoring is feasible and precise with good correlation to arterial and venous blood gas carbon-dioxide analysis during complex catheter ablations under conscious sedation and may contribute to additional safety. Funding Acknowledgement Type of funding source: None

A New Equal Area Method to Calculate and Represent Physiologic, Anatomical, and Alveolar Dead Spaces

2006 ◽  
Vol 104 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Yongquan Tang ◽  
Martin J. Turner ◽  
A Barry Baker
Keyword(s):  
Carbon Dioxide ◽  
Dead Space ◽  
Graphical Method ◽  
Mean Difference ◽  
Equal Area ◽  
Area Method ◽  
Physiologic Dead Space ◽  
Anatomical Dead Space ◽  
The Mean ◽  
The Difference

Background Physiologic dead space is usually estimated by the Bohr-Enghoff equation or the Fletcher method. Alveolar dead space is calculated as the difference between anatomical dead space estimated by the Fowler equal area method and physiologic dead space. This study introduces a graphical method that uses similar principles for measuring and displaying anatomical, physiologic, and alveolar dead spaces. Methods A new graphical equal area method for estimating physiologic dead space is derived. Physiologic dead spaces of 1,200 carbon dioxide expirograms obtained from 10 ventilated patients were calculated by the Bohr-Enghoff equation, the Fletcher area method, and the new graphical equal area method and were compared by Bland-Altman analysis. Dead space was varied by varying tidal volume, end-expiratory pressure, inspiratory-to-expiratory ratio, and inspiratory hold in each patient. Results The new graphical equal area method for calculating physiologic dead space is shown analytically to be identical to the Bohr-Enghoff calculation. The mean difference (limits of agreement) between the physiologic dead spaces calculated by the new equal area method and Bohr-Enghoff equation was -0.07 ml (-1.27 to 1.13 ml). The mean difference between new equal area method and the Fletcher area method was -0.09 ml (-1.52 to 1.34 ml). Conclusions The authors' equal area method for calculating, displaying, and visualizing physiologic dead space is easy to understand and yields the same results as the classic Bohr-Enghoff equation and Fletcher area method. All three dead spaces--physiologic, anatomical, and alveolar--together with their relations to expired volume, can be displayed conveniently on the x-axis of a carbon dioxide expirogram.

Decreased Carbon Dioxide Sensitivity in Infants of Substance-Abusing Mothers

PEDIATRICS ◽  
1995 ◽  
Vol 95 (6) ◽  
pp. 864-867
Author(s):  
Janet G. Wingkun ◽  
Janet S. Knisely ◽  
Sidney H. Schnoll ◽  
Gary R. Gutcher
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Minute Ventilation ◽  
Demographic Data ◽  
Substance Abusing ◽  
Quiet Sleep ◽  
Co2 Level ◽  
The Difference ◽  
End Tidal ◽  
Drug Free

Objective. To determine whether there is a demonstrable abnormality in control of breathing in infants of substance-abusing mothers during the first few days of life. Methods. We enrolled 12 drug-free control infants and 12 infants of substance abusing mothers (ISAMs). These infants experienced otherwise uncomplicated term pregnancies and deliveries. The infants were assigned to a group based on the results of maternal histories and maternal and infant urine toxicology screens. Studies were performed during quiet sleep during the first few days of life. We measured heart rate, oxygen saturations via a pulse oximeter, end-tidal carbon dioxide (ET-CO2) level, respiratory rate, tidal volume, and airflow. The chemoreceptor response was assessed by measuring minute ventilation and the ET-CO2 level after 5 minutes of breathing either room air or 4% carbon dioxide. Results. The gestational ages by obstetrical dating and examination of the infants were not different, although birth weights and birth lengths were lower in the group of ISAMs. Other demographic data were not different, and there were no differences in the infants' median ages at the time of study or in maternal use of tobacco and alcohol. The two groups had comparable baseline (room air) ET-CO2 levels, respiratory rates, tidal volumes, and minute ventilation. When compared with the group of ISAMs, the drug-free group had markedly increased tidal volume and minute ventilation on exposure to 4% carbon dioxide. These increases accounted for the difference in sensitivity to carbon dioxide, calculated as the change in minute ventilation per unit change in ET-CO2 (milliliters per kg/min per mm Hg). The sensitivity to carbon dioxide of control infants was 48.66 ± 7.14 (mean ± SE), whereas that of ISAMs was 16.28 ± 3.14. Conclusions. These data suggest that ISAMs are relatively insensitive to challenge by carbon dioxide during the first few days of life. We speculate that this reflects an impairment of the chemoreceptor response.

