Feasibility of Venovenous Extracorporeal Membrane Oxygenation Without Systemic Anticoagulation

Impact of C-reactive Protein on Anticoagulation Monitoring in Extracorporeal Membrane Oxygenation

OBJECTIVE

To evaluate the impact of inflammation on anticoagulation monitoring for patients supported with extracorporeal membrane oxygenation (ECMO).

DESIGN

Prospective single-center cohort study.

SETTING

University-affiliated tertiary care academic medical center.

PARTICIPANTS

Adult venovenous and venoarterial ECMO patients anticoagulated with heparin/ MEASUREMENTS AND MAIN RESULTS: C-Reactive protein (CRP) was used as a surrogate for overall inflammation. The relationship between CRP and the partial thromboplastin time (PTT, seconds) was evaluated using a CRP-insensitive PTT assay (PTT-CRP) in addition to measurement using a routine PTT assay. Data from 30 patients anticoagulated with heparin over 371 ECMO days was included. CRP levels (mg/dL) were significantly elevated (median, 17.2; interquartile range [IQR], 9.2-26.1) and 93% of patients had a CRP of ≥5. The median PTT (median 58.9; IQR, 46.9-73.3) was prolonged by 11.3 seconds compared with simultaneously measured PTT-CRP (median, 47.6; IQR, 40.1-55.5; p < 0.001). The difference between PTT and PTT-CRP generally increased with CRP elevation from 2.7 for a CRP of <5.0 to 13.0 for a CRP between 5 and 10, 17.7 for a CRP between 10 and 15, and 15.1 for a CRP of >15 (p < 0.001). In a subgroup of patients, heparin was transitioned to argatroban, and a similar effect was observed (median PTT, 62.1 seconds [IQR, 53.0-78.5 seconds] vs median PTT-CRP, 47.6 seconds [IQR, 41.3-57.7 seconds]; p < 0.001).

CONCLUSIONS

Elevations in CRP are common during ECMO and can falsely prolong PTT measured by commonly used assays. The discrepancy due to CRP-interference is important clinically given narrow PTT targets and may contribute to hematological complications.

A rare case of spontaneous hemoperitoneum in a bone marrow transplant recipient on VV-ECMO

A 53-year-old man with acute myeloid leukemia received an allogeneic hematopoietic cell transplant (HCT) from a matched unrelated donor. One month after his transplantation, he developed ARDS requiring initiation of VV-ECMO. He suffered from pancytopenia, managed with frequent transfusions, granulocyte-colony stimulating factor (G-CSF) and weekly thrombopoietin receptor agonist. On ECMO day 17, the patient developed severe hypotension after insertion of a chest tube for a large right-sided pneumothorax. CT angiography of the abdomen showed hemoperitoneum. Exploratory laparotomy revealed approximately 4 L of blood and a ruptured splenic hilum. A splenectomy was performed. Unfortunately, the patient continued to require multiple daily blood products and his condition continued to decline despite two reoperations. His family chose to discontinue ECMO and he passed away peacefully. Spontaneous splenic rupture after GM-CSF has never been reported in patients on VV-ECMO. This manuscript reviews the literature regarding the pathophysiology and clinical manifestation of this rare occurrence.

Impact of bridging veno-venous extracorporeal membrane oxygenation to COVID-19 lung transplantation

Background

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) therapy is being increasingly used as respiratory support for patients with severe coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome (ARDS). However, the long-term outcome of VV-ECMO as a bridge to lung transplantation in COVID-19-associated ARDS remains unclear, hence the purpose of this study aimed to evaluate its long-term outcome, safety, and feasibility.

Methods

This was a retrospective cohort study from an institutional lung transplantation database between June 2020 and June 2022. Data on demographics, pre-transplantation laboratory values, postoperative outcomes, preoperative and postoperative transthoracic echocardiography findings, and survival rates were collected. Chi-square, Mann-Whitney U, Student's t, Kaplan-Meier, and Wilcoxon signed-rank tests were used for analysis.

Results

Twenty-five patients with COVID-19-associated ARDS underwent lung transplant surgery with VV-ECMO bridge. Unfortunately, six patients with COVID-19-associated ARDS using VV-ECMO died while waiting for transplantation during the same study period. Patients with VV-ECMO bridge were a more severe cohort than 16 patients without VV-ECMO bridge (lung allocation score: 88.1 vs. 74.9, P<0.001). These patients had longer intensive care unit and hospital stays (P=0.03 and P=0.02, respectively) and a higher incidence of complications after lung transplantation. The one-year survival rate of patients with VV-ECMO bridge was lower than that of patients without (78.3% vs. 100.0%, P=0.06), but comparable to that of patients with other lung transplant indications (84.2%, P=0.95). Echocardiography showed a decrease in the right ventricular systolic pressure (P=0.01), confirming that lung transplantation improved right heart function.

Conclusions

Our findings suggest that VV-ECMO can be used to safely bridge patients with COVID-19 associated ARDS with right heart failure.

Association of anti-factor Xa-guided anticoagulation with hemorrhage during ECMO support: A systematic review and meta-analysis

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) is associated with complex hemostatic changes. Systemic anticoagulation is initiated to prevent clotting in the ECMO system, but this comes with an increased risk of bleeding. Evidence on the use of anti-Xa-guided monitoring to prevent bleeding during ECMO support is limited. Therefore, we aimed to analyze the association between anti-factor Xa-guided anticoagulation and hemorrhage during ECMO.

METHODS

A systematic review and meta-analysis was performed (up to August 2023).

PROSPERO

CRD42023448888.

RESULTS

Twenty-six studies comprising 2293 patients were included in the analysis, with six works being part of the meta-analysis. The mean anti-Xa values did not show a significant difference between patients with and without hemorrhage (standardized mean difference -0.05; 95% confidence interval [CI]: -0.19; 0.28, p = .69). We found a positive correlation between anti-Xa levels and unfractionated heparin dose (UFH; pooled estimate of correlation coefficients 0.44; 95% CI: 0.33; 0.55, p < .001). The most frequent complications were any type of hemorrhage (pooled 36%) and thrombosis (33%). Nearly half of the critically ill patients did not survive to hospital discharge (47%).

CONCLUSIONS

The most appropriate tool for anticoagulation monitoring in ECMO patients is uncertain. Our analysis did not reveal a significant difference in anti-Xa levels in patients with and without hemorrhagic events. However, we found a moderate correlation between anti-Xa and the UFH dose, supporting its utilization in monitoring UFH anticoagulation. Given the limitations of time-guided monitoring methods, the role of anti-Xa is promising and further research is warranted.

Temporal correlation between postreperfusion complement deposition and severe primary graft dysfunction in lung allografts

Growing evidence implicates complement in the pathogenesis of primary graft dysfunction (PGD). We hypothesized that early complement activation postreperfusion could predispose to severe PGD grade 3 (PGD-3) at 72 hours, which is associated with worst posttransplant outcomes. Consecutive lung transplant patients (n = 253) from January 2018 through June 2023 underwent timed open allograft biopsies at the end of cold ischemia (internal control) and 30 minutes postreperfusion. PGD-3 at 72 hours occurred in 14% (35/253) of patients; 17% (44/253) revealed positive C4d staining on postreperfusion allograft biopsy, and no biopsy-related complications were encountered. Significantly more patients with PGD-3 at 72 hours had positive C4d staining at 30 minutes postreperfusion compared with those without (51% vs 12%, P < .001). Conversely, patients with positive C4d staining were significantly more likely to develop PGD-3 at 72 hours (41% vs 8%, P < .001) and experienced worse long-term outcomes. In multivariate logistic regression, positive C4d staining remained highly predictive of PGD-3 (odds ratio 7.92, 95% confidence interval 2.97-21.1, P < .001). Hence, early complement deposition in allografts is highly predictive of PGD-3 at 72 hours. Our data support future studies to evaluate the role of complement inhibition in patients with early postreperfusion complement activation to mitigate PGD and improve transplant outcomes.

