Transfusion policy in pediatric extracorporeal membrane oxygenation patients: Less could be more

OBJECTIVE

To evaluate a restrictive transfusion policy of red blood cells (RBC) and platelets in pediatric patients submitted to extracorporeal membrane oxygenation (ECMO).

METHODS

Retrospective descriptive study of pediatric patients supported with ECMO, from January 2010 to December 2019. Hemoglobin, platelet, lactate and mixed venous oxygen saturation (SvO2) values of each patient while on ECMO, were collected. Transfusion efficiency and tissue oxygenation were statistically evaluated comparing pre-transfusion hemoglobin, lactate and SvO2 with post-transfusion values. Ranges of hemoglobin and platelets were established, and the number of transfusions registered. The bleeding complications and outcome were documented.

RESULTS

Of a total of 1016 hemoglobin values, the mean value before transfusion was 8.6 g/dl. Hemoglobin and SvO2 increased significantly post-transfusion. Red blood cell transfusion varied with hemoglobin values: when hemoglobin value was less than 7 g/dl, 89% (41/46) were transfused but just 23% (181/794) when greater or equal to 7 g/dl. In the presence of active bleeding, the frequency of RBC transfusion increased from 32% to 62%, with hemoglobin between 7 g/dl and 8 g/dl.The mean value for platelet transfusion was 32 x 109/L. Thirty-eight (43%) platelet values between 20 x 109/L and 30x109/L, and 31 (40%) between 30 x 109/L and 40 x 109/L led to platelet transfusion; between 40 x 109/L and 50 x 109/L, only 7 (9%) prompted platelet transfusion.Comparing the 2010-2015 to 2016-2019 periods there was a decrease in RBC and platelet transfusion threshold with similar survival (p = .528). Survival to discharge was 68%.

CONCLUSIONS

Using a restrictive RBC and platelet transfusion policy was safe and allowed a good outcome in this case series. The presence of active bleeding was an important decision factor when hemoglobin was above 7 g/dl and platelets were above 30 x 109/L.

Veno-arterial extracorporeal membrane oxygenation without allogeneic blood transfusion: An observational cohort study

INTRODUCTION

It remains unclear whether patients who will not accept allogeneic blood transfusion can be managed successfully with veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO). The objective of our study was to determine what percentage of V-A ECMO patients were managed without allogeneic blood transfusion.

METHODS

This was a retrospective, observational cohort study of patients with cardiogenic shock requiring V-A ECMO between January 2016 and January 2019. The primary outcome was avoidance of any allogeneic blood transfusion.

RESULTS

Of the 206 patients included, 23 (11.2%) were managed without any allogeneic blood transfusion. Fourteen (60.9%) avoided allogeneic blood transfusion during their entire hospitalization. "No-transfusion" patients were younger, more commonly men, were less likely to have a prior diagnosis of hypertension or coronary artery disease, had higher baseline hemoglobin, had higher SAVE scores, and were less likely to have received aspirin before ECMO. No patients in the "no-transfusion" group had major bleeding compared to 35% of patients in the blood transfusion group (p < 0.001). In-hospital mortality was 17.4% for those who avoided blood transfusion and 41.5% for those who received blood transfusion (p = 0.04). ECMO duration was significantly shorter in patients who avoided blood transfusion compared to those who received blood transfusion (median 3.5 vs 7 days, p < 0.001).

CONCLUSIONS

Select patients can be successfully managed on V-A ECMO without allogeneic blood transfusion. Jehovah's Witnesses and other patients with objections to allogeneic transfusion might be offered V-A ECMO if its anticipated duration is short (e.g. <7 days) and baseline hemoglobin concentration is high (e.g. ≥10 mg/dL).

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.

HEROES V-A-HEmoRrhagic cOmplications in veno-arterial Extracorporeal life Support-Development and internal validation of a multivariable prediction model in adult patients

BACKGROUND

Risk factors for bleeding complications during extracorporeal life support (ECLS) indicated for cardiac support remain poorly investigated. The aim is to develop and internally validate a prediction model to calculate the risk for bleeding complications in adult patients receiving veno-arterial (V-A) ECLS.

