Venoarterial extracorporeal membrane oxygenation (va-ECMO) is an advanced life support for critically ill patients with refractory cardiogenic shock. This temporary support bridges time for recovery, permanent assist, or transplantation in patients with high risk of mortality. However, the benefit of this modality is still subject of discussion and despite the continuous development of critical care medicine, severe cardiogenic shock remains associated with high mortality. Therefore, this work aims to analyze the current literature regarding in-hospital mortality and complication rates of va-ECMO in patients with cardiogenic shock. We conducted a systematic review and meta-analysis of the most recent literature to analyze the outcomes of va-ECMO support. Using the PRISMA guidelines, Medline (PubMed) and Scopus (Elsevier) databases were systematically searched up to May 2022. Meta-analytic pooled estimation of publications variables was performed using a weighted random effects model for study size. Thirty-two studies comprising 12756 patients were included in the final analysis. Between 1994 and 2019, 62% (pooled estimate, 8493/12756) of patients died in the hospital. More than one-third of patients died during ECMO support. The most frequent complications were renal failure (51%, 693/1351) with the need for renal replacement therapy (44%, 4879/11186) and bleeding (49%, 1971/4523), bearing the potential for permanent injury or death. Univariate meta-regression analyses identified age over 60 years, shorter ECMO duration and presence of infection as variables associated with in-hospital mortality, while the studies reporting a higher incidence of cannulation site bleeding were unexpectedly associated with a reduced in-hospital mortality. Extracorporeal membrane oxygenation is an invasive life support with a high risk of complications. We identified a pooled in-hospital mortality of 62% with patient age, infection and ECMO support duration being associated with a higher mortality. Protocols and techniques must be developed to reduce the rate of adverse events. Finally, randomized trials are necessary to demonstrate the effectiveness of va-ECMO in cardiogenic shock.

Objective: To study angiotensin-converting enzyme 2 in a piglet model with acute respiratory distress syndrome and to evaluate the therapeutic potential of this substance in a preclinical setting, as this model allows the assessment of the same parameters required for monitoring the disease in human intensive care medicine. The acute respiratory distress syndrome is the most severe form of acute lung injury with a high mortality rate. As yet, there is no specific therapy for improving the clinical outcome. Recently, angiotensin-converting enzyme 2, which inactivates angiotensin II, has been shown to ameliorate acute lung injury in mice. Design: Prospective, randomized, double-blinded animal study. Setting: Animal research laboratory. Subjects: Fifteen anesthetized and mechanically ventilated piglets. Interventions: Acute respiratory distress syndrome was induced by lipopolysaccharide infusion. Thereafter, six animals were assigned randomly into angiotensin-converting enzyme 2 group, whereas another six animals served as control. Three animals received angiotensin-converting enzyme 2 without lipopolysaccharide pretreatment. Measurements and Main Results: Systemic and pulmonary hemodynamics, blood gas exchange parameters, tumor necrosis factor-α, and angiotensin II levels were examined before acute respiratory distress syndrome induction and at various time points after administering angiotensin-converting enzyme 2 or saline. In addition, ventilation-perfusion distribution of the lung tissue was assessed by the multiple inert gas elimination technique. Animals treated with angiotensin-converting enzyme 2 maintained significantly higher Pao₂ than the control group, and pulmonary hypertension was less pronounced. Furthermore, angiotensin II and tumor necrosis factor-α levels, both of which were substantially increased, returned to basal values. Multiple inert gas elimination technique revealed a more homogeneous pulmonary blood flow after treatment with angiotensin-converting enzyme 2. In intergroup comparisons, there were no differences in pulmonary blood flow to lung units with subnormal ventilation/perfusion ratios. Conclusions: Angiotensin-converting enzyme 2 attenuates arterial hypoxemia, pulmonary hypertension, and redistribution of pulmonary blood flow in a piglet model of acute respiratory distress syndrome, and may be a promising substance for clinical use.

The development of extracorporeal life support technology has added a new dimension to the care of critically ill patients who fail conventional treatment options. Extracorporeal membrane oxygenation (ECMO)—specialized temporary life support for patients with severe cardiac or pulmonary failure—plays a role in bridging the time for organ recovery, transplant, or permanent assistance. The overall patient outcome is dependent on the underlying disease, comorbidities, patient reaction to critical illness, and potential adverse events during ECMO. Moreover, the contact of the blood with the large artificial surface of an extracorporeal system circuit triggers complex inflammatory and coagulation responses. These processes may further lead to endothelial injury and disrupted microcirculation with consequent end-organ dysfunction and the development of adverse events like thromboembolism. Therefore, systemic anticoagulation is considered crucial to alleviate the risk of thrombosis and failure of ECMO circuit components. The gold standard and most used anticoagulant during extracorporeal life support is unfractionated heparin, with all its benefits and disadvantages. However, therapeutic anticoagulation of a critically ill patient carries the risk of clinically relevant bleeding with the potential for permanent injury or death. Similarly, thrombotic events may occur. Therefore, different anticoagulation strategies are employed, while the monitoring and the balance of procoagulant and anticoagulatory factors is of immense importance. This narrative review summarizes the most recent considerations on anticoagulation during ECMO support, with a special focus on anticoagulation monitoring and future directions.