Fixed, Dilated, and Cannulated - Medical Management of Elevated Intracranial Pressures due to a Large Intracranial Hemorrhage in a Patient on Veno-Venous Extracorporeal Membrane Oxygenation: Case Report

A 40-year-old woman presented with mediastinitis, necrotizing pancreatitis, and severe acute respiratory distress syndrome with refractory acidemia (pH 7.14) and hypercapnia (PaCO2 115 mmHg), requiring veno-venous extracorporeal membrane oxygenation (ECMO). Eight hours after cannulation, and rapid correction of PaCO2 to 44 mmHg, she was found to have bilaterally fixed and dilated pupils. Imaging showed a 60 mL left-sided temporoparietal intracranial hemorrhage with surrounding edema, 8 mm midline shift, intraventricular hemorrhage, and impending herniation. Decompressive hemicraniectomy was not offered due to concern for medical instability. After receiving a dose of mannitol, her pupillary and motor exam improved. An intracranial pressure (ICP) monitor was placed to guide hyperosmolar therapy administration, hemodynamic targets, and sweep gas titration. On hospital day (HD) 5, her ICP monitor was removed. Follow-up imaging revealed resolution of mass effect and no brainstem injury. She was subsequently extubated (HD 9) and discharged home (HD 40). One year after hospitalization, she is living at home with minimal residual deficits. This case highlights the utility of targeted, medical ICP management and importance of assessing response to conservative therapies when considering prognosis in patients on ECMO with severe acute brain injury.

Acute Respiratory Failure in Severe Acute Brain Injury

Acute respiratory failure is commonly encountered in severe acute brain injury due to a multitude of factors related to the sequelae of the primary injury. The interaction between pulmonary and neurologic systems in this population is complex, often with competing priorities. Many treatment modalities for acute respiratory failure can result in deleterious effects on cerebral physiology, and secondary brain injury due to elevations in intracranial pressure or impaired cerebral perfusion. High-quality literature is lacking to guide clinical decision-making in this population, and deliberate considerations of individual patient factors must be considered to optimize each patient's care.

Indication for ECMO predicts time to first actionable bleeding complication

Purpose

Bleeding is a major complication of patients requiring extracorporeal membrane oxygenation (ECMO). Several risk factors have been identified; however, there remains a paucity of evidence for optimal management of anticoagulation and bleeding in ECMO patients.

Methods

A total of 255 patients required ECMO from January 1996 to December 2021 at a single institution. The Bleeding Academic Research Consortium (BARC) Score was used for defining actionable bleeding. Univariate and multivariate testing were used for outcome analysis. Kaplan-Meier survival curves were plotted for time-to-event analysis.

Results

Of the 255 patients, 147 patients had no actionable bleeding complications, while 108 had at least one actionable bleeding complication. Duration of support (p<0.001) and total number of transfusions (p<0.001) differed between the two groups significantly, with no significant difference in survival to discharge (p=0.894). On multivariate regression, significant predictors for actionable bleeding complications included diabetes (OR 2.01, p=0.03), precannulation hematocrit (OR 0.97, p<0.001), length of support (OR 1.00, p<0.001), use of warfarin (OR 2.28, p=0.03), and post-cardiotomy indication for ECMO (OR 0.77, p=0.02). The median time to first actionable bleeding complication after cannulation was 141.2 h. When stratified by indication for ECMO or type of ECMO circuit, there was a significant difference in time to first actionable bleeding complication (p=0.001, p=0.018).

Conclusions

Indication for ECMO and type of ECMO circuit both are predictive of timing to first actionable bleeding complication in our study. Further data are needed to reliably establish individualized anticoagulation strategies and bleeding management based on indication and circuit setup.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01601-9.

Thromboelastography versus thromboelastometry for unfractionated heparin monitoring in adult patients on extracorporeal membrane oxygenation

Background: Monitoring the anticoagulant effect of unfractionated heparin (UFH) in extracorporeal membrane oxygenation (ECMO) patients is complex but critically important to balance the risks of treatment related bleeding and circuit thrombosis. While guidelines recommend using more than one method to monitor UFH activity, the use of thromboelastometry (ROTEM) to monitor UFH in ECMO patients has not been investigated in detail.Methods: This is an observational, single-center retrospective study looking at adult ECMO patients on UFH that had ROTEM and thromboelastography (TEG) tests obtained concurrently. A total of 20 samples were obtained from nine patients during the study period, seven of which were on veno-arterial (VA) ECMO and two of which were on veno-venous (VV) ECMO.Results: Under institutional standard operating practice, when TEG and/or activated partial thromboplastin time (aPTT) were considered therapeutic, intrinsic thromboelastometry clotting time (INTEM CT) was only 1.2 times higher than the normal range. TEG based monitoring compared to aPTT based monitoring tended to result in lower anti-Xa levels and less intensive anticoagulation. For the total cohort, bleeding events, driven by the need for blood transfusions, were more common compared to ischemic events (77% vs 11%; p = 0.02).Conclusion: INTEM CT tended to be less sensitive to lower doses of UFH with a value of 1.2 times higher than the normal range when aPTT and/or TEG were considered therapeutic. Due to the relative insensitivity of ROTEM, our institution decided to continue to use TEG instead of ROTEM. Larger, multicenter trials may be helpful to validate these findings.

The History of Extracorporeal Membrane Oxygenation and the Development of Extracorporeal Membrane Oxygenation Anticoagulation

Extracorporeal membrane oxygenation (ECMO) was first started for humans in early 1970s by Robert Bartlett. Since its inception, there have been numerous challenges with extracorporeal circulation, such as coagulation and platelet activation, followed by consumption of coagulation factors and platelets, and biocompatibility of tubing, pump, and oxygenator. Unfractionated heparin (heparin hereafter) has historically been the defacto anticoagulant until recently. Also, coagulation monitoring was mainly based on bedside activated clotting time and activated partial thromboplastin time. In the past 50 years, the technology of ECMO has advanced tremendously, and thus, the survival rate has improved significantly. The indication for ECMO has also expanded. Among these are clinical conditions such as postcardiopulmonary bypass, sepsis, ECMO cardiopulmonary resuscitation, and even severe coronavirus disease 2019 (COVID-19). Not surprisingly, the number of ECMO cases has increased according to the Extracorporeal Life Support Organization Registry and prolonged ECMO support has become more prevalent. It is not uncommon for patients with COVID-19 to be on ECMO support for more than 1 year until recovery or lung transplant. With that being said, complications of bleeding, thrombosis, clot formation in the circuit, and intravascular hemolysis still remain and continue to be major challenges. Here, several clinical ECMO experts, including the "Father of ECMO"-Dr. Robert Bartlett, describe the history and advances of ECMO.

Left Main Bronchus Obstruction in a Patient with Small-cell Lung Cancer Successfully Treated with Venovenous Extracorporeal Membrane Oxygenation

Lung cancer can cause fatal central airway obstruction. Rapid airway clearance is necessary in some cases, but ventilator management may be insufficient to maintain oxygenation levels. Venovenous extracorporeal membrane oxygenation (VV-ECMO) may be an effective rescue therapy for respiratory failure, but its efficacy in treating tumor-related airway obstruction is unknown. We herein report a case of central airway obstruction and severe acute respiratory failure due to small-cell lung cancer successfully treated with VV-ECMO, bronchoscopic airway intervention, and chemotherapy. VV-ECMO can be an effective option for the treatment of central airway obstruction with acute respiratory failure due to lung cancer.