METHODS

Data of the Extracorporeal Life Support Organization registry of adult patients undergoing V-A ECLS between 2010 and 2020 were analyzed. The primary outcome was bleeding complications recorded during V-A ECLS. Multivariable logistic regression with backward stepwise elimination was used to develop the prediction model. Performance of the model was tested by discriminative ability and calibration with receiver operator characteristic, area under the curve, and visual inspection of the calibration plot. Internal validation was performed to detect overfitting of the model.

RESULTS

In total 28 767 adult patients were included, of which 29.0% developed bleeding complications. Sex, body mass index, surgical cannulation, pre-ECLS respiratory and hemodynamic variables, pre-ECLS support and interventions, and different type of diagnosis were included in the prediction model. This prediction model showed a predictive capability with an AUC of 0.66.

CONCLUSION

The model is based on the largest cohort of V-A ECLS patients and is the best available predictive model for bleeding events given the predictors that are available in V-A ECLS compared to current literature. The model can help in identifying patients at high risk for bleeding complications and will help in developing further research and decision-making in terms of anticoagulation management. External validation is warranted to extrapolate this model in the clinical setting.

Impact of Altered Vena Cava Flow Rates on Right Atrium Flow Characteristics

The right atrium (RA) combines the superior (SVC) and inferior vena cava (IVC) flows. Treatments like extracorporeal membrane oxygenation (ECMO) and hemodialysis by catheter alter IVC/SVC flows. Here we assess how altered IVC/SVC flow contributions impact RA flow. Four healthy volunteers were imaged with CT, reconstructed and combined into a patient-averaged model. Large Eddy Simulations (LES) were performed for a range of IVC/SVC flow contributions (30-70% each, increments of 5%) and common flow metrics were recorded. Model sensitivity to reconstruction domain extent, constant/pulsatile inlets and hematocrit was also assessed. Consistent with literature, a single vortex occupied the central RA across all flowrates with a smaller counter-rotating vortex, not previously reported, in the auricle. Vena cava flow was highly helical. RA turbulent kinetic energy (TKE) (P=0.027) and time-averaged wall shear stress (WSS) (P<0.001) increased with SVC flow. WSS was lower in the auricle (2 Pa, P<0.001). WSS in the vena cava were equal at IVC/SVC =65/35%. The model was highly sensitive to the reconstruction domain with cropped geometries lacking helicity in the vena cavae, altering RA flow. RA flow was not significantly affected by constant inlets or hematocrit. The rotational flow conventionally described in the RA is confirmed however a new, smaller vortex was also recorded in the auricle. When IVC flow dominates, as is normal, TKE in the RA is reduced and WSS in the vena cavae equalize. Significant helicity exists in the vena cava, a result of distal geometry and this geometry appears crucial to accurately simulating RA flow.

Extracorporeal cardiopulmonary resuscitation in a woman with twin pregnancy

INTRODUCTION

Maternal cardiac arrest is a rare condition. Cardiopulmonary resuscitation (CPR) in pregnancy is different from that in other populations due to physiological changes in patients. Extracorporeal cardiopulmonary resuscitation (ECPR) is recommended in patients having cardiac arrest with potentially reversible etiologies. However, data regarding ECPR in pregnancy are limited.

CASE SUMMARY

A 24-year-old woman with a 33-week twin pregnancy developed witnessed cardiac arrest in an antenatal clinic. She underwent perimortem cesarean delivery (PMCD) and ECPR, but uterine atony with massive bleeding occurred. Emergency hysterectomy and massive blood transfusion were performed in the emergency department and the patient was transferred to the intensive care unit after hemodynamics was stable.

CONCLUSION

Cardiac arrest in pregnancy is a complex condition. Several aspects of management have not been evaluated. Prospective studies for improving the outcomes are needed.

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 Transfusion Threshold in Patients Receiving Extracorporeal Membrane Oxygenation Support for Cardiac and Respiratory Failure-A Systematic Review and Meta-Analysis

OBJECTIVE

To review studies that have evaluated the effects of liberal or restrictive red cell transfusion thresholds on clinical outcomes in patients requiring extracorporeal membrane oxygenation (ECMO) support for cardiac or respiratory failure.

DESIGN

A systematic review and meta-analysis.

