Conceptual and Design Features of a Practical, Clinically Effective Intravenous Mechanical Blood Oxygen/Carbon Dioxide Exchange Device (Ivox)

1989 ◽  
Vol 12 (6) ◽  
pp. 384-389 ◽  
Author(s):  
JD Mortensen ◽  
G. Berry
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Venous Blood ◽  
Vena Cava ◽  
Hollow Fibers ◽  
Carbon Dioxide Exchange ◽  
Gas Transfer ◽  
Blood Gas ◽  
Design Features ◽  
Planning Stage

Conceptual and design features of a new intravascular blood gas exchange device include: placing multiple, thin-walled microporous hollow fibers in an elongated arrangement with a small overall outside diameter; covering the outer surface of each microporous hollow fiber with an ultrathin continuous silicone coating; forming the hollow fibers into a configuration that produces disturbed flow of blood over the external surface of each fiber; placing the device in the subject's vena cava through a femoral or jugular venotomy; producing a flow of oxygen through the lumens of the hollow fibers, permitting exchange of oxygen and carbon dioxide between the venous blood outside and the gas inside the hollow fibers. Based on these principles, a practical, easily insertible, disposable, intravenacaval blood gas exchange device (IVOX) has been fabricated. Currently, devices with from 2,000 to 6,000 square centimeters of gas transfer surface area are being placed in the vena cavae of dogs and sheep for up to 7 days without altering the animal's hemodynamics, without producing serious hematologic sequelae, and with the capability of transferring in excess of 100 ml of oxygen and carbon dioxide to and from the venous blood of an intact, awake, standing animal. Clinical trials on human subjects with severe, acute, potentially reversible respiratory failure are in the planning stage.

Gas Transfer in a Spontaneously Ventilating, Blood-Perfused Trout Preparation

1982 ◽  
Vol 101 (1) ◽  
pp. 17-34
Author(s):  
PETER S. DAVIE ◽  
CHARLES DAXBOECK ◽  
STEVE F. PERRY ◽  
DAVID J. RANDALL
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Vascular Resistance ◽  
Respiratory Quotient ◽  
Venous Blood ◽  
Cardiovascular Responses ◽  
Systemic Circulation ◽  
Aortic Pressure ◽  
Gas Transfer

1. A spontaneously ventilating, blood-perfused trout preparation is described and its suitability for the study of gas exchange in fish assessed. 2. Cardiovascular dynamics closely approximated those found in vivo; perfusion flow rate (Q) = 1·62 ml−1.100 g−1, ventral aortic pressure (VAP) = 58·8 cm H2O, dorsal aortic pressure (DAP) = 34·8 cm H2O. 3. Gas exchange characteristics in the branchial and systemic circulations also were similar to those described for resting, intact rainbow trout. All preparations showed consistent oxygen uptake (Mg,O2, 1·17 μmol. min−1.100 g−1) and carbon dioxide excretion rates (Mg,CO2, 2·05 μmol. min−1.100 g−1) across the gills. Across the systemic circulation, oxygen was extracted (Ms,O2, 1·97 μmol. min−1.100 g−1) and carbon dioxide produced by the metabolizing tissue (Ms,CO2, 1·63 μmol. min−1.100 g−1). The respiratory quotient (REg) for gas transfer across the gills was 1·85. This high value was a reflection of the fact that much more oxygen than carbon dioxide was added to venous blood in the tonometer. The respiratory quotient for the tissues (RQs) was 0·83, a more reasonable value. Breathing rate (fg) was maintained at 69·4 ventilations.min−1. 4. The mean vascular resistance of blood-perfused gills (Rg) was 14·2 cm H2O.ml−1.min.100 g−1, a value higher than that usually measured in vivo. Mean systemic vascular resistance (Rs) was 19·2 cm H2O.ml−1.min.100 g−1 which is similar to that measured in intact fish. 5. Cardiovascular responses to hypoxia and adrenergic responses in the branchial and systemic circulations of these preparations also closely approximated those found in vivo. 6. This preparation is deemed suitable for studies of the cardiovascular system as well as gas transfer. The results from these experiments are representative of the in vivo condition in fish.

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

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.

