Extracorporeal CO2 Removal and the Alveolar Gas Equation.
Ontology highlight
ABSTRACT:
SUBMITTER: Dickstein ML
PROVIDER: S-EPMC7528807 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description: Not available
| S-EPMC7528775 | biostudies-literature
Project description:BackgroundChronic obstructive pulmonary disease (COPD) exacerbation and protective mechanical ventilation of acute respiratory distress syndrome (ARDS) patients induce hypercapnic respiratory acidosis.Main textExtracorporeal carbon dioxide removal (ECCO2R) aims to eliminate blood CO2 to fight against the adverse effects of hypercapnia and related acidosis. Hypercapnia has deleterious extrapulmonary consequences, particularly for the brain. In addition, in the lung, hypercapnia leads to: lower pH, pulmonary vasoconstriction, increases in right ventricular afterload, acute cor pulmonale. Moreover, hypercapnic acidosis may further damage the lungs by increasing both nitric oxide production and inflammation and altering alveolar epithelial cells. During an exacerbation of COPD, relieving the native lungs of at least a portion of the CO2 could potentially reduce the patient's respiratory work, Instead of mechanically increasing alveolar ventilation with MV in an already hyperinflated lung to increase CO2 removal, the use of ECCO2R may allow a decrease in respiratory volume and respiratory rate, resulting in improvement of lung mechanic. Thus, the use of ECCO2R may prevent noninvasive ventilation failure and allow intubated patients to be weaned off mechanical ventilation. In ARDS patients, ECCO2R may be used to promote an ultraprotective ventilation in allowing to lower tidal volume, plateau (Pplat) and driving pressures, parameters that have identified as a major risk factors for mortality. However, although ECCO2R appears to be effective in improving gas exchange and possibly in reducing the rate of endotracheal intubation and allowing more protective ventilation, its use may have pulmonary and hemodynamic consequences and may be associated with complications.ConclusionIn selected patients, ECCO2R may be a promising adjunctive therapeutic strategy for the management of patients with severe COPD exacerbation and for the establishment of protective or ultraprotective ventilation in patients with ARDS without prognosis-threatening hypoxemia.
| S-EPMC7951130 | biostudies-literature
Project description:Removal of trace CO impurities is an essential step in the utilization of Hydrogen as a clean energy source. While various solutions are currently employed to address this challenge, there is an urgent need to improve their efficiency. Here, we show that a bead-structured Mg, Cu, and Ce-based sorbent, Mg13CuCeOx, demonstrates superior removal capacity of trace CO from H2 with high stability. The incorporation of Mg boosts sorption performance by enhancing the porous structure and Cu+ surface area. Remarkably, compared to existing pelletized sorbents, Mg13CuCeOx exhibits 15.5 to 50 times greater equilibrium capacity under pressures below 10 Pa CO and 31 times longer breakthrough time in removing 50 ppm CO in H2. Energy-efficient oxidative regeneration using air at 120 °C allows its stable sorption performance over 20 cycles. Through in-situ DRIFTS analysis, we elucidate the reaction mechanism that Mg augments the surface OH groups, promoting the formation of bicarbonate and formate species. This study highlights the potential of MgCuCeOx sorbents in advancing the hydrogen economy by effectively removing trace CO from H2.
