Background: While recommended by international societal guidelines in the paediatric population, the use of venoarterial extracorporeal membrane oxygenation (VA ECMO) as mechanical circulatory support for refractory septic shock in adults is controversial. We aimed to characterise the outcomes of adults with septic shock requiring VA ECMO, and identify factors associated with survival. Methods: We searched Pubmed, Embase, Scopus and Cochrane databases from inception until 1st June 2021, and included all relevant publications reporting on > 5 adult patients requiring VA ECMO for septic shock. Study quality and certainty in evidence were assessed using the appropriate Joanna Briggs Institute checklist, and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach, respectively. The primary outcome was survival to hospital discharge, and secondary outcomes included intensive care unit length of stay, duration of ECMO support, complications while on ECMO, and sources of sepsis. Random-effects meta-analysis (DerSimonian and Laird) were conducted. Data synthesis: We included 14 observational studies with 468 patients in the meta-analysis. Pooled survival was 36.4% (95% confidence interval [CI]: 23.6%–50.1%). Survival among patients with left ventricular ejection fraction (LVEF) < 20% (62.0%, 95%-CI: 51.6%–72.0%) was significantly higher than those with LVEF > 35% (32.1%, 95%-CI: 8.69%–60.7%, p = 0.05). Survival reported in studies from Asia (19.5%, 95%-CI: 13.0%–26.8%) was notably lower than those from Europe (61.0%, 95%-CI: 48.4%–73.0%) and North America (45.5%, 95%-CI: 16.7%–75.8%). GRADE assessment indicated high certainty of evidence for pooled survival. Conclusions: When treated with VA ECMO, the majority of patients with septic shock and severe sepsis-induced myocardial depression survive. However, VA ECMO has poor outcomes in adults with septic shock without severe left ventricular depression. VA ECMO may be a viable treatment option in carefully selected adult patients with refractory septic shock.

Objectives: Perform a systematic review and meta-analysis of vascular complications associated with extracorporeal membrane oxygenation and identify prognostic and predictive factors. Data Sources: Systematic search for publications reporting vascular complications on extracorporeal membrane oxygenation, published from 1972 to January 31, 2020, was conducted via PubMed, Scopus, and Embase. Study Selection: Of 4,076 references screened, 47 studies with 6,583 patients were included in final analyses. Studies with fewer than 10 patients were excluded. Data Extraction: Relevant data, including demographics, comorbidities, extracorporeal membrane oxygenation and cannulation characteristics, occurrence rates of early and late vascular complications, patient outcomes, and use of distal perfusion cannula, were extracted from selected articles into an excel sheet specifically designed for this review. Data Synthesis: Random-effects meta-analyses and meta-regression analyses were undertaken. Overall pooled estimate of vascular complications in our meta-analysis was 29.5% (95% CI, 23.6–35.9%). Two-thousand three-hundred forty-seven vascular complications in 6,124 venoarterial extracorporeal membrane oxygenation patients compared with 95 in 459 venovenous extracorporeal membrane oxygenation patients (odds ratio, 2.35; 95% CI, 1.87–2.96; p < 0.0001) were analyzed. Successful weaning off extracorporeal membrane oxygenation occurred in 60.6% of pooled patients; 46.2% were eventually discharged. Pooled prevalences of vascular complications like significant bleeding, limb ischemia, and cannula site bleeding were 15.4% (95% CI, 8.6–23.7%), 12.6% (95% CI, 10.0–15.5%), and 12.6% (95% CI, 9.6–18.5%), respectively. Meta-analysis showed that the use of distal perfusion cannula was associated with lower odds of limb ischemia (odds ratio, 1.93; 95% CI, 1.17–2.47; p = 0.03) Meta-regression showed that male sex, smoking, advanced age, and comorbidities contributed to higher in-hospital mortality, while distal perfusion cannula was protective. Conclusions: Nearly a third of patients on extracorporeal membrane oxygenation develop vascular complications; elderly males with comorbidities appear vulnerable. The use of distal perfusion cannulas caused significant reduction in limb ischemia and mortality.

Background: Extracorporeal membrane oxygenation (ECMO) has been used extensively for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS). Reports early in the pandemic suggested that mortality in patients with COVID-19 receiving ECMO was comparable to non-COVID-19-related ARDS. However, subsequent reports suggested that mortality appeared to be increasing over time. Therefore, we conducted an updated systematic review and meta-analysis, to characterise changes in mortality over time and elucidate risk factors for poor outcomes.Methods: We conducted a meta-analysis (CRD42021271202), searching MEDLINE, Embase, Cochrane, and Scopus databases, from 1 December 2019 to 26 January 2022, for studies reporting on mortality among adults with COVID-19 receiving ECMO. We also captured hospital and intensive care unit lengths of stay, duration of mechanical ventilation and ECMO, as well as complications of ECMO. We conducted random-effects meta-analyses, assessed risk of bias of included studies using the Joanna Briggs Institute checklist and evaluated certainty of pooled estimates using GRADE methodology.Results: Of 4522 citations, we included 52 studies comprising 18,211 patients in the meta-analysis. The pooled mortality rate among patients with COVID-19 requiring ECMO was 48.8% (95% confidence interval 44.8–52.9%, high certainty). Mortality was higher among studies which enrolled patients later in the pandemic as opposed to earlier (1st half 2020: 41.2%, 2nd half 2020: 46.4%, 1st half 2021: 62.0%, 2nd half 2021: 46.5%, interactionpvalue = 0.0014). Predictors of increased mortality included age, the time of final patient enrolment from 1 January 2020, and the proportion of patients receiving corticosteroids, and reduced duration of ECMO run.Conclusions: The mortality rate for patients receiving ECMO for COVID-19-related ARDS has increased as the pandemic has progressed. The reasons for this are likely multifactorial; however, as outcomes for these patients evolve, the decision to initiate ECMO should include the best contextual estimate of mortality at the time of ECMO initiation.