The Interplay of Inflammation and Coagulation in COVID-19 Patients Receiving Extracorporeal Membrane Oxygenation Support

Objective Bleeding and thrombosis are common complications during Extracorporeal Membrane Oxygenation (ECMO) support for COVID-19 patients. We sought to examine the relationship between inflammatory status, coagulation effects, and observed bleeding and thrombosis in patients receiving venovenous (VV) ECMO for COVID-19 respiratory failure. Study Design Cross-sectional cohort study Settings Quaternary care institution. Patients The study period from April 1, 2020, to January 1, 2021, we included all patients with confirmed COVID-19 who received VV ECMO support. Intervention None. Measurements and Main Results Thirty-two patients were supported with VV ECMO during the study period, and 17 patients (53%) survived to hospital discharge. The ECMO nonsurvivors mean lactate dehydrogenase (LDH) levels were markedly elevated in comparison to survivors (1046 u/L [IQR = 509, 1305] vs 489 u/L [385 658], p = 0.003). Platelet/fibrinogen dysfunction, as reflected by the low Maximum Amplitude (MA) on viscoelastic testing, was worse in nonsurvivors (65.25 mm [60.68, 67.67] vs 74.80 mm [73.10, 78.40], p = 0.01). Time-group interaction for the first seven days of ECMO support, showed significantly lower platelet count in the nonsurvivors (140 k/ul [103, 170] vs 189.5 k/ul [ 146, 315], p < 0.001) and higher D-dimer in (21 μg/mL [13, 21] vs 14 μg/mL [3, 21], p < 0.001) in comparison to the survivors. Finally, we found profound statistically significant correlations between the clinical markers of inflammation and markers of coagulation in the nonsurvivors group. The ECMO nonsurvivors experienced higher rate of bleeding (73.3% vs 35.3%, p = 0.03), digital ischemia (46.7% vs 11.8%, p = 0.02), acute renal failure (60% vs 11.8%, p = 0.01) and bloodstream infection (60% vs 23.5%, p = 0.03). Conclusion The correlation between inflammation and coagulation in the nonsurvivors supported with VV ECMO could indicate dysregulated inflammatory response and worse clinical outcomes.

Simple technique of distal leg perfusion during heart transplant in patients with preoperative veno-arterial extracorporeal membrane oxygenation support

Direct heart transplant from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is challenging. Continuation of postoperative VA-ECMO support may be required in the setting of primary graft dysfunction or severe vasoplegia. We describe a simple technique to perfuse the ipsilateral leg of an arterial ECMO cannula during heart transplant while the ECMO circuit is turned off but maintaining the arterial cannula and distal perfusion catheter in place. This technique minimizes the number of intraoperative procedures with a minimal risk of leg ischemia, and provides a smooth transition to postoperative VA-ECMO support if necessary.

An Ovine Model of Awake Veno-Arterial Extracorporeal Membrane Oxygenation

Background: Large animal models are developed to help understand physiology and explore clinical translational significance in the continuous development of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) technology. The purpose of this study was to investigate the establishment methods and management strategies in an ovine model of VA-ECMO.Methods: Seven sheep underwent VA-ECMO support for 7 days by cannulation via the right jugular vein and artery. The animals were transferred into the monitoring cages after surgery and were kept awake after anesthesia recovery. The hydraulic parameters of ECMO, basic hemodynamics, mental state, and fed state of sheep were observed in real time. Blood gas analysis and activated clotting time (ACT) were tested every 6 h, while the complete blood count, blood chemistry, and coagulation tests were monitored every day. Sheep were euthanized after 7 days. Necropsy was performed and the main organs were removed for histopathological evaluation.Results: Five sheep survived and successfully weaned from ECMO. Two sheep died within 24–48 h of ECMO support. One animal died of fungal pneumonia caused by reflux aspiration, and the other died of hemorrhagic shock caused by bleeding at the left jugular artery cannulation site used for hemodynamic monitoring. During the experiment, the hemodynamics of the five sheep were stable. The animals stayed awake and freely ate hay and feed pellets and drank water. With no need for additional nutrition support or transfusion, the hemoglobin concentration and platelet count were in the normal reference range. The ECMO flow remained stable and the oxygenation performance of the oxygenator was satisfactory. No major adverse pathological injury occurred.Conclusions: The perioperative management strategies and animal care are the key points of the VA-ECMO model in conscious sheep. This model could be a platform for further research of disease animal models, pathophysiology exploration, and new equipment verification.