| S-EPMC10624860 | biostudies-literature
Project description:BackgroundWhile outcome improvement with extracorporeal CO2 removal (ECCO2R) is not demonstrated, a strong pathophysiological rational supports its use in the setting of acute respiratory distress syndrome (ARDS) and COPD exacerbation. We aimed to describe our single-center experience of ECCO2R indications and outcome.MethodsPatients treated with ECCO2R in our medial ICU, from March 2014 to November 2017, were retrospectively enrolled. Primary end point was evolution of ventilator settings during the two first days following ECCO2R start.ResultsThirty-three patients received ECCO2R. Seventeen were managed with Hemolung®, 10 with Prismalung®, 4 with ILA®, and 2 with Cardiohelp®. Indications for ECCO2R were mild or moderate ARDS (n = 16), COPD exacerbation (n = 11), or uncontrolled hypercapnia due to other causes (n = 6). Four patients were not intubated at the time of ECCO2R start. Median duration of ECCO2R treatment was 7 days [5-10]. In ARDS patients, between baseline and day 2, median tidal volume and driving pressure decreased from 5.3 [4.4-5.9] mL/kg and 10 [8-15] to 3.8 [3.3-4.1] mL/kg and 9 [8-11], respectively. Prone positioning was performed in 10 of the 16 patients, without serious adverse event. In COPD patients, between baseline and day 2, median ventilation minute and PaCO2 decreased significantly from respectively 7.6 [6.6-8.7] L/min and 9.4 [8.4-10.1] kPa to 5.8 [4.9-6.2] L/min and 6 [5.3-6.8] kPa. Four out of 11 COPD patients were extubated while on ECCO2R. Device thrombosis occurred in 5 patients (15%). Hemolysis was documented in 16 patients (48%). One patient died of intracranial hemorrhage, while on ECCO2R. Twenty-four patients were discharged from ICU alive. Twenty-eight day mortality was 31% in ARDS, 9% in COPD patients, and 50% in other causes of refractory hypercapnic respiratory failure.ConclusionECCO2R was useful to apply ultra-protective ventilation among ARDS patients and improved PaCO2, pH, and minute ventilation in COPD patients.
| S-EPMC6022441 | biostudies-literature
Project description:BackgroundVeno-venous extracorporeal CO2 removal (vv-ECCO2R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates through the device range from 200 ml/min to more than 1500 ml/min, and the membrane surface areas range from 0.35 to 1.3 m2. The present study in an animal model with similar CO2 production as an adult patient was aimed at determining the optimal membrane lung surface area and technical requirements for successful vv-ECCO2R.MethodsFour different membrane lungs, with varying lung surface areas of 0.4, 0.8, 1.0, and 1.3m2 were used to perform vv-ECCO2R in seven anesthetized, mechanically ventilated, pigs with experimentally induced severe respiratory acidosis (pH 7.0-7.1) using a 20Fr double-lumen catheter with a sweep gas flow rate of 8 L/min. During each experiment, the blood flow was increased stepwise from 250 to 1000 ml/min.ResultsAmelioration of severe respiratory acidosis was only feasible when blood flow rates from 750 to 1000 ml/min were used with a membrane lung surface area of at least 0.8 m2. Maximal CO2 elimination was 150.8 ml/min, with pH increasing from 7.01 to 7.30 (blood flow 1000 ml/min; membrane lung 1.3 m2). The membrane lung with a surface of 0.4 m2 allowed a maximum CO2 elimination rate of 71.7 mL/min, which did not result in the normalization of pH, even with a blood flow rate of 1000 ml/min. Also of note, an increase of the surface area above 1.0 m2 did not result in substantially higher CO2 elimination rates. The pressure drop across the oxygenator was considerably lower (<10 mmHg) in the largest membrane lung, whereas the smallest revealed a pressure drop of more than 50 mmHg with 1000 ml blood flow/min.ConclusionsIn this porcine model, vv-ECCO2R was most effective when using blood flow rates ranging between 750 and 1000 ml/min, with a membrane lung surface of at least 0.8 m2. In contrast, low blood flow rates (250-500 ml/min) were not sufficient to completely correct severe respiratory acidosis, irrespective of the surface area of the membrane lung being used. The converse was also true, low surface membrane lungs (0.4 m2) were not capable of completely correcting severe respiratory acidosis across the range of blood flows used in this study.
