Trends in U.S. Extracorporeal Membrane Oxygenation Use and Outcomes: 2002-2012

Prognostic Significance of Driving Pressure for Initiation and Maintenance of ECMO in Patients with Severe ARDS: A Systematic Review and Meta-analysis

Introduction

In life-threatening conditions like severe acute respiratory distress syndrome (ARDS), rescue interventions like extracorporeal membrane oxygenation (ECMO) should be initiated urgently to resolve an otherwise potentially adverse clinical outcome. Driving pressure (DP) is an independent prognosticator of the survival of ARDS during mechanical ventilation. We conducted this review with the objective to identify the optimal DP for initiating ECMO in severe ARDS and to study the change in DP during ECMO strategy in survivors and non-survivors.

Materials and methods

A systematic search of EMBASE, PubMed, Cochrane Library, and SCOPUS databases was conducted from their inception to January 2024. Two investigators independently carried out the processes of literature search, study selection, data extraction, and quality assessment. The analysis was conducted using comprehensive meta-analysis software (CMA).

Results

For meta-analysis, six studies comprising 668 patients were included. In survivors, the DP at ECMO initiation was lower (mean DP = 14.56 cm H2O, 95% CI: [11.060-18.060]) than non-survivors (mean DP = 17.77 cm H2O, 95% CI: [12.935-22.607]). During ECMO, the survivors had lower DP (mean DP = 11.63 cm H2O, 95% CI: [10.070-13.195]) than non-survivors (mean DP = 14.67 cm H2O, 95% CI: [12.810-15.831]).

Conclusion

The optimum DP to initiate ECMO in severe ARDS patients on MV is 15 cm H2O. Extracorporeal membrane oxygenation reduces the intensity of MV, as reflected by a reduction in DP in both survivors and non-survivors during the ECMO by 3 cm H2O. The DP ≤ 12 cm H2O during ECMO strategy is a predictor of survival, and DP persisting ≥ 15 cm H2O on ECMO prompts the search for strategies to reduce DP.

Trial Registration

PROSPERO CRD42022327846.

How to cite this article

Todur P, Nileshwar A, Chaudhuri S, Nagendra D, Shanbhag V, Vennila J. Prognostic Significance of Driving Pressure for Initiation and Maintenance of ECMO in Patients with Severe ARDS: A Systematic Review and Meta-analysis. Indian J Crit Care Med 2025;29(2):177-185.

Acute Vascular Complications of VA-ECMO in COVID-19 Patients. Does COVID-19 Affect the Outcome?

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) through the femoral artery and vein can lead to significant vascular complications. We retrospectively studied the acute vascular complications of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) in COVID-19 patients compared to non-COVID patients during the period from January 2020 to July 2023.

RESULTS

Seventy-eight patients underwent VA-ECMO for various indications from January 2020 to July 2023. The studied patients had a mean age of 59.6 ± 6.9 years for non-COVID patients (38 patients), and 62.2 ± 7.6 years for COVID patients (40 patients), with a P = 0.268. In non-COVID patients, The baseline characteristics were similar in both groups. The primary indications for ECMO were cardiac diseases, followed by respiratory failure (78.9% vs 10.5%). Conversely, in COVID patients, respiratory failure due to COVID-19 infection was the main indication (45% vs 40%). The overall incidence of general complications, including cerebrovascular stroke, acute kidney injury, intracardiac thrombi, and wound infection, was comparable in both groups (31.6% vs 45%). The overall incidence of vascular complications in both groups was 33.3%. Ipsilateral acute lower limb ischemia occurred in 5.3% vs 10% of non-COVID and COVID patients, respectively. Thrombosis of the distal perfusion catheter (DPC) occurred in 10.5% vs 15%, respectively.

CONCLUSION

During the COVID-19 pandemic, an increasing number of patients required VA-ECMO due to associated respiratory failure. Patients undergoing VA-ECMO are at high risk of developing various vascular complications. COVID-19 significantly increases the risk of acute limb ischemia and distal perfusion catheter thrombosis in both upper and lower limbs. However, other VA-ECMO-related vascular complications are comparable between COVID-19 and non-COVID patients.

Clinical Use of Bedside Portable Ultra-Low-Field Brain Magnetic Resonance Imaging in Patients on Extracorporeal Membrane Oxygenation: Results From the Multicenter SAFE MRI ECMO Study

BACKGROUND

Early detection of acute brain injury (ABI) at the bedside is critical in improving survival for patients with extracorporeal membrane oxygenation (ECMO) support. We aimed to examine the safety of ultra-low-field (ULF; 0.064-T) portable magnetic resonance imaging (pMRI) in patients undergoing ECMO and to investigate the ABI frequency and types with ULF-pMRI.

METHODS

This was a multicenter prospective observational study (SAFE MRI ECMO study [Assessing the Safety and Feasibility of Bedside Portable Low-Field Brain Magnetic Resonance Imaging in Patients on ECMO]; NCT05469139) from 2 tertiary centers (Johns Hopkins, Baltimore, MD and University of Texas-Houston) with specially trained intensive care units. Primary outcomes were safety of ULF-pMRI during ECMO support, defined as completion of ULF-pMRI without significant adverse events.

RESULTS

Of 53 eligible patients, 3 were not scanned because of a large head size that did not fit within the head coil. ULF-pMRI was performed in 50 patients (median age, 58 years; 52% male), with 34 patients (68%) on venoarterial ECMO and 16 patients (32%) on venovenous ECMO. Of 34 patients on venoarterial ECMO, 11 (22%) were centrally cannulated and 23 (46%) were peripherally cannulated. In venovenous ECMO, 9 (18%) had single-lumen cannulation and 7 (14%) had double-lumen cannulation. Of 50 patients, adverse events occurred in 3 patients (6%), with 2 minor adverse events (ECMO suction event; transient low ECMO flow) and one serious adverse event (intra-aortic balloon pump malfunction attributable to electrocardiographic artifacts). All images demonstrated discernible intracranial pathologies with good quality. ABI was observed in 22 patients (44%). Ischemic stroke (36%) was the most common type of ABI, followed by intracranial hemorrhage (6%) and hypoxic-ischemic brain injury (4%). Of 18 patients (36%) with both ULF-pMRI and head computed tomography within 24 hours, ABI was observed in 9 patients with a total of 10 events (8 ischemic, 2 hemorrhagic events). Of the 8 ischemic events, pMRI observed all 8, and head computed tomography observed only 4 events. For intracranial hemorrhage, pMRI observed only 1 of them, and head computed tomography observed both (2 events).

CONCLUSIONS

Our study demonstrates that ULF-pMRI can be performed in patients on ECMO across different ECMO cannulation strategies in specially trained intensive care units. The incidence of ABI was high, seen in 44% of ULF-pMRI studies. ULF-pMRI imaging appears to be more sensitive to ABI, particularly ischemic stroke, compared with head computed tomography.

A Guide to Contrast-Enhanced Computed Tomography in Adult Patients Supported With Extracorporeal Membrane Oxygenation

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) fundamentally alters patient physiology and blood flow relevant to contrast delivery for computed tomography (CT) imaging. Here, we present a comprehensive guide to contrast-enhanced CT scanning in adult ECMO patients, addressing common questions related to contrast delivery via the ECMO circuit, and modifications to ECMO settings and scanning techniques, to avoid non-diagnostic CT scans. The approach is described in detail for patients supported on VA ECMO, with the return cannula sited in the femoral artery. Lesser modifications required for veno-venous ECMO (VV ECMO) are included in the supplemental material. Establishing a common understanding between the intensive care clinician, the CT radiographer, and the radiologist, concerning the patient's blood-flow-physiology, is the overarching goal. Our stepwise approach facilitates clear communication around modifications to the ECMO pump settings, contrast route and rate, as well as the scanning technique, for each individual scenario.

Post-cardiotomy extracorporeal life support: A cohort of cannulation in the general ward

OBJECTIVES

Post-cardiotomy extracorporeal life support (ECLS) cannulation might occur in a general post-operative ward due to emergent conditions. Its characteristics have been poorly reported and investigated This study investigates the characteristics and outcomes of adult patients receiving ECLS cannulation in a general post-operative cardiac ward.

METHODS

The Post-cardiotomy Extracorporeal Life Support (PELS) is a retrospective (2000-2020), multicenter (34 centers), observational study including adult patients who required ECLS for post-cardiotomy shock. This PELS sub-analysis analyzed patients´ characteristics, in-hospital outcomes, and long-term survival in patients cannulated for veno-arterial ECLS in the general ward, and further compared in-hospital survivors and non-survivors.

