Noninvasive cardiac output determination using inhaled oxygen-15-labeled carbon dioxide

1982 ◽  
Vol 53 (5) ◽  
pp. 1125-1132 ◽  
Author(s):  
N. M. Braslow ◽  
C. A. Hales ◽  
B. Hoop ◽  
D. J. Kanarek ◽  
H. Kazemi
Keyword(s):  
Carbon Dioxide ◽  
Cardiac Output ◽  
Linear Regression ◽  
Indocyanine Green ◽  
Correlation Coefficient ◽  
Animal Studies ◽  
Noninvasive Technique ◽  
Indocyanine Green Dye ◽  
Arterial Blood ◽  
Carbon Dioxide Co2

Inhaled oxygen-15-labeled carbon dioxide (CO2*) is hydrated in the alveolar capillary blood to produce oxygen-15-labeled water (H2O*). This allows noninvasive delivery of a traceable indicator into the pulmonary circulation. Removal of oxygen-15 marker from the lung is a function of pulmonary perfusion. Two techniques were evaluated for computing cardiac output (CO) following single bolus inhalation of CO2*: 1) continuous monitoring of arterial blood activity through an external detector and 2) noninvasive positron imaging of oxygen-15-label washout from the chest and simultaneous emergence of activity in arterial blood. In seven mongrel dogs studied using technique 1, 46 determinations of CO were made from 1.2 to 8.0 l/min and compared with simultaneous indocyanine green dye-dilution determination. Correlation coefficient was 0.90 with slope of linear regression of 1.05. In 12 mongrel dogs studied using technique 2, 23 determinations of CO were made from 0.9 to 9.2 l/min and compared with simultaneous indocyanine green dye determination. Correlation coefficient was 0.985 (P less than 0.001) with slope of linear regression of 0.898. This noninvasive technique (2) for determination of CO is independent of assumptions regarding regional ventilation or perfusion of the lung and appears valid in animal studies.

Quantitation of right-to-left shunting by double indicator and oxygen techniques

1976 ◽  
Vol 41 (3) ◽  
pp. 409-415 ◽  
Author(s):  
D. P. Copley ◽  
R. A. Klocke ◽  
F. J. Klocke
Keyword(s):  
Cardiac Output ◽  
Sulfur Hexafluoride ◽  
Venous Return ◽  
Right Heart ◽  
Indocyanine Green Dye ◽  
Arterial Blood ◽  
Vascular Space ◽  
Systemic Venous Return ◽  
Low Solubility ◽  
Right Heart Bypass

An improved double indicator technique for quantitating right-to-left shunting has been validated in a canine right-heart bypass shunt model and compared to standard O2 shunt measurements in the same preparation. A bolus of dissolved sulfur hexafluoride (SF6) and indocyanine green dye (ICG) is injected into systemic venous return and a single, time-averaged arterial blood sample is collected during the initial circulation of indicators. Because of its low solubility, SF6 is eliminated essentially quantitatively from blood traversing gas-filled alveoli; correction for volatile tracer in arterial blood derived from nonshunt pathways in therefore unnecessary. ICG remains confined to the vascular space and SF6 is not lost in shunt pathways. Ratios of SF6-ICG shunt to directly measured shunt averaged 0.99 +/- 0.27 (SD) in 55 comparisons of shunts ranging from 2 to 25% of cardiac output; differences between actual and measured shunt averaged 0.5 +/- 2.9% of cardiac output. Simultaneously determined ratios of O2 shunt to directly measured shunt averaged 0.98 +/- 0.48 in 34 comparisons; differences between actual and measured shunt were 0.7 +/- 3.4% of cardiac output.

scholarly journals ANALISIS EFEK KARBON DIOKSIDA (CO2) TERHADAP KENAIKAN TEMPERATUR DI BUKIT KOTOTABANGTAHUN 2005 – 2009

2010 ◽  
Vol 2 (2) ◽  
pp. 56-67
Author(s):  
Dwi Pujiastuti
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Correlation Coefficient ◽  
Radiative Forcing ◽  
Co2 Concentration ◽  
Weather Station ◽  
Automatic Weather Station ◽  
Temperature Deviation ◽  
Carbon Dioxide Co2 ◽  
Main Factor

