Serial S100B Sampling Detects Intracranial Lesion Development in Patients on Extracorporeal Membrane Oxygenation

Introduction: Intracranial lesion development is a recognized complication in adults treated with extracorporeal membrane oxygenation (ECMO) and is associated with increased mortality. As neurological assessment during ECMO treatment remains challenging, protein biomarkers of cerebral injury could provide an opportunity to detect intracranial lesion development at an early stage. The aim of this study was to determine if serially sampled S100B could be used to detect intracranial lesion development during ECMO treatment.Methods: We conducted an observational cohort study of all patients treated with ECMO at ECMO Center Karolinska (Karolinska University Hospital, Stockholm, Sweden) between January and August 2018, excluding patients who did not undergo a computerized tomography scan (CT) during treatment. S100B was prospectively collected at hospital admission and then once daily. The primary end-point was any type of CT verified intracranial lesion. Receiver operating characteristics (ROC) curves and Cox proportional hazards models were employed.Results: Twenty-nine patients were included, of which 15 (52%) developed an intracranial lesion and exhibited higher levels of S100B overall. S100B had a robust association with intracranial lesion development, especially during the first 200 hours following admission. The best area-under-curve (AUC) to predict intracranial lesion development was 40 and 140 hours following ECMO initiation, were a S100B level of 0.69μg/L had an AUC of 0.81 (0.628-0.997). S100B levels were markedly increased following the development of intracranial hemorrhage.Conclusions: Serial serum S100B samples in ECMO patients were both significantly elevated and had an increasing trajectory in patients developing intracranial lesions. Larger prospective trials are warranted to validate these findings and to ascertain their clinical utility

Recirculation in single lumen cannula venovenous extracorporeal membrane oxygenation: A non-randomized bi-centric trial

Background: Recirculation is a common problem in venovenous (VV) extracorporeal membrane oxygenation (ECMO). The aims of this study were to compare recirculation fraction (Rf) between femoro-jugular and jugulo-femoral VV ECMO configurations, to identify risk factors for recirculation and to assess the impact on hemolysis. Methods: Patients in the medical intensive care unit (ICU) at the University Medical Center Regensburg, Germany receiving VV ECMO with femoro-jugular, and jugulo-femoral configuration at the ECMO Center Karolinska, Sweden, were included in this non-randomized prospective study. Total ECMO flow (QEC), recirculated flow (QREC), and recirculation fraction Rf = QREC/QEC were determined using ultrasound dilution technology. Effective ECMO flow (QEFF) was defined as QEFF = QEC * (1–Rf). Demographics, cannula specifics, and markers of hemolysis were assessed. Survival was evaluated at discharge from ICU. Results: Thirty-seven patients with femoro-jugular configuration underwent 595 single-point measurements and 18 patients with jugulo-femoral configuration 231 measurements. Rf was lower with femoro-jugular compared to jugulo-femoral configuration [5 (0, 11) vs. 19 (13, 28) %, respectively (p 8 vs. ≤ 8%. Explorative data on survival showed comparable results in the femoro-jugular and the jugulo-femoral group (81 vs. 72%, p = 0.455). Conclusion: VV ECMO with femoro-jugular configuration caused less recirculation. Further risk factors for higher Rf were shorter distance between the two cannula tips, higher ECMO flow, and lower heart rate. Rf did not affect hemolysis

Validation of Prognostic Scores in Extracorporeal Life Support: A Multi-Centric Retrospective Study

Multiple prognostic scores have been developed for both veno-arterial (VA) and veno-venous (VV) extracorporeal membrane oxygenation (ECMO), mostly in single-center cohorts. The aim of this study was to compare and validate different prediction scores in a large multicenter ECMO-population. Methods: Data from five ECMO centers included 300 patients on VA and 329 on VV ECMO support (March 2008 to November 2016). Different prognostic scores were compared between survivors and non-survivors: APACHE II, SOFA, SAPS II in all patients; SAVE, modified SAVE and MELD-XI in VA ECMO; RESP, PRESET, ROCH and PRESERVE in VV ECMO. Model performance was compared using receiver-operating-curve analysis and assessment of model calibration. Survival was assessed at intensive care unit discharge. Results: The main indication for VA ECMO was cardiogenic shock; overall survival was 51%. ICU survivors had higher Glasgow Coma Scale scores and pH, required cardiopulmonary resuscitation (CPR) less frequently, had lower lactate levels and shorter ventilation time pre-ECMO at baseline. The best discrimination between survivors and non-survivors was observed with the SAPS II score (area under the curve [AUC] of 0.73 (95% CI 0.67–0.78)). The main indication for VV ECMO was pneumonia; overall survival was 60%. Lower PaCO2, higher pH, lower lactate and lesser need for CPR were observed among survivors. The best discrimination between survivors and non-survivors was observed with the PRESET score (AUC 0.66 (95% CI 0.60–0.72)). Conclusion: The prognostic performance of most scores was moderate in ECMO patients. The use of such scores to decide about ECMO implementation in potential candidates should be discouraged