RESULTS

The PELS study included 2058 patients of whom 39 (1.9%) were cannulated in the general ward. Most patients underwent isolated coronary bypass grafting (CABG, n = 15, 38.5%) or isolated non-CABG operations (n = 20, 51.3%). The main indications to initiate ECLS included cardiac arrest (n = 17, 44.7%) and cardiogenic shock (n = 14, 35.9%). ECLS cannulation occurred after a median time of 4 (2-7) days post-operatively. Most patients' courses were complicated by acute kidney injury (n = 23, 59%), arrhythmias (n = 19, 48.7%), and postoperative bleeding (n = 20, 51.3%). In-hospital mortality was 84.6% (n = 33) with persistent heart failure (n = 11, 28.2%) as the most common cause of death. No peculiar differences were observed between in-hospital survivors and nonsurvivors.

CONCLUSIONS

This study demonstrates that ECLS cannulation due to post-cardiotomy emergent adverse events in the general ward is rare, mainly occurring in preoperative low-risk patients and after a postoperative cardiac arrest. High complication rates and low in-hospital survival require further investigations to identify patients at risk for such a complication, optimize resources, enhance intervention, and improve outcomes.

Characteristics and Outcomes of Prolonged Venoarterial Extracorporeal Membrane Oxygenation After Cardiac Surgery: The Post-Cardiotomy Extracorporeal Life Support (PELS-1) Cohort Study

OBJECTIVES

Most post-cardiotomy (PC) extracorporeal membrane oxygenation (ECMO) runs last less than 7 days. Studies on the outcomes of longer runs have provided conflicting results. This study investigates patient characteristics and short- and long-term outcomes in relation to PC ECMO duration, with a focus on prolonged (> 7 d) ECMO.

DESIGN

Retrospective observational cohort study.

SETTING

Thirty-four centers from 16 countries between January 2000 and December 2020.

PATIENTS

Adults requiring post PC ECMO between 2000 and 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Characteristics, in-hospital, and post-discharge outcomes were compared among patients categorized by ECMO duration. Survivors and nonsurvivors were compared in the subgroup of patients with ECMO duration greater than 7 days. The primary outcome was in-hospital mortality. Two thousand twenty-one patients were included who required PC ECMO for 0-3 days ( n = 649 [32.1%]), 4-7 days ( n = 776 [38.3%]), 8-10 days ( n = 263 [13.0%]), and greater than 10 days ( n = 333 [16.5%]). There were no major differences in the investigated preoperative and procedural characteristics among ECMO duration groups. However, the longer ECMO duration category was associated with multiple complications including bleeding, acute kidney injury, arrhythmias, and sepsis. Hospital mortality followed a U-shape curve, with lowest mortality in patients with ECMO duration of 4-7 days ( n = 394, 50.8%) and highest in patients with greater than 10 days ECMO support ( n = 242, 72.7%). There was no significant difference in post-discharge survival between ECMO duration groups. In patients with ECMO duration greater than 7 days, age, comorbidities, valvular diseases, and complex procedures were associated with nonsurvival.

CONCLUSIONS

Nearly 30% of PC ECMO patients were supported for greater than 7 days. In-hospital mortality increased after 7 days of support, especially in patients undergoing valvular and complex surgery, or who had complications, although the long-term post-discharge prognosis was comparable to PC ECMO patients with shorter support duration.

Ultra-Low-Field Portable MRI and Extracorporeal Membrane Oxygenation: Preclinical Safety Testing

CONTEXT

Conventional MRI is incompatible with extracorporeal membrane oxygenation (ECMO) cannulas and pumps. Ultra-low-field portable MRI (ULF-pMRI) with 0.064 Tesla may provide a solution, but its safety and compatibility is unknown.

HYPOTHESIS

ULF-pMRI does not cause significant displacement and heating of ECMO cannulas and does not affect ECMO pump function.

METHODS AND MODELS

ECMO cannulas in various sizes were tested ex vivo using phantom models to assess displacement force and heating according to the American Society for Testing and Materials criteria. ECMO pump function was assessed by pump flow and power consumption. In vivo studies involved five female domestic pigs (20-42 kg) undergoing different ECMO configurations (peripheral and central cannulation) and types of cannulas with an imaging protocol consisting of T2-weighted, T1-weighted, FLuid-Attenuated Inversion Recovery, and diffusion-weighted imaging sequences.

RESULTS

Phantom models demonstrated that ECMO cannulas, both single lumen with various sizes (15-24-Fr) and double lumen cannula, had average displacement force less than gravitational force within 5 gauss safety line of ULF-pMRI and temperature changes less than 1°C over 15 minutes of scanning and ECMO pump maintained stable flow and power consumption immediately outside of the 5 gauss line. All pig models showed no visible motion due to displacement force or heating of the cannulas. ECMO flow and the animals' hemodynamic status maintained stability, with no changes greater than 10%, respectively.

INTERPRETATION AND CONCLUSIONS

ULF-pMRI is safe and feasible for use with standard ECMO configurations, supporting its clinical application as a neuroimaging modality in ECMO patients.

Challenges in determining death by neurologic criteria in extracorporeal membrane oxygenation - A single center experience

INTRODUCTION

Apnea test (AT) in patients on extracorporeal membrane oxygenation (ECMO) support is challenging, leading to variation in determining death by neurologic criteria (DNC). We aim to describe the diagnostic criteria and barriers for DNC in adults on ECMO in a tertiary care center.

METHODS

A retrospective review of a prospective observational standardized neuromonitoring study was conducted in adult VA- and VV-ECMO patients at a tertiary center from June 2016 to March 2022. Brain death was defined according to the 2010 American Academy of Neurology guidelines and following the 2020 World Brain Death Project recommendations for performing AT in ECMO patients.

RESULTS

Eight (2.7%) ECMO patients (median age = 44 years, 75% male, 50% VA-ECMO) met criteria for DNC, six (75%) of whom were determined with AT. In the other two patients who did not undergo AT due to safety concerns, ancillary tests (transcranial doppler and electroencephalography) were consistent with DNC. An additional seven (2.3%) patients (median age = 55 years, 71% male, 86% VA-ECMO) were noted to have absent brainstem reflexes but failed to complete determination of DNC as they underwent withdrawal of life-sustaining treatment (WLST) before a full evaluation was completed. In these patients, AT was never performed, and ancillary tests were inconsistent with either neurological exam findings and/or neuroimaging supporting DNC, or with each other.

CONCLUSION

AT was used safely and successfully in 6 of the 8 ECMO patients diagnosed with DNC and was always consistent with the neurological exam and imaging findings, as opposed to ancillary tests alone.

Machine learning based predictive modeling of readmissions following extracorporeal membrane oxygenation hospitalizations

Background

Despite increasing utilization and survival benefit over the last decade, extracorporeal membrane oxygenation (ECMO) remains resource-intensive with significant complications and rehospitalization risk. We thus utilized machine learning (ML) to develop prediction models for 90-day nonelective readmission following ECMO.

Methods

All adult patients receiving ECMO who survived index hospitalization were tabulated from the 2016-2020 Nationwide Readmissions Database. Extreme Gradient Boosting (XGBoost) models were developed to identify features associated with readmission following ECMO. Area under the receiver operating characteristic (AUROC), mean Average Precision (mAP), and the Brier score were calculated to estimate model performance relative to logistic regression (LR). Shapley Additive Explanation summary (SHAP) plots evaluated the relative impact of each factor on the model. An additional sensitivity analysis solely included patient comorbidities and indication for ECMO as potential model covariates.

Results

Of ∼22,947 patients, 4495 (19.6 %) were readmitted nonelectively within 90 days. The XGBoost model exhibited superior discrimination (AUROC 0.64 vs 0.49), classification accuracy (mAP 0.30 vs 0.20) and calibration (Brier score 0.154 vs 0.165, all P < 0.001) in predicting readmission compared to LR. SHAP plots identified duration of index hospitalization, undergoing heart/lung transplantation, and Medicare insurance to be associated with increased odds of readmission. Upon sub-analysis, XGBoost demonstrated superior disclination compared to LR (AUROC 0.61 vs 0.60, P < 0.05). Chronic liver disease and frailty were linked with increased odds of nonelective readmission.

Conclusions

ML outperformed LR in predicting readmission following ECMO. Future work is needed to identify other factors linked with readmission and further optimize post-ECMO care among this cohort.