Analysis of radiative forcing of carbon dioxide (CO2) by using IPCC (Intergovermental on Panel Climate Change) method over Bukit Kototabang (Agam, West Sumatera) for period of 2005 to 2009 has been conducted. The result is correlated with temperature deviation which measured by using AWS (Automatic Weather Station). Result showed that CO2 concentration increased from 375.256 ppm in 2005 to 381.736 ppm in 2009 but still below the global CO2 concentration in every year. In addition, CO2 radiative forcing has derived increased from 1.605 Wm-2 in 2005 to 1.697 Wm-2 in 2009 but still below the global CO2 radiative forcing. Concentration of CO2 has the same trend with CO2 radiative forcing. Temperature deviation was influenced by CO2 radiative forcing but with low correlation coefficient, about 6.9%. It can be concluded that the CO2 radiative forcing is not the main factor which is influences the temperature deviation in Bukit Kototabang.

scholarly journals P123 Accuracy and Reliability of the Transcutaneous Carbon Dioxide (TcCO2) Signal in the Sleep Laboratory

2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A61-A61
Author(s):  
A Rossely ◽  
A Turton ◽  
T Roebuck ◽  
S Ho ◽  
M Naughton ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sleep Laboratory ◽  
Blood Gas ◽  
Sleep Study ◽  
Arterial Blood Gas ◽  
Transcutaneous Carbon Dioxide ◽  
Arterial Blood ◽  
Co2 Monitoring ◽  
Sleep Laboratories ◽  
Carbon Dioxide Co2

Abstract Carbon Dioxide (CO2) monitoring is an essential part of assessing and treating disorders of hypoventilation in the sleep laboratory. While reliablity issues have been previously reported with the Transcutaneous Carbon Dioxide (TcCO2) signal, there is limited data assessing the validity of this signal or its trend in the sleep laboratory context. Therefore, this study aimed to investigate the change in TcCO2 accuracy from the beginning to the end of the sleep study in real world conditions across two different Victorian public hospital sleep laboratories that used two different TcCO2 monitors. The sample included 13 consecutive patients from Monash Health and 44 consecutive patients from Alfred Health with an average age of 64 and 56 years respectively. Arterial Blood Gas (ABG) measurements were taken prior to and following each sleep study and compared concurrently with the TcCO2 value. Bland-Altman analysis revealed an average difference between TcCO2 and PaCO2 of 3.29mmHg with agreement between -11.44 and 16.64mmHg for the TCM4 device and 1.31mmHg with agreement between -7.64 and 9.05mmHg for the TCM5 device. When accuracy was compared across time points for each patient, 46% of patients had an overnight accuracy change of ≥ 8mmHg when using the TCM4 compared with 20% when using the TCM5. It was concluded that the TcCO2 signal was un-reliable across the different monitors and that the TcCO2 trend may be difficult to interpret with confidence without blood gas calibration at the commencement and conclusion of the sleep study.

Pulmonary arterial shunting in man during forward acceleration

1961 ◽  
Vol 16 (6) ◽  
pp. 1081-1086 ◽  
Author(s):  
Sheldon H. Steiner ◽  
Gustave C. E. Mueller
Keyword(s):  
Carbon Dioxide ◽  
Cardiac Output ◽  
Technical Assistance ◽  
Recovery Period ◽  
Blood Gases ◽  
Carbon Dioxide Content ◽  
Arterial Blood ◽  
Acceleration Period ◽  
Peripheral Areas ◽  
The Individual

The arterial blood gases were determined during forward acceleration 90∘ to the acceleration vector at 6 g and 8 g breathing room air and at 8 g breathing 100% oxygen. Arterial saturation fell to 84% at 6 gand 75% at 8 g. Prebreathing O2 for 15 min prior to acceleration with continued inhalation during the acceleration plateau only partially corrected the undersaturation to 86% at 8 g. Recovery was not complete in 3 min unless O g therapy was used. Whole blood carbon dioxide content was depressed at 6 g and 8 g on room air, but this was corrected by O g inhalation. However, during the recovery period while breathing oxygen the carbon dioxide content was depressed. pH was reduced and pCO g elevated slightly during each acceleration period. Since cardiac output and alveolar ventilation have been reported to be essentially unaltered during forward acceleration at these magnitudes, the observed effects must represent substantial alterations in the individual ventilation to blood flow ratios throughout the lung, with approximately 50% of the cardiac output shunted through totally nonventilated areas at 8 g. There also must be some inadequately perfused or nonperfused peripheral areas, as evidenced by the fall in CO g content and pH and the accumulation of a substantial O g debt previously reported during acceleration. Note: With the Technical Assistance of Alice M. Caton and Justin L. Taylor, Jr. Submitted on June 12, 1961

