Risk factors for intracranial hemorrhage in adults on extracorporeal membrane oxygenation

Association of Activated Clotting Time-Guided Anticoagulation with Complications during Extracorporeal Membrane Oxygenation Support: A Systematic Review and Meta-Analysis

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) requires systemic anticoagulation to reduce the risk of thromboembolic events. Despite its historic role, activated clotting time (ACT) remains a widely used heparin monitoring method. Systematic evidence on the association of ACT-guided monitoring with hemorrhagic or thromboembolic complications does not exist.

DESIGN

Systematic literature review and meta-analysis (Scopus and PubMed, July 2023).

SETTING

All cohort studies.

PARTICIPANTS

Patients receiving ECMO support.

INTERVENTION

Anticoagulation monitoring with ACT.

MEASUREMENTS AND MAIN RESULTS

We identified 3,177 publications, with 8 studies reporting the average ACT values for patients with and without bleeding. Meta-analysis revealed no significant difference in the compared groups (SMD = 0.69; 95% CI -0.05 to 1.43, p = 0.069; I2 = 87.4%). Three studies (n = 117 patients) reported on the average ACT values for patients with thrombosis, without significant differences in ACT between patients with and without thrombosis (SMD = 0.47; 95% CI -0.50 to 1.44, p = 0.342; I2 = 81.1%).

CONCLUSIONS

Even though ACT is a widely used heparin monitoring tool, the evidence on its association with hemorrhagic or thromboembolic events is still controversial and limited. Further studies are essential to elucidate the role of ACT in anticoagulation monitoring during ECMO support.

Characterizing the Relationship Between Arterial Carbon Dioxide Trajectory and Serial Brain Biomarkers with Central Nervous System Injury During Veno-Venous Extracorporeal Membrane Oxygenation: A Prospective Cohort Study

BACKGROUND

Central nervous system (CNS) injury following initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) is common. An acute decrease in partial pressure of arterial carbon dioxide (PaCO2) following VV-ECMO initiation has been suggested as an etiological factor, but the challenges of diagnosing CNS injuries has made discerning a relationship between PaCO2 and CNS injury difficult.

METHODS

We conducted a prospective cohort study of adult patients undergoing VV-ECMO for acute respiratory failure. Arterial blood gas measurements were obtained prior to initiation of VV-ECMO, and at every 2-4 h for the first 24 h. Neuroimaging was conducted within the first 7-14 days in patients who were suspected of having neurological injury or unable to be examined because of sedation. We collected blood biospecimens to measure brain biomarkers [neurofilament light (NF-L); glial fibrillary acidic protein (GFAP); and phosphorylated-tau 181] in the first 7 days following initiation of VV-ECMO. We assessed the relationship between both PaCO2 over the first 24 h and brain biomarkers with CNS injury using mixed methods linear regression. Finally, we explored the effects of absolute change of PaCO2 on serum levels of neurological biomarkers by separate mixed methods linear regression for each biomarker using three PaCO2 exposures hypothesized to result in CNS injury.

RESULTS

In our cohort, 12 of 59 (20%) patients had overt CNS injury identified on head computed tomography. The PaCO2 decrease with VV-ECMO initiation was steeper in patients who developed a CNS injury (- 0.32%, 95% confidence interval - 0.25 to - 0.39) compared with those without (- 0.18%, 95% confidence interval - 0.14 to - 0.21, P interaction < 0.001). The mean concentration of NF-L increased over time and was higher in those with a CNS injury (464 [739]) compared with those without (127 [257]; P = 0.001). GFAP was higher in those with a CNS injury (4278 [11,653] pg/ml) compared with those without (116 [108] pg/ml; P < 0.001). The mean NF-L, GFAP, and tau over time in patients stratified by the three thresholds of absolute change of PaCO2 showed no differences and had no significant interaction for time.

CONCLUSIONS

Although rapid decreases in PaCO2 following initiation of VV-ECMO were slightly greater in patients who had CNS injuries versus those without, data overlap and absence of relationships between PaCO2 and brain biomarkers suggests other pathophysiologic variables are likely at play.

The impact of sex on epidemiology, management, and outcome of spontaneous intracerebral hemorrhage (sICH)

OBJECTIVE

Data on sex differences in spontaneous intracerebral hemorrhages are limited.

METHODS

An automated comprehensive scoping literature review was performed using PubMed and Scopus. Articles written in English about spontaneous intracerebral hemorrhage and sex were reviewed.

RESULTS

Males experience spontaneous intracerebral hemorrhage more frequently than females, at younger ages, and have a higher prevalence of deep bleeds compared to females. Risk factors between sexes vary and may contribute to differing incidences and locations of spontaneous intracranial hemorrhage. Globally, females receive less aggressive care than males, likely impacting survival.

CONCLUSIONS

Epidemiology, risk factors, and treatment of spontaneous intracranial hemorrhage vary by sex, with limited and oftentimes conflicting data available. Further research into the sex-based differences of spontaneous intracranial hemorrhage is necessary for clinicians to better understand how to evaluate and guide treatment in the future.

Definitions of major bleeding for predicting mortality in critically ill adult patients who survived 24 hours while supported with peripheral veno-arterial extracorporeal membrane oxygenation for cardiogenic shock: a comparative historical cohort study

PURPOSE

The severity of bleeding events is heterogeneously defined during peripheral veno-arterial extracorporeal membrane oxygenation (pVA-ECMO). We studied three bleeding definitions in pVA-ECMO: the Extracorporeal Life Support Organization (ELSO)-serious bleeding, the Bleeding Academic Research Consortium (BARC), and the universal definition of postoperative bleeding (UPDB) classifications.

METHODS

We included consecutive adult patients supported by pVA-ECMO for refractory cardiogenic shock admitted to Lille academic hospitals between January 2013 and December 2019. We assessed the association of bleeding definitions with the primary endpoint of 28-day all-cause mortality with the use of multivariate models accounting for time-dependent and competing variables. We compared models' performances using the Harrell's C-Index and the Akaike information criteria.

RESULTS

Twenty-eight-day mortality occurred in 128/308 (42%) 308 patients. The ELSO-serious bleeding (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.09 to 2.56) and BARC ≥ type 2 (HR, 1.55; 95% CI, 1.01 to 2.37) were associated with 28-day mortality (Harrell's C-index, 0.69; 95% CI, 0.63 to 0.74 for both). Predictors of ELSO-serious bleeding were postcardiotomy, body mass index, baseline platelets count, fibrinogen, and hemoglobin levels.

CONCLUSION

Extracorporeal Life Support Organization-serious bleeding and BARC ≥ type 2 are relevant definitions of major bleeding regarding their association with mortality in critically ill patients who survived the first 24 hr while supported with pVA-ECMO for cardiogenic shock.

STUDY REGISTRATION

CERAR (IRB 00010254-2022-050, Paris, France); first submitted on 18 April 2022.

Review of anticoagulation considerations in extracorporeal membrane oxygenation support

Since its first success in 1975, extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency for pulmonary and cardiopulmonary bypass. Use in adults has increased exponentially since the early 2000s, but despite thousands of international cannulations using both veno-arterial (VA) and veno-venous (VV) ECMO, there are still significant hemocompatibility-related adverse events. Current management of anticoagulation has been based on the Extracorporeal Life Support Organization guidance published in 2014 with recent updates published in 2022. Despite this guidance, there is still limited international consensus on how to manage anticoagulation in ECMO. For this review, we completed a comprehensive search of multiple electronic databases to identify studies pertaining to anticoagulation of adult patients on VV or VA-ECMO. The highest priority was given to sources that were prospective, randomized, controlled studies, but in the absence of such resources, observational studies, retrospective uncontrolled studies, and case series/reports were considered for inclusion. This document serves to provide a comprehensive review of the current understanding of management pertaining to anticoagulation relating to ECMO.

Factor XI Inhibition With Heparin Reduces Clot Formation in Simulated Pediatric Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) supplies circulatory support and gas exchange to critically ill patients. Despite the use of systemic anticoagulation, blood exposure to ECMO surfaces causes thromboembolism complications. Inhibition of biomaterial surface-mediated activation of coagulation factor XI (FXI) may prevent device-associated thrombosis. Blood was collected from healthy volunteers (n = 13) following the U.S. Army Institute of Surgical Research standard operating procedure for testing in an ex vivo ECMO circuit. A roller-pump circuit circulated either 0.5 U/ml of unfractionated heparin alone or in combination with the anti-FXI immunoglobulin G (IgG) (AB023) for 6 hours or until clot formation caused device failure. Coagulation factor activity, platelet counts, time to thrombin generation, peak thrombin, and endogenous thrombin potential were quantified. AB023 in addition to heparin sustained circuit patency in all tested circuits (5/5) after 6 hours, while 60% of circuits treated with heparin alone occluded (3/8), log-rank p < 0.03. AB023 significantly prolonged the time to clot formation as compared to heparin alone (15.5 vs . 3.3 minutes; p < 0.01) at the 3-hour time point. AB023 plus heparin significantly reduced peak thrombin compared to heparin alone (123 vs . 217 nM; p < 0.01). Inhibition of contact pathway activation of FXI may be an effective adjunct to anticoagulation in extracorporeal life support.

