Transfusion practice in patients receiving VV ECMO (PROTECMO): a prospective, multicentre, observational study.

BACKGROUND: In patients receiving venovenous (VV) extracorporeal membrane oxygenation (ECMO) packed red blood cell (PRBC) transfusion thresholds are usually higher than in other patients who are critically ill. Available guidelines suggest a restrictive approach, but do not provide specific recommendations on the topic. The main aim of this study was, in a short timeframe, to describe the actual values of haemoglobin and the rate and the thresholds for transfusion of PRBC during VV ECMO. METHODS: PROTECMO was a multicentre, prospective, cohort study done in 41 ECMO centres in Europe, North America, Asia, and Australia. Consecutive adult patients with acute respiratory distress syndrome (ARDS) who were receiving VV ECMO were eligible for inclusion. Patients younger than 18 years, those who were not able to provide informed consent when required, and patients with an ECMO stay of less than 24 h were excluded. Our main aim was to monitor the daily haemoglobin concentration and the value at the point of PRBC transfusion, as well as the rate of transfusions. The practice in different centres was stratified by continent location and case volume per year. Adjusted estimates were calculated using marginal structural models with inverse probability weighting, accounting for baseline and time varying confounding. FINDINGS: Between Dec 1, 2018, and Feb 22, 2021, 604 patients were enrolled (431 [71%] men, 173 [29%] women; mean age 50 years [SD 13·6]; and mean haemoglobin concentration at cannulation 10·9 g/dL [2·4]). Over 7944 ECMO days, mean haemoglobin concentration was 9·1 g/dL (1·2), with lower concentrations in North America and high-volume centres. PRBC were transfused on 2432 (31%) of days on ECMO, and 504 (83%) patients received at least one PRBC unit. Overall, mean pretransfusion haemoglobin concentration was 8·1 g/dL (1·1), but varied according to the clinical rationale for transfusion. In a time-dependent Cox model, haemoglobin concentration of less than 7 g/dL was consistently associated with higher risk of death in the intensive care unit compared with other higher haemoglobin concentrations (hazard ratio [HR] 2·99 [95% CI 1·95-4·60]); PRBC transfusion was associated with lower risk of death only when transfused when haemoglobin concentration was less than 7 g/dL (HR 0·15 [0·03-0·74]), although no significant effect in reducing mortality was reported for transfusions for other haemoglobin classes (7·0-7·9 g/dL, 8·0-9·9 g/dL, or higher than 10 g/dL). INTERPRETATION: During VV ECMO, there was no universally accepted threshold for transfusion, but PRBC transfusion was invariably associated with lower mortality only when done with haemoglobin concentration of less than 7 g/dL. FUNDING: Extracorporeal Life Support Organization.

Extracorporeal Membrane Oxygenation Selection by Multidisciplinary Consensus: The ECMO Council.

Coronavirus disease 2019 (COVID-19) has increased the demand for extracorporeal membrane oxygenation (ECMO) and introduced distinct challenges to patient selection for ECMO. Standardized processes for patient selection amidst resource limitations are lacking, and data on ECMO consults are underreported. We retrospectively reviewed consecutive adult ECMO consults for acute respiratory failure received at a single academic medical center from April 1, 2020, to February 28, 2021, and evaluated the implementation of a multidisciplinary selection committee (ECMO Council) and standardized framework for patient selection for ECMO. During the 334-day period, there were 202 total ECMO consults; 174 (86.1%) included a diagnosis of COVID-19. Among all consults, 157 (77.7%) were declined and 41 (20.3%) resulted in the initiation of ECMO. Frequent reasons for decline included the presence of multiple relative contraindications (n = 33), age greater than 60 years (n = 32), and resource limitations (n = 27). The ECMO Council deliberated on every case in which an absolute contraindication was not present (n = 96) via an electronic teleconference platform. Utilizing multidisciplinary consensus together with a standardized process for patient selection in ECMO is feasible during a pandemic and may be reliably exercised over time. Whether such an approach is feasible at other centers remains unknown.

