Carbon Dioxide Kinetics During Anesthesia

Breen, Peter H.

doi:10.1016/s0889-8537(05)70017-1

Cited by 17 publications

(27 citation statements)

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“…The bymixer-flow measurement of VCO 2 and VO 2 by airway indirect calorimetry may help detect and manage critical events during anesthesia [5][6][7][8][9][10] and onset of anaerobic metabolism. 6,11 Further clinical studies are required to delineate the clinical significance of these monitoring technologies during anesthesia and surgery, and how they augment or compare with current monitoring modalities.…”

Section: Discussionmentioning

confidence: 99%

“…[1][2][3][4] The ability to measure airway oxygen uptake (VO 2 ) and carbon dioxide elimination (VCO 2 ) during anesthesia by indirect calorimetry may help the detection and management of critical events during anesthesia, such as an abrupt decrease in cardiac output or onset of pulmonary embolism. [5][6][7][8][9][10] Moreover, the respiratory exchange ratio (R = VCO 2 /VO 2 ) is an index of cellular metabolism. An increase in R may signal onset of anaerobic metabolism.…”

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confidence: 99%

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Bymixer system can measure O2 uptake and CO2 elimination in the anesthesia circle circuit

Rosenbaum

Kirby

Breen

2007

Can J Anesth/J Can Anesth

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Background:The ability to measure carbon dioxide elimination (VCO 2 ), oxygen uptake (VO 2 ), and R (respiratory exchange ratio, VCO 2 /VO 2 ) during anesthesia may help the non-invasive detection of critical events (e.g., abrupt decrease in cardiac output) and metabolic upset (e.g., onset of anaerobic metabolism). Methods:We have developed a new clinical bymixer (inline mixing chamber) that can measure mixed inspired and expired gas fractions in the anesthesia circle circuit. The addition of a standard anesthesia gas analyzer and flowmeter, and a new airway temperature and humidity sensor, allow determinations of VCO 2 and VO 2 at the airway opening of the circle circuit. Over a range of tidal volume and frequency, VCO 2 and VO 2 were compared to reference values generated by the combustion of metered liquid ethanol in a new metabolic lung simulator.Results: By linear regression, bymixer-flow measurements of VCO 2 (slope = 1.02, Y-intercept = -5.31, coefficient of determination, R 2 = 0.998) and VO 2 (slope = 1.05, Y-intercept = -4.34, R 2 = 0.993) correlated closely to the reference values generated by the metabolic lung simulator. Limits of agreement analysis generated percent errors (mean ± 1.96 SD) of -1.2 ± 7.2% for VCO 2 and 2.5 ± 9.8% for VO 2 . Conclusions:The new clinical bymixer is compact, lightweight, disposable, inexpensive, and has a fast and adjustable response time (time constant about 14 sec). Anesthesia circle circuit integrity is maintained. Bymixer-flow measurements of VCO 2 and VO 2 are accurate and may add to clinical monitoring under anesthesia and surgery.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Bymixer system can measure O2 uptake and CO2 elimination in the anesthesia circle circuit

Rosenbaum

Kirby

Breen

2007

Can J Anesth/J Can Anesth

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“…The gradual reduction in pulmonary blood flow caused by the inflation of the intramediastinal balloon catheter (Fig. 3A) led to a significant reduction in the Max Vp and a concomitant fall in the PE CO 2 (Fig. 3A).…”

Section: Effects Of Maximal Intramediastinal Balloon Catheter Inflatimentioning

confidence: 99%

“…3B), which were maintained under a constant respiratory frequency and tidal volume to minimize the extent of any ventilation-perfusion mismatch. To further evaluate the influence of ventilation-perfusion mismatch (1) on the relationship between Max Vp and PE CO 2 , we investigated the effects of changes in respiratory frequency and tidal volume on the PE CO 2 and Max Vp of the anesthetized rabbits. Representative findings are shown in Fig.…”

Section: Effects Of Maximal Intramediastinal Balloon Catheter Inflatimentioning

confidence: 99%

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In vivo support for the new concept of pulmonary blood flow-mediated CO₂ gas excretion in the lungs

