Extracorporeal life support devices and strategies for management of acute cardiorespiratory failure in adult patients: a comprehensive review

Web-based Dashboard on ECMO Utilization in Germany: An Interactive Visualization, Analyses, and Prediction Based on Real-life Data

In Germany, a comprehensive reimbursement policy for extracorporeal membrane oxygenation (ECMO) results in the highest per capita use worldwide, although benefits remain controversial. Public ECMO data is unstructured and poorly accessible to healthcare professionals, researchers, and policymakers. In addition, there are no uniform policies for ECMO allocation which confronts medical personnel with ethical considerations during health crises such as respiratory virus outbreaks.Retrospective information on adult and pediatric ECMO support performed in German hospitals was extracted from publicly available reimbursement data and hospital quality reports and processed to create the web-based ECMO Dashboard built on Open-Source software. Patient-level and hospital-level data were merged resulting in a solid base for ECMO use analysis and ECMO demand forecasting with high spatial granularity at the level of 413 county and city districts in Germany.The ECMO Dashboard ( https://www.ecmo-dash.de/ ), an innovative visual platform, presents the retrospective utilization patterns of ECMO support in Germany. It features interactive maps, comprehensive charts, and tables, providing insights at the hospital, district, and national levels. This tool also highlights the high prevalence of ECMO support in Germany and emphasizes districts with ECMO surplus - where patients from other regions are treated, or deficit - origins from which ECMO patients are transferred to other regions. The dashboard will evolve iteratively to provide stakeholders with vital information for informed and transparent resource allocation and decision-making.Accessible public routine data could support evidence-informed, forward-looking resource management policies, which are urgently needed to increase the quality and prepare the critical care infrastructure for future pandemics.

Neutrophil extracellular traps - a potential trigger for the development of thrombocytopenia during extracorporeal membrane oxygenation

Neutrophil extracellular traps (NETs) have recently emerged as a potential link between inflammation, immunity, and thrombosis, as well as other coagulation disorders which present a major challenge in the context of extracorporeal membrane oxygenation (ECMO). By examining blood from ECMO patients for NETs and their precursors and correlating them with clinical and laboratory biomarkers of coagulation and inflammation, this study aims to evaluate the association between the presence of NETs in the bloodstream of ECMO patients and the development of potentially severe coagulation disorders during ECMO therapy. Therefore, blood samples were collected from healthy volunteers (n=13) and patients receiving veno-venous (VV) ECMO therapy (n=10). To identify NETs and their precursors, DNA and myeloperoxidase as well as granulocyte marker CD66b were visualized simultaneously by immunofluorescence staining in serial blood smears. Differentiation of DNA-containing objects and identification of NETs and their precursors was performed semiautomatically by a specific algorithm using the shape and size of DNA staining and the intensity of MPO and CD66b signal. Neutrophil extracellular traps and their precursors could be detected in blood smears from patients requiring VV ECMO. Compared to volunteers, ECMO patients presented significantly higher rates of NETs and NET precursors as well as an increased proportion of neutrophil granulocytes in all detected nucleated cells. A high NET rate prior to the initiation of ECMO therapy was associated with both increased IL-6 and TNF-α levels as an expression of a high cytokine burden. These patients with increased NET release also presented an earlier and significantly more pronounced decrease in platelet counts and ATIII activity following initiation of therapy compared with patients with less elevated NETs. These findings provide further indications for the development of immune-mediated acquired thrombocytopenia in ECMO patients.

Kinetics of C-reactive protein during extracorporeal membrane oxygenation

BACKGROUND

The exposure of blood to the artificial circuit during extracorporeal membrane oxygenation (ECMO) can induce an inflammatory response. C-reactive protein (CRP) is a commonly used biomarker of systemic inflammation.

METHODS

In this retrospective observational study, we analyzed results of daily plasma CRP measurements in 110 critically ill patients, treated with ECMO. We compared CRP levels during the first 5 days of ECMO operation, between different groups of patients according to ECMO configurations, Coronavirus disease 2019 (COVID-19) status, and mechanical ventilation parameters.

RESULTS

There was a statistically significant decrease in CRP levels during the first 5 days of veno-venous (VV) ECMO (173 ± 111 mg/L, 154 ± 107 mg/L, 127 ± 97 mg/L, 114 ± 100 mg/L and 118 ± 90 mg/L for days 1-5 respectively, p < 0.001). Simultaneously, there was a significant reduction in ventilatory parameters, as represented by the mechanical power (MP) calculation, from 24.02 ± 14.53 J/min to 6.18 ± 4.22 J/min within 3 h of VV ECMO initiation (p < 0.001). There was non-significant trend of increase in CRP level during the first 5 days of veno arterial (VA) ECMO (123 ± 80 mg/L, 179 ± 91 mg/L, 203 ± 90 mg/L, 179 ± 95 mg/L and 198 ± 93 for days 1-5 respectively, p = 0.126) and no significant change in calculated MP (from 14.28 ± 8.56 J/min to 10.81 ± 8.09 J/min within 3 h if ECMO initiation, p = 0.071).

CONCLUSIONS

We observed a significant decrease in CRP levels during the first 5 days of VV ECMO support, and suggest that the concomitant reduction in ventilatory MP may have mitigated the degree of alveolar stress and strain that could have contributed to a decrease in the systemic inflammatory process.

Buying time! VA-ECMO as a bridge to successful reoperative cardiac surgery in a case of traumatic tricuspid valve injury

Cardiac surgery performed on patients in cardiogenic shock is associated with a high mortality and morbidity. Preoperative Extra Corporeal Membrane Oxygenation (ECMO) in cardiogenic shock gives critically-ill patients a chance for surgical intervention and is associated with better surgical outcomes. We present a 29-year-old male who had a ventricular septal defect closure as a child and presented with multi-organ injuries following polytrauma. He was in cardiogenic shock despite maximal inotropic support. Transesophageal echocardiography demonstrated torrential tricuspid regurgitation (TR) from a flail tricuspid valve (TV) leaflet as the cause of cardiogenic shock. He was stabilized on Veno-Arterial ECMO and underwent reoperative cardiac surgery. Intra-operatively, the anterior leaflet of his TV and its papillary muscle was detached from the right ventricle. He had a successful tissue TV replacement. Early surgery was indicated to treat right ventricular failure due to torrential TR, but due to his restricting non-cardiac injuries, ECMO was successfully used as a short-term support strategy and as a bridge to definitive surgery.

Developing a competency framework for extracorporeal membrane oxygenation nurses: A qualitative study

AIM

To develop a competency framework applicable to Chinese extracorporeal membrane oxygenation (ECMO) nurses.

DESIGN

A qualitative study was performed following the consolidated criteria for reporting qualitative research.

METHODS

Semi-structured interviews based on the critical incident technique were conducted among 21 ECMO care providers recruited from five well-known ECMO centres in Guangzhou, China. Interview transcripts were coded and analysed using the constant comparative method. The data collection period lasted from November 2021 to April 2022.

RESULTS

A competency framework for ECMO nurses was identified. It included four domains: knowledge, skills, behaviours and attitudes, containing 33 subcompetencies and 66 items.

RELEVANCE TO CLINICAL PRACTICE

This framework can be a reference for the assessment and training of ECMO nurses.

Predictive models in extracorporeal membrane oxygenation (ECMO): a systematic review

PURPOSE

Extracorporeal membrane oxygenation (ECMO) has been increasingly used in the last years to provide hemodynamic and respiratory support in critically ill patients. In this scenario, prognostic scores remain essential to choose which patients should initiate ECMO. This systematic review aims to assess the current landscape and inform subsequent efforts in the development of risk prediction tools for ECMO.

METHODS

PubMed, CINAHL, Embase, MEDLINE and Scopus were consulted. Articles between Jan 2011 and Feb 2022, including adults undergoing ECMO reporting a newly developed and validated predictive model for mortality, were included. Studies based on animal models, systematic reviews, case reports and conference abstracts were excluded. Data extraction aimed to capture study characteristics, risk model characteristics and model performance. The risk of bias was evaluated through the prediction model risk-of-bias assessment tool (PROBAST). The protocol has been registered in Open Science Framework ( https://osf.io/fevw5 ).

RESULTS

Twenty-six prognostic scores for in-hospital mortality were identified, with a study size ranging from 60 to 4557 patients. The most common candidate variables were age, lactate concentration, creatinine concentration, bilirubin concentration and days in mechanical ventilation prior to ECMO. Five out of 16 venous-arterial (VA)-ECMO scores and 3 out of 9 veno-venous (VV)-ECMO scores had been validated externally. Additionally, one score was developed for both VA and VV populations. No score was judged at low risk of bias.

CONCLUSION

Most models have not been validated externally and apply after ECMO initiation; thus, some uncertainty whether ECMO should be initiated still remains. It has yet to be determined whether and to what extent a new methodological perspective may enhance the performance of predictive models for ECMO, with the ultimate goal to implement a model that positively influences patient outcomes.