Comparing Outcomes of Post-Cardiotomy Cardiogenic Shock Patients: On-Site Cannulation vs. Retrieval for V-A ECMO Support

Background: Post-cardiotomy cardiogenic shock (PCCS) remains a life-threatening complication after cardiac surgery. Extracorporeal membrane oxygenation (ECMO) represents the mainstay of mechanical circulatory support for PCCS; however, its availability is limited to larger experienced centers, leading to a mismatch between centers performing cardiac surgery and hospitals offering ECMO management beyond cannulation. We sought to evaluate the outcomes and complications of PCCS patients requiring veno-arterial (V-A) ECMO cannulated at our hospital compared to those cannulated at referral hospitals. Methods: A retrospective analysis of PCCS patients requiring V-A ECMO was conducted between October 2014 to December 2022. Results: A total of 121 PCCS patients required V-A ECMO support, of which 62 (51%) patients were cannulated at the referring institutions and retrieved (retrieved group), and 59 (49%) were cannulated at our hospital (on-site group). The baseline demographics and pre-ECMO variables were similar between groups, except retrieved patients had higher lactic acid levels (retrieved group: 8.5 mmol/L ± 5.8 vs. on-site group: 6.6 ± 5; p = 0.04). Coronary artery bypass graft was the most common surgical intervention (51% in the retrieved group vs. 47% in the on-site group). There was no difference in survival-to-discharge rates between the groups (45% in the retrieved group vs. 51% in the on-site group; p = 0.53) or in the rate of patient-related complications. Conclusions: PCCS patients retrieved on V-A ECMO can achieve similar outcomes as those cannulated at experienced centers. An established network in a hub-and-spoke model is critical for the PCCS patients managed at hospitals without ECMO abilities to improve outcomes.

Novel tubing connectors reduce ECMO circuit thrombosis

BACKGROUND

Thrombosis within extracorporeal membrane oxygenation (ECMO) circuits is a common complication that dominates clinical management of patients receiving mechanical circulatory support. Prior studies have identified that over 80% of circuit thrombosis can be attributed to tubing-connector junctions.

METHODS

A novel connector was designed that reduces local regions of flow stagnation at the tubing-connector junction to eliminate a primary source of ECMO circuit thrombi. To compare clotting between the novel connectors and the traditional connectors, both in vitro loops and an in vivo caprine model of long-term (48 h) ECMO were used to generate tubing-connector junction clots.

RESULTS

In vitro, the traditional connectors uniformly (9/9) formed large thrombi, while novel connectors formed a small thrombus in only one of nine (p < 0.0001). In the long-term goat ECMO circuits, the traditional connectors exhibited more thrombi (p < 0.04), and these thrombi were more likely to protrude into the lumen of the tubing (p < 0.001).

CONCLUSION

Both in vitro and in vivo validation experiments successfully recreated circuit thrombosis and demonstrate that the adoption of novel connectors can reduce the burden of circuit thrombosis.

Effects of levosimendan on the outcome of veno-arterial extracorporeal membrane oxygenation: a systematic review and meta-analysis

OBJECTIVES

For patients with severe cardiopulmonary failure, such as cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is primarily utilized to preserve their life by providing continuous extracorporeal respiration and circulation. However, because of the complexity of patients' underlying diseases and serious complications, successful weaning from ECMO is often difficult. At present, there have been limited studies on ECMO weaning strategies, so the principal purpose of this meta-analysis is to examine how levosimendan contributes to the weaning of extracorporeal membrane oxygenation.

METHODS

The Cochrane Library, Embase, Web of Science, and PubMed were browsed for all potentially related research about clinical benefits of levosimendan in weaning patients receiving VA-ECMO and included 15 of them. The main outcome is success of weaning from extracorporeal membrane oxygenation, with the secondary outcomes of 1-month mortality (28 or 30 days), ECMO duration, hospital or intensive care unit (ICU) length of stay, and use of vasoactive drugs.

RESULTS

1772 patients altogether from 15 publications were incorporated in our meta-analysis. We used fixed and random-effect models to combine odds ratio (OR) and 95% confidence interval (CI) for dichotomous outcomes and standardized mean difference (SMD) for continuous outcomes. The weaning success rate in the levosimendan group was considerably higher in contrast to the comparison (OR = 2.78, 95% CI 1.80-4.30; P < 0.00001; I2 = 65%), and subgroup analysis showed that there was less heterogeneity in patients after cardiac surgery (OR = 2.06, 95% CI, 1.35-3.12; P = 0.0007; I2 = 17%). In addition, the effect of levosimendan on improving weaning success rate was statistically significant only at 0.2 mcg/kg/min (OR = 2.45, 95% CI, 1.11-5.40; P = 0.03; I2 = 38%). At the same time, the 28-day or 30-day proportion of deaths in the sample receiving levosimendan also decreased (OR = 0.47, 95% CI, 0.28-0.79; P = 0.004; I2 = 73%), and the difference was statistically significant. In terms of secondary outcomes, we found that individuals undergoing levosimendan treatment had a longer duration of VA-ECMO support.

CONCLUSIONS

In patients receiving VA-ECMO, levosimendan treatment considerably raised the weaning success rate and helped lower mortality. Since most of the evidence comes from retrospective studies, more randomized multicenter trials are required to verify the conclusion.

Impact of extracorporeal membrane oxygenation-related complications on in-hospital mortality

INTRODUCTION

Although extracorporeal membrane oxygenation (ECMO) is a well-established treatment for supporting severe cardiopulmonary failure, the morbidity and mortality of patients requiring ECMO support remain high. Evaluating and correcting potential risk factors associated with any ECMO-related complications may improve care and decrease mortality. This study aimed to assess the predictors of ECMO-related vascular and cerebrovascular complications among adult patients and to test the hypothesis that ECMO-related complications are associated with higher in-hospital mortality rates.

METHODS

This single-center, retrospective study included 856 ECMO runs administered via cannulation of the femoral vessels of 769 patients: venoarterial (VA) ECMO (n = 709, 82.8%) and venovenous (VV) ECMO (n = 147, 17.2%). The study outcomes included the occurrence of ECMO-related vascular and cerebrovascular complications and in-hospital death. The association of ECMO-related complications with the risk of in-hospital death was analyzed.

RESULTS

The incidences of ECMO-related vascular and cerebrovascular complications were 20.2% and 13.6%, respectively. The overall in-hospital mortality rate was 48.7%: 52.8% among VA ECMO runs and 29.3% among VV ECMO runs. Multivariable analysis indicated that age (P < 0.01), cardiopulmonary cerebral resuscitation (P < 0.01), continuous renal replacement therapy (P < 0.01), and initial platelet count [<50×103/μL (P = 0.02) and 50-100(×103)/μL (P < 0.01)] were associated with an increased risk of in-hospital death. ECMO-related vascular and cerebrovascular complications were not independently associated with higher in-hospital mortality rates for VA or VV ECMO runs.

CONCLUSION

ECMO-related vascular and cerebrovascular complications were not associated with an increased risk of in-hospital death among adult patients.

Clinical Use of Bedside Portable Low-field Brain Magnetic Resonance Imaging in Patients on ECMO: The Results from Multicenter SAFE MRI ECMO Study

Purpose

Early detection of acute brain injury (ABI) is critical for improving survival for patients with extracorporeal membrane oxygenation (ECMO) support. We aimed to evaluate the safety of ultra-low-field portable MRI (ULF-pMRI) and the frequency and types of ABI observed during ECMO support.

Methods

We conducted a multicenter prospective observational study (NCT05469139) at two academic tertiary centers (August 2022-November 2023). Primary outcomes were safety and validation of ULF-pMRI in ECMO, defined as exam completion without adverse events (AEs); secondary outcomes were ABI frequency and type.

Results

ULF-pMRI was performed in 50 patients with 34 (68%) on venoarterial (VA)-ECMO (11 central; 23 peripheral) and 16 (32%) with venovenous (VV)-ECMO (9 single lumen; 7 double lumen). All patients were imaged successfully with ULF-pMRI, demonstrating discernible intracranial pathologies with good quality. AEs occurred in 3 (6%) patients (2 minor; 1 serious) without causing significant clinical issues.ABI was observed in ULF-pMRI scans for 22 patients (44%): ischemic stroke (36%), intracranial hemorrhage (6%), and hypoxic-ischemic brain injury (4%). Of 18 patients with both ULF-pMRI and head CT (HCT) within 24 hours, ABI was observed in 9 patients with 10 events: 8 ischemic (8 observed on ULF-oMRI, 4 on HCT) and 2 hemorrhagic (1 observed on ULF-pMRI, 2 on HCT).

Conclusions

ULF-pMRI was shown to be safe and valid in ECMO patients across different ECMO cannulation strategies. The incidence of ABI was high, and ULF-pMRI may more sensitive to ischemic ABI than HCT. ULF-pMRI may benefit both clinical care and future studies of ECMO-associated ABI.

Postcardiotomy Shock Syndrome: A Narrative Review of Perioperative Diagnosis and Management

Postcardiotomy shock (PCS) is generally described as the inability to separate from cardiopulmonary bypass due to ineffective cardiac output after cardiotomy, which is caused by a primary cardiac disorder, resulting in inadequate tissue perfusion. Postcardiotomy shock occurs in 0.5% to 1.5% of contemporary cardiac surgery cases, and is accompanied by an in-hospital mortality of approximately 67%. In the last 2 decades, the incidence of PCS has increased, likely due to the increased age and baseline morbidity of patients requiring cardiac surgery. In this narrative review, the authors discuss the epidemiology and pathophysiology of PCS, the rationale and evidence behind the initiation, continuation, escalation, and discontinuation of mechanical support devices in PCS, and the anesthetic implications.