scholarly journals A Persistently High End-Tidal Carbon Dioxide Value: Can This Be Spurious?

2019 ◽  
Vol 07 (02) ◽  
pp. 104-106
Author(s):  
Barkha Bindu ◽  
Gyaninder P. Singh ◽  
Varun Jain ◽  
Arvind Chaturvedi
Keyword(s):  
Carbon Dioxide ◽  
Unusual Case ◽  
Clinical Observation ◽  
Standard Of Care ◽  
Non Invasive ◽  
Correct Placement ◽  
Arterial Blood ◽  
End Tidal Carbon Dioxide ◽  
Carbon Dioxide Co2 ◽  
End Tidal

AbstractEnd-tidal carbon dioxide (EtCO2) monitoring has now become the standard of care not only during anesthesia but also in intensive care units for patients on mechanical ventilation, emergency department, and pre-hospital settings to confirm and monitor the correct placement of endotracheal tube. It is a non-invasive and continuous method of measuring exhaled carbon dioxide (CO2). Continuous waveform capnography measures EtCO2 and monitors ventilation. EtCO2 often correlates with partial pressure of carbon dioxide in arterial blood (PaCO2) and is a reliable indicator of PaCO2. A rise in EtCO2 often implies increased production of CO2 or decreased excretion (rebreathing, decrease ventilation) of CO2. We report an unusual case where the monitor malfunction per se lead to spuriously increased EtCO2 values without any clinical cause and did not correlate with PaCO2, thereby re-emphasizing that various monitors must always be interpreted in correlation with clinical observation.

Minimal compartmental model of circulatory mixing of indocyanine green

1992 ◽  
Vol 262 (3) ◽  
pp. H903-H910 ◽  
Author(s):  
T. K. Henthorn ◽  
M. J. Avram ◽  
T. C. Krejcie ◽  
C. A. Shanks ◽  
A. Asada ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Indocyanine Green ◽  
Blood Volume ◽  
High Performance ◽  
Compartmental Model ◽  
Drug Distribution ◽  
Circulation Model ◽  
Total Blood ◽  
Arterial Blood ◽  
The Right

A model of indocyanine green (ICG) disposition from the moment of its injection in blood was developed. ICG disposition was characterized in five dogs deeply anesthetized with halothane, which decreased cardiac output and prolonged intravascular mixing. After ICG injection into the right atrium, femoral arterial blood samples were collected every 3 s for the 1st min and less frequently to 20 min. ICG concentrations were measured by high-performance liquid chromatography and modeled with SAAM 30.1. A fully identifiable recirculatory compartmental model with time delays was used to describe ICG disposition. The central blood volume averaged 23.4 ml/kg, and total blood volume averaged 78.9 ml/kg. Fifty-three percent of the cardiac output flowed through 14% of the peripheral blood volume while the remaining 47% flowed through 86% of the peripheral volume. This new model is isomorphic with a parallel channel, lumped-parameter circulation model and provides more information than stochastic, noncompartmental recirculatory pharmacokinetic techniques. This intravascular mixing model can be applied to determine the contribution of the circulation to drug distribution.