Neurological monitoring in ECMO patients: current state of practice, challenges and lessons

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) in critically ill patients serves as a management option for end-stage cardiorespiratory failure in medical and surgical conditions. Patients on ECMO are at a high risk of neurologic adverse events including intracranial hemorrhage (ICH), acute ischemic stroke (AIS), seizures, diffuse cerebral edema, and hypoxic brain injury. Standard approaches to neurological monitoring for patients receiving ECMO support can be challenging for multiple reasons, including the severity of critical illness, deep sedation, and/or paralysis. This narrative literature review provides an overview of the current landscape for neurological monitoring in this population.

METHODS

A literature search using PubMed was used to aid the understanding of the landscape of published literature in the area of neurological monitoring in ECMO patients.

RESULTS

Review articles, cohort studies, case series, and individual reports were identified. A total of 73 varied manuscripts were summarized and included in this review which presents the challenges and strategies for performing neurological monitoring in this population.

CONCLUSION

Neurological monitoring in ECMO is an area of interest to many clinicians, however, the literature is limited, heterogenous, and lacks consensus on the best monitoring practices. The evidence for optimal neurological monitoring that could impact clinical decisions and functional outcomes is lacking. Additional studies are needed to identify effective measures of neurological monitoring while on ECMO.

Case report: Thyroid carcinoma invading trachea: Multidisciplinary resection and reconstruction assisted by extracorporeal membrane oxygenation

Background

When thyroid cancer invades the trachea, tumor resection and trachea reconstruction are required. Although the traditional way of anesthesia and tracheal intubation can maintain the necessary ventilation function during the operation, tracheal intubation affects the surgical field of vision and is not conducive to the protection of the recurrent laryngeal nerve beside the trachea during the operation.

Case presentation

Extracorporeal membrane oxygenation (ECMO) is used to replace traditional tracheal intubation in the process of resection and end-to-end anastomosis of tracheal tumors, and complete tracheal tumor resection and trachea reconstruction are achieved.

Conclusion

Using ECMO for thyroid carcinoma resection, invaded trachea resection, and trachea reconstruction is safe and effective, which reduces the obstruction of endotracheal intubation on the operative field, guarantees the rapid and efficient end-to-end anastomosis in the upper trachea, and clearly avoids laryngeal recurrent nerve injury in the process of anastomosis.

Extracorporeal Carbon Dioxide Removal: From Pathophysiology to Clinical Applications; Focus on Combined Continuous Renal Replacement Therapy

Lung-protective ventilation (LPV) with low tidal volumes can significantly increase the survival of patients with acute respiratory distress syndrome (ARDS) by limiting ventilator-induced lung injuries. However, one of the main concerns regarding the use of LPV is the risk of developing hypercapnia and respiratory acidosis, which may limit the clinical application of this strategy. This is the reason why different extracorporeal CO₂ removal (ECCO₂R) techniques and devices have been developed. They include low-flow or high-flow systems that may be performed with dedicated platforms or, alternatively, combined with continuous renal replacement therapy (CRRT). ECCO₂R has demonstrated effectiveness in controlling PaCO₂ levels, thus allowing LPV in patients with ARDS from different causes, including those affected by Coronavirus disease 2019 (COVID-19). Similarly, the suitability and safety of combined ECCO₂R and CRRT (ECCO₂R-CRRT), which provides CO₂ removal and kidney support simultaneously, have been reported in both retrospective and prospective studies. However, due to the complexity of ARDS patients and the limitations of current evidence, the actual impact of ECCO₂R on patient outcome still remains to be defined. In this review, we discuss the main principles of ECCO₂R and its clinical application in ARDS patients, in particular looking at clinical experiences of combined ECCO₂R-CRRT treatments.

Impact of volute design features on hemodynamic performance and hemocompatibility of centrifugal blood pumps used in ECMO

BACKGROUND

The centrifugal blood pump volute has a significant impact on its hemodynamic performance hemocompatibility. Previous studies about the effect of volute design features on the performance of blood pumps are relatively few.

METHODS

In the present study, the computational fluid dynamics (CFD) method was utilized to evaluate the impact of volute design factors, including spiral start position, volute tongue radius, inlet height, size, shape and diffuser pipe angle on the hemolysis index and thrombogenic potential of the centrifugal blood pump.

RESULTS

Correlation analysis shows that flow losses affect the hemocompatibility of the blood pump by influencing shear stress and residence time. The closer the spiral start position of the volute, the better the hydraulic performance and hemocompatibility of the blood pump. Too large or too small volute inlet heights can worsen hydraulic performance and hemolysis, and higher volute inlet height can increase the thrombogenic potential. Small volute sizes exacerbate hemolysis and large volute sizes increase the thrombogenic risk, but volute size does not affect hydraulic performance. When the diffuser pipe is tangent to the base circle of the volute, the best hydraulic performance and hemolysis performance of the blood pump is achieved, but the thrombogenic potential is increased. The trapezoid volute has poor hydraulic performance and hemocompatibility. The round volute has the best hydraulic and hemolysis performance, but the thrombogenic potential is higher than that of the rectangle volute.

CONCLUSION

This study found that the hemolysis index shows a significant correlation with spiral start position, volute size, and diffuser pipe angle. Thrombogenic potential exhibits a good correlation with all the studied volute design features. The flow losses affect the hemocompatibility of the blood pump by influencing shear stress and residence time. The finding of this study can be used to guide the optimization of blood pump for improving the hemodynamic performance and hemocompatibility.

Electrospun Nanofiber/Textile Supported Composite Membranes with Improved Mechanical Performance for Biomedical Applications

Textile-supported nanocomposite as a scaffold has been extensively used in the medical field, mainly to give support to weak or harmed tissues. However, there are some challenges in fabricating the nanofiber/textile composite, i.e., suitable porous structure with defined pore size, less skin contact area, biocompatibility, and availability of degradable materials. Herein, polyamide-6 (PA) nanofibers were synthesized using needleless electrospinning with the toothed wheel as a spinneret. The electrospinning process was optimized using different process and solution parameters. In the next phase, optimized PA nanofiber membranes of optimum fiber diameter with uniform distribution and thickness were used in making nanofiber membrane-textile composite. Different textile fabrics (woven, non-woven, knitted) were developed. The optimized nanofiber membranes were combined with non-woven, woven, and knitted fabrics to make fabric-supported nanocomposite. The nanofiber/fabric composites were compared with available market woven and knitted meshes for mechanical properties, morphology, structure, and chemical interaction analysis. It was found that the tear strength of the nanofiber/woven composite was three times higher than market woven mesh, and the nanofiber/knitted composite was 2.5 times higher than market knitted mesh. The developed composite structures with woven and knitted fabric exhibited improved bursting strength (613.1 and 751.1 Kpa), tensile strength (195.76 and 227.85 N), and puncture resistance (68.76 and 57.47 N), respectively, than market available meshes. All these properties showed that PA nanofibers/textile structures could be utilized as a composite with multifunctional properties.

Adult essential extracorporeal membrane oxygenation (ECMO) skills for use in an e-learning program for ICU physicians, nurses and perfusionists: a consensus by a modified Delphi questionnaire

BACKGROUND

Education in ECMO starts with basic theory and physiology. For this type of training, self-assessment e-learning modules may be beneficial. The aim of this study was to generate consensus on essential ECMO skills involving various professional groups involved in caring for ECMO patients. These skills can be used for educational purposes: development of an e-learning program and fine-tuning of ECMO-simulation programs.

METHODS

Experts worldwide received an e-mail inviting them to participate in the modified Delphi questionnaire. A mixture of ECMO experts was contacted. The expert list was formed based on their scientific track record mainly in adult ECMO (research, publications, and invited presentations). This survey consisted of carefully designed questionnaires, organized into three categories, namely knowledge skills, technical skills, and attitudes. Each statement considered a skill and was rated on a 5-point Likert-scale and qualitative comments were made if needed. Based on the summarized information and feedback, the next round Delphi questionnaire was developed. A statement was considered as a key competency when at least 80% of the experts agreed or strongly agreed (rating 4/5 and 5/5) with the statement. Cronbach's Alpha score tested internal consistency. Intraclass correlation coefficient was used as reliability index for interrater consistency and agreement.

RESULTS

Consensus was achieved in two rounds. Response rate in the first round was 45.3% (48/106) and 60.4% (29/48) completed the second round. Experts had respectively for the first and second round: a mean age of 43.7 years (8.2) and 43.4 (8.8), a median level of experience of 11.0 years [7.0-15.0] and 12.0 years [8.3-14.8]. Consensus was achieved with 29 experts from Australia (2), Belgium (16), France (1), Germany (1), Italy (1), Russia (2), Spain (1), Sweden, (1), The Netherlands (4). The consensus achieved in the first round was 90.9% for the statements about knowledge, 54.5% about technical skills and 75.0% about attitudes. Consensus increased in the second round: 94.6% about knowledge skills, 90.9% about technical skills and 75.0% about attitudes.