Predictors of intracranial hemorrhage in neonatal patients on extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a life-supportive treatment in neonatal patients with refractory lung and/or heart failure. Intracranial hemorrhage (ICH) is a severe complication and reliable predictors are warranted. The aims of this study were to explore the incidence and possible predictors of ICH in ECMO-treated neonatal patients. We performed a single-center retrospective observational cohort study. Patients aged ≤ 28 days treated with ECMO between 2010 and 2018 were included. Exclusion criteria were ICH, ischemic stroke, cerebrovascular malformation before ECMO initiation or detected within 12 h of admission, ECMO treatment < 12 h, or prior treatment with ECMO at another facility > 12 h. The primary outcome was a CT-verified ICH. Logistic regression models were employed to identify possible predictors of the primary outcome. Of the 223 patients included, 29 (13%) developed an ICH during ECMO treatment. Thirty-day mortality was 59% in the ICH group and 16% in the non-ICH group (p < 0.0001). Lower gestational age (p < 0.01, odds ratio (OR) 0.96; 95%CI 0.94-0.98), and higher pre-ECMO lactate levels (p = 0.017, OR 1.1; 95%CI 1.01-1.18) were independently associated with increased risk of ICH-development. In the clinical setting, identification of risk factors and multimodal neuromonitoring could help initiate steps that lower the risk of ICH in these patients.

Invasive Pulmonary Aspergillosis After Sars-CoV-2 Infection as Limitation of Contemporary Transplantology: A Case Report

Invasive fungal infections are uncommon in pediatric heart transplant recipients. Risk and mortality are highest in the first 6 months post-transplant, especially in patients with previous surgery and those requiring mechanical support. There is a possibility that prior SARS-CoV-2 infection may cause a more severe course of pulmonary aspergillosis, especially in immunosuppressed individuals. This report describes a female patient, eight years of age, who was admitted to the pediatric cardiac surgery department with symptoms of end-stage heart failure in urgent need of mechanical circulatory support (MCS). A left ventricular assist device (LVAD) was implanted as a bridge to transplantation. During over a year on the waiting list, LVAD was replaced twice due to the presence of fibrin on the inlet valve. While staying in the ward, the patient underwent SARS-CoV-2 infection. An orthotopic heart transplant was successfully performed after 372 days of MCS with LVAD. One month after transplantation, the girl developed severe pulmonary aspergillosis complicated by sudden cardiac arrest and implantation of venovenous extracorporeal membrane oxygenation (VV ECMO) used for 25 days. Unfortunately, a few days after weaning from VV ECMO, the patient died due to intracerebral bleeding.

Dual titration of minute ventilation and sweep gas flow to control carbon dioxide variations in patients on venovenous extracorporeal membrane oxygenation

BACKGROUND

The implantation of venovenous extracorporeal membrane oxygenation (VV-ECMO) support to manage severe acute respiratory distress syndrome generates large variations in carbon dioxide partial pressure (PaCO₂) that are associated with intracranial bleeding. We assessed the feasibility and efficacy of a pragmatic protocol for progressive dual titration of sweep gas flow and minute ventilation after VV-ECMO implantation in order to limit significant PaCO₂ variations.

PATIENTS AND METHODS

A protocol for dual titration of sweep gas flow and minute ventilation following VV-ECMO implantation was implemented in our unit in September 2020. In this single-centre retrospective before-after study, we included patients who required VV-ECMO from March, 2020 to May, 2021, which corresponds to two time periods: from March to August, 2020 (control group) and from September, 2020 to May, 2021 (protocol group). The primary endpoint was the mean absolute change in PaCO₂ in consecutive arterial blood gases samples drawn over the first 12 h following VV-ECMO implantation. Secondary endpoints included large (> 25 mmHg) initial variations in PaCO₂, intracranial bleedings and mortality in both groups.

RESULTS

Fifty-one patients required VV-ECMO in our unit during the study period, including 24 in the control group and 27 in the protocol group. The protocol was proved feasible. The 12-h mean absolute change in PaCO₂ was significantly lower in patients of the protocol group as compared with their counterparts (7 mmHg [6-12] vs. 12 mmHg [6-24], p = 0.007). Patients of the protocol group experienced less large initial variations in PaCO₂ immediately after ECMO implantation (7% vs. 29%, p = 0.04) and less intracranial bleeding (4% vs. 25%, p = 0.04). Mortality was similar in both groups (35% vs. 46%, p = 0.42).

CONCLUSION

Implementation of our protocol for dual titration of minute ventilation and sweep gas flow was feasible and associated with less initial PaCO₂ variation than usual care. It was also associated with less intracranial bleeding.

aPTT-guided anticoagulation monitoring during ECMO support: A systematic review and meta-analysis

INTRODUCTION

The initiation of the extracorporeal membrane oxygenation (ECMO) is associated with complex coagulatory and inflammatory processes and consequently needed anticoagulation. Systemic anticoagulation bears an additional risk of serious bleeding, and its monitoring is of immense importance. Therefore, our work aims to analyze the association of anticoagulation monitoring with bleeding during ECMO support.

MATERIAL AND METHODS

Systematic literature review and meta-analysis, complying with the PRISMA guidelines (PROSPERO-CRD42022359465).

RESULTS

Seventeen studies comprising 3249 patients were included in the final analysis. Patients experiencing hemorrhage had a longer activated partial thromboplastin time (aPTT), a longer ECMO duration, and higher mortality. We could not find strong evidence of any aPTT threshold association with the bleeding occurrence, as less than half of authors reported a potential relationship. Finally, we identified the acute kidney injury (66%, 233/356) and hemorrhage (46%, 469/1046) to be the most frequent adverse events, while almost one-half of patients did not survive to discharge (47%, 1192/2490).

CONCLUSION

The aPTT-guided anticoagulation is still the standard of care in ECMO patients. We did not find strong evidence supporting the aPTT-guided monitoring during ECMO. Based on the weight of the available evidence, further randomized trials are crucial to clarify the best monitoring strategy.

Cerebral Neural Changes in Venous-Arterial Extracorporeal Membrane Oxygenation Survivors

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is used as temporary cardiorespiratory support in patients with critical ailments, but very little is known about the functional cerebral changes in ECMO survivors. Degree centrality (DC), a graph-based assessment of network organization, was performed to explore the neural connectivity changes in ECMO survivors compared to controls and their correlation with cognitive and neurological measures.

METHODS

This exploratory observational study was conducted from August 2020 to May 2022. ECMO survivors and controls underwent functional magnetic resonance imaging (fMRI) of the brain. We performed DC analysis to identify voxels that showed changes in whole-brain functional connectivity with other voxels. DC was measured by the fMRI graph method and comparisons between the two groups were performed. All participants underwent neuropsychological assessment (Montreal Cognitive Assessment, MoCA). Blood serum neuron-specific enolase and the Glasgow Coma Scale (GCS) were assessed in ECMO survivors.

RESULTS

DC values in the right insula and right precuneus gyrus were lower in ECMO survivors and higher in the right medial superior frontal gyrus compared to controls (all p < 0.001). Decreased connectivity in the right insular and right precuneus gyrus correlated with total MoCA scores, delayed recollection, and calculation (all p < 0.05). Increased serum NSE levels, GCS score, and GCS-motor response correlated with decreased connectivity in the right insular and right precuneus gyrus and increased connectivity in the right medial superior frontal gyrus (all p < 0.05).

CONCLUSIONS

We showed that both functional impairment and adaptation were observed in survivors of ECMO, suggesting that neural connectivity changes may provide insights into the mechanisms that may potentially link ECMO survivors to neurological and cognitive disorders.

Gender-Related Discrepancies in Short-Term Outcomes in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting Surgery

The sex differences in patients undergoing off-pump coronary artery bypass grafting (OPCAB) surgery are still unclear. Our aim was to investigate the impact of gender on short-term outcomes in males and females after off-pump bypass procedures. Our research was designed as a double-center retrospective analysis. Generally, 343 patients (men (n = 255) and women (n = 88)) who underwent an OPCAB procedure were included in our study. To provide a statistical analysis of unequal cohorts, we created a propensity score-based matching (PSM) analysis (men, n = 61; women, n = 61). The primary endpoint was all-cause in-hospital mortality. Dialysis, transient ischemic attack (TIA), low cardiac output syndrome (LCOS), reoperation due to postoperative bleeding, wound infection and duration of hospital stay were secondary outcomes in our analysis. No significant differences were detected within the male and female groups regarding age (p = 0.116), BMI (p = 0.221), diabetes (p = 0.853), cardiogenic shock (0.256), STEMI (p = 0.283), NSTEMI (p = 0.555) and dialysis (p = 0.496). Males underwent significantly more frequently (p = 0.005) total-arterial revascularization with T-graft technique (p = 0.005) than females. In contrast, temporary pacer use was significantly higher (p = 0.022) in females compared to males. The in-hospital mortality rate was not significantly higher (p = 0.496) in the female group compared to the male group. Likewise, secondary outcomes did not differ significantly between the non-adjusted and the adjusted groups. Based on our findings, gender has no impact on short-term outcomes after OPCAB surgery.

