The preliminary study of extracorporeal carbon dioxide removal in acute respiratory distress syndrome for a pediatric patient / 中国小儿急救医学

Objective:Extracorporeal carbon dioxide removal(ECCO 2R) is a technique that aims to decarboxylate the blood and thus to correct hypercapnia and respiratory acidosis in acute respiratory failure, but is rarely used in children.We successfully completed the ECCO 2R treatment for a pediatric case with adenovirus pneumonia, severe acute respiratory distress syndrome(ARDS) and hypercapnia in PICU, which provided clinical references for the use of ECCO 2R in acute respiratory failure for children. Methods:A patient with adenovirus pneumonia and severe ARDS was successfully treated with ECCO 2R-continuous renal replacement therapy(CRRT)combined system after weaning from extracorporeal membrane oxygenation(ECMO). We reported the treatment process, ECCO 2R treatment effect and side effects, so as to provide clinical reference for ECCO 2R treatment of children with ARDS. Results:One-year and four-month-old boy was treated with mechanical ventilation and venous-arterial ECMO due to adenovirus pneumonia and severe ARDS.After ECMO treatment for 25 days, he developed severe hypercapnia after weaning from ECMO.ECCO 2R was initiated.The pH value increased by 11.2%(from 7.222 to 7.303) 1 hour after ECCO 2R treatment, partial pressure of blood carbon dioxide(PCO 2)decreased by 29.1%(from 72.6 mmHg to 51.5 mmHg, 1 mmHg=0.133 kPa) and the average airway pressure of high-frequency ventilation decreased by 5 cmH 2O(from 20 cmH 2O to 15 cmH 2O, 1 cmH 2O=0.098 kPa) after 6 hours of ECCO 2R.The CO 2 removal rate of ECCO 2R system was 29.1 mL/min.It was stopped because of ECCO 2R-membrane clotting after 72 h. There was no increase of PCO 2.Extubation was successfully after undergoing invasive mechanical ventilation for 39 days and with noninvasive ventilation for 5 days.The boy was hospitalized in PICU for 54 days, improved and discharged from the hospital.Followed up for 2 years after discharge, the growth and development were good, but the strenuous exercise endurance was still poor. Conclusion:ECCO 2R is effective in improving gas exchange, reducing PCO 2 and lowering ventilator pressure in children with ARDS and hypercapnia, which allow more protective ventilation.ECCO 2R provide transitional treatment for ECMO weaning and provide meaningful clinical reference for the use of ECCO 2R as part of respiratory support in children with respiratory failure.

Application of continuous renal replacement therapy combined with extracorporeal carbon dioxide removal in children with acute respiratory failure / 中华急诊医学杂志

Objective:To explore the role of continuous renal replacement therapy (CRRT) combined with extracorporeal carbon dioxide removal (ECCO 2R) in the treatment of children with respiratory failure. Methods:The clinical data of 12 children with respiratory failure who were treated with CRRT+ECCO 2R in PICU of Jinan Children's Hospital from July 2020 to August 2022 were collected and analyzed retrospectively. The outcomes and the external pipeline usage of the patients were observed, and the blood gas analysis and ventilator parameters before 1 h and after 1, 6, 12 and 24 h of the treatment were compared by one-way ANOVA with LSD post hoc correction. Results:Six patients successfully withdrew from CRRT+ECCO 2R and mechanical ventilation, three patients were transferred to ECMO treatment. Three cases died after voluntary withdrawal of treatment, and two cases died due to treatment failure. The mortality rate was 41.7%. After continuous treatment of CRRT+ECCO 2R for 15 to 112 h, two cases experienced extracorporeal circuit obstruction. After 1 h of treatment, PaCO 2 decreased from (64.67±24.4) mmHg to (49.42±15.54) mmHg, pH increased from (7.28±0.20) to (7.38±0.11), FiO 2 decreased from (0.85±0.13) to (0.78±0.15), PC decreased from (19.42±4.34) cmH 2O to (17.75±4.00) cmH 2O. After 24 h of treatment, PaCO 2 decreased to (39.2±5.55) mmHg, pH increased to (7.41±0.04), FiO 2 decreased to (0.46±0.11), and PC decreased to (13.8±3.36) cmH 2O, and the differences were statistically significant compared with before treatment ( P < 0.05). Conclusions:The combination of CRRT and ECCO 2R therapy can safely substitute for partial lung ventilation/perfusion function, and play a role in protecting right heart function and improving lung-kidney interaction. It can be considered as an option for extracorporeal respiratory, circulatory, and renal support, and consequently has broad prospects.

