Continuous monitoring of membrane lung carbon dioxide removal during ECMO: experimental testing of a new volumetric capnometer

Background: Extracorporeal membrane oxygenation constitutes a complex support modality, and accurate monitoring is required. An ideal monitoring system should promptly detect ECMO malfunctions and provide real-time information to optimize the patient–machine interactions. We tested a new volumetric capnometer which enables continuous monitoring of membrane lung carbon dioxide removal (V′CO2ML), to help in estimating the oxygenator performance, in terms of CO2 removal and oxygenator dead space (VDsML). Methods: This study was conducted on nine pigs undergoing veno-arterial ECMO due to cardiogenic shock after induced acute myocardial infarction. The accuracy and reliability of the prototype of the volumetric capnometer (CO2RESET™, by Eurosets srl, Medolla, Italy) device was evaluated for V′CO2ML and VDsML measurements by comparing the obtained measurements from the new device to a control capnometer with the sweep gas values. Measurements were taken at five different levels of gas flow/blood flow ratio (0.5-1.5). Agreement between the corresponding measurements was taken with the two methods. We expected that 95% of differences were between d − 1.96s and d + 1.96s. Results: In all, 120 coupled measurements from each device were obtained for the V′CO2ML calculation and 40 for the VDsML. The new capnometer mean percentage bias (95% confidence interval limits of agreement) was 3.86% (12.07-4.35%) for V′CO2ML and 2.62% (8.96-14.20%) for VDsML. A negative proportional bias for V′CO2ML estimation with the new device was observed with a mean of 3.86% (12.07-4.35%). No correlations were found between differences in the coupled V′CO2ML and VDsML measurements and the gas flow/blood flow ratio or temperature. Coupled measurements for V′CO2ML showed strong correlation (rs = 0.991; p = 0.0005), as did VDsML calculations (rs = 0.973; p = 0.0005). Conclusion: The volumetric capnometer is reliable for continuous monitoring of CO2 removal by membrane lung and VDsML calculations. Further studies are necessary to confirm these data.

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Regional Blood Acidification Enhances Extracorporeal Carbon Dioxide Removal

Anesthesiology ◽

10.1097/aln.0000000000000099 ◽

2014 ◽

Vol 120 (2) ◽

pp. 416-424 ◽

Cited By ~ 29

Author(s):

Alberto Zanella ◽

Paolo Mangili ◽

Sara Redaelli ◽

Vittorio Scaravilli ◽

Marco Giani ◽

...

Keyword(s):

Carbon Dioxide ◽

Blood Flow ◽

Lactic Acid ◽

Blood Flow Rate ◽

Carbon Dioxide Removal ◽

Low Flow ◽

Extracorporeal Carbon Dioxide Removal ◽

Membrane Lung ◽

Extracorporeal Blood ◽

Patients At Risk

Abstract Background: Extracorporeal carbon dioxide removal has been proposed to achieve protective ventilation in patients at risk for ventilator-induced lung injury. In an acute study, the authors previously described an extracorporeal carbon dioxide removal technique enhanced by regional extracorporeal blood acidification. The current study evaluates efficacy and feasibility of such technology applied for 48 h. Methods: Ten pigs were connected to a low-flow veno-venous extracorporeal circuit (blood flow rate, 0.25 l/min) including a membrane lung. Blood acidification was achieved in eight pigs by continuous infusion of 2.5 mEq/min of lactic acid at the membrane lung inlet. The acid infusion was interrupted for 1 h at the 24 and 48 h. Two control pigs did not receive acidification. At baseline and every 8 h thereafter, the authors measured blood lactate, gases, chemistry, and the amount of carbon dioxide removed by the membrane lung (VCO2ML). The authors also measured erythrocyte metabolites and selected cytokines. Histological and metalloproteinases analyses were performed on selected organs. Results: Blood acidification consistently increased VCO2ML by 62 to 78%, from 79 ± 13 to 128 ± 22 ml/min at baseline, from 60 ± 8 to 101 ± 16 ml/min at 24 h, and from 54 ± 6 to 96 ± 16 ml/min at 48 h. During regional acidification, arterial pH decreased slightly (average reduction, 0.04), whereas arterial lactate remained lower than 4 mEq/l. No sign of organ and erythrocyte damage was recorded. Conclusion: Infusion of lactic acid at the membrane lung inlet consistently increased VCO2ML providing a safe removal of carbon dioxide from only 250 ml/min extracorporeal blood flow in amounts equivalent to 50% production of an adult man.

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Determination of Low Blood Flow Limits for Arteriovenous Carbon Dioxide Removal

ASAIO Journal ◽

10.1097/00002480-199609000-00110 ◽

1996 ◽

Vol 42 (5) ◽

pp. M845-849 ◽

Cited By ~ 18

Author(s):

ROBERT L. BRUNSTON ◽

WEIKE TAO ◽

AKHIL BIDANI ◽

VICTOR J. CARDENAS ◽

DANIEL L. TRABER ◽

...