Extracorporeal membrane oxygenation circuits in parallel for refractory hypoxemia in patients with COVID-19.

OBJECTIVES: Refractory hypoxemia can occur in patients with acute respiratory distress syndrome from COVID-19 despite support with venovenous (VV) extracorporeal membrane oxygenation (ECMO). Parallel ECMO circuits can be used to increase physiologic support. We report our clinical experience using ECMO circuits in parallel for select patients with persistent severe hypoxemia despite the use of a single ECMO circuit. METHODS: We performed a retrospective cohort study of all patients with COVID-19-related acute respiratory distress syndrome who received VV-ECMO with an additional circuit in parallel at Vanderbilt University Medical Center between March 1, 2020, and March 1, 2022. We report demographic characteristics and clinical characteristics including ECMO settings, mechanical ventilator settings, use of adjunctive therapies, and arterial blood gas results after initial cannulation, before and after receipt of a second ECMO circuit in parallel, and before removal of the circuit in parallel, and outcomes. RESULTS: Of 84 patients with COVID-19 who received VV-ECMO during the study period, 22 patients (26.2%) received a circuit in parallel. The median duration of ECMO was 40.0 days (interquartile range, 31.6-53.1 days), of which 19.0 days (interquartile range, 13.0-33.0 days) were spent with a circuit in parallel. Of the 22 patients who received a circuit in parallel, 16 (72.7%) survived to hospital discharge and 6 (27.3%) died before discharge. CONCLUSIONS: In select patients, the additional use of an ECMO circuit in parallel can increase ECMO blood flow and improve oxygenation while allowing for lung-protective mechanical ventilation and excellent outcomes.

Clinical course of SARS-CoV-2 infection and recovery in lung transplant recipients.

BACKGROUND: Reports on outcomes following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in lung transplant recipients remain limited. METHODS: We performed a single-center, observational study of outcomes in lung transplant recipients diagnosed with SARS-CoV-2 between 5/1/2020 and 3/15/2022 that were followed for a median of 123 days. We analyzed changes in spirometry, acute lung allograft dysfunction (ALAD) incidence, hospitalization, mechanical ventilation needs, secondary infection, and survival. RESULTS: In our cohort of 336 patients, 103 developed coronavirus disease (COVID) (27 pre-Delta, 20 Delta, and 56 Omicron-era). Twenty-five patients (24%) required hospitalization and 10 patients ultimately died (10%). Among 85 survivors who completed ambulatory spirometry, COVID-19 did not alter change in forced expiratory volume in 1 s (FEV1 ) or forced vital capacity (FVC) over time compared to the preceding 6 months. The pre-COVID FEV1 change was -0.05 ml/day (IQR -0.50 to 0.60) compared to -0.20 ml/day (IQR -1.40 to 0.70) post-COVID (p = .16). The pre-COVID change in FVC was 0.20 ml/day (IQR -0.60 to 0.70) compared to 0.05 ml/day (IQR -1.00 to 1.10) post-COVID (p = .76). Although the cohort overall had stable lung function, 33 patients (39%) developed ALAD or accelerated chronic lung allograft dysfunction (FEV1 decline >10% from pre-COVID baseline). Nine patients (35%) with ALAD recovered lung function. Within 3 months of acute COVID infection, 18 patients (17%) developed secondary infections, the majority being bacterial pneumonia. Finally, vaccination with at least two doses of mRNA vaccine was not associated with improved outcomes. CONCLUSIONS: This study describes the natural history of SARS-CoV-2 infection in a large cohort of lung transplant recipients. Although one third of patients develop ALAD requiring augmented immunosuppression, infection with SARS-CoV-2 is not associated with worsening lung function.