Eddy covariance flux measurements of momentum, heat and carbon dioxide in Hudson Bay at the onset of sea ice melt 

2021 ◽  
Author(s):  
Richard Sims ◽  
Brian Butterworth ◽  
Tim Papakyriakou ◽  
Mohamed Ahmed ◽  
Brent Else
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Sea Ice ◽  
Eddy Covariance ◽  
Open Water ◽  
The Arctic ◽  
Gas Transfer ◽  
Hudson Bay ◽  
Flux Measurements ◽  
Ice Fraction

<p>Remoteness and tough conditions have made the Arctic Ocean historically difficult to access; until recently this has resulted in an undersampling of trace gas and gas exchange measurements. The seasonal cycle of sea ice completely transforms the air sea interface and the dynamics of gas exchange. To make estimates of gas exchange in the presence of sea ice, sea ice fraction is frequently used to scale open water gas transfer parametrisations. It remains unclear whether this scaling is appropriate for all sea ice regions. Ship based eddy covariance measurements were made in Hudson Bay during the summer of 2018 from the icebreaker CCGS Amundsen. We will present fluxes of carbon dioxide (CO<sub>2</sub>), heat and momentum and will show how they change around the Hudson Bay polynya under varying sea ice conditions. We will explore how these fluxes change with wind speed and sea ice fraction. As freshwater stratification was encountered during the cruise, we will compare our measurements with other recent eddy covariance flux measurements made from icebreakers and also will compare our turbulent CO<sub>2 </sub>fluxes with bulk fluxes calculated using underway and surface bottle pCO<sub>2</sub> data. </p><p> </p>

scholarly journals Severe portal and systemic acidosis during CO2-laparoscopy compared to helium or gasless laparoscopy and laparotomy in a rodent model: an experimental study

2021 ◽  
Author(s):  
Devdas T. Inderbitzin ◽  
Tobias U. Mueller ◽  
Grischa Marti ◽  
Simone Eichenberger ◽  
Benoît Fellay ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Experimental Study ◽  
Vena Cava ◽  
Blood Gas ◽  
Central Venous ◽  
Gasless Laparoscopy ◽  
Insufflation Pressure ◽  
Arterial Ph ◽  
Peripheral Arterial ◽  
Spontaneously Breathing

Abstract Background and aims This experimental study assesses the influence of different gases and insufflation pressures on the portal, central-venous and peripheral-arterial pH during experimental laparoscopy. Methods Firstly, 36 male WAG/Rij rats were randomized into six groups (n = 6) spontaneously breathing during anaesthesia: laparoscopy using carbon dioxide or helium at 6 and 12 mmHg, gasless laparoscopy and laparotomy. 45 and 90 min after setup, blood was sampled from the portal vein, vena cava and the common femoral artery with immediate blood gas analysis. Secondly, 12 animals were mechanically ventilated at physiological arterial pH during 90 min of laparotomy (n = 6) or carbon dioxide laparoscopy at 12 mmHg (n = 6) with respective blood gas analyses. Results Over time, in spontaneously breathing rats, carbon dioxide laparoscopy caused significant insufflation pressure-dependent portal acidosis (pH at 6 mmHg, 6.99 [6.95–7.04] at 45 min and 6.95 [6.94–6.96] at 90 min, pH at 12 mmHg, 6.89 [6.82–6.90] at 45 min and 6.84 [6.81–6.87] at 90 min; p < 0.05) compared to laparotomy (portal pH 7.29 [7.23–7.30] at 45 min and 7.29 [7.20–7.30] at 90 min; p > 0.05). Central-venous and peripheral-arterial acidosis was significant but less severely reduced during carbon dioxide laparoscopy. Laparotomy, helium laparoscopy and gasless laparoscopy showed no comparable acidosis in all vessels. Portal and central-venous acidosis during carbon dioxide laparoscopy at 12 mmHg was not reversible by mechanical hyperventilation maintaining a physiological arterial pH (pH portal 6.85 [6.84–6.90] (p = 0.004), central-venous 6.93 [6.90–6.99] (p = 0.004), peripheral-arterial 7.29 [7.29–7.31] (p = 0.220) at 90 min; Wilcoxon–Mann–Whitney test). Conclusion Carbon dioxide laparoscopy led to insufflation pressure-dependent severe portal and less severe central-venous acidosis not reversible by mechanical hyperventilation.