Cannula-Associated Deep Vein Thrombosis After Venovenous Extracorporeal Membrane Oxygenation in Patients with and Without Systemic Anticoagulation

OBJECTIVE

To identify and compare the rates of cannula-associated deep vein thrombosis (CaDVT) in patients on venovenous extracorporeal membrane oxygenation (VV-ECMO) who receive systemic anticoagulation (AC) and those who do not receive AC.

DESIGN

Retrospective observational study.

SETTING

Tertiary academic medical center.

PARTICIPANTS

Consecutive patients who successfully have been decannulated from VV-ECMO for treatment of refractory acute respiratory distress syndrome between 2017 and 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

After decannulation of ECMO, a duplex sonograph was performed on the cannulation sites to determine the incidence and characteristics of cannula-related thrombosis. Thrombosis was classified as occlusive or nearly occlusive. Ninety-four of 161 patients were weaned from VV-ECMO. Nineteen patients who were placed on VV-ECMO due to COVID-19 were excluded. Twenty-seven of 52 patients (52%) who did not receive AC were identified to have thrombus. Twelve of 23 patients (52%) who received AC were identified to have thrombus. Patients who received AC required more blood products during the ECMO run and required longer support on VV-ECMO.

CONCLUSION

This study showed a high incidence of cannula-related venous thrombosis after VV-ECMO decannulation. Surprisingly, the incidence of CaDVT in anticoagulation-free patients was the same as in patients requiring anticoagulation. Anticoagulated patients required longer support on VV-ECMO and required more transfusions. Routine post-decannulation screening for DVT is recommended due to the high incidence of CaDVT.

Single-institution experience of extracorporeal membrane oxygenation for near-fatal asthma

Near-fatal asthma (NFA) is the most severe presentation of asthma. It is characterized by hypoxemic and hypercapnic respiratory failure requiring ventilatory assistance, including non-invasive ventilation and mechanical ventilation. However, NFA has a high mortality rate despite conventional therapy. Extracorporeal membrane oxygenation (ECMO) is a treatment modality that is increasingly being utilized as rescue therapy in patients with NFA that is refractory to mechanical ventilation. Prior analyses of the international Extracorporeal Life Support Organization (ELSO) registry data showed a survival rate of over 83% in patients placed on venovenous (VV) ECMO for NFA, but with notable rate of hemorrhagic complications. We report seven cases of adults with NFA requiring ECMO support at our large quaternary care institution between the years 2019 and 2022. All seven patients presented with respiratory failure in the setting of asthma exacerbation that progressed despite standard pharmacotherapy and mechanical ventilation. All patients survived to hospital discharge after ECMO support without hemorrhagic complications, highlighting the effectiveness and safety of ECMO when appropriately used in this population.

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.

Treatment of malignant airway stenosis with extracorporeal membrane oxygenation under low-dose anticoagulation: A case report

The occurrence of airway obstruction due to severe stenosis from lung cancer poses a significant risk of asphyxia. Although the placement of a metallic stent may relieve the obstruction, the procedure is associated with a high risk of asphyxia. To mitigate this risk, extracorporeal membrane pulmonary oxygenation (ECMO) has been proposed to temporarily substitute for cardiopulmonary function during the procedure. However, the use of systemic anticoagulation with heparin during ECMO may increase the likelihood of bleeding during surgery. This case report describes a successful treatment of a patient with malignant central airway obstruction through low-dose heparin veno-venous ECMO. This approach resulted in reduced intraoperative bleeding and invasive operation time, allowing for prompt postoperative withdrawal and recovery.

Risk Factors for Bleeding in Coronavirus Disease 2019 Patients on Extracorporeal Membrane Oxygenation and Effects of Transcatheter Arterial Embolization for Hemostasis

Purpose

To evaluate risk factors for bleeding events in coronavirus disease 2019 (COVID-19) patients on extracorporeal membrane oxygenation (ECMO) and to share the initial results of transcatheter arterial embolization (TAE) for hemostasis.

Material and Methods

Forty-three COVID-19 patients who received ECMO from May 2020 to September 2021 were enrolled in this study. Patients with sudden onset anemia immediately underwent computed tomography to assess bleeding. We compared laboratory data, duration of ECMO, hospitalization period, and fatality of patients' groups with and without significant hemorrhagic events using the chi-square test and Mann-Whitney U test. We also assessed the results of TAE in patients who received hemostasis.

Results

A total of 25 bleeding events occurred in 24 of the 43 patients. Age was a risk factor for bleeding events and fatality. The average duration of ECMO and hospitalization period were significantly longer in those with bleeding events (42.9 and 54.3 days) than in those without bleeding events (16.2 and 25.0 days) (p < 0.05). In addition, those with bleeding had higher fatality (45.8%) than those without (15.8%) (p < 0.05). Active extravasation was confirmed for 5 events in 4 of 24 patients. TAE was attempted and performed successfully in all but one of these four cases, in whom bleeding ceased spontaneously.

Conclusions

Elderly COVID-19 patients on ECMO had a greater risk of bleeding complications and fatal outcomes. TAE was effective in providing prompt hemostasis for patients who have the treatment indication.

Update on Anticoagulation Strategies in Patients with ECMO-A Narrative Review

The use of extracorporeal membrane oxygenation (ECMO) has recently increased exponentially. ECMO has become the preferred mode of organ support in refractory respiratory or circulatory failure. The fragile balance of haemostasis physiology is massively altered by the patient's critical condition and specifically the aetiology of the underlying disease. Furthermore, an application of ECMO conveys another disturbance of haemostasis due to blood-circuit interaction and the presence of an oxygenator. The purpose of this review is to summarise current knowledge on the anticoagulation management in patients undergoing ECMO therapy. The unfractionated heparin modality with monitoring of activated partial thromboplastin tests is considered to be a gold standard for anticoagulation in this specific subgroup of intensive care patients. However, alternative modalities with other agents are comprehensively discussed. Furthermore, other ways of monitoring can represent the actual state of coagulation in a more complex fashion, such as thromboelastometric/graphic methods, and might become more frequent. In conclusion, the coagulation system of patients with ECMO is altered by multiple variables, and there is a significant lack of evidence in this area. Therefore, a highly individualised approach is the best solution today.

Temporary venovenous extracorporeal membrane oxygenation after cardiopulmonary bypass in minimally invasive cardiac surgery via right minithoracotomy

OBJECTIVES

In minimally invasive cardiac surgery, it can be difficult at times to maintain adequate oxygenation with single-lung ventilation after weaning from cardiopulmonary bypass (CPB), and intermittent double-lung ventilation is required during hemostasis. Venovenous extracorporeal membrane oxygenation (VV-ECMO) after weaning from CPB eliminates the necessity of overinflation of the left lung and intermittent double-lung ventilation and enables secure and fast hemostasis. We investigated the effectiveness and safety of temporary VV-ECMO in MICS.

METHODS

Between May 2018 and March 2021, 149 patients underwent temporary VV-ECMO during minimally invasive cardiac surgery in our institutions. After weaning from CPB, the arterial circuit was reconnected to the right internal jugular venous cannula, the femoral venous cannula was pulled down by 20 cm, and VV-ECMO was established using the CPB machine and cannulas. After starting VV-ECMO, we administered protamine and performed hemostasis. Operative data and outcomes were retrospectively reviewed.

