Extracorporeal Membrane Oxygenation For ARDS Research Articles

ECMO, ARDS and meta-analyses: Bayes to the rescue?

A recent meta-analysis by Munshi et al. (Lancet Respiratory Medicine, 2019) claimed mortality treatment efficacy for extra corporeal membrane oxygenation (ECMO) in the acute respitratory syndrome (ARDS) despite very low meta-analytic study numbers (n=2 (RCTs), risk-ratio (RR) 0·73 (95%CI: 0·58-0·92); n=5 (2 RCT, 3 observational), RR 0·69 (95%CI: 0·50-0·95)). We explore this efficacy claim by a comprehensive re-analysis of the data. Data were sourced from the two- and five-study meta-analyses, conducted using the Der-Simonian & Laird (DSL) method. A variety of frequentist (DSL, restricted maximum likelihood (REML), Paul-Mandel (PM), with/without Hartung-Knapp-Sidik-Jonkman variance correction), a beta-binomial model (BBN)) and Bayesian models (2 finite-mixture and several Markov-Chain-Monte-Carlo) were used to estimate treatment effects. Fragility-indices, the minimum patients changing mortality outcome needed to induce a conclusion change were also applied. For the 2-study and 5-study meta-analysis only the uncorrected frequentist estimators (DSL, REML, PM) demonstrated significant RR. Except for the BBN model, which was significant for the 2-study meta-analysis, intervals for all other models included the null. Both meta-analyses demonstrated fragility. Having canvassed the conduct of both meta-analyses presented by Munshi et al. and proffered alternative methods, we find no certainty regarding the efficacy of ECMO in ARDS.

Extracorporeal membrane oxygenation for acute respiratory distress syndrome in burn patients:\xa0a case series and literature update

BackgroundAcute respiratory distress syndrome (ARDS) has a reported incidence of 34–43% in ventilated burn patients and is associated with a mortality of 59% in the severe form. The use and experience with extracorporeal membrane oxygenation (ECMO) in burn patients developing ARDS are still limited. We present our results and discuss the significance of ECMO in treating burn patients.MethodsA retrospective analysis of burn patients treated with ECMO for ARDS between January 2017 and January 2019 was performed. Demographic, clinical, and outcome data were collected and analyzed.ResultsEight burn patients were treated at our institution with ECMO in the designated time period. Of these, all but one patient had inhalation injury, burn percentage of TBSA was 37 ± 23%, ABSI score was 8.4 ± 2, and R-Baux-score was 98 ± 21. Seven patients developed severe ARDS and one patient moderate ARDS according to the Berlin classification with a PaO2/FiO2 ratio upon initiation of ECMO therapy of 62 ± 22 mmHg. ECMO duration was 388 ± 283 h. Three patients died from severe sepsis while five patients survived to hospital discharge.ConclusionsECMO is a viable therapy option in burn patients developing severe ARDS and can contribute to survival rates similar to ECMO therapy in non-burn-associated severe ARDS. Consequently, patients with severe respiratory insufficiency with unsuccessful conventional treatment and suspected worsening should be transferred to burn units with the possibility of ECMO treatment to improve outcome.

Extra-corporeal membrane oxygenation in paediatric acute respiratory distress syndrome: overrated or underutilized?

Extracorporeal membrane oxygenation (ECMO) is a modified form of cardiopulmonary bypass which may provide support for severe cardiorespiratory failure including paediatric acute respiratory distress syndrome (PARDS). While ECMO was initially demonstrated to successfully support neonates with severe respiratory failure, the use of ECMO has expanded rapidly to support both paediatric and adult respiratory failure. Extracorporeal Life Support Organization (ELSO) registry data shows that the use of ECMO for paediatric respiratory failure has expanded rapidly over the past decades with increasing use of venovenous ECMO. Despite the increasing complexity of children supported by ECMO for ARDS, outcomes have remained consistent with survival to hospital discharge greater than 50%. ECMO complications are still common and potentially devastating, especially neurological complications. There is grade 1 evidence to support the use of ECMO in both neonatal and adult respiratory failure but evidence in paediatric respiratory failure is confined to case series and case-control studies. While there are no published guidelines for use of ECMO in PARDS, in particular no clearly defined inclusion and exclusion criteria, current evidence suggests that children with severe ARDS may benefit from ECMO support, with survival to hospital discharge equivalent or better than conventional management in children with severe ARDS.