CONCLUSION

An expert consensus was accomplished about the content of "adult essential ECMO skills". This consensus was mainly created with participation of physicians, as the response rate for nurses and perfusion decreased in the second round.

Impact of duration of mechanical support on heart transplantation: Hasty transplantation may not have a good long-term outcome

BACKGROUND

Mechanical circulatory support (MCS) has been widely utilized in critically ill cardiac transplant candidates. Few studies have investigated the impact of duration of MCS before heart transplantation (HTx) on long-term patient survival.

METHODS

A retrospective HTx database was reviewed between 2009 and 2019. Patients who did not or did undergo MCS before HTx were categorized into two groups: (1) A (did not) and (2) B (did), respectively. A receiver operating characteristic (ROC) curve was plotted to assess the cutoff level of MCS duration before HTx in evaluating 5-year survival.

RESULT

A total of 270 HTx patients (group A: 120, group B: 150) were analyzed. Group B patients had a higher percentage of blood type O, a higher incidence of resuscitation, a shorter listing duration, and a higher likelihood of having United Network for Organ Sharing (UNOS) 1A status than group A. The ROC curve revealed 24 days as a good cut-off level for determining the best MCS before HTx timing. Group B was categorized into two subgroups: (1) B1 (MCS < 24 days, n = 65) and (2) B2 (MCS > 24 days, n = 85). B2 had a higher incidence of cardiopulmonary resuscitation (CPR), hemodialysis, longer waiting time after MCS, and better ventricular assist device implantation than B1. However, the survival curves showed that B1 outcomes were significantly worse than in groups A and B2. Groups A and B2 had similar survival curves without an increased incidence of infection.

CONCLUSION

The preliminary data demonstrated that a longer duration of MCS may be associated with better outcomes than urgent HTx.

Lacosamide Intoxication-induced Wide QRS Tachycardia Successfully Treated with Veno-arterial Extracorporeal Membrane Oxygenation

Lacosamide is an antiepileptic drug that acts on voltage-gated sodium channels and was approved as an antiepileptic by the Food and Drug Administration in 2008. Although the efficacy and safety of lacosamide have been established in many previous trials, some case reports have shown that it may lead to cardiovascular side effects, especially in patients with electrical conduction system disorders. We herein report a case of life-threatening cardiac arrhythmia caused by lacosamide intoxication that was successfully treated with veno-arterial extracorporeal membrane oxygenation.

Anticoagulation Strategies during Extracorporeal Membrane Oxygenation: A Narrative Review

The development of extracorporeal life support technology has added a new dimension to the care of critically ill patients who fail conventional treatment options. Extracorporeal membrane oxygenation (ECMO)—specialized temporary life support for patients with severe cardiac or pulmonary failure—plays a role in bridging the time for organ recovery, transplant, or permanent assistance. The overall patient outcome is dependent on the underlying disease, comorbidities, patient reaction to critical illness, and potential adverse events during ECMO. Moreover, the contact of the blood with the large artificial surface of an extracorporeal system circuit triggers complex inflammatory and coagulation responses. These processes may further lead to endothelial injury and disrupted microcirculation with consequent end-organ dysfunction and the development of adverse events like thromboembolism. Therefore, systemic anticoagulation is considered crucial to alleviate the risk of thrombosis and failure of ECMO circuit components. The gold standard and most used anticoagulant during extracorporeal life support is unfractionated heparin, with all its benefits and disadvantages. However, therapeutic anticoagulation of a critically ill patient carries the risk of clinically relevant bleeding with the potential for permanent injury or death. Similarly, thrombotic events may occur. Therefore, different anticoagulation strategies are employed, while the monitoring and the balance of procoagulant and anticoagulatory factors is of immense importance. This narrative review summarizes the most recent considerations on anticoagulation during ECMO support, with a special focus on anticoagulation monitoring and future directions.

Infections Acquired During Venoarterial Extracorporeal Membrane Oxygenation Postcardiac Surgery in Children: A Retrospective Observational Study

Introduction Extracorporeal membrane oxygenation (ECMO) is increasingly being used in refractory cardiac and pulmonary dysfunction as a rescue modality. The common indications for establishing venoarterial ECMO (VA-ECMO) support in children postcardiac surgery are failure to wean from cardiopulmonary bypass (CPB), postcardiotomy cardiogenic shock (PCCS), refractory pulmonary arterial hypertension, and as a bridge to recovery or transplant. The survival rate of children on VA-ECMO support is 45%. The most frequently encountered complications during VA-ECMO are bleeding, thrombosis, acute kidney injury, and infections. Among those, infections acquired during VA-ECMO lead to high morbidity and mortality. Hence, this study aimed to determine infection rates, causal microorganisms, and mortality risk factors in children developing an infection during VA-ECMO therapy.

Methods This retrospective observational study was conducted on 106 children under 14 years of age who underwent elective or emergent cardiac surgery (between 2016 and 2020) and required VA-ECMO support. Medical records were reviewed to collect the targeted variables and analyzed.

Results Out of 106 children, 49 (46.23%) acquired infections representing a prevalence of 46.23% and an infection rate of 186.4 episodes per 1,000 ECMO days. Prevalence and acquired infection rate/1,000 ECMO days were higher in the nonsurvivor group than in the survivor group (26.42 vs.19.81%) and (215.07 vs. 157.49), respectively. The bloodstream infection (BSI) and catheter-associated urinary tract infection (CAUTI) episodes were 53.04 and 68.19 per 1,000 ECMO days, and the ventilator-associated pneumonia (VAP) rate was 44.50 per 1,000 ventilator days. The mean preoperative admission duration, aortic cross-clamping duration, CPB duration (minutes), and vasoactive-inotropic score were higher in the nonsurviving children (p < 0.001). Similarly, prolonged mean ECMO duration was also found in the nonsurvivor group compared with the survivor group (p = 0.03).

Conclusion In our study, the prevalence of acquired infection during VA-ECMO was 46.23%. The incidence of BSI, CAUTI, and VAP per 1,000 ECMO days was higher in the nonsurvivor group than in survivors. Acinetobacter baumannii was the most common cultured gram-negative organism in VAP and BSI, with 67.65% Acinetobacter spp. resistant to carbapenems. CAUTI was predominately due to Candida species during VA-ECMO.

Investigation of the influence of blade configuration on the hemodynamic performance and blood damage of the centrifugal blood pump

PURPOSE

The design and optimization of centrifugal blood pumps is crucial for improved extracorporeal membrane oxygenation system performances. Secondary flow passages are common in centrifugal blood pumps, allowing for a high volume of unstable flow. Traditional design theory offers minimal guidance on the design and optimization of centrifugal blood pumps, so it's critical to understand how design parameter variables affect hydraulic performances and hemocompatibility.

METHODS

Computational fluid dynamics (CFD) was employed to investigate the effects of blade number, blade wrap angle, blade thickness, and splitters on pressure head, hemolysis, and platelet activation state. Eulerian and Lagrangian features were used to analyze the flow fields and hemocompatibility metrics such as scalar shear stress, velocity distribution, and their correlation.

RESULTS

The equalization of frictional and flow losses allow impellers with more blades and smaller wrap angles to have higher pressure heads, whereas the trade-off between the volume of high scalar shear stress and exposure time allows impellers with fewer blades and larger blade wrap angles to have a lower HI; there are configurations that increase the possibility of platelet activation for both number of blades and wrap angles. The hydraulic performance and hemocompatibility of centrifugal blood pumps are not affected by blade thickness. Compared to the main blades, a splitters can improve the blood compatibility of a centrifugal blood pump with a small reduction in pressure head, but there is a trade-off between the length and location of the splitter that suppresses flow losses while reducing the velocity gradient. According to correlation analysis, pressure head, HI, and the volume of high shear stress were all substantially connected, and exposure time had a significant impact on HI. The platelet activation state was influenced by the average scalar shear stress and the volume of low velocity.

CONCLUSION

The findings reveal the impact of design variables on the performance of centrifugal blood pumps with secondary flow passages, as well as the relationship between hemocompatibility, hydraulic performance, and flow characteristics, and are useful for the design and optimization of this type of blood pump, as well as the prediction of clinical complications.