RESULTS

The mean VV-ECMO time and flow were 26 ± 13 minutes and 2.38 ± 0.40 L/m2, respectively. There was no thrombus in the CPB circuit, including the oxygenator. The trans-oxygenator pressure gradient index at the end of VV-ECMO significantly correlated with that at the start of VV-ECMO (r = 0.88; 95% CI, 0.79-0.94; P = .01). The 30-day mortality rate was 2.0%. The incidences of unilateral pulmonary edema, prolonged ventilation, and re-exploration for bleeding were 2.7%, 5.4%, and 2.0%, respectively.

CONCLUSIONS

Temporary VV-ECMO is safe and useful to maintain single-lung ventilation without overinflation after weaning from CPB for secure and fast hemostasis in minimally invasive cardiac surgery. No thrombotic event was found during temporary VV-ECMO without heparinization.

Primary graft dysfunction grade correlates with acute kidney injury stage after lung transplantation

BACKGROUND

Primary graft dysfunction (PGD) and acute kidney injury (AKI) are major early complications of lung transplantation and are associated with increased mortality. Lung injury after PGD can contribute to renal dysfunction; however, the association between PGD and AKI severity has not been thoroughly investigated. We analyzed the association between PGD grading and AKI staging, and the impact of AKI on subsequent changes to chronic kidney disease (CKD), including glomerular filtration rate (GFR), over time.

METHODS

This was a retrospective review of a single-center lung transplantation database between January 2018 and June 2022. AKI and GFR categories were classified according to the Kidney Disease: Improving Global Outcomes criteria. Spearman's and Kaplan-Meier tests were used to compare disease severity and assess survival.

RESULTS

In a total of 206 patients: 119 (57.8%), 25 (12.1%), 34 (16.5%), and 28 (13.6%) had PGD grades 0, 1, 2, and 3, respectively; 96 (46.6%), 47 (22.8%), 27 (13.1%), and 36 (17.5%) had AKI stages 0, 1, 2, and 3, respectively. Twenty-one of the 28 patients (75.0%) with PGD grade 3 had AKI stage 3. There was a significant correlation between PGD grade and AKI stage (P<0.001). There was also a significant correlation between AKI stage and GFR category of CKD at 3, 6, 9, and 12 months after lung transplantation (all P<0.001). For all AKI stages, GFR categories worsened with postoperative time.

CONCLUSIONS

PGD grade was significantly correlated with AKI stage, and AKI stage was correlated with GFR categories of CKD.

Shear-induced acquired von Willebrand syndrome: an accomplice of bleeding events in adults on extracorporeal membrane oxygenation support

Extracorporeal membrane oxygenation (ECMO) is an increasingly acceptable life-saving mechanical assistance system that provides cardiac and/or respiratory support for several reversible or treatable diseases. Despite important advances in technology and clinical management, bleeding remains a significant and common complication associated with increased morbidity and mortality. Some studies suggest that acquired von Willebrand syndrome (AVWS) is one of the etiologies of bleeding. It is caused by shear-induced deficiency of von Willebrand factor (VWF). VWF is an important glycoprotein for hemostasis that acts as a linker at sites of vascular injury for platelet adhesion and aggregation under high shear stress. AVWS can usually be diagnosed within 24 h after initiation of ECMO and is always reversible after explantation. Nonetheless, the main mechanism for the defect in the VWF multimers under ECMO support and the association between AVWS and bleeding complications remains unknown. In this review, we specifically discuss the loss of VWF caused by shear induction in the context of ECMO support as well as the current diagnostic and management strategies for AVWS.

COVID-19 and Pregnancy: An Updated Review about Evidence-Based Therapeutic Strategies

The COVID-19 pandemic posed a significant challenge for clinicians in managing pregnant women, who were at high risk of virus transmission and severe illness. While the WHO declared in May 2023 that COVID-19 is no longer a public health emergency, it emphasized that it remains a global health threat. Despite the success of vaccines, the possibility of new pandemic waves due to viral mutations should be considered. Ongoing assessment of the safety and effectiveness of pharmacological therapies is crucial in clinical practice. This narrative review summarizes the evidence-based therapeutic strategies for pregnant women with COVID-19, considering over three years of pandemic experience. The review discusses the safety and effectiveness of various drug regimens (antivirals, anticoagulants, corticosteroids, immunoglobulins, monoclonal antibodies, and therapeutic gases) and procedures (prone positioning and extracorporeal membrane oxygenation). Drugs with contraindications, inefficacy during pregnancy, or unknown adverse effects were excluded from our evaluation. The aim is to provide healthcare professionals with a comprehensive guide for managing pregnant women with COVID-19 based on lessons learned from the pandemic outbreak.

Anticoagulation-Free Pediatric Extracorporeal Membrane Oxygenation: Single-Center Retrospective Study

OBJECTIVES

To analyze hemorrhage and thrombosis data related to anticoagulation-free pediatric extracorporeal membrane oxygenation (ECMO).

DESIGN

Retrospective cohort study.

SETTINGS

High-volume ECMO single institution data.

PATIENTS

Children (0-18 yr) supported with ECMO (>24 hr) with initial anticoagulation-free period of greater than or equal to 6 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Utilizing consensus American Thoracic Society definitions for hemorrhage and thrombosis on ECMO, we evaluated thrombosis and associated patient and ECMO characteristics during anticoagulation-free period. Thirty-five patients met inclusion criteria from 2018 to 2021 having a median age (interquartile range [IQR]) of 13.5 months (IQR, 3-91 mo), median ECMO duration of 135 hours (IQR, 64-217 hr), and 964 anticoagulation-free hours. Increased RBC transfusion needs were associated with longer anticoagulation-free periods ( p = 0.03). We identified 20 thrombotic events: only four during the anticoagulation-free period and occurring in three of 35 (8%) patients. Compared with those without thrombotic events, anticoagulation-free clotting events were associated with younger age (i.e., 0.3 mo [IQR, 0.2-0.3 mo] vs 22.9 mo [IQR, 3.6-112.9 mo]; p = 0.02), lower weight (2.7 kg [IQR, 2.7-3.25 kg] vs 13.2 kg [5.9-36.4 kg]; p = 0.006), support with lower median ECMO flow rate (0.5 kg [IQR, 0.45-0.55 kg] vs 1.25 kg [IQR, 0.65-2.5 kg]; p = 0.04), and longer anticoagulation-free ECMO duration (44.5 hr [IQR, 40-85 hr] vs 17.6 hr [IQR, 13-24.1]; p = 0.008).

CONCLUSIONS

In selected high-risk-for-bleeding patients, our experience is that we can use ECMO in our center for limited periods without systemic anticoagulation, with lower frequency of patient or circuit thrombosis. Larger multicentered studies are required to assess weight, age, ECMO flow, and anticoagulation-free time limitations that are likely to pose risk for thrombotic events.

Does Tracheostomy Improve Outcomes in Those Receiving Venovenous Extracorporeal Membrane Oxygenation?

Patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO) often require extended periods of ventilation. We examined the role of tracheostomy on outcomes of patients supported with VV-ECMO. We reviewed all patients at our institution who received VV-ECMO between 2013 and 2019. Patients who received a tracheostomy were compared with VV-ECMO-supported patients without tracheostomy. The primary outcome measure was survival to hospital discharge. Secondary outcome measures included length of intensive care unit (ICU) and hospital stay and adverse events related to the tracheostomy procedure. Multivariable analysis was performed to identify predictors of in-hospital mortality. We dichotomized patients receiving tracheostomy into an "early" and "late" group based on median days to tracheostomy following ECMO cannulation and separate analysis was performed. One hundred and fifty patients met inclusion criteria, 32 received a tracheostomy. Survival to discharge was comparable between the groups (53.1% vs. 57.5%, p = 0.658). Predictors of mortality on multivariable analysis included Respiratory ECMO Survival Prediction (RESP) score (odds ratio [OR] = 0.831, p = .015) and blood urea nitrogen (BUN) (OR = 1.026, p = 0.011). Tracheostomy performance was not predictive of mortality (OR = 0.837, p = 0.658). Bleeding requiring intervention occurred in 18.7% of patients following tracheostomy. Early tracheostomy (<7 days from the initiation of VV-ECMO) was associated with shorter ICU (25 vs. 36 days, p = 0.04) and hospital (33 vs. 47, p = 0.017) length of stay compared with late tracheostomy. We conclude that tracheostomy can be performed safely in patients receiving VV-ECMO. Mortality in these patients is predicted by severity of the underlying disease. Performance of tracheostomy does not impact survival. Early tracheostomy may decrease length of stay.

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.

Early initiation of physical and occupational therapy while on extracorporeal life support improves patients' functional activity

PURPOSE

Managing acute respiratory distress syndrome (ARDS) patients on venovenous extracorporeal membrane oxygenation (V-V ECMO), without sedation/neuromuscular blockade to allow physical and occupational therapy (PT/OT) participation, is untraditional. Here, we investigate the impact of early PT/OT initiation on discharge functional activity for ARDS patients managed on V-V ECMO.

METHODS

This is a retrospective review of 67 ARDS patients managed with V-V ECMO at a single academic center from February 2018 to June 2021. Data collected included patient characteristics, days of V-V ECMO support, day of PT/OT initiation, and ambulation distance and Activity Measure for Post-Acute Care (AMPAC) Six-Clicks score on day of discharge.

RESULTS

Patients with >7 days of V-V ECMO support had decreased ambulation and AMPAC scores compared to those with <7 days (70.5 vs. 162.1, p < 0.01 and 12.3 vs. 16.4, p = 0.01, respectively). PT/OT initiation within 7 days after starting V-V ECMO significantly improved ambulation and AMPAC scores (163.5 vs. 59.5, p < 0.001, and 16.6 vs. 11.8, p < 0.01, respectively). Additionally, in patients with >7 days of V-V ECMO support, those who began PT/OT within 8 days of V-V ECMO cannulation had significantly improved ambulation and AMPAC scores (151.8 vs. 44.2, p < 0.01, and 16.5 vs. 11.0, p < 0.01, respectively).

CONCLUSION

Early PT/OT initiation in severe ARDS patients managed on V-V ECMO is associated with improved patient functional activity on day of discharge. Our study further supports the use of V-V ECMO in treatment of severe ARDS without sedation/neuromuscular blockade and specifically demonstrates PT/OT should be started early following V-V ECMO cannulation.

Association of aPTT-Guided Anticoagulation Monitoring with Thromboembolic Events in Patients Receiving V-A ECMO Support: A Systematic Review and Meta-Analysis

BACKGROUND

The initiation of extracorporeal membrane oxygenation (ECMO) is associated with complex inflammatory and coagulatory processes, raising the need for systemic anticoagulation. The balance of anticoagulatory and procoagulant factors is essential, as therapeutic anticoagulation confers a further risk of potentially life-threatening bleeding. Therefore, our study aims to systematize and analyze the most recent evidence regarding anticoagulation monitoring and the thromboembolic events in patients receiving veno-arterial ECMO support.

METHODS

Using the PRISMA guidelines, we systematically searched the Scopus and PubMed databases up to October 2022. A weighted effects model was employed for the meta-analytic portion of the study.

RESULTS

Six studies comprising 1728 patients were included in the final analysis. Unfractionated heparin was used for anticoagulation, with an activated partial thromboplastin time (aPTT) monitoring goal set between 45 and 80 s. The majority of studies aimed to investigate the incidence of adverse events and potential risk factors for thromboembolic and bleeding events. None of the authors found any association of aPTT levels with the occurrence of thromboembolic events. Finally, the most frequent adverse events were hemorrhage (pooled 43%, 95% CI 28.4; 59.5) and any kind of thrombosis (pooled 36%, 95% CI 21.7; 53.7), and more than one-half of patients did not survive to discharge (pooled 54%).

CONCLUSIONS

Despite the tremendous development of critical care, aPTT-guided systemic anticoagulation is still the standard monitoring tool. We did not find any association of aPTT levels with thrombosis. Further evidence and new trials should clarify the true incidence of thromboembolic events, along with the best anticoagulation and monitoring strategy in veno-arterial ECMO patients.

Neurologic Complications of Patients With COVID-19 Requiring Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

In COVID-19 patients requiring extracorporeal membrane oxygenation (ECMO), our primary objective was to determine the frequency of intracranial hemorrhage (ICH). Secondary objectives were to estimate the frequency of ischemic stroke, to explore association between higher anticoagulation targets and ICH, and to estimate the association between neurologic complications and in-hospital mortality.

DATA SOURCES

We searched MEDLINE, Embase, PsycINFO, Cochrane, and MedRxiv databases from inception to March 15, 2022.

STUDY SELECTION

We identified studies that described acute neurological complications in adult patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requiring ECMO.

DATA EXTRACTION

Two authors independently performed study selection and data extraction. Studies with 95% or more of its patients on venovenous or venoarterial ECMO were pooled for meta-analysis, which was calculated using a random-effects model.

DATA SYNTHESIS

Fifty-four studies (n = 3,347) were included in the systematic review. Venovenous ECMO was used in 97% of patients. Meta-analysis of ICH and ischemic stroke on venovenous ECMO included 18 and 11 studies, respectively. The frequency of ICH was 11% (95% CI, 8-15%), with intraparenchymal hemorrhage being the most common subtype (73%), while the frequency of ischemic strokes was 2% (95% CI, 1-3%). Higher anticoagulation targets were not associated with increased frequency of ICH (p = 0.06). In-hospital mortality was 37% (95% CI, 34-40%) and neurologic causes ranked as the third most common cause of death. The risk ratio of mortality in COVID-19 patients with neurologic complications on venovenous ECMO compared with patients without neurologic complications was 2.24 (95% CI, 1.46-3.46). There were insufficient studies for meta-analysis of COVID-19 patients on venoarterial ECMO.

CONCLUSIONS

COVID-19 patients requiring venovenous ECMO have a high frequency of ICH, and the development of neurologic complications more than doubled the risk of death. Healthcare providers should be aware of these increased risks and maintain a high index of suspicion for ICH.

The Use of Extracorporeal Circulation to Facilitate the Resection of a Large Retroperitoneal Sarcoma With Major Vessel Involvement: A Single-Center Review of 20 Cases

OBJECTIVE

To describe the introduction of extracorporeal corporeal oxygenation (ECMO) to facilitate the surgical resection of large retroperitoneal sarcomas involving major vessels and to report preliminary outcomes.

DESIGN

A case series.

SETTING

At a tertiary university hospital and state sarcoma center.

PARTICIPANTS

Patients undergoing retroperitoneal sarcoma resection requiring inferior vena cava (IVC) reconstruction between June 2018 and March 2022.

INTERVENTION

ECMO for retroperitoneal tumor resection requiring IVC reconstruction.