New OPTN/UNOS data demonstrates higher than previously reported waitlist mortality for lung transplant candidates supported with ECMO

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) is not currently incorporated into US allocation models due to the historical lack of complete data in the national US registry which changed in 2016 to include ECMO at the time of waitlist removal and more granular timing and configuration data.

METHODS

We studied adult lung transplant candidates from May 1, 2016 to June 1, 2020 with data abstracted from multiple sources in the US Scientific Registry of Transplant Recipients. Waitlist analyses included cumulative incidence functions and Cox proportional hazards models considering ECMO as a time-dependent variable. Post-transplant analyses included Kaplan Meier, Cox proportional hazards models, and observed to expected survival ratios.

RESULTS

A total of 867 candidates were on ECMO prior to transplant; 247 were identified using new sources of data. Candidates on ECMO had a 23.9 increased adjusted likelihood of waitlist removal for being too sick or death, but only a 4.08 increased adjusted likelihood of transplant. Candidates bridged with ECMO who underwent lung transplant (N = 587) experienced an increased overall hazard of post-transplant mortality with veno-arterial and veno-venous configurations conferring hazard ratio (HR) = 1.67 (95% CI, 1.16, 2.40), HR = 1.45 (95% CI, 1.15, 1.82), respectively.

CONCLUSIONS

We identified an additional 28.5% of candidates bridged with ECMO prior to transplant using new data. This study of the newly identified full cohort of ECMO candidates demonstrates higher utilization of ECMO as well as an underestimation of waitlist mortality risk factors that should inform strategies to provide timely access to transplants for this population.

National Trends, Risk Factors, and Outcomes of Acute In-Hospital Stroke Following Lung Transplantation in the United States: Analysis of the United Network for Organ Sharing Registry

BACKGROUND

Lung transplantation (LTx) is the definitive treatment for end-stage lung failure. However, there have been no large, long-term studies on the impact of acute in-hospital stroke in this population.

RESEARCH QUESTION

What are the trends, risk factors, and outcomes of acute stroke in patients undergoing LTx in the United States?

STUDY DESIGN AND METHODS

We identified adult first-time isolated LTx recipients from the United Network for Organ Sharing database, which comprehensively captures every transplant in the United States, between May 2005 and December 2020. Stroke was defined as occurring at any time after LTx but prior to discharge. Multivariable logistic regression with stepwise feature elimination was used to identify risk factors for stroke. Freedom from death in patients with a stroke vs those without a stroke was evaluated with Kaplan-Meier analysis. Cox proportional hazards analysis was used to identify predictors of death at 24 months.

RESULTS

Of 28,564 patients (median age, 60 years; 60% male), 653 (2.3%) experienced an acute in-hospital stroke after LTx. Median follow-up was 1.2 (stroke) and 3.0 (non-stroke) years. Annual incidence of stroke increased (1.5% in 2005 to 2.4% in 2020; P for trend = .007), as did lung allocation score and utilization of post-LTx extracorporeal membrane oxygenation (P = .01 and P < .001, respectively). Compared with those without stroke, patients with stroke had lower survival at 1 month (84% vs 98%), 12 months (61% vs 88%), and 24 months (52% vs 80%) (log-rank test, P < .001 for all). In Cox analysis, acute stroke conferred a high hazard of mortality (hazard ratio, 3.01; 95% CI, 2.67-3.41). Post-LTx extracorporeal membrane oxygenation was the strongest risk factor for stroke (adjusted OR, 2.98; 95% CI, 2.19-4.06).

INTERPRETATION

Acute in-hospital stroke post-LTx has been increasing over time and is associated with markedly worse short- and long-term survival. As increasingly sicker patients undergo LTx as well as experience stroke, further research on stroke characteristics, prevention, and management strategies is warranted.

Intracranial hemorrhage in patients treated for SARS-CoV-2 with extracorporeal membrane oxygenation: A systematic review and meta-analysis

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is routinely used in patients with severe respiratory failure and has been increasingly needed during the COVID-19 pandemic. In patients treated with ECMO, significant intracranial hemorrhage (ICH) risk exists due to circuit characteristics, anticoagulation, and disease characteristics. ICH risk may be substantially higher in COVID-19 patients than patients treated with ECMO for other indications.

METHODS

We systematically reviewed current literature regarding ICH during ECMO treatment of COVID-19. We utilized Embase, MEDLINE, and Cochrane Library databases. Meta-analysis was performed for included comparative studies. Quality assessment was performed using MINORS criteria.

RESULTS

A total of 54 studies with 4000 ECMO patients were included, all retrospective. Risk of bias was increased via MINORS score primarily due to retrospective designs. ICH was more likely in COVID-19 patients (RR 1.72, 95% CI 1.23, 2.42). Mortality among COVID patients on ECMO with ICH was 64.0%, compared with 41% in patients without ICH (RR1.9, 95% 1.44, 2.51).

CONCLUSION

This study suggests increased hemorrhage rates in COVID-19 patients on ECMO compared to similar controls. Hemorrhage reduction strategies may include atypical anticoagulants, conservative anticoagulation strategies, or biotechnology advances in circuit design and surface coatings.

Bridging the gap: safety and outcomes of intensivist-led ECMO retrievals

Purpose

Most extracorporeal membrane oxygenation (ECMO) cannulations are performed by cardiothoracic surgeons (CTS). Due to an increase in utilization of ECMO and limited availability of CTS, there is a mismatch between ECMO demand and CTS accessibility for remote cannulations. We report our intensivist-led program's experience in remote ECMO cannulations, retrievals, complications, and outcomes.

Materials and methods

A prospective, single-center, observational study was performed on patients that required ECMO cannulation at the referring facilities and were transported to our institution between program initiation, on October 1, 2014 to September 30, 2022. Results were presented as mean ± SD, median (min - max) or number (%).

Results

Since program commencement, 305 patients were accepted for ECMO retrieval. Three hundred and three patients were placed on ECMO at the 47 referring hospitals among 5 states. In our study, 185 (61%) patients required veno-arterial ECMO and 115 (38%) were placed on veno-venous ECMO. Three patients (1%) were cannulated for veno-arteriovenous ECMO. Twenty patients were cannulated under cardio-pulmonary resuscitation. Most of the patients were transported by ambulance (79%), 14% by helicopter, and 7% by airplane. Six out of the 303 patients did not leave the referring facility. All patients that left the referring hospitals arrived safely to our institution. No major complications occurred in route.

Conclusion

Our study's findings indicate that non-CTS physicians can successfully cannulate and retrieve patients with a low complication profile.

Extracorporeal Membrane Oxygenation in Postcardiotomy Cardiogenic Shock

Postcardiotomy extracorporeal membrane oxygenation (PC-ECMO), the most frequent indication for ECMO in the United States, is increasingly used as the first-line mechanical circulatory support in patients who are refractory to conventional treatment. Despite increasing use of PC-ECMO, limited evidence is available regarding its safety, efficacy, and optimal timing for initiation and weaning. The decision to use PC-ECMO often is made in the absence of robust clinical data, leading to variability in patient selection, management, and outcomes across different institutions. This article summarizes current evidence on ECMO use in postcardiotomy cardiogenic shock and discusses its potential benefits, management, complications, and outcomes.

Disparities in Adult Patient Selection for Extracorporeal Membrane Oxygenation in the United States: A Population-Level Study

Rationale: Disparities in patient selection for advanced therapeutics in health care have been identified in multiple studies, but it is unclear if disparities exist in patient selection for extracorporeal membrane oxygenation (ECMO), a rapidly expanding critical care resource. Objectives: To determine if disparities exist in patient selection for ECMO based on sex, primary insurance, and median income of the patient's neighborhood. Methods: In a retrospective cohort study using the Nationwide Readmissions Database 2016-2019, we identified patients treated with mechanical ventilation (MV) and/or ECMO with billing codes. Patient sex, insurance, and income level for patients receiving ECMO were compared with the patients treated with MV only, and hierarchical logistic regression with the hospital as a random intercept was used to determine odds of receiving ECMO based on patient demographics. Results: We identified 2,170,752 MV hospitalizations with 18,725 cases of ECMO. Among patients treated with ECMO, 36.1% were female compared with 44.5% of patients treated with> MV only (adjusted odds ratio [aOR] for ECMO, 0.73; 95% confidence interval [CI], 0.70-0.75). Of patients treated with ECMO, 38.1% had private insurance compared with 17.4% of patients treated with MV only. Patients with Medicaid were less likely to receive ECMO than patients with private insurance (aOR, 0.55; 95% CI, 0.52-0.57). Patients treated with ECMO were more likely to live in the highest-income neighborhoods compared with patients treated with MV only (25.1% vs. 17.3%). Patients living in the lowest-income neighborhoods were less likely to receive ECMO than those living in the highest-income neighborhoods (aOR, 0.63; 95% CI, 0.60-0.67). Conclusions: Significant disparities exist in patient selection for ECMO. Female patients, patients with Medicaid, and patients living in the lowest-income neighborhoods are less likely to be treated with ECMO. Despite possible unmeasured confounding, these findings were robust to multiple sensitivity analyses. On the basis of previous work describing disparities in other areas of health care, we speculate that limited access in some neighborhoods, restrictive/biased interhospital transfer practices, differences in patient preferences, and implicit provider bias may contribute to the observed differences. Future studies with more granular data are needed to identify and modify drivers of observed disparities.