Outcomes of Extubated COVID and Non-COVID Patients Receiving Awake Venovenous Extracorporeal Membrane Oxygenation

Cessation of continuous analgesia and sedation in patients with acute respiratory distress syndrome (ARDS) receiving venovenous (VV) extracorporeal membrane oxygenation (ECMO) facilitates early extubation, family, patient and provider engagement, and mobility. Outcomes associated with an awake ECMO strategy have not been well described in the literature. The purpose of this study was to evaluate outcomes in patients receiving this strategy. This was a retrospective review of ARDS patients receiving awake VV ECMO. The primary outcome was survival to hospital discharge. Secondary outcomes included days requiring ECMO, time from cannulation to extubation, complications, patients requiring tracheostomy, hospital and intensive care unit (ICU) length of stay (LOS), and discharge disposition. In a subgroup analysis, outcomes were compared between non-COVID and COVID ECMO patients. Sixty-two patients were included with a survival to hospital discharge of 85.5%. Days requiring ECMO was 33.0 (0.0-75.0) and cannulation to extubation was 6.0 (4.0-11.0). Three patients received a tracheostomy (4.8%). Bleeding and infection were reported in 80.6% and 82.3% of patients, respectively. Intensive care unit length of stay was 46.0 days (29.0-90.0) and hospital LOS was 51.0 days (32.0-91.0). Over half of the patients (51.6%) were discharged to an acute rehabilitation facility and 27.4% were discharged home. There was similar survival to hospital discharge between the COVID and non-COVID awake ECMO patients (85% in both groups, p = 1.000). This study highlights the impact of an awake ECMO approach on survival to hospital discharge. Future studies are needed to evaluate this approach as compared to current practice to determine if this should become the standard.

Exploration of the Utility of Speckle-Tracking Echocardiography During Mechanical Ventilation and Mechanical Circulatory Support

This narrative review aims to discuss the potential applicability of speckle-tracking echocardiography (STE) in patients under mechanical ventilation (MV) and mechanical circulatory support (MCS). Both its benefits and limitations were considered through critical analyses of the current available evidence.

Friend or Foe? Venoarterial ECMO via Carotid Artery "Jump Graft": A Case Series

Extracorporeal life support is used in adult and pediatric patients for refractory cardiac and respiratory failure. The great arteries and veins of the neck and groin are often used for cannulation to extracorporeal membrane oxygenation (ECMO). Newer cannulation techniques use the subclavian or axillary arteries, in addition to synthetic grafts anastomosed in end-to-side fashion, from which the cannula is positioned. These newer techniques can prevent need for ligation and sacrifice of important major vessels that is often undertaken in "traditional" direct surgical cannulation strategies. To our knowledge this graft technique has not been performed in pediatric ECMO patients. We describe a case series of nine patients from 2012 to 2017 supported with venoarterial (V-A) ECMO utilizing a synthetic Gore-Tex^® "jump graft" sewn in an end-to-side fashion to the right carotid artery, for the arterial cannula insertion. Each patient's hospital course was reviewed with particular consideration given to disease process, site of cannulation, neurologic examination abnormalities noted during ECMO, computed tomography (CT) or magnetic resonance imaging (MRI) evidence of intracranial hemorrhage, and outcomes. Eight of nine patients were successfully cannulated utilizing this technique without neurologic complication. One suffered catastrophic intracerebral hemorrhage. This series is limited by small sample size and single center experience. Further work is needed to determine the advantages and disadvantages of utilizing a synthetic graft in pediatric V-A ECMO.

The Association of Oxygenation, Carbon Dioxide Removal, and Mechanical Ventilation Practices on Survival During Venoarterial Extracorporeal Membrane Oxygenation

Introduction: Oxygenation and carbon dioxide removal during venoarterial extracorporeal membrane oxygenation (VA ECMO) depend on a complex interplay of ECMO blood and gas flows, native lung and cardiac function as well as the mechanical ventilation strategy applied. Objective: To determine the association of oxygenation, carbon dioxide removal, and mechanical ventilation practices with in-hospital mortality in patients who received VA ECMO. Methods: Single center, retrospective cohort study. All consecutive patients who received VA ECMO in a tertiary ECMO referral center over a 5-year period were included. Data on demographics, ECMO and ventilator support details, and blood gas parameters for the duration of ECMO were collected. A multivariable logistic time-series regression model with in-hospital mortality as the primary outcome variable was used to analyse the data with significant factors at the univariate level entered into the multivariable regression model. Results: Overall, 52 patients underwent VA ECMO: 26/52 (50%) survived to hospital discharge. The median PaO2 for the duration of ECMO support was 146 mmHg [IQR 131-188] and PaCO2 was 37.2 mmHg [IQR 35.3, 39.9]. Patients who survived to hospital discharge had a significantly lower median PaO2 (117 [98, 140] vs. 154 [105, 212] mmHg, P = 0.04) and higher median PaCO2 (38.3 [36.1, 41.1] vs. 36.3 [34.5, 37.8] mmHg, p = 0.03). Survivors also had significantly lower median VA ECMO blood flow rate (EBFR, 3.6 [3.3, 4.2] vs. 4.3 [3.8, 5.2] L/min, p = < 0.001) and greater measured minute ventilation (7.04 [5.63, 8.35] vs. 5.32 [4.43, 6.83] L/min, p = 0.01). EBFR, PaO2, PaCO2, and minute ventilation, however, were not independently associated with death in a multivariable analysis. Conclusion: This exploratory analysis in a small group of VA ECMO supported patients demonstrated that hyperoxemia was common during VA ECMO but was not independently associated with increased mortality. Survivors also received lower EBFR and had greater minute ventilation, but this was also not independently associated with survival. These findings highlight that interactions between EBFR, PaO2, and native lung ventilation may be more relevant than their individual association with survival. Further research is indicated to determine the optimal ECMO and ventilator settings on outcomes in VA ECMO.

Peripheral neuropathy after extra-corporeal membrane oxygenation therapy in children: A case report

RATIONALE

In recent years, the use of extracorporeal membrane oxygenation (ECMO) treatment for pediatric patients with cardiorespiratory failure has increased, with emphasis being given to the prevention of complications in ECMO-treated patients. Several studies have reported ECMO-related central nervous system complications, such as intracranial hemorrhage, cerebral infarction, and seizure. However, few cases of peripheral nerve injury have been reported in ECMO-treated adults; there have also been no reported cases of peripheral nerve injury in the pediatric population.

PATIENT CONCERNS

Two pediatric patients aged 16 and 6 experienced motor weakness in the extremities after the insertion of ECMO equipment.

DIAGNOSES

They were diagnosed with peripheral nerve injuries through an electrodiagnostic study that showed femoral/sciatic neuropathies and brachial plexopathy. Arteriography and doppler sonography was performed to find the cause of peripheral nerve injury, and this may be the results of vascular compromise and compressive injuries, respectively.

INTERVENTIONS

Surgical embolectomy was performed to remove thrombus in one patient. Two patients received orthosis, and physical therapy and occupational therapy were performed to prevent contracture and improve strength and functional use.

OUTCOMES

Two pediatric patients showed a gradual improvement in motor power and function.

LESSONS

Through this case report, we present rare ECMO-related complications and emphasize the importance of early diagnosis and monitoring of peripheral nerve injury in ECMO-treated children.

Disposable Component Selection in Extracorporeal Life Support: A Cost Analysis

Extracorporeal life support (ECLS) is a resource-intensive technology. Disposable components are modifiable through device selection. Cost analysis tools are needed to inform cost-conscious device selection. We generated a disposable cost analysis to forecast estimated costs of device disposables that included an assumption table, net present value (NPV) analysis, and sensitivity analysis to examine device disposable costs over 5 years with different case volumes and device mixes. To demonstrate the function of the analysis, we included four device options using the following assumptions: 100 cases in year 1, 2.5% case growth rate, 10% discount rate, and $5,000 incremental cost (Device 4 only). Using estimated device costs of $3,000, $12,000, $13,000, and $20,000 and device mix percentages of 65%, 8%, 25%, and 2% for Device 1, 2, 3, and 4, respectively, the 5 year unadjusted and NPV of disposable device costs were $3,691,000 and $2,765,000, respectively. The sensitivity analysis incorporated six separate models with different device mix percentages. The highest and lowest estimated costs were found in Model F (75% Device 3 and 25% Device 4; NPV = $6,64,400) and Model B (100% Device 1; NPV = 1,246,000) respectively. Extracorporeal life support programs may apply this disposable cost analysis tool to reduce programmatic costs.

Survival in cystic fibrosis after acute respiratory failure supported by extracorporeal membrane oxygenation and/or invasive mechanical ventilation

BACKGROUND

Despite therapeutic advances, people with cystic fibrosis (CF) develop progressive worsening and exacerbations of their lung disease, which can lead to acute respiratory failure. Historically, survival after mechanical ventilation (MV) has been poor. Outcomes related to use of extracorporeal membrane oxygenation (ECMO) have not been well described in CF.

METHODS

We conducted a retrospective analysis of adult patients with CF admitted to the ICU for acute respiratory failure and requiring invasive MV with or without ECMO between July 1, 2006 and June 30, 2016. Separate analysis for the subgroup of MV patients who were eligible for transplant was conducted.