MEASUREMENTS AND MAIN RESULTS

A total of 20 patients underwent ECMO-assisted retroperitoneal sarcoma resection and IVC reconstruction. The median age was 60.5 years (IQR 48-69); 15 women and 5 men. The median procedure and ECMO durations were 10.8 hours (IQR 8.5-12.4 hours) and 2.2 hours (IQR 62-218 minutes), respectively. The median intensive care unit and hospital lengths of stay were 4 days (IQR 3-5 days) and 21 days (IQR 14-31 days), respectively. All 20 patients received packed cell transfusions (median 8 per patient [IQR 4-14]); 11 patients required fresh frozen plasma, 6 required platelets, and 11 required fibrinogen supplementation. One patient required recombinant activated factor VII. Sixteen patients experienced acute kidney injury, with 12 patients progressing to chronic kidney disease. Three patients were required to return to the operating room within 7 days, with no returns within the first 24 hours. There was no in-hospital or 30-day mortality. Survival at 3 years was 84%.

CONCLUSIONS

ECMO for resecting large retroperitoneal tumor resection was introduced successfully and facilitated satisfactory outcomes for many patients who might otherwise have been considered too high risk.

Recipient, donor, and surgical factors leading to primary graft dysfunction after lung transplant

Background

Primary graft dysfunction is a major cause of early mortality following lung transplantation. The International Society for Heart and Lung Transplantation subdivides it into 4 grades of increasing severity.

Methods

A retrospective review of the institutional lung transplant database from March 2018 to September 2021 was performed. Patients were stratified into three groups: primary graft dysfunction grade 0 patients, grade 1 or 2 patients, and grade 3 patients. Recipient, donor, and surgical variables were analyzed by logistic regression analysis to identify risk factors for primary graft dysfunction grade 1 or 2 and grade 3.

Results

Primary graft dysfunction grade 1 to 3 occurred in 45.0% of the cohort (n=68) of whom 33.3% (n=23) had primary graft dysfunction grade 3. Longer operative time was more common in primary graft dysfunction grade 1 to 3 patients (P<0.001). The 1-year survival of the patients with primary graft dysfunction grade 3 was lower than the others (grade 0-2 vs. 3, 93.7% vs. 65.2%, P=0.0006). Univariate analysis showed that acute respiratory distress syndrome, operative time, and intraoperative veno-arterial extracorporeal membrane oxygenation use were risk factors for primary graft dysfunction grades 1 or 2 and grade 3. Multivariate analysis identified that intraoperative veno-arterial extracorporeal membrane oxygenation use was an independent risk factor of primary graft dysfunction grade 1 or 2. Patients with an operative time of more than 8.18 hours had significantly higher incidence of primary graft dysfunction grade 3, acute kidney injury, and digital ischemia.

Conclusions

The calculated predictors of primary graft dysfunction grade 1 or 2 were similar to those of primary graft dysfunction grade 3.

Mechanical Ventilation in Patients with Traumatic Brain Injury: Is it so Different?

Patients with traumatic brain injury (TBI) frequently require invasive mechanical ventilation and admission to an intensive care unit. Ventilation of patients with TBI poses unique clinical challenges, and careful attention is required to ensure that the ventilatory strategy (including selection of appropriate tidal volume, plateau pressure, and positive end-expiratory pressure) does not cause significant additional injury to the brain and lungs. Selection of ventilatory targets may be guided by principles of lung protection but with careful attention to relevant intracranial effects. In patients with TBI and concomitant acute respiratory distress syndrome (ARDS), adjunctive strategies include sedation optimization, neuromuscular blockade, recruitment maneuvers, prone positioning, and extracorporeal life support. However, these approaches have been largely extrapolated from studies in patients with ARDS and without brain injury, with limited data in patients with TBI. This narrative review will summarize the existing evidence for mechanical ventilation in patients with TBI. Relevant literature in patients with ARDS will be summarized, and where available, direct data in the TBI population will be reviewed. Next, practical strategies to optimize the delivery of mechanical ventilation and determine readiness for extubation will be reviewed. Finally, future directions for research in this evolving clinical domain will be presented, with considerations for the design of studies to address relevant knowledge gaps.

Lung transplantation for coronavirus disease 2019 associated severe acute respiratory distress syndrome

PURPOSE OF REVIEW

The purpose of this review is to analyze the most recent and relevant literature involving lung transplantation for coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS), the pathological mechanisms of lung injury, selection criteria and outcomes.

RECENT FINDINGS

Pathological analysis of lungs after COVID-19 ARDS has shown architectural distortion similar to that observed in explanted lungs from patients undergoing lung transplantation for end-stage lung diseases such as emphysema. Short-term outcomes after lung transplantation for COVID-19 associated respiratory failure are comparable to those performed for other indications.

SUMMARY

Lung transplantation after COVID-19 ARDS is a potentially life-saving procedure for appropriately selected patients with no evidence of lung function recovery despite maximal treatment. Lung transplantation should be ideally performed in high-volume centers with expertise.

Anticoagulation in adult patients supported with extracorporeal membrane oxygenation: guidance from the Scientific and Standardization Committees on Perioperative and Critical Care Haemostasis and Thrombosis of the International Society on Thrombosis and Haemostasis

Anticoagulation of patients supported by extracorporeal membrane oxygenation is challenging because of a high risk of both bleeding and thrombotic complications, and often empirical. Practice in anticoagulation management is therefore highly variable. The scope of this guidance document is to provide clinicians with practical advice on the choice of an anticoagulant agent, dosing, and the optimal anticoagulant monitoring strategy during extracorporeal membrane oxygenation support in adult patients.

Anticoagulation Management during Extracorporeal Membrane Oxygenation-A Mini-Review

Extracorporeal membrane oxygenation (ECMO) has been established as a life-saving technique for patients with the most severe forms of respiratory or cardiac failure. It can, however, be associated with severe complications. Anticoagulation therapy is required to prevent ECMO circuit thrombosis. It is, however, associated with an increased risk of hemocoagulation disorders. Thus, safe anticoagulation is a cornerstone of ECMO therapy. The most frequently used anticoagulant is unfractionated heparin, which can, however, cause significant adverse effects. Novel drugs (e.g., argatroban and bivalirudin) may be superior to heparin in the better predictability of their effects, functioning independently of antithrombin, inhibiting thrombin bound to fibrin, and eliminating heparin-induced thrombocytopenia. It is also necessary to keep in mind that hemocoagulation tests are not specific, and their results, used for setting up the dosage, can be biased by many factors. The knowledge of the advantages and disadvantages of particular drugs, limitations of particular tests, and individualization are cornerstones of prevention against critical events, such as life-threatening bleeding or acute oxygenator failure followed by life-threatening hypoxemia and hemodynamic deterioration. This paper describes the effects of anticoagulant drugs used in ECMO and their monitoring, highlighting specific conditions and factors that might influence coagulation and anticoagulation measurements.

Outcomes of Venovenous Extracorporeal Membrane Oxygenation in Viral Acute Respiratory Distress Syndrome

Our study assessed the relationship between the duration of venovenous extracorporeal membrane oxygenation (V-V ECMO) and patient outcomes. We studied patients undergoing V-V ECMO support for acute respiratory distress syndrome (ARDS) between 2009 and 2017 who were reported to the Extracorporeal Life Support Organization registry. We evaluated survival, major bleeding, renal failure, pulmonary complications, mechanical complications, neurologic complications, infection, and duration of V-V ECMO support. Multivariable regression modeling assessed risk factors for adverse events. Of the 4,636 patients studied, the mean support duration was 12.2 ± 13.7 days. There was a progressive increase in survival after the initiation of V-VECMO, peaking at a survival rate of 73% at 10 days of support. However, a single-day increase in V-V ECMO duration was associated with increased bleeding events (odds ratio [OR] 1.038; 95% confidence interval [CI]: 1.029-1.047; p < 0.0001), renal failure (OR 1.018; 95% CI: 1.010-1.027; p < 0.0001), mechanical complications (OR 1.065; 95% CI: 1.053-1.076; p < 0.0001), pulmonary complications (OR 1.04; 95% CI: 1.03-1.05; p < 0.0001), and infection (OR 1.04; 95% CI: 1.03-1.05; p < 0.0001). V-V ECMO progressively increases survival for ARDS over the first 10 days of support. Thereafter, rising complications associated with prolonged durations of support result in a progressive decline in survival.