Management of Anticoagulation Therapy in ECMO-Associated Ischemic Stroke and Intracranial Hemorrhage

OBJECTIVE

Despite the common occurrence of extracorporeal membrane oxygenation (ECMO)-associated acute ischemic stroke (AIS) and intracranial hemorrhage (ICH), there are little data to guide optimal anticoagulation management. We sought to describe antithrombotic therapy management after stroke and outcomes.

METHODS

A retrospective analysis was conducted of venoarterial (VA) and venovenous (VV) ECMO patients treated at a tertiary care center from June 2016 to February 2021. Patients with image-confirmed diagnosis of AIS or ICH while receiving ECMO were included for study with data collected regarding anticoagulation management and clinical outcomes.

RESULTS

Overall, 216 patients (153 VA-ECMO, 63 VV-ECMO) were included in this study. Of the 153 patients on VA-ECMO, 13 (8.4%) had AIS and 6 (3.9%) had ICH. Of the 63 patients on VV-ECMO, none had AIS and 5 (7.9%) had ICH. One patient (9%) received anticoagulation reversal after ICH. Anticoagulation was discontinued and later resumed in all 5 ICH survivors (median cessation time, 30 h) and 1 of 2 (50%) AIS survivors (median cessation time, 96 h). While off anticoagulation, 2 of 11 patients (18%) had thromboembolic events and none had new AIS. Upon resumption, there were no cases of hemorrhagic transformation of AIS or ICH expansion. There was no difference in in-hospital mortality between patients with ICH and those without in both the VA-ECMO and VV-ECMO cohorts nor between VA-ECMO patients with AIS and those without.

CONCLUSIONS

Early cessation and judicious resumption of anticoagulation appeared feasible in the cohort of patients with ECMO-associated AIS and ICH.

Sex-Related Differences in Short-Term Outcomes after Mobile VA-ECMO Implantation: Five-Year Experience of an ECMO Retrieval Program

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) represents an increasingly used method for circulatory support. Despite the ongoing research, survival following VA-ECMO therapy remains low. Sex-related differences might impact the outcome of therapeutic measures. We aimed to compare all-cause mortality among female and male patients who underwent VA-ECMO as a bridge to recovery investigating sex-related differences. From January 2015 until August 2020, 87 patients were supported by VA-ECMO as a part of our out-of-center mobile ECMO program. In order to analyze sex-associated differences in early clinical outcomes, patients were divided into two sex categories: men (n = 62) and women (n = 25). All relevant data (in-hospital mortality, ICU and hospital stay, renal failure requiring dialysis, lung failure, bleeding, stroke and septic shock) were analyzed retrospectively after the extraction from our institutional database. Mean age of the study population was 53 ± 14 years. Mean EuroSCORE II predicted mortality was 6.5 ± 3.7. In-hospital mortality rate was not significantly lower in the female group (58.3%) vs. the male group (71.2%), p = 0.190. The mean length of ICU and hospital stay was 9 ± 11 in the male group vs. 10 ± 13 in the female group, p = 0.901, and 10 ± 12 (male group) vs. 11 ± 13 (female group), p = 0.909, respectively. Renal failure requiring hemodialysis (36.2% (males) vs. 28.6% (females), p = 0.187) was comparable between both groups. Respiratory failure was diagnosed in 31 (56.4%) male vs. 8 (34.8%) female patients, p = 0.068, while 16 (28.6%) male vs. 3 (13.0%) female patients (p = 0.118) suffered from septic shock. Based on our data, there were no sex-specific outcome discrepancies in patients treated with mobile VA-ECMO implantation.

Intracranial haemorrhage in adult patients on venoarterial extracorporeal membrane oxygenation

AIMS

Intracranial haemorrhage (ICH) is one of the most serious complications of adult patients treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO) and is associated with increased morbidity and mortality. However, the prevalence and risk factors of ICH in this cohort are still insufficiently understood. We hypothesized that a considerable proportion of patients undergoing VA-ECMO support suffer from ICH and that specific risk factors are associated with the occurrence of ICH. Therefore, the purpose of this study was to further investigate the prevalence and associated mortality as well as to identify risk factors for ICH in VA-ECMO patients.

METHODS AND RESULTS

We conducted a retrospective multicentre study including adult patients (≥18 years) treated with VA-ECMO in cardiac intensive care units (ICUs) at five German clinical sites between January 2016 and March 2020, excluding patients with ICH upon admission. Differences in baseline characteristics and clinical outcome between VA-ECMO patients with and without ICH were analysed and risk factors for ICH were identified. Among the 598 patients included, 70/598 (12%) developed ICH during VA-ECMO treatment. In-hospital mortality in patients with ICH was 57/70 (81%) and 1-month mortality 60/70 (86%), compared to 332/528 (63%) (P = 0.002) and 340/528 (64%) (P < 0.001), respectively, in patients without ICH. Intracranial haemorrhage was positively associated with diabetes mellitus [odds ratio (OR) 2, 95% confidence interval (CI) 1.11-3.56; P = 0.020] and lactate (per mmol/L) (OR 1.06, 95% CI 1.01-1.11; P = 0.020), and negatively associated with platelet count (per 100 G/L) (OR 0.32, 95% CI 0.15-0.59; P = 0.001) and fibrinogen (per 100 mg/dL) (OR 0.64, 95% CI 0.49-0.83; P < 0.001).

CONCLUSION

Intracranial haemorrhage was associated with a significantly higher mortality rate. Diabetes mellitus and lactate were positively, platelet count, and fibrinogen level negatively associated with the occurrence of ICH. Thus, platelet count and fibrinogen level were revealed as potentially modifiable, independent risk factors for ICH. The findings address an area with limited data, provide information about risk factors and the epidemiology of ICH, and may be a starting point for further investigations to develop effective strategies to prevent and treat ICH.

Bleeding During Veno-Venous ECMO: Prevention and Treatment

Veno-venous extracorporeal membrane oxygenation (vvECMO) has become a routine treatment for severe lung failure in specialized centers. Spontaneous bleeding complications, however, are observed in 30–60% of patients during vvECMO treatment. Bleeding increases mortality by factors 2–3. Anticoagulation in combination with several acquired bleeding disorders caused by the mechanical pump and the foreign layer of the extracorporeal system contribute to the risk of bleeding. In this review, the mechanisms of the underlying pathologies and the route from diagnosis to treatment are described.

Longitudinal Trends in Bleeding Complications on Extracorporeal Life Support Over the Past Two Decades—Extracorporeal Life Support Organization Registry Analysis

OBJECTIVES

Data about inhospital outcomes in bleeding complications during extracorporeal life support (ECLS) have been poorly investigated.

DESIGN

Retrospective observational study.

SETTING

Patients reported in Extracorporeal Life Support Organization Registry.

PATIENTS

Data of 53.644 adult patients (greater than or equal to 18 yr old) mean age 51.4 ± 15.9 years, 33.859 (64.5%) male supported with single ECLS run between 01.01.2000 and 31.03.2020, and 19.748 cannulated for venovenous (V-V) ECLS and 30.696 for venoarterial (V-A) ECLS.

INTERVENTIONS

Trends in bleeding complications, bleeding risk factors, and mortality.

MEASUREMENT AND MAIN RESULTS

Bleeding complications were reported in 14.786 patients (27.6%), more often in V-A ECLS compared with V-V (30.0% vs 21.9%; p < 0.001). Hospital survival in those who developed bleeding complications was lower in both V-V ECLS (49.6% vs 66.6%; p < 0.001) and V-A ECLS (33.9 vs 44.9%; p < 0.001). Steady decrease in bleeding complications in V-V and V-A ECLS was observed over the past 20 years (coef., -1.124; p < 0.001 and -1.661; p < 0.001). No change in mortality rates was reported over time in V-V or V-A ECLS (coef., -0.147; p = 0.442 and coef., -0.195; p = 0.139).Multivariate regression revealed advanced age, ecls duration, surgical cannulation, renal replacement therapy, prone positioning as independent bleeding predictors in v-v ecls and female gender, ecls duration, pre-ecls arrest or bridge to transplant, therapeutic hypothermia, and surgical cannulation in v-a ecls.

CONCLUSIONS

A steady decrease in bleeding over the last 20 years, mostly attributable to surgical and cannula-site-related bleeding has been found in this large cohort of patients receiving ECLS support. However, there is not enough data to attribute the decreasing trends in bleeding to technological refinements alone. Especially reduction in cannulation site bleeding is also due to changes in timing, patient selection, and ultrasound guided percutaneous cannulation. Other types of bleeding, such as CNS, have remained stable, and overall bleeding remains associated with a persistent increase in mortality.