Recent research on extracorporeal carbon dioxide removal / 中国当代儿科杂志

Extracorporeal carbon dioxide removal is an artificial lung auxiliary technique based on extrapulmonary gas exchange and can effectively remove carbon dioxide and provide oxygenation to a certain extent, and it is one of the effective treatment techniques for hypercapnia developed after mechanical ventilation and extracorporeal membrane oxygenation in recent years and has wide application prospect. This article elaborates on the development, working principle, advantages, classification, complications, and clinical application of extracorporeal carbon dioxide removal, so as to provide a new choice for extracorporeal carbon dioxide removal in clinical practice.

A Study on the Determination of Extracorporeal Blood Flow Rate for Extracorporeal Carbon Dioxide Removal(ECCO2R) / 대한마취과학회지

Extracorporeal membrane oxygenation(ECMO) is to be recommended when hypoxemia and hepercarbia are refractory to conventional treatments. Neonatal venoarterial(VA) ECMO in the USA is recognized as a therapeutic modality to neonatal respiratory failure and extracorporeal carbon dioxide removal(ECCO2R) in Europe is used for adult respiratory distress syndrome. The partial bypass using the membrane oxygenator aims at lung rest while relieving the hard ventilatory setting on the diseased lung. ECCO2R adopts low-flow venovenous(VV) bapss. VV bypass provides gas exchange without cardiac support. Venous drainage and perfusion catheters are placed in the right atrium or vena cavae via the femoral or internal jugular veins. Compared to VA bypass, the consequences of embolizations are potentially fewer and no major artery is sacrificed in ECCO2R. Highly oxygenated blood flows into pulmonary circulation which may relieve pulmonary hypertension. To evaluate the effectiveness of ECCO2R, we developed an experimental model on 7 mongrel dogs. Under general anesthesia with i. v. pentobarbital, two thin-walled polyurethane tubes in the external jugular vein and the femoral vein were connected with the extracorporeal circuit. Without ventilating the oxygenator duting VV bypass, control hemodynamic and blood gas values under conventional mechanical ventilation(CMV) were obtained. We proceeded to oxygen insufflation(OI), and extra- corporeal CO2 removal (ECCO2R) in that order. Oxygen was delivered at 300ml/min to the animal lung for OI and ECCO2R and was added at 21/min to the oxygenator only for ECCO2R. Hemodynamic parameteres did not vary among CMV, OI and ECCO2R. Arterial PH in CMV was 7.35+/-0.07 and was decreased to 7.19+/-0.05 in OI due to the increase of PaCO (70+/-3 mmHg). PaO2 was remained constant through the experiment. Mixed venous PH in CMV was 7.31+/-0.05 and was decreased to 7.15+/-0.08 in OI, Blood gas analysis values were same between CMV and ECCO2R. Carbon dioxide removal through the lung (V(L)CO2) were 47+/-3 ml/min in CMV, 9+/-3 ml/min in OI and 8+/-2 ml/min in ECCO2R. The amount of carbon dioxide removed via the oxygenator (VoCO2) was 38+/-5 ml/min in ECCO2R. The total amount of CO2 removal (VCO2) between CMV and ECCO2R was same statistically. The bypass flowrate at the lowest E(T)CO2 (end-tidal CO2) was 60+/-9 ml/min, resulting in 35+/-4% of bypass ratio. It can be concluded that ECCO2R can alleviate hypercapnea using a low flow VV bypass and may be used as an altermative of mechanical ventilator in the setting of acute respiratory failure.

An Experimental Study on the Extracorporeal Carbon Dioxide Removal with a Double Lumen Tube / 대한마취과학회지