Veno-venous Extracorporeal Membrane Oxygenation for pregnant women with Acute Respiratory Distress Syndrome: a narrative review

Acute respiratory distress syndrome remains an uncommon condition during pregnancy. In patients with severe acute respiratory distress syndrome, when oxygenation or ventilation cannot be supported sufficiently using best practice conventional mechanical ventilation and additional therapies, veno-venous extracorporeal membrane oxygenation may be considered. In the past two decades, there has been increasing adoption of this technique to support adult patients with refractory acute respiratory distress syndrome. However, its use for the management of pregnant women is rare and remains a challenge. This narrative review addresses acute respiratory distress syndrome and its management during pregnancy, and then focuses on indications, contraindications, challenges, potential complications, and outcomes of the use of veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome in the pregnant patient.

Brain-Lung Crosstalk: Management of Concomitant Severe Acute Brain Injury and Acute Respiratory Distress Syndrome

Purpose of Review

To summarize pathophysiology, key conflicts, and therapeutic approaches in managing concomitant severe acute brain injury (SABI) and acute respiratory distress syndrome (ARDS).

Recent Findings

ARDS is common in SABI and independently associated with worse outcomes in all SABI subtypes. Most landmark ARDS trials excluded patients with SABI, and evidence to guide decisions is limited in this population. Potential areas of conflict in the management of patients with both SABI and ARDS are (1) risk of intracranial pressure (ICP) elevation with high levels of positive end-expiratory pressure (PEEP), permissive hypercapnia due to lung protective ventilation (LPV), or prone ventilation; (2) balancing a conservative fluid management strategy with ensuring adequate cerebral perfusion, particularly in patients with symptomatic vasospasm or impaired cerebrovascular blood flow; and (3) uncertainty about the benefit and harm of corticosteroids in this population, with a mortality benefit in ARDS, increased mortality shown in TBI, and conflicting data in other SABI subtypes. Also, the widely adapted partial pressure of oxygen (P_aO₂) target of > 55 mmHg for ARDS may exacerbate secondary brain injury, and recent guidelines recommend higher goals of 80–120 mmHg in SABI. Distinct pathophysiology and trajectories among different SABI subtypes need to be considered.

Summary

The management of SABI with ARDS is highly complex, and conventional ARDS management strategies may result in increased ICP and decreased cerebral perfusion. A crucial aspect of concurrent management is to recognize the risk of secondary brain injury in the individual patient, monitor with vigilance, and adjust management during critical time windows. The care of these patients requires meticulous attention to oxygenation and ventilation, hemodynamics, temperature management, and the neurological exam. LPV and prone ventilation should be utilized, and supplemented with invasive ICP monitoring if there is concern for cerebral edema and increased ICP. PEEP titration should be deliberate, involving measures of hemodynamic, pulmonary, and brain physiology. Serial volume status assessments should be performed in SABI and ARDS, and fluid management should be individualized based on measures of brain perfusion, the neurological exam, and cardiopulmonary status. More research is needed to define risks and benefits in corticosteroids in this population.

Indwelling Central Venous Catheters Drive Bloodstream Infection During Veno-venous Extracorporeal Membrane Oxygenation Support

Blood stream infection (BSI) is a potentially lethal complication in patients receiving extracorporeal membrane oxygenation (ECMO). It may be particularly common in patients with veno-venous ECMO due to their long hospitalization in the intensive care unit. Given that these patients have concurrent indwelling central venous catheters (CVC), it is unclear whether the ECMO circuit, CVC, or both, contribute to BSI. This study evaluated the risk factors associated with BSI in patients receiving veno-venous ECMO in a single institution study of 61 patients from 2016 through 2019. All ECMO catheters and the circuit oxygenator fluid were aseptically collected and analyzed for microorganisms at the time of decannulation. New BSI was diagnosed in 15 (24.6%) patients and increased mortality by threefold. None of the ECMO catheters or oxygenator fluid were culture positive. BSI increased with CVC use of over 8 days and was significantly lowered when CVC were exchanged by day 8 compared with patients with exchanges at later points (15.0% vs. 42.8%, p = 0.02). Median length of CVC use in the BSI-negative and BSI-positive group were 6.3 ± 5.0 and 9.4 ± 5.1, respectively (p = 0.04). In summary, BSI is a potentially lethal complication in patients receiving ECMO. Indwelling CVC, not the ECMO circuitry, is the likely contributor for BSI, and exchanging CVC by day 8 can reduce the incidence of BSI.

Inpatient Management of the Acutely Decompensating Lung Transplant Candidate

Lung allocation in the US changed nearly 15 years ago from time accrued on the waiting list to disease severity and likelihood of posttransplant survival, represented by the lung allocation score (LAS). Notably, the risk of death within a year plays a stronger role on the score calculation than posttransplant survival. While this change was associated with the intended decrease in waitlist mortality (most recently reported at 14.6%), it was predictable that transplant teams would have to care for increasingly older and complex candidates and recipients. This urgency-based allocation also led centers to routinely consider transplanting patients with higher acuity, often hospitalized and, not infrequently, in the intensive care unit (ICU). According to the Scientific Registry for Transplant Recipients, from 2009 to 2019, the proportion of lung recipients hospitalized and those admitted to the ICU at the time of transplant increased from 18.9% to 26.8% and from 9.2% to 16.5%, respectively..

Hemostatic Management in Extracorporeal Membrane Oxygenation

The use of extracorporeal membrane oxygenation (ECMO) for acute cardiac and/or respiratory failure has grown exponentially in the past several decades. Systemic anticoagulation is a fundamental element of caring for ECMO patients. Hemostatic management during ECMO walks a fine line to balance the risk of safe and effective anticoagulant delivery to mitigate thromboembolic complications and minimizing hemorrhagic sequelae. This review discusses the pharmacology, monitoring parameters, and special considerations for anticoagulation in patients requiring ECMO.

Uninterrupted Continuation of VV-ECMO without Anticoagulation for 44 days in COVID-19 ARDS: A Precarious Quandary

Venovenous extracorporeal membrane oxygenation (VV-ECMO) has become a mainstay treatment modality for a select patient population who do not respond to conventional medical therapy suffering from severe acute respiratory distress syndrome (ARDS) due to COVID-19. This therapy necessitates the utilization of anticoagulation, whether unfractionated heparin or bivalirudin, to prevent thrombotic complications. Scarce are reports of VV-ECMO implementation leading to acute hemorrhage mandating cessation of anticoagulation in a patient suffering from COVID-19 ARDS. Herein, the authors report a case of a successful outcome in a COVID-19 ARDS patient who suffered an acute hemorrhagic complication leading to pre-emptive termination of systemic anticoagulation. The authors believe this to be one of the first such cases in the literature.

Outcomes after extracorporeal membrane oxygenation support in COVID-19 and non-COVID-19 patients

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) support is increasingly used in the management of COVID-19-related acute respiratory distress syndrome (ARDS). However, the clinical decision-making to initiate V-V ECMO for severe COVID-19 still remains unclear. In order to determine the optimal timing and patient selection, we investigated the outcomes of both COVID-19 and non-COVID-19 patients undergoing V-V ECMO support.

