Comparison of atrio-femoral and femoro-atrial venovenous extracorporeal membrane oxygenation in adult

Introduction: Different cannulation approaches existed for veno-venous extracorporeal membrane oxygenation (VV ECMO). We aimed to compare the atrio-femoral (AF) and femoro-atrial (FA) configuration in terms of their flow efficiency and influence on patient outcome. Method: This was a single-centre, retrospective case control study. Adult patients admitted to the Intensive Care Unit and required VV ECMO service at Tuen Mun Hospital, Hong Kong, from June 2015 to January 2020 were included. Data were collected from our ECMO database for comparison. Results: Between June 2015 and January 2020, eight patients received AF configuration and 19 patients received FA configuration. The maximum achieved flow in the AF group was significantly higher than that in the FA group (4.08 ± 0.57 L/min vs. 3.52 ± 0.58 L/min, p = 0.03). The fluid balance in first 3 days of ECMO was significantly lower in the AF group compared to that in the FA group (1.16 ± 2.71 L vs. 3.46 ± 1.97 L, p = 0.02). As well, the chance for successful awake ECMO was statistically higher in the AF group (p = 0.048). Conclusion: Atrio-femoral configuration in VV ECMO was associated with a higher maximum achieved ECMO flow, less fluid gain in first 3 days of ECMO and more successful awake ECMO.

Time-Resolved Echo-Particle Image/Tracking Velocimetry Measurement of Interactions Between Native Cardiac Output and Veno-Arterial ECMO Flows

Determination of optimal hemodynamic and pressure–volume loading conditions for patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) would benefit from understanding the impact of ECMO flow rates (QE) on the native cardiac output in the admixing zone, i.e., aortic root. This study characterizes the flow in the aortic root of a pig with severe myocardial ischemia using contrast-enhanced ultrasound particle image/tracking velocimetry (echo-PIV/PTV). New methods for data preprocessing are introduced, including autocontouring to remove surrounding tissues, followed by blind deconvolution to identify the centers of elongated bubble traces in images with low signal to noise ratio. Calibrations based on synthetic images show that this procedure increases the number of detected bubbles and reduces the error in their locations by 50%. Then, an optimized echo-PIV/PTV procedure, which integrates image enhancement with velocity measurements, is used for characterizing the time-resolved two-dimensional (2D) velocity distributions. Phase-averaged and instantaneous flow fields show that the ECMO flow rate influences the velocity and acceleration of the cardiac output during systole, and secondary flows during diastole. When QE is 3.0 L/min or higher, the cardiac ejection velocity, phase interval with open aortic valve, velocity-time integral (VTI), and mean arterial pressure (MAP) increase with decreasing QE, all indicating sufficient support. For lower QE, the MAP and VTI decrease as QE is reduced, and the deceleration during transition to diastole becomes milder. Hence, for this specific case, the optimal ECMO flow rate is 3.0 L/min.

Multidisciplinary shock team is associated with improved outcomes in patients undergoing ECPR

Objectives: Veno-arterial extracorporeal membrane oxygenation (VA ECMO) has been increasingly used in cardiopulmonary resuscitation (ECPR) in select patients. Few centers have published their experience or outcomes with ECPR. The aim of our study was to evaluate outcomes of adult patients in cardiac arrest placed on VA ECMO in the catheterization laboratory. Methods: We performed a retrospective analysis of adult patients in refractory cardiac arrest who underwent ECPR at the Minneapolis Heart Institute (MHI) at Abbott Northwestern Hospital from January 2012 to December 2017. Relevant data were obtained from electronic medical records, including arrest to ECMO flow time, total ECMO support time, and outcomes. Results: Twenty-six adult patients underwent ECPR at the study site during the defined time period. Seven patients (27%) sustained cardiac arrest out of hospital, 19 patients arrested in-hospital with eight of those occurring in the catheterization laboratory. Seventeen (65%) patients had initial rhythm of ventricular fibrillation or tachycardia (VF/VT). All patients underwent mechanical CPR with LUCAS device. Overall 30 day and 6 month survival was 69%. Median time from arrest to ECMO flow was 46 mins (21,68) vs 61 mins (36,71) in survivors and non-survivors, respectively. Sixteen of 18 survivors discharged with a CPC score of 1 or 2. Conclusions: We demonstrate that adult patients in cardiac arrest initiated on VA ECMO in the cardiac catheterization laboratory and cared for by a multidisciplinary shock team in the critical care unit have superior long-term survival and functionally favorable neurologic recovery when compared to current literature.

