Prone positioning during venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review and meta-analysis.

BACKGROUND: Prone positioning (PP) improves oxygenation and respiratory mechanics and is associated with lower mortality in patients with moderate to severe acute respiratory distress syndrome (ARDS). Despite this, some patients develop refractory hypoxemia and hypercapnia requiring venovenous extracorporeal membrane oxygenation (VV ECMO) support and are usually cared for in supine position. The physiologic and outcome benefits of routine PP of patients during VV ECMO remains unclear. Hence, we conducted the systematic review and meta-analysis to evaluate the outcome benefits of PP for patients with ARDS being treated with VV ECMO. METHODS: After registration with PROSPERO (CRD42020199723), MEDLINE, EMBASE, Scopus and Cochrane databases were searched for relevant studies that reported PP in more than 10 adult patients supported with VV ECMO from origin to 1 March 2021. Studies were reviewed for quality using appropriate Joanna Briggs Institute (JBI) checklists, and certainty of evidence was assessed using the GRADE approach. The random-effects model (DerSimonian and Laird) was used. The primary outcome of interest was cumulative survival. Secondary outcomes were intensive care unit length of stay (ICU LOS) and ECMO duration. Changes in arterial blood gas (ABG) values, ventilator mechanics and complication rates were also studied. RESULTS: Of 812 potentially relevant publications, 12 studies (640 patients) met our inclusion criteria. Due to overlapping study populations, 11 studies were included in the final meta-analysis. Cumulative survival in patients that underwent PP was 57% (95% CI 41.9-71.4, high certainty). Patients that underwent PP had longer ICU LOS (+ 14.5 days, 95% CI 3.4-25.7, p = 0.01) and ECMO duration (+ 9.6 days, 95% CI 5.5-13.7, p < 0.0001). After PP, patients had significantly higher PaO2/FiO2 ratio, lower PaCO2 and reduced ventilator driving pressure, and no major complications were reported. CONCLUSIONS: PP during VV ECMO appears safe with a cumulative survival of 57% and may result in longer ECMO runs and ICU LOS. However, evidence from appropriately designed randomized trials is needed prior to widespread adoption of PP on VV ECMO.

Severe COVID-19 and coagulopathy: A systematic review and meta-analysis.

INTRODUCTION: Coronavirus disease 2019 (COVID-19)-induced coagulopathy (CIC) has been widely reported in the literature. However, the spectrum of abnormalities associated with CIC has been highly variable. METHODS: We conducted a systematic review of the literature (until 1 June 2020) to assess CIC and disease severity during the early COVID-19 pandemic. Primary outcomes were pooled mean differences in platelet count, D-dimer level, prothrombin time, activated partial thromboplastin time (aPTT) and fibrinogen level between non-severe and severe patients, stratified by degree of hypoxaemia or those who died. The risk factors for CIC were analysed. Random-effects meta-analyses and meta-regression were performed using R version 3.6.1, and certainty of evidence was rated using the Grading of Recommendation, Assessment, Development, and Evaluation approach. RESULTS: Of the included 5,243 adult COVID-19 patients, patients with severe COVID-19 had a significantly lower platelet count, and higher D-dimer level, prothrombin time and fibrinogen level than non-severe patients. Pooled mean differences in platelet count (-19.7×109/L, 95% confidence interval [CI] -31.7 to -7.6), D-dimer level (0.8µg/mL, 95% CI 0.5-1.1), prothrombin time (0.4 second, 95% CI 0.2-0.6) and fibrinogen level (0.6g/L, 95% CI 0.3-0.8) were significant between the groups. Platelet count and D-dimer level were significant predictors of disease severity on meta-regression analysis. Older men had higher risks of severe coagulopathic disease. CONCLUSION: Significant variability in CIC exists between non-severe and severe patients, with platelet count and D-dimer level correlating with disease severity. Routine monitoring of all coagulation parameters may help to assess CIC and decide on the appropriate management.

Outcomes of Pediatric Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review and Meta-Analysis.

OBJECTIVE: The goal of this work is to provide insight into survival and neurologic outcomes of pediatric patients supported with extracorporeal cardiopulmonary resuscitation. DATA SOURCES: A systematic search of Embase, PubMed, Cochrane, Scopus, Google Scholar, and Web of Science was performed from January 1990 to May 2020. STUDY SELECTION: A comprehensive list of nonregistry studies with pediatric patients managed with extracorporeal cardiopulmonary resuscitation was included. DATA EXTRACTION: Study characteristics and outcome estimates were extracted from each article. DATA SYNTHESIS: Estimates were pooled using random-effects meta-analysis. Differences were estimated using subgroup meta-analysis and meta-regression. The Meta-analyses Of Observational Studies in Epidemiology guideline was followed and the certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation system. Twenty-eight studies (1,348 patients) were included. There was a steady increase in extracorporeal cardiopulmonary resuscitation occurrence rate from the 1990s until 2020. There were 32, 338, and 1,094 patients' articles published between 1990 and 2000, 2001 and 2010, and 2010 and 2020, respectively. More than 70% were cannulated for a primary cardiac arrest. Pediatric extracorporeal cardiopulmonary resuscitation patients had a 46% (CI 95% = 43-48%; p < 0.01) overall survival rate. The rate of survival with favorable neurologic outcome was 30% (CI 95% = 27-33%; p < 0.01). CONCLUSIONS: The use of extracorporeal cardiopulmonary resuscitation is rapidly expanding, particularly for children with underlying cardiac disease. An overall survival of 46% and favorable neurologic outcomes add credence to this emerging therapy.

Vascular Complications of Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Regression Analysis.

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.