Restrictive Transfusion Practice in Adults Receiving Venovenous Extracorporeal Membrane Oxygenation: A Single-Center Experience

Association of RBC Transfusion Thresholds and Outcomes in Medical Patients With Acute Respiratory Failure Supported With Extracorporeal Membrane Oxygenation: A Single-Center Retrospective Cohort Study

BACKGROUND

The hemoglobin value to trigger RBC transfusion for patients receiving venovenous extracorporeal membrane oxygenation (ECMO) is controversial. Previous guidelines recommended transfusing to a normal hemoglobin level, but recent studies suggest that more RBC transfusions are associated with increased adverse outcomes.

RESEARCH QUESTION

Is implementation of different institutional RBC transfusion thresholds for patients receiving venovenous ECMO associated with changes in RBC use and patient outcomes?

STUDY DESIGN AND METHODS

This single-center retrospective study of patients receiving venovenous ECMO used segmented regression to test associations between implementation of institutional transfusion thresholds and trends in RBC use. Associations with secondary outcomes, including in-hospital survival, also were assessed.

RESULTS

The study included 229 patients: 91 in the no threshold cohort, 48 in the hemoglobin < 8 g/dL cohort, and 90 in the hemoglobin < 7 g/dL cohort. Despite a decrease in number of RBC units transfused per day of ECMO support after implementation of different thresholds (mean ± SD: 0.6 ± 1.0 in the no threshold cohort, 0.3 ± 0.8 in the hemoglobin < 8 g/dL cohort, and 0.3 ± 1.1 in the hemoglobin < 7 g/dL cohort; P < .001), segmented regression showed no association between implementation of transfusion thresholds and changes in trends in number of RBC units per day of ECMO. We observed an increased hazard of death in the no threshold cohort compared with the hemoglobin < 8 g/dL cohort (adjusted hazard ratio [aHR], 2.08; 95% CI, 1.12-3.88) and in the hemoglobin < 7 g/dL cohort compared with the hemoglobin < 8 g/dL cohort (aHR, 1.93; 95% CI, 1.02-3.62). No difference was found in the hazard of death between the no threshold and hemoglobin < 7 g/dL cohorts (aHR, 1.08; 95% CI, 0.69-1.69).

INTERPRETATION

We observed a decrease in number of RBC units per day of ECMO over time, but changes were not associated temporally with implementation of transfusion thresholds. A transfusion threshold of hemoglobin < 8 g/dL was associated with a lower hazard of death, but these findings are limited by study methodology. Further research is needed to investigate optimal RBC transfusion practices for patients supported with venovenous ECMO.

Prognostic of red blood cell transfusion during extracorporeal membrane oxygenation therapy on mortality: A meta-analysis

BACKGROUND

This meta-analysis aimed to explore the impact of red blood cell (RBC) transfusion on mortality during extracorporeal membrane oxygenation (ECMO). Previous studies investigated the prognostic impact of RBC transfusion during ECMO on the risk of mortality, but no meta-analysis has been published before.

METHODS

The PubMed, Embase, and the Cochrane library were systematically searched for papers published up to 13 December 2021, using the MeSH terms "ECMO", "'Erythrocytes", and "Mortality" to identify meta-analyses. Total or daily RBC transfusion during ECMO and mortality were examined.

RESULTS

The random-effect model was used. Eight studies (794 patients, including 354 dead) were included. The total volume of RBC was associated with higher mortality standardized weighted difference (SWD = -0.62, 95% CI: -1.06,-0.18, p = .006; I2 = 79.7%, Pheterogeneity = 0.001). The daily volume of RBC was associated with higher mortality (SWD = -0.77, 95% CI: -1.11,-0.42, p < .001; I2 = 65.7%, Pheterogeneity = 0.020). The total volume of RBC was associated with mortality for venovenous (VV) (SWD = -0.72, 95% CI: -1.23, -0.20, p = .006) but not venoarterial ECMO (p = .126) or when reported together (p = .089). The daily volume of RBC was associated with mortality for VV (SWD = -0.72, 95% CI: -1.18, -0.26, p = 0.002; I2 = 0.0%, Pheterogeneity = 0.642) and venoarterial (SWD = -0.95, 95% CI: -1.32, -0.57, p < .001) ECMO, but not when reported together (p = .067). The sensitivity analysis suggested the robustness of the results.

CONCLUSION

When considering the total and daily volumes of RBC transfusion during ECMO, the patients who survived received smaller total and daily volumes of RBC transfusion. This meta-analysis suggests that RBC transfusion might be associated with a higher risk of mortality during ECMO.