RESULTS

Mortality for all patients with respiratory failure requiring advanced support was 37%. Ten of 28 (36%) MV patients, 10 of 26 (38%) ECMO+MV patients and 7 of the 21 (33%) transplant eligible MV patients died. Intensive care unit (ICU) length of stay (LOS) was 24.5±16.6 days for ECMO+MV; 12.9±9.0 days for MV (p=0.001), and 12.3 ±10 days for transplant eligible MV patients (p=0.005 for ECMO+MV comparison). Seven transplant eligible MV patients (33%) and 16 ECMO+MV patients (62%) underwent lung transplantation (p<0.001) during the hospital admission. One and 2-year survival for individuals who survived ICU admission was similar regardless of mode of support. Cox-proportional hazards model did not yield any variables that significantly influenced ICU mortality, 1-year or 2-year mortality.

CONCLUSION

Survival for CF patients with acute respiratory failure requiring MV with or without ECMO has improved over time. ECMO may be an appropriate modality for respiratory support in patients with CF and acute respiratory failure who have greater risk of death from MV alone.

The Atrial Flow Regulator: A Novel Device for Left Ventricular Unloading in Patients Receiving Venoarterial Extracorporeal Membrane Oxygenation Support?

Severe pulmonary edema, secondary to left ventricular afterload increment, is a common problem occurring in patients receiving venoarterial extracorporeal membrane oxygenation. No consensus is currently available for its management, but several devices/procedures have been described, including an Impella device (Abiomed), balloon atrial septostomy, intraaortic balloon counterpulsation, or an additional venous cannula, as possible adjuncts. We report the feasibility and efficacy of the atrial flow regulator device (Occlutech) for left ventricular unloading in a 58-year-old patient receiving extracorporeal membrane oxygenation. However, the benefits of this device relative to simple balloon atrial septostomy need to be further investigated.

Early Positive Fluid Balance is Associated with Mortality in Patients Treated with Veno-Arterial Extra Corporeal Membrane Oxygenation For Cardiogenic Shock: a Retrospective Cohort Study

PURPOSE

Veno-arterial Extracoporeal Membrane Oxygenation (VA-ECMO) provides circulatory assistance for patients in cardiogenic shock. Large quantities of fluids are often required, especially during the early stages, but can result in a potentially harmful fluid-overload. The objective was to determine the association of early fluid-balance and mortality.

METHODS

Retrospective single-center study in 101 VA-ECMO patients between 2013 and 2016. Daily fluid-balance and weight changes over the 5 first days were observed. Analyses between survivors and non-survivors were conducted using Mann-Whitney tests and logistic regression multivariable and Cox hazard-proportional analyses to determine any association with 28-days mortality.

RESULTS

Mortality was 47.5%. The fluid-balance was higher in non-survivors at day-1 (47.3[18.1-71.9] vs. 19.3[1.5-36.2] mL/kg, P < 0.0001) and day-2 (30.6[14.8-71.0] vs. 10.1[-9.8 to 34.7] mL/kg, P = 0.025), as was the cumulative fluid-balance over the first 5 days (107.3[40.5-146.2] vs. 53.0[7.5-74.3] mL/kg, P = 0.04). The administration of unintentional fluids (used for preparation and infusion of drugs) represented an important part of the administrated fluids (15 mL/kg/d-23 mL/kg/d). A significant but moderate correlation was observed between fluid-balance and weight variations over the 5 days (r values ranging from 0.36 to 0.54). Among other parameters, day-1 fluid-balance was independently associated with mortality (OR = 14.34 [1.58-129.79], P = 0.02) and day-1 and day-2 with time to death (HR = 8.26 [1.12-60.98], P = 0.04 and 2.89 [1.26-6.65], P = 0.01). A threshold of 38.8 mL/kg predicted mortality with a sensitivity of 60% and specificity of 83% (area under the curve: 0.749).

CONCLUSION

Early positive fluid-balance is associated with mortality in VA-ECMO patients.

Transition from Simple V-V to V-A and Hybrid ECMO Configurations in COVID-19 ARDS

In SARS-CoV-2 patients with severe acute respiratory distress syndrome (ARDS), Veno-Venous Extracorporeal Membrane Oxygenation (V-V ECMO) was shown to provide valuable treatment with reasonable survival in large multi-centre investigations. However, in some patients, conversion to modified ECMO support forms may be needed. In this single-centre retrospective registry, all consecutive patients receiving V-V ECMO between 1 March 2020 to 1 May 2021 were included and analysed. The patient cohort was divided into two groups: those who remained on V-V ECMO and those who required conversion to other modalities. Seventy-eight patients were included, with fourteen cases (18%) requiring conversions to veno-arterial (V-A) or hybrid ECMO. The reasons for the ECMO mode configuration change were inadequate drainage (35.7%), inadequate perfusion (14.3%), myocardial infarction (7.1%), hypovolemic shock (14.3%), cardiogenic shock (14.3%) and septic shock (7.1%). In multivariable analysis, the use of dobutamine (p = 0.007) and a shorter ICU duration (p = 0.047) predicted the conversion. The 30-day mortality was higher in converted patients (log-rank p = 0.029). Overall, only 19 patients (24.4%) survived to discharge or lung transplantation. Adverse events were more common after conversion and included renal, cardiovascular and ECMO-circuit complications. Conversion itself was not associated with mortality in the multivariable analysis. In conclusion, as many as 18% of patients undergoing V-V ECMO for COVID-19 ARDS may require conversion to advanced ECMO support.

Extracorporeal membrane oxygenation and V/Q ratios: an ex vivo analysis of CO2 clearance within the Maquet Quadrox-iD oxygenator

While hypercapnia is typically well treated with modern membrane oxygenators, there are cases where respiratory acidosis persists despite maximal extracorporeal membrane oxygenation support. To better understand the physiology of gas exchange within the membrane oxygenator, CO₂ clearance within an adult Maquet Quadrox-iD oxygenator was evaluated at varying blood CO₂ tensions and V/Q ratios in an ex vivo extracorporeal membrane oxygenation circuit. A closed blood-primed circuit incorporating two Maquet Quadrox-iD oxygenators in series was attached to a Maquet PLS Rotaflow pump. A varying blend of CO₂ and air was connected to the first oxygenator to provide different levels of pre-oxygenator blood CO₂ levels (P_vCO₂) to the second oxygenator. Varying sweep gas flows of 100% O₂ were connected to the second oxygenator to provide different V/Q ratios. Exhaust CO₂ was directly measured, and then VCO₂ and oxygenator dead space fraction (V_D/V_T) were calculated. VCO₂ increased with increasing gas flow rates with plateauing at V/Q ratios greater than 4.0. Exhaust CO₂ increased with P_vCO₂ in a linear fashion with the slope of the line decreasing at high V/Q ratios. Oxygenator dead space fraction varied with V/Q ratio-at lower ratios, dead space fraction was 0.3-0.4 and rose to 0.8-0.9 at ratios greater than 4.0. Within the Maquet Quadrox-iD oxygenator, CO₂ clearance is limited at high V/Q ratios and correlated with elevated oxygenator dead space fraction. These findings have important implications for patients requiring high levels of extracorporeal membrane oxygenation support.

Microbiological Spectrum of Nosocomial ECMO Infections in a Tertiary Care Center

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment in cardiogenic and respiratory shock. It is prone to various complications, infection being among the most frequent. This study aims to define the prevalence and characteristics of infections in ECMO patients in a tertiary care center for cardiac diseases.

METHODS

All ECMO patients between 2012 and 2016 in a single cardiac center were retrospectively included. Demographic data, ECMO indications, type, site, duration, and infection-related data were recorded. Data were analyzed among all patients and separately between pediatric and adult patient groups.

RESULTS

One hundred and twenty-six patients, 66 (53.4%) pediatric and 60 (47.6%) adult, received ECMO within the study period. Mean age was 3.54±4.27 years in the pediatric group and 54.92±15.57 years in the adult group. The main indication for ECMO was postcardiotomy shock (77.8%). Forty-six (36.5%) of all cases developed a culture-proven nosocomial infection with a rate of 49/1000 ECMO days. Infection was associated with > 5 days of ECMO duration and hemodialysis requirement in all patients and lower age in the pediatric group. The most frequent infection site was the lower respiratory tract (14.3%), while the most common isolated organisms were Klebsiella (8.7%) and Streptococcus (4.8%) species.

CONCLUSION

The respiratory tract is the most common site of infection, however, all sites impose a threat to recovery, with longer treatment durations required for patients with culture-proven infections. A better understanding of the infectious spectrum and its effect on the mortality and morbidity is required for more successful treatment of ECMO patients.