Elevated oxygen demand in a case of COVID-19 with severe ARDS: a point for optimal oxygenation therapy including ECMO management

Background: Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has become a global pandemic, and those developing critically ill conditions have been reported to have mortality in the range of 39% to 61%. Due to the lack of definitive treatments, mechanical ventilation and supportive oxygenation therapy are key management strategies for the survival of patients with acute respiratory distress syndrome (ARDS). Optimizing oxygenation therapy is mandatory to treat patients with severe respiratory failure, to sufficiently compensate for the oxygen (O2) demand. We experienced a case of severe ARDS due to COVID-19 successfully treated with extracorporeal membrane oxygenation (ECMO) after increasing oxygen delivery according to O2 consumption measurement by indirect calorimetryCase Presentation: A 29-year-old obese but otherwise healthy man was hospitalized for treatment of COVID-19 pneumonia presenting with a 4-day history of persisting cough, high fever, and dyspnea. Mechanical ventilation, nitric oxide inhalation, and prone positioning were initiated in the ICU against severe respiratory dysfunction. Indirect calorimetry on the 3rd and 6th ICU days revealed persistent elevation of oxygen consumption (VO2) of 380 mL/min. Veno-venous ECMO was initiated on the 7th ICU day after further deterioration of respiratory failure. Periodic events of SpO2 decline due to effortful breathing was not resolved by neuromuscular blockade in attempt to reduce O2 consumption. Increasing the ECMO flow induced hemolysis and hyperkalemia despite the use of large bore cannulas and ECMO circuit free of clots and defects. The hemoglobin management level was elevated from 10 g/dL to 13 g/dL to increase blood oxygen capacity, enabling the reduction of ECMO flow while attenuating respiratory effort and maintaining SpO2. Lung protective ventilation strategy and prone positioning were continued for successful weaning from ECMO on the 16th ICU day, and the ventilator on the 18th ICU day.Conclusion: The present case of severe ARDS due to COVID-19 was successfully treated with ECMO. Enhancing oxygen delivery was crucial to compensate for the elevated O2 demand. Measuring O2 consumption by indirect calorimetry can elucidate the oxygen demand for optimizing the oxygenation therapy for successful management and survival of critically ill COVID-19 patients.

Quantitative assessment of peripheral limb perfusion using a modified distal arterial cannula in venoarterial ECMO settings

In cases of severe cardiopulmonary deterioration, quick establishment of venoarterial extracorporeal membrane oxygenation (ECMO) represents a support modality. After successful arterial peripheral cannulation, a certain grade of peripheral limb malperfusion is a fairly common phenomenon. Detection of peripheral malperfusion is vital, since it can result in compartment syndrome or even loss of the affected limb. To prevent or resolve emerging lower limb ischaemia, a newly designed perfusion catheter is placed into the superficial femoral artery, distal to the arterial cannula via ECMO. The aim of our study was to evaluate flow and haemodynamic characteristics of this novel distal limb perfusion cannula for ECMO therapy and present these important findings for the first time. The distal perfusion cannula blood flow increases in linear correlation with ECMO blood flow The variability of distal perfusion cannula blood flow with a 15 Fr cannula ranges between 160 ± 0.40 mL min−1 at 1.5 L min−1 ECMO flow rate and 480 ± 80 mL min−1 at 5.0 L min−1 ECMO blood flow, respectively. Comparatively, the 17-Fr-sized cannula performs on a scale of 140 ± 20 to 390 ± 60 mL distal perfusion cannula blood flow at 1.5-5.0 L min−1 ECMO blood flow, respectively. The quantitative assessment of the distal perfusion cannula blood flow has revealed that distal perfusion cannula blood flow can measure up to 10% of the ECMO blood flow. Furthermore, it has been also well demonstrated that the novel distal perfusion cannula is sufficient to compensate peripheral limb ischaemia.

Long venous cannula on the arterial position for VA-ECMO

Differential hypoxia and the arterial mixing zone are two important factors in managing peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO). With the aim of improving perfusion to the aortic arch branches and coronaries, we describe our approach for VA-ECMO cannulation: bicaval drainage through the femoral vein and proximal retrograde ECMO flow using a multi-stage venous cannula inserted in the femoral artery and the tip placed at the proximal descending thoracic aorta. We report the use of this VA-ECMO approach on a 15-year-old female with combined cardiorespiratory failure and on a 12-year-old male with acute cardiac failure.