Patient and Management Variables Associated With Survival After Postcardiotomy Extracorporeal Membrane Oxygenation in Adults: The PELS-1 Multicenter Cohort Study

Background Extracorporeal membrane oxygenation (ECMO) has been increasingly used for postcardiotomy cardiogenic shock, but without a concomitant reduction in observed in-hospital mortality. Long-term outcomes are unknown. This study describes patients' characteristics, in-hospital outcome, and 10-year survival after postcardiotomy ECMO. Variables associated with in-hospital and postdischarge mortality are investigated and reported. Methods and Results The retrospective international multicenter observational PELS-1 (Postcardiotomy Extracorporeal Life Support) study includes data on adults requiring ECMO for postcardiotomy cardiogenic shock between 2000 and 2020 from 34 centers. Variables associated with mortality were estimated preoperatively, intraoperatively, during ECMO, and after the occurrence of any complications, and then analyzed at different time points during a patient's clinical course, through mixed Cox proportional hazards models containing fixed and random effects. Follow-up was established by institutional chart review or contacting patients. This analysis included 2058 patients (59% were men; median [interquartile range] age, 65.0 [55.0-72.0] years). In-hospital mortality was 60.5%. Independent variables associated with in-hospital mortality were age (hazard ratio [HR], 1.02 [95% CI, 1.01-1.02]) and preoperative cardiac arrest (HR, 1.41 [95% CI, 1.15-1.73]). In the subgroup of hospital survivors, the overall 1-, 2-, 5-, and 10-year survival rates were 89.5% (95% CI, 87.0%-92.0%), 85.4% (95% CI, 82.5%-88.3%), 76.4% (95% CI, 72.5%-80.5%), and 65.9% (95% CI, 60.3%-72.0%), respectively. Variables associated with postdischarge mortality included older age, atrial fibrillation, emergency surgery, type of surgery, postoperative acute kidney injury, and postoperative septic shock. Conclusions In adults, in-hospital mortality after postcardiotomy ECMO remains high; however, two-thirds of those who are discharged from hospital survive up to 10 years. Patient selection, intraoperative decisions, and ECMO management remain key variables associated with survival in this cohort. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03857217.

Impact of Nosocomial Infection on in-Hospital Mortality Rate in Adult Patients Under Venoarterial Extracorporeal Membrane Oxygenation After Cardiac Surgery

Objective

There was no consensus on the impact of nosocomial infection on In-hospital mortality rate in patients receiving ECMO. This study aimed to investigate the impact of nosocomial infection (NI) on In-hospital mortality rate in adult patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) after cardiac surgery.

Materials and Methods

This retrospective study included 503 adult patients who underwent VA-ECMO after cardiac surgery. The impact of time-dependent NIs on In-hospital mortality rate within 28 days of ECMO initiation was investigated using a Cox regression model. The cumulative incidence function for death was compared between patients with NIs and those without NIs using a competing risk model.

Results

Within 28 days after ECMO initiation, 206 (41.0%) patients developed NIs, and 220 (43.7%) patients died. The prevalence rates of NIs were 27.8% and 20.3% during and after ECMO therapy, respectively. The incidence rates of NIs during and after ECMO therapy were 49‰ and 25‰, respectively. Time-dependent NI was an independent risk factor for predicting death (hazard ratio = 1.05, 95% confidence interval = 1.00-1.11). The cumulative incidence of death in patients with NI was significantly higher than that in patients without NI at each time point within 28 days of ECMO initiation. (Z = 5.816, P = 0.0159).

Conclusion

NI was a common complication in adult patients who received VA-ECMO after cardiac surgery, and time-dependent NI was an independent risk factor for predicting mortality in these patients. Using a competing risk model, we confirmed that NIs increased the risk of In-hospital mortality rate in these patients.

Racial and ethnical discrepancy in hypoxemia detection in patients on extracorporeal membrane oxygenation

Objective

To determine whether there is racial/ethnical discrepancy between pulse oximetry (SpO2) and oxygen saturation (SaO2) in patients receiving extracorporeal membrane oxygenation (ECMO).

Methods

This was a retrospective observational study at a tertiary academic ECMO center with adults (>18 years) on venoarterial (VA) or venovenous (VV) ECMO. Datapoints were excluded if oxygen saturation ≤70% or SpO2-SaO2 pairs were not measured within 10 minutes. The primary outcome was the presence of a SpO2-SaO2 discrepancy between different races/ethnicities. Bland-Altman analyses and linear mixed-effects modeling, adjusting for prespecified covariates, were used to assess the SpO2-SaO2 discrepancy between races/ethnicities. Occult hypoxemia was defined as SaO2 <88% with a time-matched SpO2 ≥92%.

Results

Of 139 patients receiving VA-ECMO and 57 patients receiving VV-ECMO, we examined 16,252 SpO2-SaO2 pairs. The SpO2-SaO2 discrepancy was greater in VV-ECMO (1.4%) versus VA-ECMO (0.15%). In VA-ECMO, SpO2 overestimated SaO2 in Asian (0.2%), Black (0.94%), and Hispanic (0.03%) patients and underestimated SaO2 in White (-0.06%) and nonspecified race (-0.80%) patients. The proportion of SpO2-SaO2 measurements considered occult hypoxemia was 70% from Black compared to 27% from White patients (P < .0001). In VV-ECMO, SpO2 overestimated SaO2 in Asian (1.0%), Black (2.9%), Hispanic (1.1%), and White (0.50%) patients and underestimated SaO2 in nonspecified race patients (-0.53%). In linear mixed-effects modeling, SpO2 overestimated SaO2 by 0.19% in Black patients (95% confidence interval, 0.045%-0.33%, P = .023). The proportion of SpO2-SaO2 measurements considered occult hypoxemia was 66% from Black compared with 16% from White patients (P < .0001).

Conclusions

SpO2 overestimates SaO2 in Asian, Black, and Hispanic versus White patients, and this discrepancy was greater in VV-ECMO versus VA-ECMO, suggesting the need for physiological studies.

Veno-arterial extracorporeal membrane oxygenation for cardiogenic shock after acute myocardial infarction: Insights from a French nationwide database

BACKGROUND

We aimed to analyze the impact of timing of implantation (strategy-outcome relationship) and volume of procedures (volume-outcome relationship) on survival of veno-arterial extracorporeal membrane oxygenation (VA ECMO) for cardiogenic shock complicating acute myocardial infarction (AMI).

METHODS

We conducted an observational retrospective study through two propensity score-based analyses using a nationwide database between January 2013 and December 2019. We classified patients into early implantation (VA ECMO on the day of primary percutaneous coronary intervention [PCI]) and delayed implantation (VA ECMO beyond the day of PCI) groups. We classified patients into low- or high-volume groups based on the median hospital volume.

RESULTS

During the study period 649 VA ECMO were implanted across 20 French hospitals. Mean age was 57.1 ± 10.4 years, 80% were male. Overall, 90-day mortality was 64.3%. Patients in the early implantation group (n = 479, 73.8%) did not show a statistical difference in 90-day mortality than in the delayed group (n = 170, 26.2%) (HR: 1.18; 95% CI 0.94-1.48; p = 0.153). The mean number of VA ECMO implanted during the study period by low-volume centers was 21.3 ± 5.4 as compared to 43.6 ± 11.8 in high-volume centers. There was no significant difference in 90-day mortality between high-volume and low-volume centers (HR: 1.00; 95% CI: 0.82-1.23; p = 0.995).

CONCLUSIONS

In this real-world nationwide study, we did not find a significant association between early VA ECMO implantation as well as high-volume centers and lower mortality in AMI-related refractory cardiogenic shock.

A bridge-to-bridge approach to heart transplantation using extracorporeal membrane oxygenation and total artificial heart

BACKGROUND

This study aims to describe the outcomes after heart transplantation using a bridge-to-bridge strategy with a sequence of extracorporeal membrane oxygenation (ECMO) support followed by temporary total artificial heart implantation (TAH-t).

METHODS

A retrospective, multicenter analysis of 54 patients who underwent TAH-t implantation following an ECMO for cardiogenic shock was performed (ECMO-TAH-t group). A control group of 163 patients who underwent TAH-t implantation as a direct bridge to transplantation (TAH-t group) was used to assess this strategy's impact on outcomes.