Microcirculatory Response to Changes in Venoarterial Extracorporeal Membrane Oxygenation Pump Flow: A Prospective Observational Study

Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) pump flow is crucial for maintaining organ perfusion in patients with cardiogenic shock, but VA-ECMO pump flow optimization remains as a clinical challenge. This study aimed to investigate the response of sublingual microcirculation to changes in VA-ECMO pump flow.

Methods: Sublingual microcirculation was measured before and after changing VA-ECMO pump flow according to the treatment plan of ECMO team within 24 h and at 24-48 h after VA-ECMO placement. In clinical events of increasing VA-ECMO pump flow, those events with increased perfused vessel density (PVD) were grouped into group A, and the others were grouped into group B. In clinical events of decreasing VA-ECMO pump flow, those events with increased PVD were grouped into group C, and the others were grouped into group D.

Results: Increased PVD was observed in 60% (95% CI, 38.5–81.5%) of the events with increasing VA-ECMO pump flow. The probability of increasing PVD after increasing VA-ECMO pump flow were higher in the events with a PVD < 15 mm/mm² at baseline than those with a PVD ≥ 15 mm/mm² [100% (95% CI, 54.1–100%) vs. 42.9% (95% CI, 17.7–71.1%), P = 0.042]. Other microcirculatory and hemodynamic parameters at baseline did not differ significantly between group A and B or between group C and D.

Conclusion: This study revealed contradictory and non-contradictory responses of sublingual microcirculation to changes in VA-ECMO pump flow. Tandem measurements of microcirculation before and after changing VA-ECMO pump flow may help to ensure a good microcirculation.

Transient perioperative inflammation following lung transplantation and major thoracic surgery with elective extracorporeal support: a prospective observational study

Background

The clinical relevance of inflammation induced by elective perioperative extracorporeal membrane oxygenation (ECMO) usage as an integral part of modern lung transplantation (LUTX) remains elusive. The aim of this study was to determine the perioperative cytokine response accompanying major thoracic surgery employing different extracorporeal devices comprising ECMO, cardiopulmonary bypass (CPB), or no extracorporeal circulation in relation to inflammation, clinically tangible as increased sequential organ failure assessment (SOFA) score, called SOFA.

Methods

In this prospective, observational pilot study 42 consecutive patients with end-stage pulmonary disease undergoing LUTX; 15 patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing pulmonary endarterectomy and 15 patients with lung cancer undergoing major lung resections were analysed. Cytokine serum concentrations and SOFA were determined before, at end of surgery and in the following postoperative days.

Results

LUTX on ECMO and pulmonary endarterectomy (PEA) on CPB triggered an immediate increase in cytokine serum concentrations at end of surgery: IL-6: 66-fold and 71-fold, IL-10: 3-fold and 2.5-fold, ST2/IL-33R: 5-fold and 4-fold and SOFA: 10.5±2.8 and 10.7±1.7, that decreased sharply to baseline levels from postoperative day 1–5. Despite low perioperative mortality (3 patients, 4.1%) extremely high SOFA ≥13 was associated with mortality after LUTX. Delta-SOFA distinguished survivors from non-survivors: −4.5±3.2 vs. −0.3±1.5 (P=0.001). Increased IL-6 serum concentrations were predictive for increased SOFA (sensitivity: 97%, specificity: 80%). Peak cytokine serum concentrations correlated with ECC duration, maximal lactate, transfusion of red-blood-cells, fresh-frozen-plasma, and catecholamine support.

Conclusions

LUTX and PEA on extracorporeal circulation with an excellent outcome triggered an immediate rise and concomitant fall of inflammation as observed in cytokine serum concentrations and SOFA. High absolute SOFA in the presence of an uncomplicated postoperative course may pertain to specific management strategies rather than organ failure.

Viscoelastic Haemostatic Assays in Cardiovascular Critical Care

The initiation and management of anticoagulation is a fundamental practice for a wide variety of indications in cardiovascular critical care, including the management of patients with acute MI, stroke prevention in patients with AF or mechanical valves, as well as the prevention of device thrombosis and thromboembolic events with the use of mechanical circulatory support and ventricular assist devices. The frequent use of antiplatelet and anticoagulation therapy, in addition to the presence of concomitant conditions that may lead to a propensity to bleed, such as renal and liver dysfunction, present unique challenges. The use of viscoelastic haemostatic assays provides an additional tool allowing clinicians to strike a delicate balance of attaining adequate anticoagulation while minimising the risk of bleeding complications. In this review, the authors discuss the role that viscoelastic haemostatic assay plays in cardiac populations (including cardiac surgery, heart transplantation, extracorporeal membrane oxygenation, acute coronary syndrome and left ventricular assist devices), and identify areas in need of further study.

Insight into ECMO, mortality and ARDS: a nationwide analysis of 45,647 ECMO runs

Background

Extracorporeal life support (ECLS) has become an integral part of modern intensive therapy. The choice of support mode depends largely on the indication. Patients with respiratory failure are predominantly treated with a venovenous (VV) approach. We hypothesized that mortality in Germany in ECLS therapy did not differ from previously reported literature

Methods

Inpatient data from Germany from 2007 to 2018 provided by the Federal Statistical Office of Germany were analysed. The international statistical classification of diseases and related health problems codes (ICD) and process keys (OPS) for extracorporeal membrane oxygenation (ECMO) types, acute respiratory distress syndrome (ARDS) and hospital mortality were used.

Results

In total, 45,647 hospitalized patients treated with ECLS were analysed. In Germany, 231 hospitals provided ECLS therapy, with a median of 4 VV-ECMO and 9 VA-ECMO in 2018. Overall hospital mortality remained higher than predicted in comparison to the values reported in the literature. The number of VV-ECMO cases increased by 236% from 825 in 2007 to 2768 in 2018. ARDS was the main indication for VV-ECMO in only 33% of the patients in the past, but that proportion increased to 60% in 2018. VA-ECMO support is of minor importance in the treatment of ARDS in Germany. The age distribution of patients undergoing ECLS has shifted towards an older population. In 2018, the hospital mortality decreased in VV-ECMO patients and VV-ECMO patients with ARDS to 53.9% (n = 1493) and 54.4% (n = 926), respectively.

Conclusions

ARDS is a severe disease with a high mortality rate despite ECLS therapy. Although endpoints and timing of the evaluations differed from those of the CESAR and EOLIA studies and the Extracorporeal Life Support Organization (ELSO) Registry, the reported mortality in these studies was lower than in the present analysis. Further prospective analyses are necessary to evaluate outcomes in ECMO therapy at the centre volume level.

Iatrogenic Iliac Vein Injury Following Extracorporeal Membrane Oxygenation Cannulation in a Patient with May-Thurner Syndrome: A Case Report and Literature Review

A 53-year-old woman presented with dyspnea. She had undergone extended thymectomy for an invasive thymoma two months prior. CT revealed numerous small nodules in the lung. After that, she deteriorated owing to acute respiratory distress syndrome (ARDS), and the vascular surgeon planned veno-venous extracorporeal membrane oxygenation (ECMO). During percutaneous cannulation through the left femoral vein, a vascular injury was suspected, and the patient's vital signs became unstable. Diagnostic angiography showed a ruptured left common iliac vein, and the bleeding was stopped by placement of a stent-graft. May-Thurner syndrome was diagnosed on abdominal CT. Here, we report a rare case of ECMO-related vascular injury in a patient with an unrecognized anatomical variant, May-Thurner syndrome.

Identification of a Circulating miRNA Signature to Stratify Acute Respiratory Distress Syndrome Patients

There is a need to improve acute respiratory distress syndrome (ARDS) diagnosis and management, particularly with extracorporeal membrane oxygenation (ECMO), and different biomarkers have been tested to implement a precision-focused approach. We included ARDS patients on veno-venous (V-V) ECMO in a prospective observational pilot study. Blood samples were obtained before cannulation, and screened for the expression of 754 circulating microRNA (miRNAs) using high-throughput qPCR and hierarchical cluster analysis. The miRNet database was used to predict target genes of deregulated miRNAs, and the DIANA tool was used to identify significant enrichment pathways. A hierarchical cluster of 229 miRNAs (identified after quality control screening) produced a clear separation of 11 patients into two groups: considering the baseline SAPS II, SOFA, and RESP score cluster A (n = 6) showed higher severity compared to cluster B (n = 5); p values < 0.05. After analysis of differentially expressed miRNAs between the two clusters, 95 deregulated miRNAs were identified, and reduced to 13 by in silico analysis. These miRNAs target genes implicated in tissue remodeling, immune system, and blood coagulation pathways. The blood levels of 13 miRNAs are altered in severe ARDS. Further investigations will have to match miRNA results with inflammatory biomarkers and clinical data.