Use of bivalirudin after initial heparin management among adult patients on long-term venovenous extracorporeal support as a bridge to lung transplant: A case series

A growing body of evidence supports the use of bivalirudin as an alternative to unfractionated heparin (UFH) for the prevention of thrombotic events in patients on venovenous (VV) extracorporeal membrane oxygenation (ECMO). However, data in patients bridged to lung transplantation are limited. In this case series, we describe the outcomes of six patients who were transitioned from UFH to bivalirudin during their course of VV ECMO support as a bridge to lung transplantation. All six patients were on VV ECMO support until transplant, with a median duration of 73 days. Bivalirudin demonstrated a shorter time to first therapeutic activated thromboplastin time (aPTT) level. Additionally, time in therapeutic range was longer while patients were receiving bivalirudin compared to UFH (median 92.9% vs. 74.6%). However, major bleeding and thrombotic events occurred while patients were receiving either anticoagulant. Based on our experience, bivalirudin appears to be a viable option for anticoagulation in VV ECMO patients bridged to lung transplantation. Larger studies evaluating the optimal anticoagulation strategy in patients bridged to transplant are needed.

A value-based approach to optimize red blood cell transfusion in patients receiving extracorporeal membrane oxygenation

INTRODUCTION

The risk, cost, and adverse outcomes associated with packed red blood cell (RBC) transfusions in patients with cardiopulmonary failure requiring extracorporeal membrane oxygenation (ECMO) have raised concerns regarding the overutilization of RBC products. It is, therefore, necessary to establish optimal transfusion criteria and protocols for patients supported with ECMO. The goal of this study was to establish specific criteria for RBC transfusions in patients undergoing ECMO.

METHODS

This was a retrospective cohort study conducted at Stanford University Hospital. Data on RBC utilization during the entire hospital stay were obtained, which included patients aged ≥18 years who received ECMO support between 1 January 2017, and 30 June 2020 (n = 281). The primary outcome was in-hospital mortality.

RESULTS

Hemoglobin (HGB) levels >10 g/dL before transfusion did not improve in-hospital survival. Therefore, we revised the HGB threshold to ≤10 g/dL to guide transfusion in patients undergoing ECMO. To validate this intervention, we prospectively compared the pre- and post-intervention cohorts for in-hospital mortality. Post-intervention analyses found 100% compliance for all eligible records and a decrease in the requirement for RBC transfusion by 1.2 units per patient without affecting the mortality.

CONCLUSIONS

As an institution-driven value-based approach to guide transfusion in patients undergoing ECMO, we lowered the threshold HGB level. Validation of this revised intervention demonstrated excellent compliance and reduced the need for RBC transfusion while maintaining the clinical outcome. Our findings can help reform value-based healthcare in this cohort while maintaining the outcome.

Haematological Trends and Transfusion during Adult Extracorporeal Membrane Oxygenation: A Single Centre Study

The temporal trends in haematological parameters and their associations with blood product transfusion requirements in patients supported with extracorporeal membrane oxygenation (ECMO) are poorly understood. We performed a retrospective data analysis to better understand the behaviour of haematological and coagulation parameters and their associations with transfusion requirements during ECMO.

METHODS

Patient demographics, haematological and coagulation parameters, plasma haemoglobin and fibrinogen concentrations, platelet count, the international normalised ratio (INR), the activated partial thromboplastin time (APTT), and blood product transfusion data from 138 patients who received ECMO in a single high-volume centre were analysed.

RESULTS

Ninety-two patients received venoarterial (VA) ECMO and 46 patients received venovenous (VV) ECMO. The median (IQR) duration of VA, and VV ECMO was 8 (5-13) days and 13 (8-23) days, respectively. There were significant reductions in haemoglobin, the platelet count, and the fibrinogen concentration upon initiation of ECMO. On average, over time, patients on VV ECMO had platelet counts 44 × 109/L higher than those on VA ECMO (p ≤ 0.001). Fibrinogen and APTT did not vary significantly based on the mode of ECMO (p = 0.55 and p = 0.072, respectively). A platelet count < 50 × 109/L or a fibrinogen level < 1.8 g/L was associated with 50% chance of PRBC transfusion, regardless of the ECMO type, and packed red blood cell (PRBC) transfusion was more common with VA ECMO. APTT was predictive of the transfusion requirement, and the decrement in APTT was discriminatory between VVECMO survivors and nonsurvivors.