scholarly journals THE MORPHOLOGICAL CHANGES IN THE TISSUES OF THE RABBIT AS A RESULT OF REDUCED OXIDATION

1918 ◽  
Vol 27 (3) ◽  
pp. 399-412 ◽  
Author(s):  
H. G. Martin ◽  
A. S. Loevenhart ◽  
C. H. Bunting
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Content ◽  
Morphological Changes ◽  
Low Oxygen ◽  
High Carbon ◽  
Red Bone Marrow ◽  
Hydropic Degeneration ◽  
Thyroid Hyperplasia ◽  
High Carbon Dioxide ◽  
Stimulation Of

Exposure of rabbits to an atmosphere of low oxygen content results in a stimulation of the cardiorespiratory systems, in an extension (hyperplasia) of red bone marrow and probably of a thyroid hyperplasia, with the further production of hydropic and hyaline degeneration in the cells of the parenchymatous organs. An atmosphere of high carbon dioxide and normal oxygen content produces, however, a stimulation of the cardiorespiratory systems, but no marrow extension and, in the concentrations used, but slight hydropic degeneration in the parenchyma of the glandular organs.

scholarly journals Effect on the bactericidal device for decontamination the air microorganisms in poultry house on the content of toxic gases

2020 ◽  
Vol 10 (1) ◽  
pp. 24-29
Author(s):  
A. P. Palii ◽  
O. V. Nanka ◽  
Y. O. Kovalchuk ◽  
A. O. Kovalchuk ◽  
V. S. Kalabska ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ultraviolet Irradiation ◽  
Cold Season ◽  
Gas Content ◽  
Poultry House ◽  
Air Contamination ◽  
Toxic Gases ◽  
Application Techniques ◽  
The Difference ◽  
Rational Construction

Litter in the poultry house is a source of toxic gases (ammonia, hydrogen sulphide and carbon dioxide), dust, and is a favourable place for the life and reproduction of microorganisms and helminths. The number of these secretions in the poultry house depends on many factors: the sanitary status of the poultry house, the species, the age of the birds, the microclimate, the season, feeding conditions, and so on. The purpose of the research was to substantiate the rational construction and modes of operation of the device for the decontamination of microorganisms in the air of the poultry house on the basis of the use of sources of ultraviolet irradiation. The necessity of development and application techniques for cage batteries with a litter removal belt system which provide reduction of microbial contamination of air in poultry houses and the content of harmful gases in it have been substantiated. The device was developed and the effective mode of disinfection of the air of the poultry house in the collector air duct of the litter drying system based on the use of sources of ultraviolet irradiation was determined. The application of the bactericidal device made it possible to reduce microbial air contamination on the 1st day of accumulation of the litter during the cold season - by 2.6 times, in the transitional season - by 2.1 times; on 5th day, the accumulation of the litter decreased by 3.0 and 2.3 times, respectively. During the operation of the air irradiation system, the content of toxic gases in it decreased compared to the period when the air was not treated with the ultraviolet irradiation - ammonia by 19.7% and carbon dioxide by 5.9%. The absolute values of microbial air contamination in the poultry house and the toxic gas content in the transitional season were lower than in the cold season, due to the higher indoor air exchange and the increase of clean outside air in the proportion. The difference in microbial air contamination between the basic and the proposed variants in the cold and transitional seasons was statistically significant.

scholarly journals RECEIVING OIL FROM CLOUDBERRIES FRUITS BY SUPERCRITICAL CARBON DIOXIDE EXTRACTION

2018 ◽  
pp. 91-97
Author(s):  
Artyom Dmitrievich Ivakhnov ◽  
Kristina Sergeevna Sadkova ◽  
Alina Sergeyevna Sobashnikova ◽  
Tat'yana Eduardovna Skrebets ◽  
Mikhail Vladislavovich Bogdanov
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Supercritical Carbon Dioxide ◽  
Unsaturated Fatty Acids ◽  
Optimum Conditions ◽  
Hexane Extraction ◽  
Rubus Chamaemorus ◽  
The Difference ◽  
Key Indicators ◽  
Supercritical Carbon

Comparative researches of ways of oil extraction from the fulfilled fruits of cloudberries (Rubus chamaemorus) with application of hexane and supercritical carbon dioxide as solvents are executed. Optimization is performed and optimum conditions of supercritical fluid extraction of oil are defined with use of central composite design of 2nd order. Pressure of carbon dioxide of 350 atm, temperature 85 °C, duration of extraction of 80 min are the optimum conditions of carrying out of the process. The yield of oil is 9.0%. Quality key indicators of the received oil were defined. The difference between the oil received by the SKF-CO2 method and the oil received by hexane extraction consists in improvement of organoleptic properties, the raised share of the combined fatty acids at decrease of a share of the free acids and high content of unsaturated fatty acids. It is shown that supercritical carbon dioxide can be an alternative to the hydrocarbons which are traditionally used for these purposes.