Keyword(s):

Carbon Dioxide ◽

Blood Flow ◽

Carbon Dioxide Removal

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A new real-time and precision capnography for human respiration carbon dioxide concentration

Perfusion ◽

10.1177/0267659110380772 ◽

2010 ◽

Vol 25 (6) ◽

pp. 399-408 ◽

Cited By ~ 3

Author(s):

Jiachen Yang ◽

Bin Wang ◽

Ran Xu ◽

Lei Wang

Keyword(s):

Carbon Dioxide ◽

Real Time ◽

Gas Flow ◽

Measurement Accuracy ◽

Carbon Dioxide Concentration ◽

Main Stream ◽

Temperature Drift ◽

New Device ◽

Human Respiration ◽

Gas Measurement

This paper is a description of the designing of a new mainstream device to measure human respiration carbon dioxide concentration, based on non-dispersive infrared (NDIR) absorption technology. The device can be used to accurately monitor the cardiopulmonary status during anaesthesia and mechanical ventilation in real time. This new device can not only make up the error of real-time gas measurement of the side-stream device, but also make up the accuracy of the main-stream device. In the paper, four issues which can affect the measurement accuracy were considered: respiration gas flow, turbulence of the light source with all ranges of wavelength, temperature drift and signal noise. The experimental results showed that the device could produce a stable output signal and deviation of measurement accuracy could be achieved to within 4%.

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Endocardial/epicardial blood flow ratio can be measured using venous infusion of microbubbies

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(98)80257-x ◽

1998 ◽

Vol 31 ◽

pp. 439

Author(s):

A. Linka ◽

J. Sklenar ◽

K. Wei ◽

A. Jayaweera ◽

S. Kaul

Keyword(s):

Blood Flow ◽

Flow Ratio ◽

Blood Flow Ratio ◽

Venous Infusion

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Stress Myocardial Blood Flow Ratio by Dynamic CT Perfusion Identifies Hemodynamically Significant CAD

JACC Cardiovascular Imaging ◽

10.1016/j.jcmg.2019.06.016 ◽

2020 ◽

Vol 13 (4) ◽

pp. 966-976 ◽

Cited By ~ 8

Author(s):

Junjie Yang ◽

Guanhua Dou ◽

Bai He ◽

Qinhua Jin ◽

Zhiye Chen ◽

...

Keyword(s):

Blood Flow ◽

Myocardial Blood Flow ◽

Ct Perfusion ◽

Dynamic Ct ◽

Flow Ratio ◽

Stress Myocardial Blood Flow ◽

Blood Flow Ratio

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Assessment of pulmonary/systemic blood flow ratio after first-stage palliation for hypoplastic left heart syndrome

Journal of Thoracic and Cardiovascular Surgery ◽

10.1067/mtc.2000.106840 ◽

2000 ◽

Vol 120 (1) ◽

pp. 81-87 ◽

Cited By ~ 30

Author(s):

Jack Rychik ◽

David M. Bush ◽

Thomas L. Spray ◽

J.William Gaynor ◽

Gil Wernovsky

Keyword(s):

Blood Flow ◽

Hypoplastic Left Heart Syndrome ◽

Left Heart ◽

Flow Ratio ◽

Hypoplastic Left Heart ◽

Systemic Blood ◽

Systemic Blood Flow ◽

Blood Flow Ratio ◽

Left Heart Syndrome

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Evaluation of a New Extracorporeal CO2 Removal Device in an Experimental Setting

Membranes ◽

10.3390/membranes11010008 ◽

2020 ◽

Vol 11 (1) ◽

pp. 8

Author(s):

Matteo Di Nardo ◽

Filippo Annoni ◽

Fuhong Su ◽

Mirko Belliato ◽

Roberto Lorusso ◽

...

Keyword(s):

Blood Flow ◽

Gas Flow ◽

High Surface ◽

Surface Membrane ◽

Respiratory Acidosis ◽

Chronic Obstructive ◽

Gas Flows ◽

Co2 Removal ◽

Extracorporeal Co2 Removal ◽

Membrane Lung

Background: Ultra-protective lung ventilation in acute respiratory distress syndrome or early weaning and/or avoidance of mechanical ventilation in decompensated chronic obstructive pulmonary disease may be facilitated by the use of extracorporeal CO2 removal (ECCO2R). We tested the CO2 removal performance of a new ECCO2R (CO2RESET) device in an experimental animal model. Methods: Three healthy pigs were mechanically ventilated and connected to the CO2RESET device (surface area = 1.8 m2, EUROSETS S.r.l., Medolla, Italy). Respiratory settings were adjusted to induce respiratory acidosis with the adjunct of an external source of pure CO2 (target pre membrane lung venous PCO2 (PpreCO2): 80–120 mmHg). The amount of CO2 removed (VCO2, mL/min) by the membrane lung was assessed directly by the ECCO2R device. Results: Before the initiation of ECCO2R, the median PpreCO2 was 102.50 (95.30–118.20) mmHg. Using fixed incremental steps of the sweep gas flow and maintaining a fixed blood flow of 600 mL/min, VCO2 progressively increased from 0 mL/min (gas flow of 0 mL/min) to 170.00 (160.00–200.00) mL/min at a gas flow of 10 L/min. In particular, a high increase of VCO2 was observed increasing the gas flow from 0 to 2 L/min, then, VCO2 tended to progressively achieve a steady-state for higher gas flows. No animal or pump complications were observed. Conclusions: Medium-flow ECCO2R devices with a blood flow of 600 mL/min and a high surface membrane lung (1.8 m2) provided a high VCO2 using moderate sweep gas flows (i.e., >2 L/min) in an experimental swine models with healthy lungs.

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