Six-Month Survival After Extracorporeal Membrane Oxygenation for Severe COVID-19

Objectives: The authors evaluated the outcome of adult patients with coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS) requiring the use of extracorporeal membrane oxygenation (ECMO). Design: Multicenter retrospective, observational study. Setting: Ten tertiary referral university and community hospitals. Participants: Patients with confirmed severe COVID-19-related ARDS. Interventions: Venovenous or venoarterial ECMO. Measurements and Main Results: One hundred thirty-two patients (mean age 51.1 +/- 9.7 years, female 17.4%) were treated with ECMO for confirmed severe COVID-19-related ARDS. Before ECMO, the mean Sequential Organ Failure Assessment score was 10.1 +/- 4.4, mean pH was 7.23 +/- 0.09, and mean PaO2/fraction of inspired oxygen ratio was 77 +/- 50 mmHg. Venovenous ECMO was adopted in 122 patients (92.4%) and venoarterial ECMO in ten patients (7.6%) (mean duration, 14.6 +/- 11.0 days). Sixty-three (47.7%) patients died on ECMO and 70 (53.0%) during the index hospitalization. Six-month all-cause mortality was 53.0%. Advanced age (per year, hazard ratio [HR] 1.026, 95% CI 1.000-1-052) and low arterial pH (per unit, HR 0.006, 95% CI 0.000-0.083) before ECMO were the only baseline variables associated with increased risk of six-month mortality. Conclusions: The present findings suggested that about half of adult patients with severe COVID-19 -related ARDS can be managed successfully with ECMO with sustained results at six months. Decreased arterial pH before ECMO was associated significantly with early mortality. Therefore, the authors hypothesized that initiation of ECMO therapy before severe metabolic derangements subset may improve survival rates significantly in these patients. These results should be viewed in the light of a strict patient selection policy and may not be replicated in patients with advanced age or multiple comorbidities. (C) 2021 The Authors. Published by Elsevier Inc.Peer reviewe

Pressure and Flow Properties of Cannulae for Extracorporeal Membrane Oxygenation I: Return (Arterial) Cannulae

Adequate extracorporeal membrane oxygenation support in the adult requires cannulae permitting blood flows up to 6-8 L/minute. In accordance with Poiseuille's law, flow is proportional to the fourth power of cannula inner diameter and inversely proportional to its length. Poiseuille's law can be applied to obtain the pressure drop of an incompressible, Newtonian fluid (such as water) flowing in a cylindrical tube. However, as blood is a pseudoplastic non-Newtonian fluid, the validity of Poiseuille's law is questionable for prediction of cannula properties in clinical practice. Pressure-flow charts with non-Newtonian fluids, such as blood, are typically not provided by the manufacturers. A standardized laboratory test of return (arterial) cannulae for extracorporeal membrane oxygenation was performed. The aim was to determine pressure-flow data with human whole blood in addition to manufacturers' water tests to facilitate an appropriate choice of cannula for the desired flow range. In total, 14 cannulae from three manufacturers were tested. Data concerning design, characteristics, and performance were graphically presented for each tested cannula. Measured blood flows were in most cases 3-21% lower than those provided by manufacturers. This was most pronounced in the narrow cannulae (15-17 Fr) where the reduction ranged from 27% to 40% at low flows and 5-15% in the upper flow range. These differences were less apparent with increasing cannula diameter. There was a marked disparity between manufacturers. Based on the measured results, testing of cannulae including whole blood flows in a standardized bench test would be recommended.info:eu-repo/semantics/publishedVersio

Six-Month Survival After Extracorporeal Membrane Oxygenation for Severe COVID-19

ObjectivesThe authors evaluated the outcome of adult patients with coronavirus disease 2019 (COVID-19)–related acute respiratory distress syndrome (ARDS) requiring the use of extracorporeal membrane oxygenation (ECMO).DesignMulticenter retrospective, observational study.SettingTen tertiary referral university and community hospitals.ParticipantsPatients with confirmed severe COVID-19–related ARDS.InterventionsVenovenous or venoarterial ECMO.Measurements and Main ResultsOne hundred thirty-two patients (mean age 51.1 ± 9.7 years, female 17.4%) were treated with ECMO for confirmed severe COVID-19–related ARDS. Before ECMO, the mean Sequential Organ Failure Assessment score was 10.1 ± 4.4, mean pH was 7.23 ± 0.09, and mean PaO2/fraction of inspired oxygen ratio was 77 ± 50 mmHg. Venovenous ECMO was adopted in 122 patients (92.4%) and venoarterial ECMO in ten patients (7.6%) (mean duration, 14.6 ± 11.0 days). Sixty-three (47.7%) patients died on ECMO and 70 (53.0%) during the index hospitalization. Six-month all-cause mortality was 53.0%. Advanced age (per year, hazard ratio [HR] 1.026, 95% CI 1.000-1-052) and low arterial pH (per unit, HR 0.006, 95% CI 0.000-0.083) before ECMO were the only baseline variables associated with increased risk of six-month mortality.ConclusionsThe present findings suggested that about half of adult patients with severe COVID-19–related ARDS can be managed successfully with ECMO with sustained results at six months. Decreased arterial pH before ECMO was associated significantly with early mortality. Therefore, the authors hypothesized that initiation of ECMO therapy before severe metabolic derangements subset may improve survival rates significantly in these patients. These results should be viewed in the light of a strict patient selection policy and may not be replicated in patients with advanced age or multiple comorbidities. Clinical Trial Registration: identifier, NCT04383678.</p