Intermittent positive pressure ventilation is used as a respiratory support for acute respiratroy failure. Adult respiratory distress syndrome(ARDS) revealed mortality rate of 70% as yet. Hypoxemia is foremost problem in ARDS. Though various ventilatory support is tried on ARDS, extracorporeal membrane oxygenation(ECMO) is to be recommended when hypoxemia and hypercarbia are refractory to conventional treatments. Neonatal venoarterial (VA) ECMO in USA is recognized as a therapeutic modality for neonatal respiratory failure and extracorporeal carhon dioxide removal(ECCO2R) in Europe is used for adult respiratory distress syndome. The partial bypass using the membrane oxygenator aims at lung rest while relieving the hard ventilatory setting on the diseased lung. VA ECMO can provide circulatory support as well but the right internal jugular vein and the right common carotid artery are ligated for the cannulation of draiaage and perfusion catheters. Recent follow up study shows that VA ECMO may not be completely free from neurologic complications such as embolism in the systemic circulation and ill effects due to the reduction of blood supply to the immature lungs. ECCO2R adopts low-flow venovenous(VV) bypass. It has been reported to be valuable for treatment of neonatal respiratory failure. VV bypass provides gas exchange but no cardiac support. Venous drainage and perfusion catheters are placed in the right atrium or vena cavae via the femoral or internal jugular veins. Compared to VA bypass, the consequences of embolizations are potentially fewer, no major artery is sacrificed. Highly oxygenated blood flows into pulmonary eirculatiom which may relieve pulmonary artery hypertension. Total respiratory support may be obtained by VV bypass, VV bypass requires approximately 20-50% more flow for total respiratory sopport due to recirculation of oxygenated blood. Recently VV bypass is chosen for neonatal resyiratoty failure in USA. They alliveate the entry criteria for ECMO using the parameter of oxygenation index(OI). VV ECCO2R using to-and-fro system is tried also for neonatal respiratory failure in Europe. A double lumen tube was developed to reduce the number of veins to be cannulated during VV bypass. It is constructed with the outer drainage cannula( 14 Fr.) and the inner perfusion cannula( 8 Fr.) whose opening is placed on the left side of outer cannula. If perfusion opening is placed on the right atrium facing the right ventricle, the venous blood can be drained from both superior and inferior vena cavae through several drainage opening. To evaluate the effectiveness of ECCO2R with a double lumen tube, we developed an experimental model of acute respiratory failure on 8 mongrel dogs. Under general anesthesia with i.v, pentobarbital, a double lumen tube was introduced via the right internal jugular vein and it was connected with the extracorporeal circuit. Without ventilating the oxygenator during VV bypass, respiratory failure was induced by hypoventilation. After obtaining control hemodynamic and blood gas values under hypoventilation, we proceed to apneic oxygenation(AO), extracorporeal CO2 removal(ECCO2R) and controlled mechanical ventilation(CMV) in that order. Arterial pH in control was 7.180.09(meanSD), and it was increased to 7.33+/-0.08 and 7.28+/-0.08 in ECCO2R and CMV, respectively. PaCO2 in control was 69+/-9mmHg and it was decreased to 41+/-4mmHg and 47+/-7mmHg in ECCO R and CMV respectively. PaCO2 in control was 62+/-15 mmHg and it was increased in AO, ECCO2R and CMV. Mixed venous blood gas analysis showed the same result as arterial blood gas analysis. There was no difference between ECCO2R and CMV. The bypass flow enough to remove CO2 was 30-50% of cardiac output. It is concluded that ECCO2R using a double lumen tube was effective to control the carbon dioxide tension in arterial blood, and a double lumen tube may permit the simplicity of an operation and patient care as well as minimizing the bleeding during extracorporeal respiratory support.

Extracorporeal Membrane Oxygenation Support for Dogs in Acute Respiratory Failure : Comparison of venovenous extracorporeal lung assist using a double lumen tube with venoarterial extracorporeal lung assist / 대한마취과학회지

Mechanical ventilation is widely used for the respiratory support in patients with acute respiratory insufficiency. Extracorporeal respiratory support using a membrane oxygenator has been developed to relieve refractory hypoxemia or hypercapnea under conventional ventilatory management. It has been called extrcorporeal membrane oxygenation (ECMO), extracorporeal carbon dioxide removal (ECCO2R) or extracorporeal lung assist (ECLA). Venoarterial (VA) ECLA drains blood from a catheter placed in the right atrium via the internal jugular vein and perfuses through a cannula at the level of the aortic arch via the right common carotid artery. While VA ECLA supports the heart as well as the lungs, but it has the disadvantage of requiring carotid artery ligation. In venovenous (VV) ECLA, perfusion cannula is placed at a large vein and the carotid artery is not ligated. In addition there is theoretical advantage of perfusing the well oxygenated blood to pulmonary artery. We hypothesized that VV ECLA is as effective as VA ECLA in the oxygenation of arterial blood when the respiratory insufficiency does not accompany heart failure. A model of acute respiratory failure was induced on 6 dogs by the injection of oleic acid 0.07 ml/ kg. Two hours later, acute hypoxemia and hypercapnea were identified with acute hemorrhagic pulmonary edema, but the hemodynamic parameters were stable for 2 hours. Oleic acid 0.07 ml/kg was injected on another 7 dogs. A double lumen tube and a perfusion cannula were introduced via the right external jugular vein and the carotid artery, respectively. The outer lumen of a double lumen tube was used for the drainge of both VV ECLA and VA ECLA. Mixed venous oxygen tension (PvO2) was higer in VV ECLA than in VA ECLA, but arterial oxygen tensian (PaO2) in VV ECLA was as high as that in VA ECLA. It could be concluded that VV ECLA using a double lumen tube can be used as an alternative to VA ECLA for the respiratory support of acute respiratory failure.