Effect of PEEP-Induced Alveolar Recruitment on Lung Injury during Extracorporeal Membrane Oxygenation for ARDS

Purpose Extracorporeal membrane oxygenation, veno-venous configuration (VV-ECMO) is an effective intervention to improve gas exchange in patients with severe respiratory failure, refractory to conventional treatments, or as a bridge to lung transplantation. However, optimal mechanical ventilation (MV) strategies during VV-ECMO to minimize ventilator-induced lung injury are undetermined. While there is general consensus in minimizing tidal ventilation, the potential benefit of high positive end-expiratory pressure (PEEP) strategies in optimizing cardiopulmonary interaction and reducing the severity of lung injury remains unclear.We hypothesize that PEEP-induced alveolar recruitment will reduce lung injury during VV-ECMO for ARDS, in comparison to atelectatic lungs. Methods Yorkshire pigs weresedated, paralyzed, mechanically ventilated,and cannulated for VV-ECMO support. Lung injury was done by two serial bronchoscopic instillations of gastric juice to achieve a P/F ratio Results During VV-ECMO, gas exchange and hemodynamic parameters remained stable and comparable in the two groups, despite the very low tidal volume delivered (HP 54 ml ±; LP 41 ml ±11). Lung volume was higher in the HP compared with the LP group, and remained unchanged during the 5 hours of VV-ECMO support. At the end of the 5 hours of ECMO support, in the dependent lung areas the W/D was significantly higher in the HP compared to LP group (HP 11.1, 95% CI: 10.5-11.7; LP 9.2, 95% CI: 8.2-10.3); in the non-dependent areas the W/D was significantly higher in the LP compared to HP group (LP 6.3, 95% CI: 5.6-6.9; HP 5.3, 95% CI: 4.9-5.8). Conclusion VV-ECMO for severe acute respiratory failure MV with very low tidal volume and LP reduces regional lung edema in the dependent areas, while HP reduces edema.More studies are required to characterize the mechanisms of these findings.

ECMO-treatment in patients with acute lung failure, cardiogenic, and septic shock: mortality and ECMO-learning curve over a 6-year period

BackgroundBased on promising results over the past 10 years, the method of extracorporeal membrane oxygenation (ECMO) has developed from being used as a ‘rescue therapy’ to become an accepted treatment option for patients with acute lung failure (ARDS). Subsequently, the indication was extended also to patients suffering from cardiogenic and septic shock. Our aim was to evaluate hospital mortality and associated prognostic variables in patients with lung failure, cardiogenic, and septic shock undergoing ECMO. Furthermore, a cumulative sum (CUSUM) analysis was used to assess the learning curve of ECMO-treatment in our department.MethodsWe retrospectively analysed the data of 131 patients undergoing ECMO treatment in the intensive care unit of the Asklepios Hospital of Langen over the time period from April 2011 to July 2016. We categorised the patients into three groups: lung failure (n = 54); cardiogenic shock (n = 58); and septic shock (n = 19). The primary outcome variable was hospital mortality along with identification of prognostic variables on mortality before initiating ECMO using logistic regression. Second outcome variable was the learning curve of our department in patients with ECMO.Results6-year hospital mortality was 54% in patients with lung failure, 59% in patients with cardiogenic shock, and 58% in patients with septic shock.The CUSUM analysis revealed a typical learning curve with a point of inflection in the year 2014. Patients treated before 2014 had a worse outcome (p = 0.04 whole cohort; p = 0.03 for lung failure). Furthermore, less than 20 treatments per year respectively treatment before 2014 were associated negatively with hospital mortality of lung failure patients showing an odds ratio of 4.04, as well as in the entire cohort with an odds ratio of 3.19.ConclusionFor the first time, a steep ECMO-learning curve using the CUSUM tool has been described. Obviously, the experience with ECMO has to be taken into account when defining the role of ECMO in ARDS, cardiogenic, and septic shock.