Plasma Transfusion and Procoagulant Product Administration in Extracorporeal Membrane Oxygenation:A Secondary Analysis of an International Observational Study on Current Practices

OBJECTIVES: To achieve optimal hemostatic balance in patients on extracorporeal membrane oxygenation (ECMO), a liberal transfusion practice is currently applied despite clear evidence. We aimed to give an overview of the current use of plasma, fibrinogen concentrate, tranexamic acid (TXA), and prothrombin complex concentrate (PCC) in patients on ECMO.DESIGN: A prespecified subanalysis of a multicenter retrospective study. Venovenous (VV)-ECMO and venoarterial (VA)-ECMO are analyzed as separate populations, comparing patients with and without bleeding and with and without thrombotic complications. SETTING: Sixteen international ICUs.PATIENTS: Adult patients on VA-ECMO or VV-ECMO.INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 420 VA-ECMO patients, 59% (n = 247) received plasma, 20% (n = 82) received fibrinogen concentrate, 17% (n = 70) received TXA, and 7% of patients (n = 28) received PCC. Fifty percent of patients (n = 208) suffered bleeding complications and 27% (n = 112) suffered thrombotic complications. More patients with bleeding complications than patients without bleeding complications received plasma (77% vs. 41%, p &lt; 0.001), fibrinogen concentrate (28% vs 11%, p &lt; 0.001), and TXA (23% vs 10%, p &lt; 0.001). More patients with than without thrombotic complications received TXA (24% vs 14%, p = 0.02, odds ratio 1.75) in VA-ECMO, where no difference was seen in VV-ECMO. Of 205 VV-ECMO patients, 40% (n = 81) received plasma, 6% (n = 12) fibrinogen concentrate, 7% (n = 14) TXA, and 5% (n = 10) PCC. Thirty-nine percent (n = 80) of VV-ECMO patients suffered bleeding complications and 23% (n = 48) of patients suffered thrombotic complications. More patients with than without bleeding complications received plasma (58% vs 28%, p &lt; 0.001), fibrinogen concentrate (13% vs 2%, p &lt; 0.01), and TXA (11% vs 2%, p &lt; 0.01). CONCLUSIONS: The majority of patients on ECMO receive transfusions of plasma, procoagulant products, or antifibrinolytics. In a significant part of the plasma transfused patients, this was in the absence of bleeding or prolonged international normalized ratio. This poses the question if these plasma transfusions were administered for another indication or could have been avoided.</p

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Conversion from Venovenous to Venoarterial Extracorporeal Membrane Oxygenation in Adults

No major study has been performed on the conversion from venovenous (VV) to venoarterial (VA) extracorporeal membrane oxygenation (ECMO) in adults. This single-center retrospective cohort study aimed to investigate the incidence, indication, and outcome in patients who converted from VV to VA ECMO. All adult patients (≥18 years) who commenced VV ECMO at our center between 2005 and 2018 were screened. Of 219 VV ECMO patients, 21% (n = 46) were converted to VA ECMO. The indications for conversion were right ventricular failure (RVF) (65%), cardiogenic shock (26%), and other (9%). In the converted patients, there was a significant increase in Sequential Organ Failure Assessment (SOFA) scores between admission 12 (9–13) and conversion 15 (13–17, p &lt; 0.001). Compared to non-converted patients, converted patients also had a higher mortality rate (62% vs. 16%, p &lt; 0.001) and a lower admission Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score (p &lt; 0.001). Outcomes were especially unfavorable in those converted due to RVF. These results indicate that VA ECMO, as opposed to VV ECMO, should be considered as the first mode of choice in patients with respiratory failure and signs of circulatory impairment, especially in those with impaired RV function. For the remaining patients, Pre-admission RESP score, daily echocardiography, and SOFA score trajectories may help in the early identification of those where conversion from VV to VA ECMO is warranted. Multi-centric studies are warranted to validate these findings

Introducing the Loop for Circuit Access during Extracorporeal Membrane Oxygenation: Feasibility and Safety

In extracorporeal membrane oxygenation (ECMO), blood is drained from the patient, and pumped through a membrane oxygenator/lung (ML) for gas exchange and then back to the patient. For monitoring blood gases, samples may be sampled downstream from the ML. This exposes the patient for embolization risk (air/clot) when the stopcocks are flushed. For safe sampling procedures, the Loop was introduced. It is a constant low-flow arteriovenous shunt (AVS) used preferably in venoarterial ECMO. It is composed of three different length and diameter three-way stopcocks connected to the circuit just downstream the ML with its return upstream the pump. It offers safe arterial blood sampling and a simultaneous access point to the venous side of the circuit. Since its introduction, no patient complications have been reported to be accounted for by the Loop. The Loop is an AVS permitting a safe access point for post membrane blood sampling and for injections in the venous pre-pump limb. It has a low cost and is easy to install and maintain. It may be used in any ECMO configuration