Extracorporeal Membrane Oxygenation Circuits in Parallel for Refractory Hypoxemia in COVID-19

Objectives Refractory hypoxemia can occur in patients with acute respiratory distress syndrome (ARDS) from Coronavirus disease 2019 (COVID-19) despite support with venovenous extracorporeal membrane oxygenation (VV-ECMO). Parallel ECMO circuits can be used to increase physiologic support. We report our clinical experience using ECMO circuits in parallel for select patients with persistent severe hypoxemia despite the use of a single ECMO circuit. Methods We performed a retrospective cohort study of all patients with COVID-19 related ARDS receiving VV-ECMO who received an additional circuit in parallel at Vanderbilt University Medical Center between March 1, 2020 and March 1, 2022. We report demographics, clinical characteristics including ECMO settings, mechanical ventilator settings, use of adjunctive therapies, and arterial blood gas results after initial cannulation, before and after receipt of a second ECMO circuit in parallel, and prior to removal of the circuit in parallel, and outcomes. Results Of 84 patients with COVID-19 who received VV-ECMO during the study period, 22 patients (26.2%) received a circuit in parallel. The median time on ECMO was 40.0 days (IQR, 31.6-53.1 days), of which 19.0 days (IQR, 13.0-33.0 days) were spent on a circuit in parallel. Of the 22 patients who received a circuit in parallel, 16 (72.7%) survived to hospital discharge and 6 (27.3%) died before discharge. Conclusions In select patients, addition of an ECMO circuit in parallel can increase ECMO blood flow and improve oxygenation while allowing for lung-protective mechanical ventilation and excellent outcomes.

Extracorporeal Membrane Oxygenation Circuits in Parallel for Refractory Hypoxemia in COVID-19: A Case Series.

Refractory hypoxemia despite the use of extracorporeal membrane oxygenation (ECMO) for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome remains a challenging problem. A single ECMO circuit may not provide adequate physiologic support in the setting of an elevated cardiac output, physiologic demand, and impaired gas exchange. In select patients with refractory hypoxemia, addition of a second ECMO circuit in parallel can improve oxygenation, facilitate lung protective ventilation, awakening, and physical rehabilitation. We report the largest case series to date of patients receiving ECMO circuits in parallel and the first to report this approach in COVID-19.

Safety and Feasibility of a Protocolized Daily Assessment of Readiness for Liberation From Venovenous Extracorporeal Membrane Oxygenation.

BACKGROUND: Decannulation from venovenous extracorporeal membrane oxygenation (ECMO) at the earliest and safest possible time may improve outcomes and reduce cost. Yet, no prospective studies have compared weaning strategies for liberation from ECMO. RESEARCH QUESTION: Is a protocolized daily assessment of readiness to liberate from venovenous ECMO safe and feasible? STUDY DESIGN AND METHODS: We conducted a prospective, single-arm safety and feasibility study of a protocol for daily assessment of readiness to liberate from venovenous ECMO among consecutive adult patients receiving venovenous ECMO across four ICUs at a single center between June 20, 2020, and November 24, 2020. The ECMO-free protocol included three phases: (1) the safety screening, (2) non-ECMO Fio2 titration, and (3) the ECMO-free trial. Enrollment, interventions, and data collection were performed prospectively by trained study staff. RESULTS: Twenty-six patients received the ECMO-free protocol on 385 patient-days. The safety screening was passed during a total of 59 ECMO-free daily assessments (15.3%) among 20 patients. Every passed safety screening proceeded to an ECMO-free trial. Twenty-eight passed ECMO-free trials (47.5%) occurred among 16 patients (61.5%). No missed safety screenings, protocol deviations, or adverse events occurred. Of the 16 patients who passed an ECMO-free trial, 14 patients (87.5%) were decannulated. Among decannulated patients, 12 patients (85.7%) were decannulated on the same day as a passed ECMO-free trial, 6 patients (42.9%) were decannulated on the first day that they passed an ECMO-free trial, and 6 patients (42.9%) passed an ECMO-free trial at least twice consecutively before decannulation. The median time from first passed ECMO-free trial to decannulation was 2 days (interquartile range, 0-3 days). INTERPRETATION: The ECMO-free protocol is feasible and may identify patients for decannulation earlier than gradual approaches to weaning.