Brain Biopsy for Neurological Diseases of Unknown Etiology in Critically Ill Patients: Feasibility, Safety, and Diagnostic Yield

OBJECTIVES

Brain biopsy is a useful surgical procedure in the management of patients with suspected neoplastic lesions. Its role in neurologic diseases of unknown etiology remains controversial, especially in ICU patients. This study was undertaken to determine the feasibility, safety, and the diagnostic yield of brain biopsy in critically ill patients with neurologic diseases of unknown etiology. We also aimed to compare these endpoints to those of non-ICU patients who underwent a brain biopsy in the same clinical context.

DESIGN

Monocenter, retrospective, observational cohort study.

SETTING

A French tertiary center.

PATIENTS

All adult patients with neurologic diseases of unknown etiology under mechanical ventilation undergoing in-ICU brain biopsy between January 2008 and October 2020 were compared with a cohort of non-ICU patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among the 2,207 brain-biopsied patients during the study period, 234 biopsies were performed for neurologic diseases of unknown etiology, including 29 who were mechanically ventilated and 205 who were not ICU patients. Specific histological diagnosis and final diagnosis rates were 62.1% and 75.9%, respectively, leading to therapeutic management modification in 62.1% of cases. Meningitis on prebiopsy cerebrospinal fluid analysis was the sole predictor of obtaining a final diagnosis (2.3 [1.4-3.8]; p = 0.02). ICU patients who experienced therapeutic management modification after the biopsy had longer survival (p = 0.03). The grade 1 to 4 (mild to severe) complication rates were: 24.1%, 3.5%, 0%, and 6.9%, respectively. Biopsy-related mortality was significantly higher in ICU patients compared with non-ICU patients (6.9% vs 0%; p = 0.02). Hematological malignancy was associated with biopsy-related mortality (1.5 [1.01-2.6]; p = 0.04).

CONCLUSIONS

Brain biopsy in critically ill patients with neurologic disease of unknown etiology is associated with high diagnostic yield, therapeutic modifications and postbiopsy survival advantage. Safety profile seems acceptable in most patients. The benefit/risk ratio of brain biopsy in this population should be carefully weighted.

HEROES V-V-HEmorRhagic cOmplications in Veno-Venous Extracorporeal life Support-Development and internal validation of multivariable prediction model in adult patients

BACKGROUND

During extracorporeal life support (ECLS), bleeding is one of the most frequent complications, associated with high morbidity and increased mortality, despite continuous improvements in devices and patient care. Risk factors for bleeding complications in veno-venous (V-V) ECLS applied for respiratory support have been poorly investigated. We aim to develop and internally validate a prediction model to calculate the risk for bleeding complications in adult patients receiving V-V ECLS support.

METHODS

Data from adult patients reported to the extracorporeal life support organization (ELSO) registry between the years 2010 and 2020 were analyzed. The primary outcome was bleeding complications recorded during V-V ECLS. Multivariable logistic regression with backward stepwise elimination was used to develop the predictive model. The performance of the model was tested by discriminative ability and calibration with receiver operating characteristic curves and visual inspection of the calibration plot.

RESULTS

In total, 18 658 adult patients were included, of which 3 933 (21.1%) developed bleeding complications. The prediction model showed a prediction of bleeding complications with an AUC of 0.63. Pre-ECLS arrest, surgical cannulation, lactate, pO₂ , HCO₃ , ventilation rate, mean airway pressure, pre-ECLS cardiopulmonary bypass or renal replacement therapy, pre-ECLS surgical interventions, and different types of diagnosis were included in the prediction model.

CONCLUSIONS

The model is based on the largest cohort of V-V ECLS patients and reveals the most favorable predictive value addressing bleeding events given the predictors that are feasible and when compared to the current literature. This model will help identify patients at risk of bleeding complications, and decision making in terms of anticoagulation and hemostatic management.

Risk factors for intracranial hemorrhage and mortality in adult patients with severe respiratory failure managed using veno-venous extracorporeal membrane oxygenation

Background:

Intracerebral hemorrhage (ICH) is one of the most severe complications during veno-venous extracorporeal membrane oxygenation (VV-ECMO). This study aimed to determine the risk factors for ICH and mortality in such patients.

Methods:

We analyzed the clinical data of 77 patients who received VV-ECMO due to severe respiratory failure from July 2013 to May 2019 at China-Japan Friendship Hospital. Demographical data, laboratory indices, imaging characteristics, and other clinical information were collected. Multivariable logistic regression analyses were performed to identify risk factors for ICH and mortality.

Results:

Of 77 patients, 11 (14.3%) suffered from ICH, and 36 (46.8%) survived. The survival rate was significantly lower (18.2% [2/11] vs. 51.5% [34/66], P = 0.040) in patients with ICH than in those without ICH. Multivariable analysis revealed that factors independently associated with ICH were diabetes mellitus (adjusted odds ratio [aOR]: 12.848, 95% confidence interval [CI]: 1.129–146.188, P = 0.040) and minimum fibrinogen during ECMO (aOR: 2.557, 95% CI: 1.244–5.252, P = 0.011). Multivariable analysis showed that factors independently associated with mortality were acute hepatic failure during ECMO (aOR: 9.205, 95% CI: 1.375–61.604, P = 0.022), CO₂ retention before ECMO (aOR: 7.602, 95% CI: 1.514–38.188, P = 0.014), and minimum platelet concentration during ECMO (aOR: 0.130, 95% CI: 0.029–0.577, P = 0.007).

Conclusions:

Diabetes mellitus and minimum fibrinogen concentration during ECMO are risk factors for ICH in patients with severe respiratory failure managed using VV-ECMO. This indicated that anticoagulants use and nervous system monitoring should be performed more carefully in patients with diabetes when treated with VV-ECMO due to severe respiratory failure.

Tracheobronchial Obstruction Due to Blood Clots in Acute Pulmonary Embolism with Cardiac Arrest Managed with Extracorporeal Membrane Oxygenation

A 66-year-old Japanese woman developed pulseless electrical activity following an acute pulmonary embolism and was treated with thrombolytic therapy. She remained hemodynamically unstable and therefore underwent extracorporeal membrane oxygenation (ECMO). While receiving treatment with ECMO, blood clots induced by endobronchial hemorrhage caused tracheobronchial airway obstruction, leading to ventilatory defect. Furthermore, her cardiac function improved, resulting in cerebral hypoxemia progression. Therefore, the blood clots were removed with a Fogarty balloon catheter and endobronchial urokinase administration, resulting in improvement in her respiratory condition. Finally, ECMO was decannulated, and the patient was discharged from our hospital without difficulties in her activities of daily living.

Neurologic Complications in Adult Post-cardiotomy Cardiogenic Shock Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation: A Cohort Study

Background: This study aims to describe the prevalence of neurologic complications and hospital outcome in adult post-cardiotomy cardiogenic shock (PCS) patients receiving veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support and factors associated with such adverse events.

Methods: Four hundred and fifteen adult patients underwent cardiac surgery and received V-A ECMO for more than 24 h because of PCS. Patients were divided into two groups: those who developed a neurological complication and those who did not (control group). Multivariable logistic regression was performed to identify factors independently associated with neurologic complications.

Results: Neurologic complications occurred in 87 patients (21.0%), including cerebral infarction in 33 patients (8.0%), brain death in 30 patients (7.2%), seizures in 14 patients (3.4%), and intracranial hemorrhage in 11 (2.7%) patients. In-hospital mortality in patients with neurologic complications was 90.8%, compared to 52.1% in control patients (p < 0.001). In a multivariable model, the lowest systolic blood pressure (SBP) level pre-ECMO (OR, 0.89; 95% CI: 0.86–0.93) and aortic surgery combined with coronary artery bypass grafting (OR, 9.22; 95% CI: 2.10–40.55) were associated with overall neurologic complications. Age (OR, 1.06; 95% CI: 1.01–1.12) and lowest SBP (OR, 0.81; 95% CI: 0.76–0.87) were correlative factors of brain death. Coagulation disorders (OR, 9.75; 95% CI: 1.83–51.89) and atrial fibrillation (OR, 12.19; 95% CI: 1.22–121.61) were shown to be associated independently with intracranial hemorrhage, whereas atrial fibrillation (OR, 8.15; 95% CI: 1.31–50.62) was also associated with cerebral infarction.

Conclusions: Neurologic complications in adult PCS patients undergoing V-A ECMO support are frequent and associated with higher in-hospital mortality. Identified risk factors of neurologic complications might help to improve ECMO management and might reduce their occurrence.

Prior Antiplatelet Therapy and Stroke Risk in Critically Ill Patients Undergoing Extracorporeal Membrane Oxygenation

We aimed to investigate whether prior exposure to antiplatelet therapy (anti-PLT) was associated with stroke incidence after the initiation of extracorporeal membrane oxygenation (ECMO) therapy. We conducted a population-based cohort study based on health records obtained from the National Health Insurance Service database in South Korea. Adult patients (aged ≥ 18 years) who underwent ECMO therapy in the intensive care unit during 2009-2018 were enrolled. In total, 17,237 patients who underwent ECMO therapy were included; stroke occurred in 779 (4.5%) of 17,237 patients within 7 days of initiating the ECMO therapy. The number of patients in the anti-PLT and control groups was 3909 (22.7%) and 13,328 (77.3%), respectively. In the multivariable logistic regression analysis, the anti-PLT group showed 33% lower incidence of stroke than the control group (odds ratio (OR): 0.67, 95% confidence interval (CI): 0.55-0.82; p < 0.001). The cardiovascular group showed 35% lower incidence of stroke than the control group (OR: 0.65, 95% CI: 0.52-0.78; p < 0.001), whereas the respiratory group (p = 0.821) and the other group (p = 0.705) did not show any significant association. Prior anti-PLT therapy was associated with a lower incidence of stroke within 7 days of initiating ECMO therapy, which was more evident in the cardiovascular group.