Influence of G-suit abdominal bladder inflation on gas exchange during +GZ stress

1985 ◽  
Vol 58 (2) ◽  
pp. 506-513
Author(s):  
H. I. Modell ◽  
P. Beeman ◽  
J. Mendenhall
Keyword(s):  
Gas Exchange ◽  
Time Course ◽  
Venous Blood ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Mixed Venous Blood ◽  
Blood Gas ◽  
Series Of Experiments ◽  
Spontaneously Breathing ◽  
Arterial Po2

Available data relating duration of +GZ stress to blood gas exchange status is limited. Furthermore, studies focusing on pulmonary gas exchange during +GZ stress when abdominal restriction is imposed have yielded conflicting results. To examine the time course of blood gas changes occurring during exposure to +GZ stress in dogs and the influence of G-suit abdominal bladder inflation on this time course, seven spontaneously breathing pentobarbital-anesthetized adult mongrel dogs were exposed to 60 s of up to +5 GZ stress with and without G-suit abdominal bladder inflation. Arterial and mixed venous blood were sampled for blood gas analysis during the first and last 20 s of the exposure and at 3 min postexposure. Little change in blood gas status was seen at +3 GZ regardless of G-suit status. However, with G-suit inflation, arterial PO2 fell by a mean of 14.7 Torr during the first 20 s at +4 Gz (P less than 0.01, t test) and 20.6 Torr at +5 GZ (P less than 0.01). It continued to fall an additional 10 Torr during the next 40 s at both +4 and +5 GZ. Arterial PO2 was still 5–10 Torr below control values (P less than 0.05) 3 min postexposure. A second series of experiments paralleling the first focused on blood gas status during repeated exposure to acceleration. Blood gas status was assessed in five dogs during the late 20 s of two 60-s exposures separated by 3 min at 0 GZ. No significant differences between the initial and repeated exposures were detected. The data indicate that G-suit abdominal bladder inflation promotes increased venous admixture.

The effects of altering gill water flow on gas transfer in rainbow trout

1987 ◽  
Vol 65 (10) ◽  
pp. 2466-2470 ◽  
Author(s):  
G. K. Iwama ◽  
R. G. Boutilier ◽  
T. A. Heming ◽  
D. J. Randall ◽  
M. Mazeaud
Keyword(s):  
Carbon Dioxide ◽  
Rainbow Trout ◽  
Blood Gases ◽  
Gas Transfer ◽  
Blood Gas ◽  
Transfer Rates ◽  
Volume Ventilation ◽  
Gill Ventilation ◽  
The Relationship ◽  
Trout Gill

The relationship between gill ventilation and gas transfer was studied in rainbow trout. Gill ventilation volumes were experimentally manipulated and blood gases as well as oxygen and carbon dioxide transfer across the gill were measured. At ventilation volumes below about 100 mL/min, there was an increase in blood carbon dioxide and a decrease in blood oxygen tensions. Both oxygen and carbon dioxide transfer rates in this range also declined with ventilation volume. Ventilation volumes below this level, therefore, may limit gas exchange and change blood gas tensions given constant metabolic rates. Ventilation volumes greater than 100 mL/min had little effect on blood gas tensions.

scholarly journals Arterio-VENouS Intra Subject agreement for blood gases within intensive care: The AVENSIS study

2019 ◽  
Vol 21 (1) ◽  
pp. 64-71
Author(s):  
Vinodh B Nanjayya ◽  
Phoebe McCracken ◽  
Shirley Vallance ◽  
Jasmin Board ◽  
Patrick J Kelly ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Partial Pressure ◽  
Repeated Measures ◽  
Life Support ◽  
Venous Blood ◽  
Blood Gases ◽  
Blood Gas ◽  
Central Venous

Background In critically ill patients, who require multiple blood gas assessments, agreement between arterial and venous blood gas values for pH and partial pressure of carbon dioxide, is not clear. Good agreement would mean that venous values could be used to assess ventilation and metabolic status of patients in intensive care unit. Methods All adult patients admitted to Alfred intensive care unit, Melbourne, from February 2013 to January 2014, who were likely to have arterial and central venous lines for three days, were enrolled. Patients on extra-corporeal life support and pregnant women were excluded. After enrolment, near simultaneous arterial and central venous sampling and analysis were performed at least once per nursing shift till the lines were removed or the patient died. Bland-Altman analysis for repeated measures was performed to assess the agreement between arterio-venous pH and partial pressure of carbon dioxide. Results A total of 394 paired blood gas analyses were performed from 59 participants. The median (IQR) number of samples per patient was 6 (5–9) with the median (IQR) sampling interval 9.4 (5.2–18.5) h. The mean bias for pH was  + 0.036 with 95% limits of agreement ranging from − 0.005 to + 0.078. For partial pressure of carbon dioxide, the values were −2.58 and −10.43 to + 5.27 mmHg, respectively. Conclusions The arterio-venous agreement for pH in intensive care unit patients appears to be acceptable. However, the agreement for partial pressure of carbon dioxide was poor.