Effectiveness of ECMO for burn-related acute respiratory distress syndrome

IntroductionAcute respiratory distress syndrome (ARDS) is a complication that affects approximately 40% of burn patients and is associated with high mortality rates. Extracorporeal membrane oxygenation (ECMO) therapy is a management option for severe refractory hypoxemic respiratory failure; however, there is little literature reporting the effectiveness of this therapy in burns. Our study objective was to review patient outcomes in burns following severe ARDS treated with ECMO. MethodsWe retrospectively reviewed all patients treated with ECMO for ARDS who received their burn care at a single regional burn center between 9/1/2006 and 8/31/2016. Primary patient outcome examined was discharge disposition. ResultsWe identified 8 patients who had ARDS secondary to burn who were placed onto ECMO during this 10-year period. The average APACHE score, SOFA score, and P/F ratio were 21±3, 9±2, and 59±8, respectively, at the time of decision for ECMO. No ECMO-related complications were identified. Out of the 8 patients reviewed, 1 died, 4 were discharged to acute rehabilitation or a long-term acute care facility, and 3 were discharged to home. ConclusionMortality in burn patients with ARDS who are managed with ECMO is extremely low. Careful selection and timely intervention with ECMO contributed to good clinical outcomes.

Extracorporeal Membrane Oxygenation for ARDS: Optimization of Lung Protective Ventilation.

The use of extracorporeal membrane oxygenation in the management of ARDS has grown considerably in the past decade, largely as a consequence of improvements in extracorporeal technology and management techniques. Recently published data has helped clarify the use of ECMO in ARDS, and its role in optimizing lung-protective ventilation and minimizing ventilator-induced lung injury has the potential to have a substantial impact on ARDS management and outcomes. In the future, novel extracorporeal management strategies may lead to a new paradigm in our approach to patients with ARDS.

Accuracy of Delivery and Effects on Absolute Humidity of Low Tidal Volume by ICU Ventilators.

During extracorporeal membrane oxygenation for ARDS, a range of 1-4 mL/kg predicted body weight tidal volume (VT) is commonly used. We explored whether such a low VT could be adequately delivered by ICU ventilators, and whether such low VTs prevent the heated humidifier (HH) from reaching the recommended target of 33 mg/L absolute humidity (AH). We attached a lung model to 5 ICU ventilators set in volume controlled mode and body temperature and pressure saturated. We ran 2 protocols over a 100-280 mL VT range used with adult or neonatal breathing circuit at a breathing frequency (f) of 15 (f15) or 30 (f30) breaths/min. In the first protocol, with the HH off, VT was measured with a dedicated data logger and expressed in body temperature and pressure saturated. The relationships of measured VT to set VT were studied, and the relative error in VT was analyzed within its 10% boundaries. In the second protocol, the HH was on, and we measured AH using a psychrometric method. The relationship of AH to set VT was analyzed with linear regression. For the 5 ventilators used, the slope (95% CI) between measured VT versus set VT averaged 0.93 (0.92-0.93), 0.93 (0.93-0.94), 0.91 (0.90-0.91), and 0.91 (0.90-0.91) mL/mL for adult and neonatal circuits at f15 and f30, respectively (P < .05 vs 1 in each instance), indicating a systematic under-delivery of VT. The VT relative error fell within the ±10% accuracy range for only 2 ventilators with adult circuits at f15 and f30. AH increased linearly with VT. The recommended target of 33 mg/L AH was reached with all of the ventilators for the adult circuit at f30 only. The minimum volume that met the recommended threshold for AH was 100, 150, 190, 160, and 100 mL for the G5, Carestation, PB980, Servo-U, and V500 ventilators, respectively, at f30. Low VT was systematically under-delivered by modern ICU ventilators by roughly 7-9%. To meet the recommended target of 33 mg/L AH, adult circuit at f30 should be used.

Extracorporeal membrane oxygenation for ARDS: Aspects of cannulation mode

Extracorporeal membrane oxygenation for ARDS: Aspects of cannulation mode