METHODS

Overall, 138 patients were included in this study. Patients were stratified into two cohorts: those with COVID-19 and non-COVID-19 ARDS.

RESULTS

The survival in patients with COVID-19 was statistically similar to non-COVID-19 patients (p = .16). However, the COVID-19 group demonstrated higher rates of bleeding (p = .03) and thrombotic complications (p < .001). The duration of V-V ECMO support was longer in COVID-19 patients compared to non-COVID-19 patients (29.0 ± 27.5 vs 15.9 ± 19.6 days, p < .01). Most notably, in contrast to the non-COVID-19 group, we found that COVID-19 patients who had been on a ventilator for longer than 7 days prior to ECMO had 100% mortality without a lung transplant.

CONCLUSIONS

These findings suggest that COVID-19-associated ARDS was not associated with a higher post-ECMO mortality than non-COVID-19-associated ARDS patients, despite longer duration of extracorporeal support. Early initiation of V-V ECMO is important for improved ECMO outcomes in COVID-19 ARDS patients. Since late initiation of ECMO was associated with extremely high mortality related to lack of pulmonary recovery, it should be used judiciously or as a bridge to lung transplantation.

2021 ELSO Adult and Pediatric Anticoagulation Guidelines

DISCLAIMER

These guidelines for adult and pediatric anticoagulation for extracorporeal membrane oxygenation are intended for educational use to build the knowledge of physicians and other health professionals in assessing the conditions and managing the treatment of patients undergoing ECLS / ECMO and describe what are believed to be useful and safe practice for extracorporeal life support (ECLS, ECMO) but these are not necessarily consensus recommendations. The aim of clinical guidelines are to help clinicians to make informed decisions about their patients. However, adherence to a guideline does not guarantee a successful outcome. Ultimately, healthcare professionals must make their own treatment decisions about care on a case-by-case basis, after consultation with their patients, using their clinical judgment, knowledge and expertise. These guidelines do not take the place of physicians' and other health professionals' judgment in diagnosing and treatment of particular patients. These guidelines are not intended to and should not be interpreted as setting a standard of care or be deemed inclusive of all proper methods of care nor exclusive of other methods of care reasonably directed to obtaining the same results. The ultimate judgment must be made by the physician and other health professionals and the patient in light of all the circumstances presented by the individual patient, and the known variability and biological behavior of the clinical condition. These guidelines reflect the data at the time the guidelines were prepared; the results of subsequent studies or other information may cause revisions to the recommendations in these guidelines to be prudent to reflect new data, but ELSO is under no obligation to provide updates. In no event will ELSO be liable for any decision made or action taken in reliance upon the information provided through these guidelines.

Massive hemoptysis managed by prolonged anticoagulation-free veno-venous extracorporeal membrane oxygenation with which thoracic surgeries were accompanied: a case report

Background

Massive hemoptysis causing inadequate ventilation results in life-threatening consequences. We present a patient who developed respiratory insufficiency produced by bronchiectatic massive hemoptysis and underwent prolonged anticoagulation-free veno-venous extracorporeal membrane oxygenation (VV-ECMO) during which thoracic surgeries were performed.

Case presentation

A 79-year-old woman suffered massive hemoptysis resulting in respiratory failure during fiberoptic bronchoscopy. Bronchial intubation followed by one lung ventilation failed to ensure adequate oxygenation. Anticoagulation-free VV-ECMO, therefore, was installed immediately. Since conservative hemostatic measures including bronchial arterial embolization were not effective, resection of the culprit lung was performed while on VV-ECMO. Next day an exploratory thoracotomy and intercostal artery embolization were needed for recurrent bleeding. The VV-ECMO was withdrawn after five days of operation.

Conclusions

Massive hemoptysis can be fatal and needs instantaneous and intensive treatments. In our case, long-term anticoagulation-free VV-ECMO during which thoracic surgeries and endovascular interventions were performed provided a favorable outcome.

Fallberichte: Kinder mit tracheoösophagealer Fistel nach Knopfbatterieningestion

Fremdkörperingestionen bei Kindern nehmen stetig zu – dabei werden u. a. Knopfbatterien sehr häufig verschluckt. Das weitverbreitete Modell CR2032 führt bereits nach kurzer Zeit zu schweren Laugenverätzungen mit möglicher Perforation in benachbarte Organe. Dieser Fallserienbericht stellt 4 Kinder vor, die nach Ingestion von Knopfbatterien eine tracheoösophageale Fistel entwickelten und in unserer Kinderklinik interdisziplinär versorgt wurden.

Clinical Characteristics and Outcomes of Patients With COVID-19-Associated Acute Respiratory Distress Syndrome Who Underwent Lung Transplant

Importance

Lung transplantation is a potentially lifesaving treatment for patients who are critically ill due to COVID-19-associated acute respiratory distress syndrome (ARDS), but there is limited information about the long-term outcome.

Objective

To report the clinical characteristics and outcomes of patients who had COVID-19-associated ARDS and underwent a lung transplant at a single US hospital.

Design, Setting, and Participants

Retrospective case series of 102 consecutive patients who underwent a lung transplant at Northwestern University Medical Center in Chicago, Illinois, between January 21, 2020, and September 30, 2021, including 30 patients who had COVID-19-associated ARDS. The date of final follow-up was November 15, 2021.

Exposures

Lung transplant.

Main Outcomes and Measures

Demographic, clinical, laboratory, and treatment data were collected and analyzed. Outcomes of lung transplant, including postoperative complications, intensive care unit and hospital length of stay, and survival, were recorded.

Results

Among the 102 lung transplant recipients, 30 patients (median age, 53 years [range, 27 to 62]; 13 women [43%]) had COVID-19-associated ARDS and 72 patients (median age, 62 years [range, 22 to 74]; 32 women [44%]) had chronic end-stage lung disease without COVID-19. For lung transplant recipients with COVID-19 compared with those without COVID-19, the median lung allocation scores were 85.8 vs 46.7, the median time on the lung transplant waitlist was 11.5 vs 15 days, and preoperative venovenous extracorporeal membrane oxygenation (ECMO) was used in 56.7% vs 1.4%, respectively. During transplant, patients who had COVID-19-associated ARDS received transfusion of a median of 6.5 units of packed red blood cells vs 0 in those without COVID-19, 96.7% vs 62.5% underwent intraoperative venoarterial ECMO, and the median operative time was 8.5 vs 7.4 hours, respectively. Postoperatively, the rates of primary graft dysfunction (grades 1 to 3) within 72 hours were 70% in the COVID-19 cohort vs 20.8% in those without COVID-19, the median time receiving invasive mechanical ventilation was 6.5 vs 2.0 days, the median duration of intensive care unit stay was 18 vs 9 days, the median post-lung transplant hospitalization duration was 28.5 vs 16 days, and 13.3% vs 5.5% required permanent hemodialysis, respectively. None of the lung transplant recipients who had COVID-19-associated ARDS demonstrated antibody-mediated rejection compared with 12.5% in those without COVID-19. At follow-up, all 30 lung transplant recipients who had COVID-19-associated ARDS were alive (median follow-up, 351 days [IQR, 176-555] after transplant) vs 60 patients (83%) who were alive in the non-COVID-19 cohort (median follow-up, 488 days [IQR, 368-570] after lung transplant).

Conclusions and Relevance

In this single-center case series of 102 consecutive patients who underwent a lung transplant between January 21, 2020, and September 30, 2021, survival was 100% in the 30 patients who had COVID-19-associated ARDS as of November 15, 2021.