Intraoperative Cardiac Arrest

Cardiac arrest in the operating room and in the immediate postoperative period is a potentially catastrophic event that is almost always witnessed and is frequently anticipated. Perioperative crises and perioperative cardiac arrest, although often catastrophic, are frequently managed in a timely and directed manner because practitioners have a deep knowledge of the patient's medical condition and details of recent procedures. It is hoped that the approaches described here, along with approaches for the rapid identification and management of specific high-stakes clinical scenarios, will help anesthesiologists continue to improve patient outcomes.

Position Paper on Global Extracorporeal Membrane Oxygenation Education and Educational Agenda for the Future: A Statement From the Extracorporeal Life Support Organization ECMOed Taskforce

OBJECTIVES

The purpose of this position paper is two-fold: first, to describe the state of extracorporeal membrane oxygenation education worldwide, noting current limitations and challenges; and second, to put forth an educational agenda regarding opportunities for an international collaborative approach toward standardization.

DESIGN

Relevant medical literature was reviewed through literature search, and materials from national organizations were accessed through the Internet. Taskforce members generated a consensus statement using an iterative consensus process through teleconferences and electronic communication.

SETTING

In 2018, the Extracorporeal Life Support Organization convened the ECMOed Taskforce at two structured, face-to-face meetings of 40 healthcare practitioners and educators with expertise in caring for the extracorporeal membrane oxygenation patient and in extracorporeal membrane oxygenation education.

PATIENTS

None.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The ECMOed Taskforce identified seven educational domains that would benefit from international collaborative efforts. Of primary importance, the Taskforce outlined actionable items regarding 1) the creation of a standardized extracorporeal membrane oxygenation curriculum; 2) defining criteria for an extracorporeal membrane oxygenation course as a vehicle for delivering the curriculum; 3) outlining a mechanism for evaluating the quality of educational offerings; 4) utilizing validated assessment tools in the development of extracorporeal membrane oxygenation practitioner certification; and 5) promoting high-quality educational research to guide ongoing educational and competency assessment development.

CONCLUSIONS

Significant variability and limitations in global extracorporeal membrane oxygenation education exist. In this position paper, we outline a road map for standardizing international extracorporeal membrane oxygenation education and practitioner certification. Ongoing high-quality educational research is needed to evaluate the impact of these initiatives.

Extracorporeal Membrane Oxygenation during Percutaneous Coronary Intervention in Patients with Coronary Heart Disease

Extracorporeal membrane oxygenation (ECMO) has become an effective method in the treatment of adults and children with severe cardiac and pulmonary dysfunction that is resistant to conventional therapy. The aim of this article was to summarize an experience of ECMO usage for cardiac dysfunction, which develops in patients with coronary heart disease (CHD) during percutaneous transluminal coronary angioplasty. The study comprised a retrospective, single-center analysis of 23 patients with CHD (19 men and four women, average age 65.7 ± 12.3 years), who undertook the ECMO technique during percutaneous transluminal coronary angioplasty. A total of 13 (56.52%) patients died directly in the hospital, or 30 days after a discharge. Independent predictors of fatal outcomes were diabetes mellitus (odds ratio [OR] = 17.58; 95% confidence interval [CI] = 6.47-47.48; p = .00125), chronic renal failure (CRF) (OR = 20.81; 95% CI = 5.95-72.21; p = .00014), and damage to the right coronary artery (RCA) (OR = 25.51; 95% CI = 8.27-79.12; p = .00013). For deceased patients, the "no reflow" phenomenon was indicated in a larger percentage of cases (23.1% in the group of deceased, vs. 10% in the group of survivors). A routine connection to ECMO before the occurrence of cardiac events was significantly more often used in the group of survived patients (90% of cases) than in the deceased (p = .0000001). Diabetes mellitus, CRF, and damage to the RCA were independent predictors of mortality during percutaneous transluminal coronary angioplasty in patients with CHD. The routine use of ECMO in high-risk patients with percutaneous transluminal coronary angioplasty was a positive prognostic factor of patient survival.

Effectiveness of Vancomycin Dosing Guided by Therapeutic Drug Monitoring in Adult Patients Receiving Extracorporeal Membrane Oxygenation

The clinical situation for patients receiving extracorporeal membrane oxygenation (ECMO) is complex, and drug dosing is complicated by significant pharmacokinetic alterations. We sought to describe the frequency of achievement of therapeutic vancomycin concentrations in critically ill patients receiving ECMO with therapeutic drug monitoring (TDM). In this retrospective observational study, we included all critically ill patients receiving TDM for vancomycin while on ECMO. The primary outcome was the proportion of plasma vancomycin concentrations in the therapeutic range (15 to 20 mg/liter). Factors associated with not achieving therapeutic concentrations were investigated, including ECMO duration and use of renal replacement therapies. Vancomycin TDM was performed for 77 of 116 (66%) patients on ECMO. Median (interquartile range) duration of ECMO support was 7 days (4 to 16 days). The proportion of measurements in the therapeutic range (15 to 20 mg/liter) was 24%, while 46% were subtherapeutic (<15 mg/liter) and 30% were supratherapeutic (>20 mg/liter). The proportion of measures in the therapeutic range was significantly higher on ECMO days for 6 to 13 (incidence rate ratio [IRR], 2.4; 95% confidence interval [CI], 1.2 to 4.6; P = 0.01). Supratherapeutic concentrations were more frequently observed in patients on renal replacement therapy (RRT) (IRR, 2.0; 95% CI, 1.3 to 3.1; P = 0.002). The vancomycin concentrations in patients did not vary with age, gender, or type of ECMO support. Patients receiving vancomycin had suboptimal concentrations early in the course of ECMO. Patients not receiving RRT and those with mild to moderate acute kidney injury (AKI) were at a risk of underdosing, while those with established AKI on RRT were likelier to experience supratherapeutic concentrations.

Rapid Training in Extracorporeal Membrane Oxygenation for a Large Health System

Background: Despite the rapid integration of extracorporeal membrane oxygenation (ECMO) into intensive care units over the past decade, established programs for training critical care clinicians to provide ECMO are lacking.

Objective: To evaluate the development and implementation of a multidisciplinary ECMO training program for the rapid deployment of ECMO training for a high volume of critical care clinicians.

Methods: We performed a prospective cohort study examining a program for rapid training of multiple disciplines of critical care clinicians to deliver ECMO during the implementation of ECMO services across the intensive care units of an academic tertiary care center between October 2018 and January 2019. The multidisciplinary ECMO training program included didactic and simulation-based teaching and emphasized new, universal clinical protocols to improve consistency of care across the institution. Pre- and post-program written examinations evaluated knowledge acquisition, and an electronically distributed program evaluation assessed perceptions of content and delivery.

Results: Among the 97 clinicians who completed the program, 49 (51%) were physicians and 48 (49%) were advanced practice providers from the departments of surgery (n = 42), medicine (n = 29), and anesthesia (n = 26). There was a significant difference in knowledge about ECMO between the pre- and post-program examination score (median [interquartile range] 70% [60–80%] vs. 90% [80–90%], respectively, P < 0.001). The median (interquartile range) individual gain from pre- to post-program score was 20% (10–30%). The program was perceived as useful and applicable to safe care.

Conclusion: Rapid deployment of a multidisciplinary ECMO training program across a large academic center was feasible, achieved knowledge acquisition, and was positively perceived.

Curriculum to Introduce Critical Care Nurses to Extracorporeal Membrane Oxygenation

BACKGROUND

Despite the growing use of extracorporeal membrane oxygenation (ECMO) in intensive care units (ICUs), no standardized ECMO training pathways are available for ECMO-naive critical care nurses.

OBJECTIVES

To evaluate a critical care nurse ECMO curriculum that may be reproducible across institutions.

METHODS

An ECMO curriculum consisting of a basic safety course and an advanced user course was designed for critical care nurses. Courses incorporated didactic and simulation components, written knowledge examinations, and electronic modules. Differences in examination scores before and after each course for the overall cohort and for participants from each ICU type were analyzed with t tests or nonparametric equality-of-medians tests. Differences in postcourse scores across ICU types were examined with multiple linear regression.

RESULTS

Critical care nurses new to ECMO (n = 301) from various ICU types participated in the basic safety course; 107 nurses also participated in the advanced user course. Examination scores improved after completion of both courses for overall cohorts (P < .001 in all analyses). Median (interquartile range) individual score improvements were 23.1% (15.4%-38.5%) for the basic safety course and 8.4% (0%-16.7%) for the advanced user course. Postcourse written examination scores stratified by ICU type, compared with the medical ICU/cardiovascular ICU group (reference group), differed only in the neurovascular ICU group for the basic safety course (percent score difference, -3.0; 95% CI, -5.3 to -0.8; P = .01).

CONCLUSIONS

Implementation of an ECMO curriculum for a high volume of critical care nurses is feasible and effective.