Extracorporeal membrane oxygenation (ECMO): Radiographic appearances, complications and imaging artefacts for radiologists

Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary support primarily used in cardiothoracic and intensive care unit (ICU) settings. The purpose of this review is to familiarise radiologists with the imaging features of ECMO devices, their associated complications and appropriate imaging protocols for contrast-enhanced CT imaging of ECMO patients. This paper will provide a brief introduction to ECMO and the imaging modalities utilised in ECMO patients, followed by a description of the types of ECMO available and cannula positioning. Indications and contraindications for ECMO will be outlined followed by a description of the complications associated with ECMO, which radiologists should recognise. Finally, the imaging protocol and interpretation of contrast-enhanced CT imaging in ECMO patients will be discussed. In the current clinical climate with millions of COVID-19 cases around the world and tens of thousands of critically ill patients, many requiring cardiopulmonary support in intensive care units, the use of ECMO in adults has increased, and thus so has the volume of imaging. Radiologists need to be familiar with the types of ECMO available, the correct positioning of the catheters depending on the type of ECMO being utilised, and the associated complications and imaging artefacts.

Incidence of early intra-cranial bleeding and ischaemia in adult veno-arterial extracorporeal membrane oxygenation and extracorporeal cardiopulmonary resuscitation patients: a retrospective analysis of risk factors

BACKGROUND

Cerebral complications in veno-arterial extracorporeal membrane oxygenation are known to have a strong impact on mortality and morbidity. Aim of this study is to investigate the early incidence, risk factors and in-hospital mortality of intra-cranial ischaemia and haemorrhage in adults undergoing veno-arterial extracorporeal membrane oxygenation treatment.

METHODS

This study is a single-centre retrospective analysis on adult patients undergoing veno-arterial extracorporeal membrane oxygenation for different indications. The inclusion criterion included patients with early routine cerebral computed tomography imaging during extracorporeal membrane oxygenation, with no clinical evidence of cerebral pathology prior to cannulation. Cerebral complications were grouped by aetiology and the territories of the brain's supplying arteries.

RESULTS

One hundred eighty-seven adult patients with a total of 190 veno-arterial extracorporeal membrane oxygenation treatments were included. A total of 16.3% (n = 31) had evidence of either cerebral ischaemia (11.1%) or haemorrhage (5.8%); one patient suffered from both. Cerebral computed tomography scans were performed early in median on the first day after extracorporeal membrane oxygenation cannulation; in-hospital mortality of intra-cranial ischaemia and haemorrhage was 71.4% and 45.5%, respectively. Associated with an increased risk for ischaemic lesions were cannulation of the ascending aorta, higher age, presence of an autoimmune disease and cardiac surgery prior to veno-arterial extracorporeal membrane oxygenation. An association with haemorrhagic lesions was found for a lower blood PaCO₂ at 2 hours, lower blood flow through the extracorporeal membrane oxygenation device at 2 hours, higher international normalized ratio and constantly higher activated partial thromboplastin time values as well as higher mean arterial pressures until haemorrhagic lesions were evident.

CONCLUSION

Cerebral complications are frequent in patients on veno-arterial extracorporeal membrane oxygenation and may be clinically silent events. Careful monitoring with routine neuroimaging seems to be the most appropriate diagnostic approach at present. Intra-cranial ischaemia occurs more frequent than haemorrhage and is associated with cannulation of the aorta ascendens.

Modifiable Risk Factors and Mortality From Ischemic and Hemorrhagic Strokes in Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation: Results From the Extracorporeal Life Support Organization Registry

OBJECTIVES

Although acute brain injury is common in patients receiving extracorporeal membrane oxygenation, little is known regarding the mechanism and predictors of ischemic and hemorrhagic stroke. We aimed to determine the risk factors and outcomes of each ischemic and hemorrhagic stroke in patients with venoarterial extracorporeal membrane oxygenation support.

DESIGN

Retrospective analysis.

SETTING

Data reported to the Extracorporeal Life Support Organization by 310 extracorporeal membrane oxygenation centers from 2013 to 2017.

PATIENTS

Patients more than 18 years old supported with a single run of venoarterial extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 10,342 venoarterial extracorporeal membrane oxygenation patients, 401 (3.9%) experienced ischemic stroke and 229 (2.2%) experienced hemorrhagic stroke. Reported acute brain injury during venoarterial extracorporeal membrane oxygenation decreased from 10% to 6% in 5 years. Overall in-hospital mortality was 56%, but rates were higher when ischemic stroke and hemorrhagic stroke were present (76% and 86%, respectively). In multivariable analysis, lower pre-extracorporeal membrane oxygenation pH (adjusted odds ratio, 0.21; 95% CI, 0.09-0.49; p < 0.001), higher PO2 on first day of extracorporeal membrane oxygenation (adjusted odds ratio, 1.01; 95% CI, 1.00-1.02; p = 0.009), higher rates of extracorporeal membrane oxygenation circuit mechanical failure (adjusted odds ratio, 1.33; 95% CI, 1.02-1.74; p = 0.03), and renal replacement therapy (adjusted odds ratio, 1.49; 95% CI, 1.14-1.94; p = 0.004) were independently associated with ischemic stroke. Female sex (adjusted odds ratio, 1.61; 95% CI, 1.16-2.22; p = 0.004), extracorporeal membrane oxygenation duration (adjusted odds ratio, 1.01; 95% CI, 1.00-1.03; p = 0.02), renal replacement therapy (adjusted odds ratio, 1.81; 95% CI, 1.30-2.52; p < 0.001), and hemolysis (adjusted odds ratio, 1.87; 95% CI, 1.11-3.16; p = 0.02) were independently associated with hemorrhagic stroke.

CONCLUSIONS

Despite a decrease in the prevalence of acute brain injury in recent years, mortality rates remain high when ischemic and hemorrhagic strokes are present. Future research is necessary on understanding the timing of associated risk factors to promote prevention and management strategy.

Brain Injury in Extracorporeal Membrane Oxygenation: A Multidisciplinary Approach

Extracorporeal membrane oxygenation (ECMO) represents an established technique to provide temporary cardiac and/or pulmonary support. ECMO, in veno-venous, veno-arterial or in extracorporeal carbon dioxide removal modality, is associated with a high rate of brain injuries. These complications have been reported in 7 to 15% of adults and 20% of neonates, and are associated with poor survival. Thromboembolic events, loss of cerebral autoregulation, alteration of the blood-brain barrier, and hemorrhage related to anticoagulation represent the main causes of severe brain injury during ECMO. The most frequent forms of acute neurological injuries in ECMO patients are intracranial hemorrhage (2-21%), ischemic stroke (2-10%), seizures (2-6%), and hypoxic-ischemic brain injury; brain death may also occur in this population. Other frequent complications are infarction (1-8%) and cerebral edema (2-10%), as well as neuropsychological and psychiatric sequelae, including posttraumatic stress disorder.

Low vs standardized dose anticoagulation regimens for extracorporeal membrane oxygenation: A meta-analysis

Background

To compare the safety and efficacy of low-dose anticoagulation (LA) with that of standardized dose anticoagulation (SA) for patients supported with extracorporeal membrane oxygenation (ECMO).

Methods

PubMed, MEDLINE, the Cochrane Library, and Web of Science were screened for original articles. Screening was performed using predefined search terms to identify cohort studies reporting the comparison of LA with SA in patients supported with ECMO from Nov 1990 to Jun 2020. The effect size was determined by the odds ratio (OR) with the 95% confidence interval (CI).

Results

An analysis of 7 studies including a total of 553 patients was performed. LA (Low-heparin group) was administered to 255 patients, whereas the other 298 patients received SA (Full-heparin group). The incidence of gastrointestinal tract hemorrhage (OR 0.36, 95% CI 0.20–0.64) and surgical site hemorrhage (OR 0.43, 95% CI 0.20–0.94) were significantly lower in patients who underwent LA compared with that in those who underwent SA. The rates of hospital mortality (OR 0.81, 95% CI 0.42–1.56), successfully weaning off of ECMO (OR 0.80, 95% CI 0.30–2.14), pulmonary embolism (OR 0.79, 95% CI 0.24–2.65), intracardiac thrombus (OR 0.34, 95% CI 0.09–1.30), intracranial hemorrhage (OR 0.62, 95% CI 0.22–1.74), and pulmonary hemorrhage (OR 0.77, 95% CI 0.30–1.93) were similar between the two groups.