The Chest Radiographic Thoracic Area Can Serve as a Prediction Marker for Morbidity and Mortality in Infants With Congenital Diaphragmatic Hernia

Objective: Valid postnatal prediction parameters for neonates with congenital diaphragmatic hernia (CDH) are lacking, but recently, the chest radiographic thoracic area (CRTA) was proposed to predict survival with high sensitivity. Here, we evaluated whether the CRTA correlated with morbidity and mortality in neonates with CDH and was able to predict these with higher sensitivity and specificity than prenatal observed-to-expected (O/E) lung-to-head ratio (LHR).Methods: In this retrospective cohort study, all neonates with CDH admitted to our institution between 2013 and 2019 were included. The CRTA was measured using the software Horos (V. 3.3.5) and compared with O/E LHR diagnosed by fetal ultrasonography in relation to outcome parameters including survival, extracorporeal membrane oxygenation (ECMO) support, and chronic lung disease (CLD).Results: In this study 255 neonates were included with a survival to discharge of 84%, ECMO support in 46%, and 56% developing a CLD. Multiple regression analysis demonstrated that the CRTA correlates significantly with survival (p = 0.001), ECMO support (p &lt; 0.0001), and development of CLD (p = 0.0193). The CRTA displayed a higher prognostic validity for survival [area under the curve (AUC) = 0.822], ECMO support (AUC = 0.802), and developing a CLD (AUC = 0.855) compared with the O/E LHR.Conclusions: Our data suggest that the postnatal CRTA might be a better prognostic parameter for morbidity and mortality than the prenatal O/E LHR.

Outcomes in Pediatric Post-Cardiotomy ECMO Support With Modification of Systematic Support Strategy

Background Utilization of extracorporeal membrane oxygenation (ECMO) support in the post-cardiotomy setting is vital to successful perioperative outcomes following pediatric cardiac surgery. Specific analysis of protocolized management strategies and staff preparedness is imperative to optimizing institutional ECMO outcomes. Methods All patients requiring post-cardiotomy ECMO support at a single institution from 2013 to 2019 were retrospectively reviewed. In 2015, several modifications were made to the ECMO support paradigm that addressed deficiencies in equipment, critical care protocols, and staff preparedness. Cases were stratified according to era of ECMO support; patients supported prior to paradigm change from 2013 to 2015 (Group EARLY, n = 20), and patients supported following the implementation of systematic modifications from 2016 to 2019 (Group LATE, n = 26). The primary outcomes of interest were survival to decannulation and hospital discharge. Results Median age at cannulation was 24.5 days (IQR 7-96) and median duration of support was 4 days (IQR 2-8). Overall survival to decannulation was 78.3% (65% EARLY vs. 88.5% LATE, P = .08) and overall survival to hospital discharge was 58.7% (35% EARLY vs. 76.9% LATE, P = .004). Conclusion Systematic modifications to ECMO support strategy and staff preparation are associated with a significant increase in perioperative survival for pediatric patients requiring post-cardiotomy ECMO support.

Veno-Arterial Extracorporeal Membrane Oxygenation for Patients Undergoing Heart Transplantation: A 7-Year Experience

Objective: Primary graft dysfunction (PGD) is the leading cause of early death after heart transplantation. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) can provide temporary mechanical circulatory support and time for functional recovery of the transplanted heart. The purpose of this study was to analyze the timing and prognoses of VA-ECMO in patients with severe PGD after heart transplantation.Methods: A total of 130 patients underwent heart transplantation at the Zhongshan Hospital Affiliated with Fudan University between January 2014 and December 2020. All patients received basiliximab immunoinduction and a classic double vena cava anastomosis orthotopic heart transplantation. Among them, 29 patients (22.3%) developed severe PGD in the early postoperative period. VA-ECMO was performed in patients with difficulty weaning from cardiopulmonary bypass (CPB) or postoperative refractory cardiogenic shock. Patients were divided into two groups according to whether or not they were successfully weaned from VA-ECMO (patients who survived for 48 h after weaning and did not need VA-ECMO assistance again). The perioperative clinical data were recorded, and all patients were followed up until discharge. Early outcomes were compared between groups.Results: A total of 29 patients with VA-ECMO support after heart transplantation were included in this study. The proportion of patients receiving VA-ECMO was 22.3% (29/130). Nineteen patients (65.5%) needed VA-ECMO due to difficulty with weaning from CPB, and 10 patients required VA-ECMO for postoperative cardiogenic shock. Nineteen patients (65.5%) were successfully weaned from VA-ECMO. Overall, in-hospital mortality of VA-ECMO support patients was 55.2%. The main causes of death were ventricular fibrillation (four cases), major bleeding (three cases), infection (four cases), and graft failure (five cases).Conclusion: Despite advances in heart transplantation, severe PGD remains a lethal complication after heart transplantation. At present, the treatment for severe PGD after heart transplantation is a challenge. VA-ECMO provides an effective treatment for severe PGD after heart transplantation, which can promote graft function recovery.