RESULTS

Fifty-four patients, averaging 47 ± 13 year old, underwent implantation of a TAH-t after 5.3 ± 3.4 days of ECMO perfusion for cardiogenic shock. In the ECMO-TAH-t group, 20 patients (20/54%; 37%) died after TAH-t implantation and 57 patients (57/163%; 35%) died in the TAH-t group (Gray test; P = .49). The top 3 causes of death of patients on TAH-t support were multisystem organ failure (40%), sepsis (20%), and neurologic events (20%). Overall, 32 patients (32/54%; 59%) underwent heart transplantation in the ECMO-TAH-t group compared with 106 patients (106/163%, 65%) in the TAH-t group (P = .44). No significant difference in survival was observed at 6 months, 1 year, and 3 years after heart transplant (ECMO-TAH-t group: 94%, 87%, and 80% vs 87%, 83%, and 76% in the TAH-t group, respectively). Deterioration of liver function (bilirubin, aspartate transaminase, and alanine aminotransferase levels on TAH-t) was associated with increased mortality before heart transplant in both groups.

CONCLUSIONS

Sequential bridging from ECMO to TAH-t followed by heart transplantation is a viable option for a group of highly selected patients.

Prognostic Implication of Pre-Cannulation Cardiac Arrest in Patients Undergoing Extracorporeal Membrane Oxygenation for the Management of Cardiogenic Shock

BACKGROUND

The application of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in contemporary management of cardiogenic shock (CS) has dramatically increased. Despite increased utilization, few predictive models exist to estimate patient survival based on pre-ECMO characteristics. Furthermore, the prognostic implications of pre-ECMO cardiac arrest are not well defined.

METHODS

Utilizing an institutional VA-ECMO database, all consecutive patients undergoing VA-ECMO for the management of CS from January 1, 2014, to July 1, 2019, were identified. Survival to hospital discharge was analyzed based on cannulation indication in patients with and without pre-ECMO cardiac arrest. Patients who received extracorporeal cardiopulmonary resuscitation (eCPR) were analyzed separately.

RESULTS

Of the 214 patients identified, 110 did not suffer a cardiac arrest prior to cannulation (cohort 1), 57 patients had a cardiac arrest with sustained ROSC (cohort 2), and 47 were cannulated as a component of eCPR (cohort 3). Despite sustained ROSC (cohort 2), the presence of pre-ECMO cardiac arrest was associated with a significant reduction in survival to hospital discharge (22.8% vs. 55.5% in cohort 1; p < 0.001). Comparatively, survival to discharge was similar in patients undergoing eCPR (22.8% vs. 17.0%; p = 0.464). Finally, patients with a cardiac arrest were significantly more likely to have a neurological etiology death with VA-ECMO than patients supported prior to hemodynamic collapse (18.3% vs. 2.7%; p < 0.001). This result is seen in those with sustained ROSC (21.1% vs. 2.7%; p < 0.001) and those with eCPR (14.9% vs. 2.7%; p = 0.004).

CONCLUSION

In our cohort, pre-ECMO cardiac arrest carries a negative prognostic value across all indications and is associated with an increased prevalence of neurological-etiology death. This finding is true in patients with sustained ROSC as well as those resuscitated with eCPR. Cardiac arrest can inform survival probability with VA-ECMO as early implementation of VA-ECMO may mitigate adverse outcomes in patients at the highest risk of hemodynamic collapse.

Mechanical Thrombectomy for Ischemic Stroke Secondary to Large Vessel Occlusions in Patients on Extracorporeal Membrane Oxygenation

INTRODUCTION

The use of short-term mechanical circulatory support (MCS) devices and procedures for function- and life-sustaining therapy is becoming a routine practice at many centers. Concomitant with the increasing use of MCS is the increasing recognition of acute brain injuries, including acute ischemic stroke, which may be caused by a myriad of MCS-driven factors. The aim of this case series was to document our experience with mechanical thrombectomy (MT) for ischemic stroke in extracorporeal membrane oxygenation (ECMO) patients.

METHODS

We retrospectively reviewed a prospectively maintained database of patients undergoing endovascular thrombectomy for large vessel occlusion at our institution. We identified patients that were on ECMO and underwent thrombectomy. Baseline demographics and procedural and functional outcomes were collected.

RESULTS

Three patients on ECMO were identified to have a large vessel occlusion and underwent thrombectomy. Two patients had an internal carotid artery terminus occlusion and one had a basilar artery occlusion. An mTICI 3 recanalization was achieved in all patients without postoperative hemorrhagic complications. Two patients achieved a 3-month mRS of 1, while one had mRS 4.

CONCLUSION

Ischemic stroke can be associated with significant morbidity in MCS patients. We demonstrate that MT can be safely performed in this patient population with good outcomes.

Quantitative evaluation of hemodynamic parameters by echocardiography in patients with post-cardiotomy cardiac shock supported by extracorporeal membrane oxygenation

BACKGROUND

When drugs fail to reverse post-cardiotomy cardiac shock (PCS), extracorporeal membrane oxygenation (ECMO) is considered the most effective adjuvant strategy. Transthoracic echocardiography is a useful imaging modality for monitoring of cardiac hemodynamics. The aim of this study was to investigate the value of echocardiography for monitoring the left and right heart hemodynamics in PCS patients before, during, and after weaning from ECMO.

METHODS

Fifty-two patients were divided into successful weaning group (group A, n = 23) and non-successful weaning group (group B, n = 29). Hemodynamic parameters measured by echocardiography were collected before, during, and after ECMO. The intra-group changes and inter-group differences were retrospectively analyzed.

RESULTS

In group A, the central venous pressure (CVP), proximal right ventricular outflow tract (RVOT), tricuspid annular plane systolic excursion (TAPSE), velocity of tricuspid valve (TVDV), and systolic velocity of tricuspid annulus ([Formula: see text]) during ECMO were significantly lower than those before ECMO. After ECMO, left ventricular ejection fraction (LVEF), systolic velocity of mitral annulus ([Formula: see text]), and velocity-time integral of LV outflow tract (LVOT-VTI) were higher than pre-ECMO levels, and CVP, LVEF, [Formula: see text], LVOT-VTI, RVOT, TAPSE, TVDV and [Formula: see text] were higher than those during ECMO (all P < 0.05). In group B, compared to pre-ECMO, subjects exhibited decreased CVP, RVOT, TAPSE, TVDV and [Formula: see text] during ECMO. TAPSE, TVDV, and [Formula: see text] were continuously lower after ECMO, while CVP and RVOT increased after ECMO (all P < 0.05). After ECMO, LVEF, [Formula: see text], LVOT-VTI, TAPSE, TVDV and [Formula: see text] in group A were higher than those in group B (all P < 0.05). Inter-group comparison showed the LVEF and RV Tei indices of group A were significantly different than those of group B before, during, and after ECMO.

CONCLUSION

Quantitative assessment of both LV and RV by echocardiography is important for ECMO weaning. Patients with better LVEF and lower RV Tei index may have a better chance of successful weaning from ECMO.

Racial disparities in outcomes for extracorporeal membrane oxygenation in the United States

BACKGROUND

Racial disparities in extracorporeal membrane oxygenation (ECMO) outcomes in patients with a broad set of indications are not well documented.

METHODS

Adults requiring ECMO were identified in the 2016-2019 National Inpatient Sample. Patient and hospital characteristics, including mortality, clinical outcomes, and resource utilization were analyzed using multivariable regressions.

RESULTS

Of 43,190 adult ECMO patients, 67.8% were classified as White, 18.1% Black, and 10.4% Hispanic. Although mortality for Whites declined from 47.5 to 41.0% (P = 0.002), it remained steady for others. Compared to White, Asian/Pacific Islander (PI) race was linked to increased odds of mortalty (AOR = 1.4, 95% CI = 1.1-2.0). Black race was associated with increased odds of acute kidney injury (AOR = 1.4, 95%-CI: 1.2-1.7), while Hispanic race was linked to neurologic complications (AOR 21.6; 95% CI 1.2-2.3). Black and Hispanic race were also associated with increased incremental costs.

CONCLUSIONS

Race-based disparities in ECMO outcomes persist in the United States. Further work should aim to understand and mitigate the underlying reasons for such findings.