Measurement of Cardiac Output with Indocyanine Green Transcutaneous Fluorescence Dilution Technique

2004 ◽  
Vol 100 (6) ◽  
pp. 1476-1483 ◽  
Author(s):  
Jean-Michel I. Maarek ◽  
Daniel P. Holschneider ◽  
Juji Harimoto ◽  
Jun Yang ◽  
Oscar U. Scremin ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Indocyanine Green ◽  
Near Infrared ◽  
Optical Probe ◽  
Thermodilution Cardiac Output ◽  
Indocyanine Green Fluorescence ◽  
Arterial Blood ◽  
Ear Artery ◽  
Hemodynamic Assessment ◽  
Baseline Conditions

Background Cardiac output is an essential parameter for the hemodynamic assessment of patients with cardiovascular disease. The authors tested in an animal model the feasibility of measuring cardiac output by transcutaneous fluorescence monitoring of an intravenous bolus injection of indocyanine green. Methods Fluorescence dilution cardiac output was measured in 10 anesthetized rabbits and compared with cardiac output measured with a pulmonary thermodilution catheter and to aortic velocity measured by Doppler ultrasound. Indocyanine green fluorescence was excited with a near-infrared laser and measured with an optical probe positioned on the central ear artery. Measurements were obtained during baseline conditions as well as during short-term decreases and increases of the cardiac output. Results The fluorescence of circulating indocyanine green detected transcutaneously varied proportionally to that of arterial blood samples, which allowed for calibration in terms of blood concentration of indocyanine green. Average values of fluorescence dilution cardiac output and thermodilution cardiac output measured in baseline conditions were 412 (+/- 13) and 366 (+/- 11) ml/min, respectively. Fluorescence dilution cardiac output showed a close, one-to-one linear relation with thermodilution cardiac output in each animal and in the pooled data from all animals (slope = 0.95 x 0.03; R = 0.94). Fluorescence dilution cardiac output overestimated thermodilution cardiac output by an average of 46 (+/- 6) ml/min during baseline conditions. Fluorescence dilution cardiac output was tightly correlated with aortic velocity. Conclusions The proposed technique yielded accurate estimates of the cardiac output in experimental animals. This study should provide an initial framework for clinical testing of this new minimally invasive method for measuring cardiac output.

scholarly journals Carbon Dioxide Sensing—Biomedical Applications to Human Subjects

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 188
Author(s):  
Emmanuel Dervieux ◽  
Michaël Théron ◽  
Wilfried Uhring
Keyword(s):  
Carbon Dioxide ◽  
Human Subjects ◽  
Measurement Techniques ◽  
Blood Gases ◽  
Good Alternative ◽  
Monitoring Methods ◽  
Non Invasive ◽  
Arterial Blood ◽  
Co2 Monitoring ◽  
Carbon Dioxide Co2

Carbon dioxide (CO2) monitoring in human subjects is of crucial importance in medical practice. Transcutaneous monitors based on the Stow-Severinghaus electrode make a good alternative to the painful and risky arterial “blood gases” sampling. Yet, such monitors are not only expensive, but also bulky and continuously drifting, requiring frequent recalibrations by trained medical staff. Aiming at finding alternatives, the full panel of CO2 measurement techniques is thoroughly reviewed. The physicochemical working principle of each sensing technique is given, as well as some typical merit criteria, advantages, and drawbacks. An overview of the main CO2 monitoring methods and sites routinely used in clinical practice is also provided, revealing their constraints and specificities. The reviewed CO2 sensing techniques are then evaluated in view of the latter clinical constraints and transcutaneous sensing coupled to a dye-based fluorescence CO2 sensing seems to offer the best potential for the development of a future non-invasive clinical CO2 monitor.

Some cardiorespiratory parameters in anesthetized sheep

1961 ◽  
Vol 16 (1) ◽  
pp. 45-47 ◽  
Author(s):  
Denis F. J. Halmagyi ◽  
H. J. H. Colebatch
Keyword(s):  
Carbon Dioxide ◽  
Cardiac Output ◽  
Oxygen Content ◽  
Lung Compliance ◽  
Carbon Dioxide Tension ◽  
Venous Admixture ◽  
Mean Values ◽  
Arterial Blood ◽  
Pulmonary Arterial ◽  
Standard Deviations

Ventilated volumes, oxygen content and carbon dioxide tension in the arterial blood, cardiac output, venous admixture, systemic and pulmonary arterial pressures, and lung compliance were determined in 50 anesthetized sheep. Mean values and standard deviations are described and compared with values obtained in 11 unanesthetized sheep. Submitted on July 25, 1960

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