Conclusions

This meta-analysis confirms that LA is a feasible and safe anticoagulation strategy in patients supported by ECMO. Future studies should focus on the long-term benefits of LA compared with SA.

Evaluation, Treatment, and Impact of Neurologic Injury in Adult Patients on Extracorporeal Membrane Oxygenation: a Review

Purpose

Extracorporeal membrane oxygen (ECMO) is increasingly used as an advanced form of life support for cardiac and respiratory failure. Unfortunately, in infrequent instances, circulatory and/or respiratory recovery is overshadowed by neurologic injury that can occur in patients who require ECMO. As such, knowledge of ECMO and its implications on diagnosis and treatment of neurologic injuries is indispensable for intensivists and neurospecialists.

Recent findings

The most common neurologic injuries include intracerebral hemorrhage, ischemic stroke, seizure, cerebral edema, intracranial hypertension, global cerebral hypoxia/anoxia, and brain death. These result from events prior to initiation of ECMO, failure of ECMO to provide adequate oxygen delivery, and/or complications that occur during ECMO. ECMO survivors also experience neurological and psychological sequelae similar to other survivors of critical illness.

Summary

Since many of the risk factors for neurologic injury cannot be easily mitigated, early diagnosis and intervention are crucial to limit morbidity and mortality from neurologic injury during ECMO.

Gender-related propensity score match analysis of ECMO therapy in postcardiotomy cardiogenic shock in patients after myocardial revascularization

BACKGROUND

Gender is known to influence the pathophysiology and pathogenesis of the coronary vascular disease. Data on gender-related differences in patients with veno-arterial extracorporeal membrane oxygenation due to postcardiotomy cardiogenic shock is lacking in current literature. We aimed to analyze the impact of gender on intraoperative and short-term outcomes of vaECMO patients after coronary surgery and postcardiotomy cardiogenic shock.

METHODS

Between 2006 and 2017, a total of 92 patients with PCS after CABG underwent vaECMO-implantation at our institution. After a 1:1 propensity score match (PSM) for relevant preoperative data, we identified a cohort of 32 patients, 16 males, and 16 females. Periprocedural and short-term outcome data were analyzed with respect to sex differences.

RESULTS

The mean age was 64 ± 11 years, and 79% (n = 73) were male patients. Clinical outcomes showed a 30-day all-cause mortality of 64% (n = 59). After PSM, male patients showed a significantly smaller number of arterial grafts (0.4 ± 0.53 male vs 1.1 ± 0.7 female; p = 0.037). Thirty-day all-cause mortality did not differ between the groups (56% male vs 75% female; p = 0.262). In general, short-term outcome data were comparable without significant differences for the matched groups.

CONCLUSION

Gender has no impact on patients with vaECMO therapy due to PCS in isolated coronary surgery.

Distinct pattern of microsusceptibility changes on brain magnetic resonance imaging (MRI) in critically ill patients on mechanical ventilation/oxygenation

Purpose

Over the years, interesting SWI abnormalities in patients from intensive care units (ICU) were observed, not attributable to a specific cause and with uncertain clinical significance. Recently, multiple SWI-hypointense foci were mentioned related to neurological complications of SARS-COV-2 infection. The purpose of the study was to describe the patterns of susceptibility brain changes in critically-ill patients who underwent mechanical ventilation and/or extracorporeal membrane oxygenation (ECMO).

Methods

An institutional board-approved, retrospective study was conducted on 250 ICU patients in whom brain MRI was performed between January 2011 and May 2020. Out of 48 patients who underwent mechanical ventilation/ECMO, in fifteen patients (median age 47.7 years), the presence of SWI abnormalities was observed and described.

Results

Microsusceptibilities were located in white-gray matter interface, in subcortical white matter (U-fibers), and surrounding subcortical nuclei in 13/14 (92,8%) patients. In 8/14 (57,1%) patients, SWI foci were seen infratentorially. The corpus callosum was affected in ten (71,4%), internal capsule in five (35,7%), and midbrain/pons in six (42,8%) patients.

Conclusion

We showed distinct patterns of diffuse brain SWI susceptibilities in critically-ill patients who underwent mechanical ventilation/ECMO. The etiology of these foci remains uncertain, but the association with mechanical ventilation, prolonged respiratory failure, and hypoxemia seems probable explanations.

Brain Histopathology of Adult Decedents After Extracorporeal Membrane Oxygenation

OBJECTIVE

To test the hypothesis that brain injury is more common and varied in patients receiving extracorporeal membrane oxygenation (ECMO) than radiographically observed, we described neuropathology findings of ECMO decedents and associated clinical factors from 3 institutions.

METHODS

We conducted a retrospective multicenter observational study of brain autopsies from adult ECMO recipients. Pathology findings were examined for correlation with demographics, clinical data, ECMO characteristics, and outcomes.

RESULTS

Forty-three decedents (n = 13 female, median age 47 years) received autopsies after undergoing ECMO for acute respiratory distress syndrome (n = 14), cardiogenic shock (n = 14), and cardiac arrest (n = 15). Median duration of ECMO was 140 hours, most decedents (n = 40) received anticoagulants; 60% (n = 26) underwent venoarterial ECMO, and 40% (n = 17) underwent venovenous ECMO. Neuropathology was found in 35 decedents (81%), including microhemorrhages (37%), macrohemorrhages (35%), infarctions (47%), and hypoxic-ischemic brain injury (n = 17, 40%). Most pathology occurred in frontal neocortices (n = 43 occurrences), basal ganglia (n = 33), and cerebellum (n = 26). Decedents with hemorrhage were older (median age 57 vs 38 years, p = 0.01); those with hypoxic brain injury had higher Sequential Organ Failure Assessment scores (8.0 vs 2.0, p = 0.04); and those with infarction had lower peak Paco₂ (53 vs 61 mm Hg, p = 0.04). Six of 9 patients with normal neuroimaging results were found to have pathology on autopsy. The majority underwent withdrawal of life-sustaining therapy (n = 32, 74%), and 2 of 8 patients with normal brain autopsy underwent withdrawal of life-sustaining therapy for suspected neurologic injury.

CONCLUSION

Neuropathological findings after ECMO are common, varied, and associated with various clinical factors. Further study on underlying mechanisms is warranted and may guide ECMO management.

Comparison of anticoagulation strategies for veno-venous ECMO support in acute respiratory failure

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) support in acute respiratory failure may be lifesaving, but bleeding and thromboembolic complications are common. The optimal anticoagulation strategy balancing these factors remains to be determined. This retrospective study compared two institutional anticoagulation management strategies focussing on oxygenator changes and both bleeding and thromboembolic events.

METHODS

We conducted a retrospective observational cohort study between 04/2015 and 02/2020 in two ECMO referral centres in Germany in patients receiving veno-venous (VV)-ECMO support for acute respiratory failure for > 24 h. One centre routinely applied low-dose heparinization aiming for a partial thromboplastin time (PTT) of 35-40 s and the other routinely used a high-dose therapeutic heparinization strategy aiming for an activated clotting time (ACT) of 140-180 s. We assessed number of and time to ECMO oxygenator changes, 15-day freedom from oxygenator change, major bleeding events, thromboembolic events, 30-day ICU mortality, activated clotting time and partial thromboplastin time and administration of blood products. Primary outcome was the occurrence of oxygenator changes depending on heparinization strategy; main secondary outcomes were the occurrence of severe bleeding events and occurrence of thromboembolic events. The transfusion strategy was more liberal in the low-dose centre.

RESULTS

Of 375 screened patients receiving VV-ECMO support, 218 were included in the analysis (117 high-dose group; 101 low-dose group). Disease severity measured by SAPS II score was 46 (IQR 36-57) versus 47 (IQR 37-55) and ECMO runtime was 8 (IQR 5-12) versus 11 (IQR 7-17) days (P = 0.003). There were 14 oxygenator changes in the high-dose group versus 48 in the low-dose group. Freedom from oxygenator change at 15 days was 73% versus 55% (adjusted HR 3.34 [95% confidence interval 1.2-9.4]; P = 0.023). Severe bleeding events occurred in 23 (19.7%) versus 14 (13.9%) patients (P = 0.256) and thromboembolic events occurred in 8 (6.8%) versus 19 (19%) patients (P = 0.007). Mortality at 30 days was 33.3% versus 30.7% (P = 0.11).

CONCLUSIONS

In this retrospective study, ECMO management with high-dose heparinization was associated with lower rates of oxygenator changes and thromboembolic events when compared to a low-dose heparinization strategy. Prospective, randomized trials are needed to determine the optimal anticoagulation strategy in patients receiving ECMO support.

Risk Factors of Ischemic and Hemorrhagic Strokes During Venovenous Extracorporeal Membrane Oxygenation: Analysis of Data From the Extracorporeal Life Support Organization Registry

OBJECTIVES

Stroke is commonly reported in patients receiving venovenous extracorporeal membrane oxygenation, but risk factors are not well described. We sought to determine preextracorporeal membrane oxygenation and on-extracorporeal membrane oxygenation risk factors for both ischemic and hemorrhagic strokes in patients with venovenous extracorporeal membrane oxygenation support.