SETTING AND PARTICIPANTS

The study comprised 1,070 patients from observational studies and randomized controlled trials analyzing transfusion policies in venoarterial (VA) and venovenous (VV) ECMO adult populations.

MEASUREMENTS AND MAIN RESULTS

Eligible studies were identified by searching the Cochrane Central Register of Controlled Trials, Medline, and EMBASE until March 4, 2020, using a combination of subject headings and text words. Risk of bias assessment was performed to assess study quality according to the ROBINS-I tool and the case series studies appraisal checklist. There was high risk of bias in the studies analyzed, and none had methodologic adequacy. Three studies analyzed VA ECMO and VV ECMO patients separately. Five datasets were related exclusively or mostly to VA ECMO. Four were retrospective analyses, and one was conducted as a prospective observational study; the median transfusion threshold reported was 8 g/dL, with a mean mortality of 52%. Eight datasets were related either exclusively or mostly to VV ECMO. Six were retrospective and two were prospective observational studies; the median transfusion threshold was 8 g/dL, and the mean mortality rate was 33%.

CONCLUSIONS

The present study did not resolve uncertainty as to transfusion management in ECMO, although several studies (most of them in VV ECMO) demonstrated that a restrictive threshold has acceptable outcomes in single-center cohorts.

Impact of massive blood transfusion during adult extracorporeal membrane oxygenation support on long-term outcomes: a nationwide cohort study in Taiwan

OBJECTIVES

Bleeding is a common problem during adult extracorporeal membranes oxygenation (ECMO) support, requiring blood transfusion for correction of volume depletion and coagulopathy. The goal of this study is to investigate the long-term outcomes for adults under support of ECMO with massive blood transfusion (MBT).

DESIGN

Retrospective nationwide cohort study.

SETTING

Data were provided from Taiwan National Health Insurance Research Database (NHIRD).

PARTICIPANTS AND INTERVENTIONS

Totally 2757 adult patients were identified to receive MBT (red blood cell ≥10 units) during ECMO support from 2000 to 2013 via Taiwan NHIRD.

MAIN OUTCOME MEASURES

The outcomes included in-hospital major complications/mortality, all-cause mortality, cardiovascular death, newly onset end-stage renal disease and respiratory failure during the follow-up period.

RESULTS

Patients with MBT had higher in-hospital mortality (65.6% vs 52.1%; OR 1.74; 95% CI 1.53 to 1.98) and all-cause mortality during the follow-up (47.0% vs 35.8%; HR 1.46; 95% CI 1.25 to 1.71) than those without MBT. Not only higher incidences of post ECMO sepsis, respiratory failure and acute kidney injury, but also longer duration of ECMO support, ventilator use and intensive care unit stay were demonstrated in the MBT group. Moreover, a subdistribution hazard model presented higher cumulative of respiratory failure (19.8% vs 16.2%; subdistribution HR 1.36; 95% CI 1.07 to 1.73) for the MBT cohort. Positive dose-dependent relationship was found between the amount of transfused red blood cell product and in-hospital mortality. In the MBT subgroup analysis for the impact of transfused ratio (fresh frozen plasma/packed red blood cell) on in-hospital mortality, ratio ≥1.0 had higher mortality.

CONCLUSIONS

Patients with MBT during ECMO support had worse long-term outcomes than non-MBT population. The transfused amount of red blood cell had positive dose-dependent effect on in-hospital mortality.

Transfusion strategies in non-bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine

OBJECTIVE

To develop evidence-based clinical practice recommendations regarding transfusion practices in non-bleeding, critically ill adults.

DESIGN

A task force involving 13 international experts and three methodologists used the GRADE approach for guideline development.

METHODS

The task force identified four main topics: red blood cell transfusion thresholds, red blood cell transfusion avoidance strategies, platelet transfusion, and plasma transfusion. The panel developed structured guideline questions using population, intervention, comparison, and outcomes (PICO) format.

RESULTS

The task force generated 16 clinical practice recommendations (3 strong recommendations, 13 conditional recommendations), and identified five PICOs with insufficient evidence to make any recommendation.

CONCLUSIONS

This clinical practice guideline provides evidence-based recommendations and identifies areas where further research is needed regarding transfusion practices and transfusion avoidance in non-bleeding, critically ill adults.