Kawai

Ajima

Kaidoh

et al. 2015

American Journal of Physiology-Lung Cellular and Molecular Phys

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To further examine the validity of the proposed concept of pulmonary blood flow-dependent CO2 gas excretion in the lungs, we investigated the effects of intramediastinal balloon catheterization-, pulmonary artery catheterization-, or isoprenaline (ISP)-induced changes in pulmonary blood flow on the end-expiratory CO2 gas pressure (PECO 2 ), the maximal velocity of the pulmonary artery (Max Vp), systemic arterial pressure, and heart rate of anesthetized rabbits. We also evaluated the changes in the PECO 2 in clinical models of anemia or pulmonary embolism. An almost linear relationship was detected between the PECO 2 and Max Vp. In an experiment in which small pulmonary arteries were subjected to stenosis, the PE CO 2 fell rapidly, and the speed of the reduction was dependent on the degree of stenosis. ISP produced significant increases in the PECO 2 of the anesthetized rabbits. Conversely, treatment with piceatannol or acetazolamide induced significant reductions in the PE CO 2 . Treatment with a cell surface F1/FO ATP synthase antibody caused significant reductions in the PE CO 2 itself and the ISP-induced increase in the PECO 2 . Neither the PECO 2 nor SAP was significantly influenced by marked anemia [%hematocrit (Ht), 70ϳ47%]. On the other hand, in the presence of less severe anemia (%Ht: 100ϳ70%) both the PE CO 2 and SAP fell significantly when the rabbits' blood viscosity was decreased. The rabbits in which pulmonary embolisms were induced demonstrated significantly reduced PECO 2 values, which was compatible with the lowering of their Max Vp. In conclusion, we reaffirm the validity of the proposed concept of CO 2 gas exchange in the lungs. carbon dioxide gas excretion; cell surface F1/Fo adenosine 5=-triphosphate synthase; pulmonary circulation; piceatannol; acetazolamide VASCULAR ENDOTHELIAL CELLS (EC) are constantly exposed to shear stress, the mechanical force generated by blood flow. The shear stress in a Newtonian fluid is defined as follows: shear stress ϭ viscosity ϫ flow velocity gradient (dv/dt), so if the viscosity is constant the level of shear stress depends upon the flow velocity gradient (23). EC recognize shear stress and transmit signals to their interior, where they trigger cellular responses, including changes in a variety of cell functions (3,5,12,25). For example, in response to shear stress, vascular EC release endogenous ATP, which is produced by the activation of cell surface F 1 /F O ATP synthase (25). Yamamoto et al. (25) also demonstrated that pulmonary arterial EC exhibited the most prominent responses to shear stress. However, how ATP release from pulmonary arteriolar EC, which might be exposed to higher shear stress levels than the EC in the pulmonary artery, is affected by shear stress is unclear. The following continuity equation suggests that the pulmonary blood flow volume-dependent flow velocity gradient of the pulmonary arterioles will be greater than that of the pulmonary artery providing the cross-sectional area of the blood vessels remains constant: (the blood flow ...

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Monitoring of O2 Uptake and CO2 Elimination During Anesthesia and Surgery

Breen

Rosenbaum

2013

Monitoring Technologies in Acute Care Environments

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Carbon Dioxide Kinetics During Anesthesia

Cited by 17 publications

References 49 publications

Bymixer system can measure O2 uptake and CO2 elimination in the anesthesia circle circuit

Bymixer system can measure O2 uptake and CO2 elimination in the anesthesia circle circuit

In vivo support for the new concept of pulmonary blood flow-mediated CO₂ gas excretion in the lungs

Monitoring of O2 Uptake and CO2 Elimination During Anesthesia and Surgery

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Carbon Dioxide Kinetics During Anesthesia

Cited by 17 publications

References 49 publications

Bymixer system can measure O2 uptake and CO2 elimination in the anesthesia circle circuit

Bymixer system can measure O2 uptake and CO2 elimination in the anesthesia circle circuit

In vivo support for the new concept of pulmonary blood flow-mediated CO2 gas excretion in the lungs

Monitoring of O2 Uptake and CO2 Elimination During Anesthesia and Surgery

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In vivo support for the new concept of pulmonary blood flow-mediated CO₂ gas excretion in the lungs