| S-EPMC5539069 | biostudies-literature
Project description:BackgroundExtracorporeal carbon dioxide removal (ECCO2R) is a promising technique for the management of acute respiratory failure, but with a limited level of evidence to support its use outside clinical trials and/or data collection initiatives. We report a collaborative initiative in a large metropolis.MethodsTo assess on a structural basis the rate of utilization as well as efficacy and safety parameters of 2 ECCO2R devices in 10 intensive care units (ICU) during a 2-year period.ResultsSeventy patients were recruited in 10 voluntary and specifically trained centers. The median utilization rate was 0.19 patient/month/center (min 0.04; max 1.20). ECCO2R was started under invasive mechanical ventilation (IMV) in 59 patients and non-invasive ventilation in 11 patients. The Hemolung Respiratory Assist System (Alung) was used in 53 patients and the iLA Activve iLA kit (Xenios Novalung) in 17 patients. Main indications were ultraprotective ventilation for ARDS patients (n = 24), shortening the duration of IMV in COPD patients (n = 21), preventing intubation in COPD patients (n = 9), and controlling hypercapnia and dynamic hyperinflation in mechanically ventilated patients with severe acute asthma (n = 6). A reduction in median V T was observed in ARDS patients from 5.9 to 4.1 ml/kg (p <0.001). A reduction in PaCO2 values was observed in AE-COPD patients from 67.5 to 51 mmHg (p< 0.001). Median duration of ECCO2R was 5 days (IQR 3-8). Reasons for ECCO2R discontinuation were improvement (n = 33), ECCO2R-related complications (n = 18), limitation of life-sustaining therapies or measures decision (n = 10), and death (n = 9). Main adverse events were hemolysis (n = 21), bleeding (n = 17), and lung membrane clotting (n = 11), with different profiles between the devices. Thirty-five deaths occurred during the ICU stay, 3 of which being ECCO2R-related.ConclusionsBased on a registry, we report a low rate of ECCO2R device utilization, mainly in severe COPD and ARDS patients. Physiological efficacy was confirmed in these two populations. We confirmed safety concerns such as hemolysis, bleeding, and thrombosis, with different profiles between the devices. Such results could help to design future studies aiming to enhance safety, to demonstrate a still-lacking strong clinical benefit of ECCO2R, and to guide the choice between different devices.Trial registrationClinicalTrials.gov: Identifier: NCT02965079 retrospectively registered https://clinicaltrials.gov/ct2/show/NCT02965079.
| S-EPMC6701003 | biostudies-literature
Project description:BackgroundVeno-venous extracorporeal CO2 removal (vv-ECCO2R) and non-invasive neurally adjusted ventilator assist (NIV-NAVA) are two promising techniques which may prevent complications related to prolonged invasive mechanical ventilation in patients with acute exacerbation of COPD.MethodsA physiological study of the electrical activity of the diaphragm (Edi) response was conducted with varying degrees of extracorporeal CO2 removal to control the respiratory drive in patients with severe acute exacerbation of COPD breathing on NIV-NAVA.ResultsTwenty COPD patients (SAPS II 37 ± 5.6, age 57 ± 9 years) treated with vv-ECCO2R and supported by NIV-NAVA were studied during stepwise weaning of vv-ECCO2R. Based on dyspnea, tolerance, and blood gases, weaning from vv-ECCO2R was successful in 12 and failed in eight patients. Respiratory drive (measured via the Edi) increased to 19 ± 10 μV vs. 56 ± 20 μV in the successful and unsuccessful weaning groups, respectively, resulting in all patients keeping their CO2 and pH values stable. Edi was the best predictor for vv-ECCO2R weaning failure (ROC analysis AUC 0.95), whereas respiratory rate, rapid shallow breathing index, and tidal volume had lower predictive values. Eventually, 19 patients were discharged home, while one patient died. Mortality at 90 days and 180 days was 15 and 25%, respectively.ConclusionsThis study demonstrates for the first time the usefulness of the Edi signal to monitor and guide patients with severe acute exacerbation of COPD on vv-ECCO2R and NIV-NAVA. The Edi during vv-ECCO2R weaning was found to be the best predictor of tolerance to removing vv-ECCO2R.
