Injection of Recombinant Tissue Plasminogen Activator into Extracorporeal Membrane Oxygenators Postpones Oxygenator Exchange in COVID-19.

Coronavirus disease 2019 (COVID-19) has drastically increased the number of patients requiring extracorporeal life support. We investigate the efficacy and safety of low-dose recombinant tissue-type plasminogen activator (rtPA) injection into exhausted oxygenators to delay exchange in critically ill COVID-19 patients on veno-venous extracorporeal membrane oxygenation (V-V ECMO). Small doses of rtPA were injected directly into the draining section of a V-V ECMO circuit. We compared transmembrane pressure gradient, pump head efficiency, membrane arterial partial oxygen pressure, and membrane arterial partial carbon dioxide pressure before and after the procedure. Bleeding was compared with a matched control group of 20 COVID-19 patients on V-V ECMO receiving standard anticoagulation. Four patients received 16 oxygenator instillations with rtPA at 5, 10, or 20 mg per dose. Administration of rtPA significantly reduced transmembrane pressure gradient (Δ pm = 54.8 ± 18.1 mmHg before vs . 38.3 ± 13.3 mmHg after, p < 0.001) in a dose-dependent manner (Pearson's R -0.63, p = 0.023), allowing to delay oxygenator exchange, thus reducing the overall number of consumed oxygenators. rtPA increased blood flow efficiency η (1.20 ± 0.28 ml/revolution before vs . 1.24 ± 0.27 ml/r, p = 0.002). Lysis did not affect membrane blood gases or systemic coagulation. Minor bleeding occurred in 2 of 4 patients (50%) receiving oxygenator lysis as well as 19 of 20 control patients (95%). Lysis of ECMO oxygenators effectively delays oxygenator exchange, if exchange is indicated by an increase in transmembrane pressure gradient. Application of lysis did not result in higher bleeding incidences compared with anticoagulated patients on V-V ECMO for COVID-19.

The Homburg Lung: Efficacy and Safety of a Minimal-Invasive Pump-Driven Device for Veno-Venous Extracorporeal Carbon Dioxide Removal.

Extracorporeal carbon dioxide removal (ECCO2R) is increasingly considered a viable therapeutic approach in the management of hypercapnic lung failure to avoid intubation or to allow lung-protective ventilator settings. This study aimed to analyze efficacy and safety of a minimal-invasive ECCO2R device, the Homburg lung. The Homburg lung is a pump-driven system for veno-venous ECCO2R with »â€³ tubing and a 0.8 m surface oxygenator. Vascular access is usually established via a 19F/21 cm bilumen cannula in the right internal jugular vein. For this work, we screened patient registries from two German centers for patients who underwent ECCO2R with the Homburg lung because of hypercapnic lung failure since 2013. Patients who underwent extracorporeal membrane oxygenation before ECCO2R were excluded. Patients who underwent ECCO2R more than one time were only included once. In total, 24 patients (aged 53.86 ± 12.49 years; 62.5% male) were included in the retrospective data analysis. Ventilatory failure occurred because of chronic obstructive pulmonary disease (50%), cystic fibrosis (16.7%), acute respiratory distress syndrome (12.5%), and other origins (20.8%). The system generated a blood flow of 1.18 ± 0.23 liters per minute (lpm). Sweep gas flow was 3.87 ± 2.97 lpm. Within 4 hours, paCO2 could be reduced significantly from 82.05 ± 15.57 mm Hg to 59.68 ± 12.27 mm Hg, thereby, increasing pH from 7.23 ± 0.10 to 7.36 ± 0.09. Cannulation-associated complications were transient arrhythmia (1/24 patients) and air embolism (1/24). Fatal complications did not occur. In conclusion, the Homburg lung provides effective carbon dioxide removal in hypercapnic lung failure. The cannulation is a safe procedure, with complication rates comparable to those in central venous catheter implantation.