STUDYING THE SUBLIMATION OF CARBON DIOXIDE

2021 ◽  
Vol 17 (37) ◽  
pp. 1-12
Author(s):  
Evgeniy N. NEVEROV ◽  
Igor A. KOROTKIY ◽  
Elena V. KOROTKAYA ◽  
Aleksandr N. RASSHCHEPKIN
Keyword(s):  
Carbon Dioxide ◽  
Storage Temperature ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Sublimation Rate ◽  
Temperature Relation ◽  
Dry Ice ◽  
Weight Losses ◽  
Ice Surface ◽  
The Difference

Background: The utilization of dry ice in cooling and storage units requires adjusting the intensity of sublimation due to the requirements of prudently using CO2 to maintain preset thermal conditions. Aim: When designing a carbon dioxide cycle, it is essential to consider the influence of thermal gradients on the adsorption and desorption of carbon dioxide. Methods: tests were conducted to study the production and sublimation of carbon dioxide. The testes were aimed to define the temperature relation of the dry ice sublimation period, the density of pressed СО2, and the humidity of the environment and concentration. Results and Discussion: According to the obtained test data, there was a linear relationship between the sublimation intensity and the ambient air temperature in the specified conditions. The effect of moisture condensation on the sublimation rate appeared weaker than expected, for the amount of moisture on the surface of the specimens was insignificant. The heat exchange was intensified by the fall of hoarfrost and the related surface expansion. However, much moisture froze out without reaching the dry ice surface, and the formed layer of ice formed a heat insulation surface, and the sublimation under that layer was less intensive. The direct influence of sublimation came from the pressure at which a specific specimen was formed; however, 75 kN pressure was optimal. Conclusion: Despite higher weight losses during the storage, the difference in spent energy is more critical than 90 kN. The factor no less important was the carbon dioxide storage temperature. The maximal sublimation time of a 55 g cylinder formed at 75 kN and stored at – 80°С was 135 hours, much higher than at similar parameters but at -60°С. That said, the amount of energy spent on operating a low-temperature chamber was almost identical.

Bicarbonate-carbon dioxide buffer system: a determinant of the mitochondrial pH gradient

1984 ◽  
Vol 247 (3) ◽  
pp. F440-F446 ◽  
Author(s):  
D. P. Simpson ◽  
S. R. Hager
Keyword(s):  
Carbon Dioxide ◽  
Renal Cortex ◽  
Ph Gradient ◽  
Buffer System ◽  
Acid Base ◽  
Bicarbonate Buffer ◽  
Inner Membrane ◽  
System A ◽  
Intact Kidney ◽  
The Difference

The influence of the bicarbonate-carbon dioxide buffer system on the pH gradient (delta pH) across the inner membrane of mitochondria from rabbit renal cortex was studied with and without phosphate in the medium. delta pH with bicarbonate buffer or phosphate in the medium was greater at low than at high medium pH so that the difference (delta delta pH) between delta pH at pH 7.1 and at 7.6 was positive. Varying the concentration of phosphate from 0 to 10 mM had little effect on delta delta pH produced by bicarbonate buffer. Inhibition of the phosphate-hydroxyl carrier with N-ethylmaleimide abolished delta delta pH when phosphate was present in non-bicarbonate-containing media. With bicarbonate buffer present, N-ethylmaleimide increased delta delta pH. Similar effects were observed in mitochondria from liver and heart as well as from kidney. The effects of the bicarbonate buffer system on delta pH may result either from an inner membrane permeable to carbon dioxide but not to bicarbonate ion or from an active carrier for bicarbonate ion in the inner membrane. In intact kidney cells, the influence of the bicarbonate buffer system on delta pH may provide a mechanism for regulating substrate metabolism in response to acid-base changes. It may also serve in many organs to reduce fluctuations in matrix pH when alterations in cytoplasmic pH occur.

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