| S-EPMC6480839 | biostudies-literature
Project description:A substantial part of COVID-19-patients suffers from multi-organ failure (MOF). We report on an 80-year old patient with pulmonary, renal, circulatory, and hepatic failure. We decided against the use of extracorporeal membrane oxygenation (ECMO) due to old age and a SOFA-score of 13. However, the patient was continuously treated with the extracorporeal multi-organ- "ADVanced Organ Support" (ADVOS) device (ADVITOS GmbH, Munich, Germany). During eight 24h-treatment-sessions blood flow (100-300 mL/min), dialysate flow (160-320 mL/min) and dialysate pH (7.6-9.0) were adapted to optimize arterial PaCO2 and pH. Effective CO2 removal and correction of acidosis could be demonstrated by mean arterial- versus post-dialyzer values of pCO2 (68.7 ± 13.8 vs. 26.9 ± 11.6 mmHg; p < 0.001). The CO2-elimination rate was 48 ± 23mL/min. The initial vasopressor requirement could be reduced in parallel to pH-normalization. Interruptions of ADVOS-treatment repeatedly resulted in reversible deteriorations of paCO2 and pH. After 95 h of continuous extracorporeal decarboxylating therapy the patient had markedly improved circulatory parameters compared to baseline. In the context of secondary pulmonary infection and progressive liver failure, the patient had a sudden cardiac arrest. In accordance with the presumed patient will, we decided against mechanical resuscitation. Irrespective of the outcome we conclude that extracorporeal CO2 removal and multiorgan-support were feasible in this COVID-19-patient. Combined and less invasive approaches such as ADVOS might be considered in old-age-COVID-19 patients with MOF.
| S-EPMC8041450 | biostudies-literature
Project description:Hydrothermal synthesis with an organic template of N,N,N trimethyl-1-adamantammonium hydroxide (TMAdaOH) is the most commonly used method to prepare an SSZ-13 zeolite membrane. In this paper, the synthesized membrane was treated in heated sodium chloride to remove TMAdaOH instead of calcination in air. The surface of the membrane was modified by the heated NaCl and resulted in an improved CO2/CH4 gas separation selectivity. TMAda+ in the channels of SSZ-13 zeolite decomposed completely, and the treatment time was shortened significantly compared with calcination in air. The recrystallization of zeolite reacting with heated NaCl was the possible reason for the improved gas separation performance of the membrane.
| S-EPMC8892680 | biostudies-literature
Project description:Mechanical ventilation (MV) represents a lifesaving treatment for patients with respiratory failure, but it could be harmful through the development of ventilator-induced lung injury (VILI). In patients with acute respiratory distress syndrome (ARDS), protective MV strategies with low tidal volume to minimize VILI have been demonstrated to reduce lung injury and mortality. However, they can be limited by the emergence of uncontrolled hypercapnia. Similarly, in COPD patients, noninvasive MV failure often is associated with a progressive rise in arterial CO2 and need for endotracheal intubation, with higher risk of hospital mortality. Minimally invasive extracorporeal CO2 removal systems (ECCO2R) theoretically can remove the entire amount of the CO2 produced in the body per minute. In ARDS patients, ECCO2R may further reduce the risk of VILI ensuring ultraprotective MV and avoiding hypercapnia. In patients with exacerbation of COPD, ECCO2R may help to avoid intubation or facilitate weaning from invasive MV. In intensive care unit, concomitant renal and respiratory failure with MV is one of the strongest risk factors for hospital mortality. Combining ECCO2R and renal replacement therapy may support respiratory and renal functions and limit the side effects of MV. However, the need for systemic anticoagulation and the related risk of bleeding still represent a concern for a wider application of ECCO2R devices. In conclusion, ECCO2R is an effective support therapy to MV to limit its invasiveness and side effects, but its efficacy and safety must be proven in well-designed clinical trials. Objectives This chapter will:1 Explain the physiology of CO2 removal during extracorporeal support.2 Describe potential clinical applications of extracorporeal CO2 removal systems (ECCO2R) support therapy in patients with acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD) as well as in those with acute kidney injury requiring renal replacement therapy.
| S-EPMC7969728 | biostudies-literature