Arterial Carbon Dioxide and Acute Brain Injury in Venoarterial Extracorporeal Membrane Oxygenation

Acute brain injury (ABI) occurs frequently in patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO). We examined the association between peri-cannulation arterial carbon dioxide tension (PaCO 2 ) and ABI with granular blood gas data. We retrospectively analyzed adult patients who underwent VA-ECMO at a tertiary care center with standardized neuromonitoring. Pre- and post-cannulation PaCO 2 were defined as the mean of all PaCO 2 values in the 12 hours before and after cannulation, respectively. Peri-cannulation PaCO 2 drop (∆PaCO 2 ) equaled pre- minus post-cannulation PaCO 2 . ABI included intracranial hemorrhage (ICH), ischemic stroke, hypoxic-ischemic brain injury, cerebral edema, seizure, and brain death. Univariable logistic regression analysis was performed for the presence of ABI. Out of 129 VA-ECMO patients (median age = 60, 63% male), 43 (33%) patients experienced ABI. Patients had a median of 11 (interquartile range: 8-14) peri-cannulation PaCO 2 values. Comparing patients with and without ABI, pre-cannulation (39 vs. 42 mm Hg; p = 0.38) and post-cannulation (37 vs. 36 mm Hg; p = 0.82) PaCO 2 were not different. However, higher pre-cannulation PaCO 2 (odds ratio [OR] = 2.10; 95% confidence interval [CI] = 1.10-4.00; p = 0.02) and larger ∆PaCO 2 (OR = 2.69; 95% CI = 1.18-6.13; p = 0.02) were associated with ICH. In conclusion, in a cohort with granular arterial blood gas (ABG) data and a standardized neuromonitoring protocol, higher pre-cannulation PaCO 2 and larger ∆PaCO 2 were associated with increased prevalence of ICH.

Temporary Mechanical Circulatory Support for Transcatheter Aortic Valve Replacement

INTRODUCTION

This study aimed to characterize the use of temporary mechanical circulatory support (tMCS) among patients undergoing transcatheter aortic valve replacement (TAVR) using a nationally representative database.

MATERIALS AND METHODS

The 2012-2018 National Inpatient Sample was queried for adult patients who underwent isolated TAVR. The tMCS group was comprised of those who required extracorporeal membrane oxygenation, percutaneous ventricular assist device, or intra-aortic balloon pump during index hospitalization. We evaluated temporal trends in the utilization of tMCS using Cuzick's test. Furthermore, a multivariable logistic regression was used to identify factors associated with tMCS use and its impact on in-hospital mortality, selected complications, and nonhome discharge.

RESULTS

Of an estimated 215,925 patients who underwent TAVR, 3085 (1.4%) required tMCS during their hospital course. The most common modality of tMCS was intra-aortic balloon pump (49%), followed by extracorporeal membrane oxygenation (27%) then percutaneous ventricular assist device (18%). Seven percent of tMCS patients were supported by > 1 device. The annual incidence of tMCS usage decreased over the study period, from 3% in 2012 to 1% in 2018 (P-trend < 0.01). Nonelective admission, congestive heart failure, coagulopathy, and liver disease were strong independent predictors of requiring tMCS. Patients requiring tMCS had a 31.8% in-hospital mortality rate (adjusted odds ratio = 23, 95% confidence interval 18.5-28.5), longer length of stay (9 d versus 3, P < 0.001), and higher costs ($84,600 versus $48,100, P < 0.001) than those who did not.

CONCLUSIONS

The use of tMCS during TAVR has decreased over time but remains associated with a 23-fold increased mortality rate and significant clinical and resource utilization burden.

Early Blood Pressure Variables Associated With Improved Outcomes in VA-ECLS: The ELSO Registry Analysis

BACKGROUND

As utilization of veno-arterial extracorporeal life support (VA-ECLS) in treatment of cardiogenic shock (CS) continues to expand, clinical variables that guide clinicians in early recognition of myocardial recovery and therefore, improved survival, after VA-ECLS are critical. There remains a paucity of literature on early postinitiation blood pressure measurements that predict improved outcomes.

OBJECTIVES

The objective of this study is to help identify early blood pressure variables associated with improved outcomes in VA-ECLS.

METHODS

The authors queried the ELSO (Extracorporeal Life Support Organization) registry for cardiogenic shock patients treated with VA-ECLS or venovenous arterial ECLS between 2009 and 2020. Their inclusion criteria included treatment with VA-ECLS or venovenous arterial ECLS; absence of pre-existing durable right, left, or biventricular assist devices; no pre-ECLS cardiac arrest; and no surgical or percutaneously placed left ventricular venting devices during their ECLS runs. Their primary outcome of interest was the survival to discharge during index hospitalization.

RESULTS

A total of 2,400 CS patients met the authors' inclusion criteria and had complete documentation of blood pressures. Actual mortality during index hospitalization in their cohort was 49.5% and survivors were younger and more likely to be Caucasian, intubated for >30 hours pre-ECLS initiation, and had a favorable baseline SAVE (Survival After Veno-arterial ECMO) score (P < 0.05 for all). Multivariable regression analyses adjusting for SAVE score, age, ECLS flow at 4 hours, and race showed that every 10-mm Hg increase in baseline systolic blood pressure (HR: 0.92 [95% CI: 0.89-0.95]; P < 0.001), and baseline pulse pressure (HR: 0.88 [95% CI: 0.84-0.91]; P < 0.001) at 24 hours was associated with a statistically significant reduction in mortality.

CONCLUSIONS

Early (within 24 hours) improvements in pulse pressure and systolic blood pressure from baseline are associated with improved survival to discharge among CS patients treated with VA-ECLS.

Effect of hospital case volume on clinical outcomes of patients requiring extracorporeal membrane oxygenation: a territory-wide longitudinal observational study

Background

The utilization of extracorporeal membrane oxygenation (ECMO) has increased rapidly around the world. Being an overall low-volume high-cost form of therapy, the effectiveness of having care delivered in segregated units across a geographical locality is debatable.

Methods

All adult extracorporeal membrane oxygenation cases admitted to public hospitals in Hong Kong between 2010 and 2019 were included. “High-volume” centers were defined as those with >20 extracorporeal membrane oxygenation cases in the respective calendar year, while “low-volume” centers were those with ≤20. Clinical outcomes of patients who received extracorporeal membrane oxygenation care in high-volume centers were compared with those in low-volume centers.

Results

A total of 911 patients received extracorporeal membrane oxygenation—297 (32.6%) veno-arterial extracorporeal membrane oxygenation, 450 (49.4%) veno-venous extracorporeal membrane oxygenation, and 164 (18.0%) extracorporeal membrane oxygenation-cardiopulmonary resuscitation. The overall hospital mortality was 456 (50.1%). The annual number of extracorporeal membrane oxygenation cases in high- and low-volume centers were 29 and 11, respectively. Management in a high-volume center was not significantly associated with hospital mortality (adjusted odds ratio (OR) 0.86, 95% confidence interval (CI): 0.61–1.21, P=0.38), or with intensive care unit mortality (adjusted OR 0.76, 95% CI: 0.54–1.06, P=0.10) compared with a low-volume center. Over the 10-year period, the overall observed mortality was similar to the Acute Physiology And Chronic Health Evaluation IV-predicted mortality, with no significant difference in the standardized mortality ratios between high- and low-volume centers (P=0.46).

Conclusions

In a territory-wide observational study, we observed that case volumes in extracorporeal membrane oxygenation centers were not associated with hospital mortality. Maintaining standards of care in low-volume centers is important and improves preparedness for surges in demand.

Clinician Ethical Perspectives on Extracorporeal Membrane Oxygenation in Practice

PURPOSE

Extracorporeal membrane oxygenation (ECMO) is an expensive and scarce life sustaining treatment provided to certain critically ill patients. Little is known about the informed consent process for ECMO or clinician viewpoints on ethical complexities related to ECMO in practice.

METHODS

We sent a cross-sectional survey to all departments providing ECMO within 7 United States hospitals in January 2021. One clinician from each department completed the 42-item survey representing their department.

RESULTS

Fourteen departments within 7 hospitals responded (response rate 78%, N = 14/18). The mean time spent consenting patients or surrogate decision-makers for ECMO varied, from 7.5 minutes (95% CI 5-10) for unstable patients to 20 minutes (95% CI 15-30) for stable patients (p = 0.0001). Few clinician respondents (29%) report patients or surrogate decision-makers always possess informed consent for ECMO. Most departments (92%) have absolute exclusion criteria for ECMO such as older age (43%, cutoffs ranging from 60-75 years), active malignancy (36%), and elevated body mass index (29%). A significant minority of departments (29%) do not always offer the option to withdraw ECMO to patients or surrogate decision-makers. For patients who cannot be liberated from ECMO and are ineligible for heart or lung transplant, 36% of departments would recommend the patient be removed from ECMO and 64% would continue ECMO support.

CONCLUSION

Adequate informed consent for ECMO is a major ethical challenge, and the content of these discussions varies. Use of categorical exclusion criteria and withdrawal of ECMO if a patient cannot be liberated from it differ among departments and institutions.