CONCLUSION

ECMO support is associated with reductions in haemoglobin, platelet count, and fibrinogen. Patients supported with VA ECMO are more likely to receive a PRBC transfusion compared to those on VV ECMO. Thrombocytopaenia, hypofibrinogenaemia, and anticoagulation effect the likelihood of requiring PRBC transfusion. Further research is needed to define optimal blood management during ECMO, including appropriate transfusion triggers and the anticoagulation intensity.

Red blood cell volume, but not platelet or plasma volume is associated with mortality in neonatal ECMO

BACKGROUND

Blood product transfusions are necessary for critically ill neonates on extracorporeal membrane oxygenation (ECMO). Transfusions are administered in response to unstudied arbitrary thresholds and may be associated with adverse outcomes. The objective of this study was to identify relationships between blood product components and mortality in neonates receiving ECMO support for respiratory indications.

STUDY DESIGN AND METHODS

A retrospective review of neonates receiving ECMO for respiratory indications from 2002 to 2019 from a single quaternary-referral neonatal intensive care unit (NICU). Demographic and outcome data and transfusion volume (ml/kg/day) were harvested from the medical record, and baseline mortality risk was assessed using NEO-RESCUERS scores. The association between volume of red blood cells (RBC), platelet, plasma transfusion rates (ml/kg/day), and mortality on ECMO were assessed after adjustment for NEO-RESCUERS score. Cox proportional hazards (CPH) competing risk model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for each variable and mortality outcome.

MEASUREMENTS AND MAIN RESULTS

Among 248 neonates undergoing ECMO for respiratory failure, overall survival was 93%. RBC, platelet, and plasma volume were highly associated with mortality during ECMO in an unadjusted model. After adjusting for NEO-RESCUERS score, RBC volume was associated with increased mortality risk (HR 1.013, 95% CI 1.004-1.022, p = .0043), but platelet and plasma volume were not associated with mortality.

CONCLUSIONS

RBC, but not platelet or plasma volume, is associated with mortality in neonates on ECMO. Our findings refute previous studies demonstrating an association between platelet volume and mortality for neonates on ECMO.

Patient Blood Management in intensive care patients

PURPOSE OF REVIEW

Patients admitted to ICUs are a heterogeneous group, displaying multiple anaemia risk factors and comorbidities. Clinicians should therefore take all possible measures to identify modifiable risks. Patient Blood Management (PBM) is an approach promoting the timely application of evidence-based interventions designed to maintain patients own blood mass.

RECENT FINDINGS

Within ICU-patients, anaemia is highly prevalent. Generally, anaemia is associated with impaired outcome and need of blood transfusion. Currently, with ICUs working at full capacity and the global blood reserves exhausted, the SARS-CoV-2 pandemic reinforces the need for PBM implementation. For instance, implementation of a comprehensive coagulation management and measures to avoid iatrogenic blood loss may prevent bleeding-associated complications and adherence to blood transfusion guidelines may reduce adverse events associated with transfusion.

SUMMARY

Critically ill patients display various morbidities often requiring individualized treatment. PBM offers patient-centred measures to improve outcome any time during hospital stay.

Intraoperative Management of Adult Patients on Extracorporeal Membrane Oxygenation: An Expert Consensus Statement From the Society of Cardiovascular Anesthesiologists-Part II, Intraoperative Management and Troubleshooting

In the second part of the Society of Cardiovascular Anesthesiologists Extracorporeal Membrane Oxygenation (ECMO) working group expert consensus statement, venoarterial (VA) and venovenous (VV) ECMO management and troubleshooting in the operating room are discussed. Expert consensus statements are provided about intraoperative monitoring, anesthetic drug dosing, and management of intraoperative problems in VA and VV ECMO patients.

The Evolution of the Use of Extracorporeal Membrane Oxygenation in Respiratory Failure

Extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency to support patients with acute respiratory failure, most commonly, and severe forms of acute respiratory distress syndrome (ARDS). The marked increase in the global use of ECMO followed the publication of a large randomized trial in 2009 and the experience garnered during the 2009 influenza A (H1N1) pandemic, and has been further supported by the release of a large, randomized clinical trial in 2018, confirming a benefit from using ECMO in patients with severe ARDS. Despite a rapid expansion of ECMO-related publications, optimal management of patients receiving ECMO, in terms of patient selection, ventilator management, anticoagulation, and transfusion strategies, is evolving. Most recently, ECMO is being utilized for an expanding variety of conditions, including for cases of severe pulmonary or cardiac failure from coronavirus disease 2019 (COVID-19). This review evaluates modern evidence for ECMO for respiratory failure and the current challenges in the field.