Hemoglobin trigger and approach to red blood cell transfusions during veno-venous extracorporeal membrane oxygenation: the international TRAIN-ECMO survey

INTRODUCTION

Optimal red blood cell transfusion practice during veno-venous extracorporeal membrane oxygenation (VV ECMO) is still under debate. This survey aimed to assess the Hb trigger (also comparing with other critically ill patients) and major physiologic determinants considered for transfusions during veno-venous extracorporeal membrane oxygenation.

METHODS

Voluntary Web-based survey, endorsed by the European Society of Intensive Care Medicine, conducted among VV ECMO pratictioners worldwide.

RESULTS

A total of 447 respondents worldwide answered the questionnaire: 277 (61.9%) from Europe, 99 (22.1%) from North America, 36 (8.2%) from Asia and Oceania, and 35 (7.8%) from Central and South America. Among the respondents, 59.2% managed less than 12 venous extracorporeal membrane oxygenation runs/year, 19.4% between 12 and 24 runs/year, and 21.4% more than 24 runs/year. Of the respondents, 54.4% do not use a predefined Hb trigger in veno-venous extracorporeal membrane oxygenation, and, while the rate of adoption of a defined trigger varied worldwide, the effective value of Hb did not differ significantly among macro-regions. In patients on veno-venous extracorporeal membrane oxygenation, the Hb trigger to initiate red blood cell transfusion, was higher than in other critically ill patients: 9.1 ± 1.8 g/dL versus 8.3 ± 1.7 g/dL, p < 0.01. The Hb trigger was lower in centers with more than 24 venous extracorporeal membrane oxygenation runs/year (8.4 mg/dL (95% CI: 7.7-8.9)); (8.9 mg/dL (95% CI: 8.2-9.7)) in centers with between 12 and 24 venous extracorporeal membrane oxygenation runs/year; and (9.6 mg/dL (95% CI: 9.1-10.0)) in centers with fewer than 12 venous extracorporeal membrane oxygenation runs/year (p < 0.01). Several and variable adjunctive parameters are considered in cases of uncertainty for transfusion: the principal are hemodynamic status, SvO2, lactates, and fluid balance.

CONCLUSION

Although the use of a predefined Hb trigger is still under-adopted among centers with low or median extracorporeal membrane oxygenation case volume, the majority of respondents use a higher Hb trigger for veno-venous extracorporeal membrane oxygenation patients compared with other critically ill patients. Higher volume centers tolerate lower Hb levels.

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

Objectives:

Restrictive transfusion policies have been adopted in critical care, although these have not included patients receiving extracorporeal membrane oxygenation. We aimed to assess survival outcomes, adverse events related to RBC transfusion, and cost implications following a change from a “liberal” to a “restrictive” RBC transfusion practice in patients receiving extracorporeal membrane oxygenation.

Design:

Retrospective observational study.

Setting:

Single high-volume tertiary critical care department at a university hospital.

Patients:

Patients 16 years old or greater receiving venovenous extracorporeal membrane oxygenation between 2011 and 2017 for more than 24 hours.

Interventions:

None.

Measurements and Main Results:

Clinical diagnoses, complications, outcomes, median hemoglobin, and hematocrit levels were obtained from patients’ electronic records. All laboratory results for hemoglobin and hematocrit were included. RBC transfusions were obtained from prescription charts. We included 402 patients: 99 during a “liberal” transfusion practice (2011–2014)—when the target hemoglobin level was greater than 100 g/L; and 303 treated during a “restrictive” transfusion practice (2014–2017) when the target hemoglobin level was greater than 80 g/L. We found that survival outcomes did not change following the implementation of a “restrictive” transfusion policy. There was also a decrease in the extracorporeal blood flow rates with restrictive transfusion of 0.5 L/min. Nonsurvivors of venovenous extracorporeal membrane oxygenation had higher usage of RBC units following a change in transfusion practice. The restrictive strategy allowed a cost saving of £454 per patient.

Conclusions:

These results suggest that the adoption of a more restrictive approach to RBC transfusion during venovenous extracorporeal membrane oxygenation is more cost-effective and associated with similar survival outcomes, than when compared with a more liberal approach.