DESIGN

Retrospective analysis.

SETTING

Data reported to the Extracorporeal Life Support Organization by 366 extracorporeal membrane oxygenation centers from 2013 to 2019.

PATIENTS

Patients older than 18 years supported with a single run of venovenous extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 15,872 venovenous extracorporeal membrane oxygenation patients, 812 (5.1%) had at least one type of acute brain injury, defined as ischemic stroke, hemorrhagic stroke, or brain death. Overall, 215 (1.4%) experienced ischemic stroke and 484 (3.1%) experienced hemorrhagic stroke. Overall inhospital mortality was 36%, but rates were higher in those with ischemic or hemorrhagic stroke (68% and 73%, respectively). In multivariable analysis, preextracorporeal membrane oxygenation pH (adjusted odds ratio = 0.10; 95% CI, 0.03-0.35; p < 0.001), hemolysis (adjusted odds ratio = 2.27; 95% CI, 1.22-4.24; p = 0.010), gastrointestinal hemorrhage (adjusted odds ratio = 2.01; 95% CI 1.12-3.59; p = 0.019), and disseminated intravascular coagulation (adjusted odds ratio = 3.61; 95% CI, 1.51-8.66; p = 0.004) were independently associated with ischemic stroke. Pre-extracorporeal membrane oxygenation pH (adjusted odds ratio = 0.28; 95% CI, 0.12-0.65; p = 0.003), preextracorporeal membrane oxygenation Po2 (adjusted odds ratio = 0.96; 95% CI, 0.93-0.99; p = 0.021), gastrointestinal hemorrhage (adjusted odds ratio = 1.70; 95% CI, 1.15-2.51; p = 0.008), and renal replacement therapy (adjusted odds ratio=1.57; 95% CI, 1.22-2.02; p < 0.001) were independently associated with hemorrhagic stroke.

CONCLUSIONS

Among venovenous extracorporeal membrane oxygenation patients in the Extracorporeal Life Support Organization registry, approximately 5% had acute brain injury. Mortality rates increased two-fold when ischemic or hemorrhagic strokes occurred. Risk factors such as lower pH and hypoxemia during the pericannulation period and markers of coagulation disturbances were associated with acute brain injury. Further research on understanding preextracorporeal membrane oxygenation and on-extracorporeal membrane oxygenation risk factors and the timing of acute brain injury is necessary to develop appropriate prevention and management strategies.

Brain magnetic resonance imaging in adult survivors of extracorporeal membrane oxygenation

Despite the common occurrence of neurologic complications in patients with extracorporeal membrane oxygenation (ECMO), data on magnetic resonance imaging (MRI) findings in adult ECMO are limited. We aimed to describe the MRI findings of patients after ECMO cannulation. Records of patients who underwent ECMO from September 2017 to June 2019 were reviewed. MRI studies were performed using multiplanar sequences consisting of T1-, T2-weighted, fluid attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and susceptibility weighted images (SWI). Of the 78 adult patients who underwent ECMO, 26 (33%) survived. Of 26, eight patients (31%) had MRI studies, with a median age of 47 years (interquartile range [IQR]: 25-57). The median ECMO support time was 8 days (IQR: 4-25) and the median time from decannulation to MRI was 12 days (IQR: 1-34). Five (63%) of eight patients had ischemic infarcts; 4 (50%) had cerebral microhemorrhage; 2 (25%) had intracranial hemorrhage; and 1 (13%) had thoracic cord ischemic infarct. There were no patients with normal MRI. All patients underwent transcranial Doppler (TCD). Four of 8 (50%) showed presence of microemboli with TCD; 3 of 4 (75%) had ischemic infarcts; and 1 of 4 (25%) had presence of multiple cerebral microhemorrhages on MRI. All ischemic infarcts had diffuse pattern of punctate to small lesions for ECMO survivors. The location of cerebral microhemorrhages included lobar (n = 4, 100%), deep (n = 2, 50%), and both (n = 2, 50%). Of the MRI studies, cerebrovascular related lesions were the most frequent, with punctate ischemic infarct being the most common type that may be associated with TCD microemboli. The results of the study suggest that subclinical cerebral lesions are commonly found in patients with ECMO support. Further research is needed to understand long-term effect of these cerebral lesions.

Bleeding, thrombosis and transfusion in patients on ECMO: A retrospective study in a tertiary center in Hong Kong

Purpose:

Use of anticoagulation in patients on ECMO, especially in Chinese, has always been difficult. This study aimed to review the incidence of bleeding, thrombosis, and transfusion requirement in Chinese ECMO patients and to identify risk factors for bleeding complications.

Materials and Methods:

This was a retrospective observational study of a tertiary hospital from 2010 to 2018. Patients aged ⩾18 years who received ECMO were included. The primary outcome was incidence of bleeding. Secondary outcomes included ICU mortality, hospital mortality, and length of the ICU and hospital stay.

Results:

Of the 130 patients, 55(42.3%) had at least one bleeding events and thrombosis occurred in 37(28.5%). A lower fibrinogen level (adjusted OR 0.56 (0.36–0.86), p = 0.009), bloodstream infection (adjusted OR 2.76 (1.01–7.53), p = 0.047) and longer duration on ECMO (adjusted OR 1.14 (1.02–1.27), p = 0.018) were independently associated with occurrence of bleeding. APTT (adjusted OR 0.99 (0.97–1.01), p = 0.370) and platelet count (adjusted OR 1.00 (0.98–1.01), p = 0.632) were not statistically significant risk factors for bleeding events.

Conclusions:

Bleeding and thrombosis were common complications in Chinese patients receiving ECMO. Hypofibrinogenemia and bloodstream infection, but not APTT nor platelet counts, were independent risk factors for bleeding events.

Intracranial hemorrhage on extracorporeal membrane oxygenation: an international survey

INTRODUCTION

Intracranial hemorrhage is one of the most dreaded complications associated with extracorporeal membrane oxygenation. However, robust data to guide clinical practice are lacking. We aimed to describe the current perceptions and practices surrounding the risk, prevention, diagnosis, management, and prognosis of intracranial hemorrhage in patients on extracorporeal membrane oxygenation.

METHODS

We conducted an international, cross-sectional survey of adult extracorporeal membrane oxygenation centers using a self-administered electronic questionnaire sent to medical directors and program coordinators of all 290 adult centers member of the Extracorporeal Life Support Organization.

RESULTS

There were 143 respondents (49%). The median proportion of patients having neuroimaging performed was only 1-25% in venovenous-extracorporeal membrane oxygenation patients and 26-50% in venoarterial-extracorporeal membrane oxygenation and extracorporeal cardiopulmonary resuscitation. The majority of participants (58%) tolerated a PaO₂ < 60 mm Hg on venovenous-extracorporeal membrane oxygenation. Lower PaO₂ targets were inversely correlated with the reported incidence of intracranial hemorrhage (r =-0.247; p = 0.024). In patients with intracranial hemorrhage, most participants reported stopping anticoagulation, and median targets for blood product administration were 70,000-99,000 platelets/µL, 1.5-1.9 of international normalized ratio, and 1.6-2.0 g/L of fibrinogen.

CONCLUSION

We found significant heterogeneity in the perceptions and practices. This underlines the need for more research to appropriately guide patient management. Importantly, neuroimaging was performed only in a minority of patients. Considering the important management implications reported by most centers when intracranial hemorrhage is diagnosed, perhaps clinicians should consider widening their indications for early neuroimaging.

Acute neurological complications in adult patients with cardiogenic shock on veno-arterial extracorporeal membrane oxygenation support

Background

Extracorporeal life support has markedly progressed over the recent years to support patients with severe cardiac and pulmonary dysfunction refractory to conventional management. Many patients developed acute neurological complications while being supported with extracorporeal membrane oxygenation (ECMO). Our objectives were to study the frequencies and outcomes of CNS complications in adult patients with cardiogenic shock on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and to study the risk factors of these CNS complications. We conducted a retrospective study including adult patients admitted to the cardiac critical care unit with cardiopulmonary instability and supported with VA-ECMO from January 2016 until December 2018 in a tertiary care hospital.

Results

After reviewing 231 patients with ECMO, 67 patients with cardiogenic shock supported with VA-ECMO were included. About 65.7% of the studied patients were supported after cardiothoracic surgeries. About 56.7% of the patients developed acute CNS events. According to brain CT imaging, ischaemic stroke was diagnosed in 14.9% and intracerebral haemorrhage (ICH) was diagnosed in 11.9% of patients while 16.4% of patients with CNS events had negative brain CT imaging. The SOFA score was significantly higher in the group with CNS events at ICU admission and after 48 hours . As compared to patients with ischaemic strokes, patients with ICH were younger with lesser BMI, had higher SOFA scores at admission and at 48 hours of ICU admission, had longer cardiopulmonary bypass and aortic cross clamping times and had more support with central than peripheral VA-ECMO. AF was more frequent in the group with CNS events especially in the ischaemic stroke subgroup. Presence of intracardiac thrombi was more frequent in the ischaemic stroke subgroup. There was no statistically significant difference between both groups regarding ECMO circuit thrombi. The use of IABP and presence of DM were more frequent in the ischaemic stroke subgroup. Patients with neurological events had hypoalbuminaemia and higher blood glucose and serum creatinine levels compared to those without CNS events. The peak lactate level and lactate after 24 hours of ECMO support were significantly higher in those with CNS events. Patients with ICH had significant thrombocytopenia and higher INR with more prolonged aPTT and PTT ratio than those with ischaemic stroke. Patients with neurological events had significant hospital mortality, more mechanical ventilation days and tracheostomy, AKI and haemodialysis compared to those without CNS events, but there were no significant differences between both groups regarding ECMO duration, ICU or post ICU stays nor 1 year mortality.