P1386Continuous, transcutaneous carbon-dioxide monitoring in complex electrophysiological procedures in conscious sedation - is there a safer way to sleep?

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
K Weinmann ◽  
A Lenz ◽  
R Heudorfer ◽  
D Aktolga ◽  
A Pott ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Deep Sedation ◽  
Venous Blood ◽  
Blood Gas ◽  
Procedure Time ◽  
Transcutaneous Carbon Dioxide ◽  
Electrophysiological Procedures ◽  
Adequate Sedation ◽  
The Difference ◽  
Venous Blood Gas

Abstract Funding Acknowledgements Karolina Weinmann was supported by the Hertha-Nathorff fellowship from Ulm University Background – Ablation of cardiac arrhythmias by complex electrophysiological procedures is a growing field. A moderate to deep sedation is needed to immobilize the patient to warrant a safe and effective intervention. The administrated medication to obtain an adequate sedation has respiratory depressant side effects and could cause respiratory complications, like hypercapnia and hypoxia. Purpose – Our aim was to investigate the feasibility and accuracy of an additional, continuous transcutaneous carbon-dioxide (tpCO2) measurement during moderate to deep sedation in complex electrophysiological catheter ablations. Methods – Consecutive patients received an electrophysiological intervention with need for deep sedation. Routine hemodynamic monitoring was performed by the measurement of non-invasive blood-pressure, oxygen saturation and half-hourly venous blood gas analysis. Additionally, patients received a tpCO2 sensor on the forehead with an automated, continuous documentation of transcutaneous oxygen saturation and carbon-dioxide. A precise sedation protocol was performed and administrated drugs were registered. Results – We included 110 patients to the analysis. Fifty patients received cryoballoon pulmonary vein isolation, 58 patients 3D-mapping procedure and two patients ventricular tachycardia ablation. The mean procedure time was 135.1 ± 63.5 minutes and the fluoroscopy time was 21.5 ± 10.9 minutes. To achieve an adequate sedation a mean of 5.0 ± 0.8 mg midazolam, 583.8 ± 320.4 mg propofol, 72.0 ± 30.3 µg fentanyl and 0.2 ± 0.1 mg remifentanil were administrated. Hypercapnia (pCO2 &gt; 70 mmHg) was detected in five patient by the tpCO2 monitoring and only in two patients using venous carbon-dioxide partial pressure (vpCO2) analysis. Correlation of tpCO2 and vpCO2 were analyzed half-hourly by Pearsons’ correlation coefficient. There was a good correlation during the investigated 120 minutes of procedure time (baseline: r = 0.65, p &lt; 0.0001; 30 minutes: r = 0.75, p &lt; 0.0001; 60 minutes: r = 0.77, p &lt; 0.0001; 90 minutes: r = 0.78, p &lt; 0.0001; 120 minutes: r = 0.85, p &lt; 0.0001). The detected difference between tpCO2 and vpCO2 was at baseline &lt;5 mmHg in 65% (79/110) and &lt;10 mmHg in 96% (103/110), after 30 minutes the difference was &lt;5 mmHg in 71% (78/110) and &lt;10 mmHg in 96% (105/110), after 60 minutes the difference was &lt;5 mmHg in 77% (60/78) and &lt;10 mmHg in 96% (75/78) and after 90 minutes the difference between the two methods was &lt;5 mmHg in 63% (30/48) and &lt;10 mmHg in 98% (47/48) of the cohort. Conclusion – The continuous tpCO2 monitoring is a feasible and precise method with a good correlation to the venous blood gas carbon-dioxide analysis of the standard monitoring during complex catheter ablations in deep sedation. Randomized trials are required to further analyze if tpCO2 monitoring adds further safety to electrophysiological procedures in deep sedation.

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