Extracorporeal Gas Exchange for Acute Respiratory Distress Syndrome: Open Questions, Controversies and Future Directions

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) in acute respiratory distress syndrome (ARDS) improves gas exchange and allows lung rest, thus minimizing ventilation-induced lung injury. In the last forty years, a major technological and clinical improvement allowed to dramatically improve the outcome of patients treated with V-V ECMO. However, many aspects of the care of patients on V-V ECMO remain debated. In this review, we will focus on main issues and controversies on caring of ARDS patients on V-V ECMO support. Particularly, the indications to V-V ECMO and the feasibility of a less invasive extracorporeal carbon dioxide removal will be discussed. Moreover, the controversies on management of mechanical ventilation, prone position and sedation will be explored. In conclusion, we will discuss evidences on transfusions and management of anticoagulation, also focusing on patients who undergo simultaneous treatment with ECMO and renal replacement therapy. This review aims to discuss all these clinical aspects with an eye on future directions and perspectives.

Device-Induced Hemostatic Disorders in Mechanically Assisted Circulation

Mechanically assisted circulation (MAC) sustains the blood circulation in the body of a patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) or on ventricular assistance with a ventricular assist device (VAD) or on extracorporeal membrane oxygenation (ECMO) with a pump-oxygenator system. While MAC provides short-term (days to weeks) support and long-term (months to years) for the heart and/or lungs, the blood is inevitably exposed to non-physiological shear stress (NPSS) due to mechanical pumping action and in contact with artificial surfaces. NPSS is well known to cause blood damage and functional alterations of blood cells. In this review, we discussed shear-induced platelet adhesion, platelet aggregation, platelet receptor shedding, and platelet apoptosis, shear-induced acquired von Willebrand syndrome (AVWS), shear-induced hemolysis and microparticle formation during MAC. These alterations are associated with perioperative bleeding and thrombotic events, morbidity and mortality, and quality of life in MCS patients. Understanding the mechanism of shear-induce hemostatic disorders will help us develop low-shear-stress devices and select more effective treatments for better clinical outcomes.

Platelet transfusion is associated with 90-day and 1-year mortality for adult patients requiring veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Studies examining one-year mortality respecting component blood transfusion are sparse. We hypothesize that component blood product transfusions are negatively associated with 90-day and 1-year survival for all patients requiring veno-arterial (VA) or veno-venous (VV) ECMO.

STUDY DESIGN AND METHODS

This was an IRB-approved retrospective cohort analysis of 676 consecutive patients requiring ECMO at the University of Pittsburgh between 2005 and 2016. Patients were analysed both as an entire cohort and as two subsets with respect to ECMO modality (VA vs. VV). Additional data collected and analysed included patient characteristics, laboratory values and blood product transfusion.

RESULTS

Multivariable analysis revealed that platelet transfusion was associated with 90-day mortality (OR: 1·05, P = 0·037) and one-year mortality for the entire cohort (OR = 1·05, P = 0·046,). Platelet transfusion volume was also associated with mortality in the VA-ECMO subset of patients at both 90 days (OR = 1·08, P = 0·03) and one year (OR: 1·11, P = 0·014). Age, peak International Normalized Raton ECMO, nadir haemoglobin (on ECMO) and final haemoglobin (after ECMO) were significantly associated with mortality for patients requiring VA-ECMO. For VV-ECMO patients, age, INR and peak creatinine on ECMO were associated with mortality. No individual component blood product was associated with one-year mortality for patients requiring VV-ECMO.

CONCLUSION

Platelet transfusion was associated with increased 90-day and 1-year mortality for patients requiring VA-ECMO.

Blood component use in critical care in patients with COVID-19 infection: a single-centre experience

There has been a significant surge in admissions to critical care during the coronavirus disease 2019 (COVID‐19) pandemic. At present, the demands on blood components have not been described. We reviewed their use during the first 6 weeks of the outbreak from 3 March 2020 in a tertiary‐level critical care department providing venovenous extracorporeal membrane oxygenation (vv‐ECMO). A total of 265 patients were reviewed, with 235 not requiring ECMO and 30 requiring vv‐ECMO. In total, 50 patients required blood components during their critical care admission. Red cell concentrates were the most frequently transfused component in COVID‐19‐infected patients with higher rates of use during vv‐ECMO. The use of fresh frozen plasma, cryoprecipitate and platelet transfusions was low in a period prior to the use of convalescent plasma.