Conclusion

Acute neurological events are frequent in patients supported with VA-ECMO and associated with significant morbidity and hospital mortality. As compared to ischaemic stroke, ICH is more frequent in younger patients with lesser BMI, central VA-ECMO after cardiothoracic surgeries, thrombocytopenia, and coagulopathy. Our findings may have major implications for the care of patients requiring VA-ECMO.

Feasibility of Venovenous Extracorporeal Membrane Oxygenation Without Systemic Anticoagulation

BACKGROUND

Venovenous extracorporeal membrane oxygenation (ECMO) is increasingly being used for acute respiratory distress syndrome and as a bridge to lung transplantation. After initiation of venovenous ECMO, systemic anticoagulation therapy is traditionally administered and can cause bleeding diathesis. Here, we investigated whether venovenous ECMO can be administered without continuous systemic anticoagulation administration for patients with acute respiratory distress syndrome.

METHODS

This is a retrospective review of an institutional ECMO database. We included consecutive patients from January 2015 through February 2019. Overall, 38 patients received low levels of continuous systemic anticoagulation (AC+) whereas the subsequent 36 patients received standard venous thromboprophylaxis (AC-). Published Extracorporeal Life Support Organization guidelines were used for the definition of outcomes and complications.

RESULTS

Overall, survival was not different between the two groups (P = .58). However, patients in the AC+ group had higher rates of gastrointestinal bleeding (28.9%, vs AC- group 5.6%; P < .001). The events per patient-day of gastrointestinal bleeding was 0.00025 in the AC- group and 0.00064 in the AC+ group (P < .001). In addition, oxygenator dysfunction was increased in the AC+ group (28.9% and 0.00067 events per patient-day, vs AC- 11.1% and 0.00062 events per patient-day; P = .02). Furthermore, the AC+ group received more transfusions: packed red blood cells, AC+ group 94.7% vs AC- group 55.5% (P < .001); fresh frozen plasma, AC+ 60.5% vs AC- 16.6% (P = .001); and platelets, AC+ 84.2% vs AC- 27.7% (P < .001). There was no circuit thrombosis in either groups throughout the duration of ECMO support.

CONCLUSIONS

Our results suggest that venovenous ECMO can be safely administered without continuous systemic anticoagulation therapy. This approach may be associated with reduced bleeding diathesis and need for blood transfusions.

ECMO in cardiogenic shock and bridge to heart transplant

Purpose

The aim of this review is to discuss the role of extracorporeal membrane oxygenation (ECMO) in cardiogenic shock and its use to bridge patients to heart transplantation.

Methods and results

Consideration of published literature reveals indications for ECMO in cardiogenic shock and tools for patient selection, adequate evidence of its efficacy, its advantages when compared with other temporary mechanical circulatory support devices and details of its use as a bridge to decision, bridge to recovery, bridge to bridge (durable ventricular assist device) and bridge to heart transplant.

Conclusion

ECMO is invaluable in treating patients with medically refractory profound cardiogenic shock and allows for cardiac recovery or planning for permanent heart replacement treatments.

Medical Optimization and Liberation of Adult Patients From VA-ECMO

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be an efficacious cardiopulmonary support for adults as rescue from refractory cardiogenic shock. It is best employed as a bridging strategy to recovery or alternative support rather than sustained, long-term mechanical circulatory support. The purpose of this paper is to discuss strategies to optimize patient management on VA-ECMO and approaches to promote successful separation from support. Rapid medical optimization will assist in reducing the time on VA-ECMO, thereby improving the likelihood of patient salvage. Suitably trained physicians and personnel, guided by structured protocols, can promote excellence in team care and provision of consistent management. Focusing on anticoagulation, careful neurologic monitoring, prevention of leg ischemia, awareness of differential hypoxemia, optimizing mechanical ventilation, identifying and timely intervention for left-ventricular distension (LVD), along with a strategic weaning algorithm, can prevent significant morbidity and mortality. LVD physiology, diagnosis, and risk factors are reviewed. Indications for LV decompression, along with medical and mechanical management options, are elucidated.

Extracorporeal membrane oxygenation: a literature review

Extracorporeal membrane oxygenation is a modality of extracorporeal life support that allows for temporary support in pulmonary and/or cardiac failure refractory to conventional therapy. Since the first descriptions of extracorporeal membrane oxygenation, significant improvements have occurred in the device and the management of patients and, consequently, in the outcomes of critically ill patients during extracorporeal membrane oxygenation. Many important studies about the use of extracorporeal membrane oxygenation in patients with acute respiratory distress syndrome refractory to conventional clinical support, under in-hospital cardiac arrest and with cardiogenic refractory shock have been published in recent years. The objective of this literature review is to present the theoretical and practical aspects of extracorporeal membrane oxygenation support for respiratory and/or cardiac functions in critically ill patients.

Acute Neurologic Complications During Extracorporeal Membrane Oxygenation: A Systematic Review

OBJECTIVES

We determine the frequency, risk factors, and mortality of neurologic complications in adults on extracorporeal membrane oxygenation and propose an algorithm for preventive strategies.

DATA SOURCES

PubMed, Embase, and Cochrane databases.

STUDY SELECTION

Screening was performed using predefined search terms to identify cohort studies reporting neurologic complications in adults during extracorporeal membrane oxygenation from 1990 to 2017.

DATA EXTRACTION

The final reference list was generated on the basis of relevance to the discussed topics. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation classification of evidence scheme.

DATA SYNTHESIS

In 44 studies, the median frequency of acute neurologic complications is 13% (1-78%; 5% intracranial hemorrhages, 5% ischemic strokes, 2% seizures). Neurologic complications are reported more frequently with venoarterial extracorporeal membrane oxygenation compared with venovenous extracorporeal membrane oxygenation (14 vs eight studies) with a median proportion of complications of 15% (6-33%; 95% CI, 8-19) for venoarterial extracorporeal membrane oxygenation. Median in-hospital mortality is higher with neurologic complications (83%; interquartile range, 54-100% vs 42%; interquartile range, 24-55% without neurologic complications; p < 0.001). Median mortality is 96% for hemorrhages, 84% for ischemic strokes 84%, and 40% for seizures. Risk factors are age, preextracorporeal membrane oxygenation cardiac arrest, hypoglycemia, and administration of inotropes. Hemorrhages are associated with female gender, duration of ventilation and extracorporeal membrane oxygenation, decreased serum fibrinogen, heparin, serum creatinine greater than 2.6 mg/dL, hemodialysis, and thrombocytopenia. Increased odds for ischemic stroke is seen with a preextracorporeal membrane oxygenation serum lactate greater than 10 mmol/L. No studies report daily coagulation monitoring and neurologic assessments, and quality of evidence was low to very low.

CONCLUSIONS

Neurologic complications are reported frequently and with high occurrence rate, especially with venoarterial extracorporeal membrane oxygenation, and associated with high mortality calling for daily weaning from sedation and neuromuscular blockers for neurologic assessment and coagulation monitoring. The low quality of evidence indicates the need for higher quality studies in this context.

ECMO without anticoagulation in patients with disease-related severe thrombocytopenia: Feasible but futile?

Severe thrombocytopenia poses a high risk for bleeding thus representing a relative contraindication for anticoagulation and therefore extracorporeal membrane oxygenation (ECMO). We herein report on a series of immunocompromised patients with severe thrombocytopenia undergoing long-term ECMO without systemic anticoagulation. We retrospectively identified seven adult patients with anticoagulation withdrawal for ≥3 days (range 5-317) during venovenous ECMO therapy due to thrombocytopenia < 50 G/L treated in a university-affiliated hospital from January 2013 to April 2017. All ECMO systems used were heparin coated. Overall, 530 ECMO days were observed, 404 (76%) of them without systemic anticoagulation. Platelet count during ECMO treatment was 24 G/L (median, range 1-138), ECMO duration was 35 days (5-317), and ECMO was run without any anticoagulation for 20 days (5-317). Altogether, five clotting events were seen leading to oxygenator exchanges. Bleeding was common including one fatal intracerebral hemorrhage. Altogether, 29 platelet concentrates per patient (7-207) were administered, which correspond to 0.8 per day (0.6-1.3). One patient survived ICU and hospital. In patients with thrombocytopenia, ECMO can be run without anticoagulation even for considerably long periods of time. Bleeding remains common, while clotting events seem to be rare. However, prognosis of this patient population undergoing ECMO support seems grim.