Assessing the SAfety and FEasibility of bedside portable low-field brain Magnetic Resonance Imaging in patients on ECMO (SAFE-MRI ECMO study): study protocol and first case series experience

BACKGROUND

To assess the safety and feasibility of imaging of the brain with a point-of-care (POC) magnetic resonance imaging (MRI) system in patients on extracorporeal membrane oxygenation (ECMO). Early detection of acute brain injury (ABI) is critical in improving survival for patients with ECMO support.

METHODS

Patients from a single tertiary academic ECMO center who underwent head CT (HCT), followed by POC brain MRI examinations within 24 h following HCT while on ECMO. Primary outcomes were safety and feasibility, defined as completion of MRI examination without serious adverse events (SAEs). Secondary outcome was the quality of MR images in assessing ABIs.

RESULTS

We report 3 consecutive adult patients (median age 47 years; 67% male) with veno-arterial (n = 1) and veno-venous ECMO (n = 2) (VA- and VV-ECMO) support. All patients were imaged successfully without SAEs. Times to complete POC brain MRI examinations were 34, 40, and 43 min. Two patients had ECMO suction events, resolved with fluid and repositioning. Two patients were found to have an unsuspected acute stroke, well visualized with MRI.

CONCLUSIONS

Adult patients with VA- or VV-ECMO support can be safely imaged with low-field POC brain MRI in the intensive care unit, allowing for the assessment of presence and timing of ABI.

Respiratory ECMO Survival Prediction (RESP) Score for COVID-19 Patients Treated with ECMO

Veno-venous extracorporeal membrane oxygenation (VV ECMO) has been used as a life-supporting modality for patients with severe respiratory failure because of coronavirus disease 2019 (COVID-19). We aim to evaluate the performance of the RESP score in predicting the hospital survival of COVID-19 patients undergoing VV ECMO. We performed retrospective analysis of the extracorporeal life support organization (ELSO) dataset for COVID-19 patients requiring ECMO support to evaluate the performance of RESP score in predicting in hospital survival. All adult (age ≥18) COVID-19 patients receiving VV ECMO for acute respiratory failure enrolled in the ELSO database from March to August 2020 were included in the analysis. A total of 1985 patients from the ELSO registry were identified and analyzed based on pre-ECMO variables. Median RESP score of survivors was 3 (IQR 1-5) compared to 2 (IQR 0-4) in deceased. A logistic model including RESP score variables poorly discriminated survival and death with AUC (area under curve) 0.61 (95% confidence interval: 0.59-0.64). In-hospital survival for COVID-19 patients based on RESP score class from I to V was 69.7%, 59.3%, 45.7%, 42.5%, and 32.3%, respectively. Patients with immunosuppression (relative risk = 0.43) and pre-ECMO cardiac arrest (relative risk = 0.48) had lower survival. RESP score is a poor predictor of survival in COVID-19 patients undergoing ECMO. Compared to the original cohort used for RESP score creation, COVID-19 patients in RESP class I-III had worse survival whereas the patients in RESP class IV-V had better survival.

Mortality Trends after Extracorporeal Membrane Oxygenation Support: A Korean Nationwide Cohort

BACKGROUND

This study aimed to investigate the prevalence of 7-, 30-, 60-, and 365-day overall and cause-specific mortality following extracorporeal membrane oxygenation (ECMO) support.

METHODS

The National Health Insurance claims database in South Korea was the data source for this population-based cohort study. We enrolled all adult patients aged ≥18 years receiving intensive care unit ECMO support from January 1, 2005 to December 31, 2018. The study population was divided into three groups based on the main diagnoses during ECMO support: 1) cardiovascular, 2) respiratory, and 3) other diagnoses group (all other main diagnoses rather than cardiovascular or respiratory diseases).

RESULTS

A total of 18,697 patients were included in the final analysis (64.5%, 10.9%, and 24.6% in the cardiovascular, respiratory, and other groups, respectively). The corresponding 7-, 30-, 60-, and 365-day mortality rates in these groups were 33.1%, 56.1%, 62.4%, and 67.7%. Kaplan-Meier curves demonstrated that the median survival time was shortest in the cardiovascular group (12.0 days, 95% confidence interval [CI]: 11.3-12.7), with 31.0 (95% CI: 28.5-33.6) and 49.0 (95% CI: 44.4-57.6) day survival in the respiratory and other diagnoses groups (p<0.001).

CONCLUSIONS

Approximately one-third of patients died within 7 days, half of the patients died within 30 days, and two-thirds died within 365 days of ECMO support. Overall survival time was shortest in the cardiovascular group, followed by that of the respiratory group.

Implementation and Outcomes of an Urban Mobile Adult Extracorporeal Life Support Program

Objective

Methods

Results

Conclusions

Acute Kidney Injury in Extracorporeal Membrane Oxygenation Patients: National Analysis of Impact of Age

BACKGROUND

The aim of this study was to determine epidemiology and outcomes of acute kidney injury (AKI) in patients on extracorporeal membrane oxygenation (ECMO) and to assess if age modifies the effect of AKI on mortality.

METHODS

Using National (Nationwide) Inpatient Sample Database for hospitalizations in the USA from 2003 to 2014, we identified adult patients on ECMO support. Using International Classification of Diseases 9th Revision, we assessed the rates of AKI and AKI requiring dialysis (AKI-D) among them and associated survival. We used a multivariable logistic regression to identify risk factors of and differential effect of age on mortality from AKI.

RESULTS

AKI was seen in 63.9% of 17,942 ECMO hospitalizations: 21.9% of those with AKI required dialysis. The percentage of those with AKI increased steadily. Mortality was higher in those with AKI, with highest in those with AKI-D (70.8% vs. 61.7%; p < 0.001). While both age and AKI were independent predictors of mortality, age was neither a risk factor for AKI nor did it modify the effect of AKI on mortality.

CONCLUSIONS

AKI is common and is increasing among patients on ECMO support. Patients on ECMO have high mortality and AKI is an independent predictor of mortality. Though age is also an independent predictor of mortality in patients on ECMO, it is neither a predictor of AKI nor does not modify the relationship between AKI and mortality.

Inpatient Mortality Among Patients With Acute Respiratory Distress Syndrome at ECMO and Non-ECMO Centers in the United States

BACKGROUND

A 2009 randomized control trial found patients with severe acute respiratory distress syndrome (ARDS) who transferred to an extra-corporeal membrane oxygenation therapy (ECMO) center had better survival, even if they did not receive ECMO. This study aimed to use a national US database to determine if care at ECMO centers offer a survival advantage in patients with ARDS with mechanical ventilation only.

METHODS

Hospitalizations of patients 18-64 years old who had ARDS and mechanical ventilation in the 2010-2016 Health care Cost and Utilization Project National Readmission Database were included. ECMO centers performed at least 1 veno-venous ECMO hospitalization annually; or >5, >20, and >50 on sensitivity analysis. Multivariable logistic regression compared inpatient mortality, after adjusting for timing of hospitalization, patient demographics, comorbidities, and hospital characteristics.

RESULTS

Of the 1 224 447 ARDS hospitalizations and mechanical ventilation, 41% were at ECMO centers. ECMO centers were more likely to be larger, private, non-profit, teaching hospitals. ARDS at admission was more common at non-ECMO centers (31% vs 23%, P < .0001); however, other patient demographics and comorbidities did not differ. After adjustment, no difference in inpatient mortality was seen between ECMO and non-ECMO centers (OR 0.99, 95% CI: 0.97, 1.02). This relationship did not change in sensitivity analyses.

DISCUSSION

Adult patients with ARDS requiring mechanical ventilation may not have improved outcomes if treated at an ECMO center and suggest that early transfer of all ARDS patients to ECMO centers may not be warranted. Further evaluation of ECMO center volume and illness severity is needed.

Proposal for a trial of early left ventricular venting during venoarterial extracorporeal membrane oxygenation for cardiogenic shock

Objective

Patients with profound cardiogenic shock may require venoarterial (VA) extracorporeal membrane oxygenation (ECMO) for circulatory support most commonly via the femoral vessels. The rate of cardiac recovery in this population remains low, possibly because peripheral VA-ECMO increases ventricular afterload. Whether direct ventricular unloading in peripheral VA-ECMO enhances cardiac recovery is unknown, but is being more frequently utilized. A randomized trial is warranted to evaluate the clinical effectiveness of percutaneous left ventricle venting to enhance cardiac recovery in the setting of VA-ECMO.

Methods

We describe the rationale, design, and initial testing of a randomized controlled trial of VA-ECMO with and without percutaneous left ventricle venting using a percutaneous micro-axial ventricular assist device.

Results

This is an ongoing prospective randomized controlled trial in adult patients with primary cardiac failure presenting in cardiogenic shock requiring peripheral VA-ECMO, designed to test the safety and effectiveness of percutaneous left ventricle venting in improving the rate of cardiac recovery.

Conclusions

The results of this nonindustry-sponsored trial will provide critical information on whether left ventricle unloading in peripheral VA-ECMO is safe and effective.