Dose Optimization of Cefpirome Based on Population Pharmacokinetics and Target Attainment during Extracorporeal Membrane Oxygenation

To obtain the optimal dosage regimen in patients receiving extracorporeal membrane oxygenation (ECMO), we developed a population pharmacokinetics model for cefpirome and performed pharmacodynamic analyses. This prospective study included 15 patients treated with cefpirome during ECMO. Blood samples were collected during ECMO (ECMO-ON) and after ECMO (ECMO-OFF) at predose and 0.5 to 1, 2 to 3, 4 to 6, 8 to 10, and 12 h after cefpirome administration. The population pharmacokinetic model was developed using nonlinear mixed effects modeling and stepwise covariate modeling. Monte Carlo simulation was used to assess the probability of target attainment (PTA) and cumulative fraction of response (CFR) according to the MIC distribution. Cefpirome pharmacokinetics were best described by a two-compartment model. Covariate analysis indicated that serum creatinine concentration (SCr) was negatively correlated with clearance, and the presence of ECMO increased clearance and the central volume of distribution. The simulations showed that patients with low SCr during ECMO-ON had lower PTA than patients with high SCr during ECMO-OFF; so, a higher dosage of cefpirome was required. Cefpirome of 2 g every 8 h for intravenous bolus injection or 2 g every 12 h for extended infusion over 4 h was recommended with normal kidney function receiving ECMO. We established a population pharmacokinetic model for cefpirome in patients with ECMO, and appropriate cefpirome dosage regimens were recommended. The impact of ECMO could be due to the change in patient status on consideration of the small population and uncertainty in covariate relationships. Dose optimization of cefpirome may improve treatment success and survival in patients receiving ECMO. (This study has been registered at ClinicalTrials.gov under identifier NCT02581280.).

Extracorporeal Membrane Oxygenation for Cardiac Indications in Adults: A Health Technology Assessment

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy used to stabilize patients with hemodynamic compromise such as refractory cardiogenic shock or cardiac arrest. When used for cardiac arrest, ECMO is also known as extracorporeal cardiopulmonary resuscitation (ECPR). We conducted a health technology assessment of venoarterial ECMO for adults (aged ≥ 18 years) with cardiac arrest refractory to conventional cardiopulmonary resuscitation (CPR) or with cardiogenic shock refractory to conventional medical management (i.e., drugs, mechanical support such as intra-aortic balloon pump and temporary ventricular assist devices). Our assessment included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding ECMO for these indications, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Risk of Bias in Systematic Reviews (ROBIS) tool for systematic reviews and the Risk of Bias Among Nonrandomized Trials (ROBINS-I) tool for observational studies, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-effectiveness analysis with a lifetime horizon from a public payer perspective. We also analyzed the budget impact of publicly funding ECMO in Ontario for patients with refractory cardiogenic shock or cardiac arrest. To contextualize the potential value of ECMO for cardiac indications, we spoke with patients and caregivers with direct experience with the procedure.

RESULTS

We included one systematic review (with 13 observational studies) and two additional observational studies in the clinical review. Compared with traditional CPR for patients with refractory cardiac arrest, ECPR was associated with significantly improved 30-day survival (pooled risk ratio [RR] 1.54; 95% CI 1.03 to 2.30) (GRADE: Very Low) and significantly improved long-term survival (pooled RR 2.17; 95% CI 1.37 to 3.44) (GRADE: Low). Overall, ECPR was associated with significantly improved 30-day favourable neurological outcome in patients with refractory cardiac arrest compared with traditional CPR; pooled RR 2.02 (95% CI 1.29 to 3.16) (GRADE: Very Low). For patients with cardiogenic shock, ECMO was associated with a significant improvement in 30-day survival compared with intra-aortic balloon pump (pooled RR 2.11; 95% CI 1.23 to 3.61) (GRADE: Very Low). Compared with temporary percutaneous ventricular assist devices, ECMO was not associated with improved survival (pooled risk ratio 0.94; 95% CI 0.67 to 1.30) (GRADE: Very Low).We estimated the incremental cost-effectiveness ratio of ECPR compared with conventional CPR is $18,722 and $28,792 per life-year gained (LYG) for in-hospital and out-of-hospital cardiac arrest, respectively. We estimated the probability of ECPR being cost-effective versus conventional CPR is 93% and 60% at a willingness-to-pay of $50,000 per LYG for in-hospital and out-of-hospital cardiac arrest, respectively. We estimate that publicly funding ECMO in Ontario over the next 5 years would result in additional total costs of $1,673,811 for cardiogenic shock (treating 314 people), $2,195,517 for in-hospital cardiac arrest (treating 126 people), and $3,762,117 for out-of-hospital cardiac arrest (treating 247 people).The eight patients and family members with whom we spoke had limited ability to assess the impact of ECMO or report their impressions because of their critical medical situations when they encountered the procedure. All had been in hospital with acute hemodynamic instability. In the decision to receive the procedure, participants generally relied on the expertise and judgment of physicians.

CONCLUSIONS

For adults treated for refractory cardiac arrest, ECPR may improve survival and likely improves long-term neurological outcomes compared with conventional cardiopulmonary resuscitation. For patients treated for cardiogenic shock, ECMO may improve 30-day survival compared with intra-aortic balloon pump, but there is considerable uncertainty.For adults with refractory cardiac arrest, ECPR may be cost-effective compared with conventional CPR. We estimate that publicly funding ECMO for people with cardiac arrest and cardiogenic shock in Ontario over the next 5 years would cost about $845,000 to $2.2 million per year.People with experience of ECMO for cardiac indications viewed it as a life-saving device and expressed gratitude that it was available and able to help stabilize their acute medical condition.

Antibiotic dosing during extracorporeal membrane oxygenation: does the system matter?

PURPOSE OF REVIEW

The aims of this review are to discuss the impact of extracorporeal membrane oxygenation (ECMO) on antibiotic pharmacokinetics and how this phenomenon may influence antibiotic dosing requirements in critically ill adult ECMO patients.

RECENT FINDINGS

The body of literature describing antibiotic pharmacokinetic and dosing requirements during ECMO support in critically adult patients is currently scarce. However, significant development has recently been made in this research area and more clinical pharmacokinetic data have emerged to inform antibiotic dosing in these patients. Essentially, these clinical data highlight several important points that clinicians need to consider when dosing antibiotics in critically ill adult patients receiving ECMO: physicochemical properties of antibiotics can influence the degree of drug loss/sequestration in the ECMO circuit; earlier pharmacokinetic data, which were largely derived from the neonatal and paediatric population, are certainly useful but cannot be extrapolated to the critically ill adult population; modern ECMO circuitry has minimal adsorption and impact on the pharmacokinetics of most antibiotics; and pharmacokinetic changes in ECMO patients are more reflective of critical illness rather than the ECMO therapy itself.

SUMMARY

An advanced understanding of the pharmacokinetic alterations in critically ill patients receiving ECMO is essential to provide optimal antibiotic dosing in these complex patients pending robust dosing guidelines. Antibiotic dosing in this patient population should generally align with the recommended dosing strategies for critically ill patients not on ECMO support. Performing therapeutic drug monitoring (TDM) to guide antibiotic dosing in this patient population appears useful.

Extracorporeal Life Support in Adult Patients: A Global Perspective of the Last Decade

Extracorporeal life support (ECLS) is an external medical device to treat critically ill patients with cardiovascular and respiratory failure. In a nutshell, ECLS is only a "bridging" mechanism that provides life support while the heart and/or the lungs is recovering either by therapeutic medical interventions, transplantation, or spontaneously. Extracorporeal life support has been developed since 1950s, and many studies were conducted to improve ECLS techniques, but unfortunately, the survival rate was not improved. Because of Dr Bartlett's success in using ECLS to treat neonates with severe respiratory distress in 1975, ECLS is made as a standard lifesaving therapy for neonates with severe respiratory distress. However, its use for adult patients remains debatable. The objectives of this study are to outline and provide a general overview of the use of ECLS especially for adult patients for the past 10 years and to elaborate on the challenges encountered by each stakeholder involved in ECLS. The data used for this study were extracted from the ELSO Registry Report of January 2018. Results of this study revealed that the number of ECLS centers and the use of ECLS are increasing over the year for the past decade. There was also a shift of the patient's age category from neonatal to adult patients. However, the survival rates for adult patients are relatively low especially for cardiac and extracorporeal cardiopulmonary resuscitation cases. To date, the complications are still the major challenge of ECLS. Other challenges encountered by the stakeholders in ECLS are the limited amount of well-trained and experienced ECLS teams and centers, the limited government expenditure on health, and the lack of improvement and development of ECLS techniques and devices. Further studies are needed to evaluate the value of ECLS for adult patients.

An experimental model of veno-venous arterial extracorporeal membrane oxygenation

INTRODUCTION

Veno-venous arterial extracorporeal membrane oxygenation is a hybrid-modality of extracorporeal membrane oxygenation combining veno-venous and veno-arterial extracorporeal membrane oxygenation. It may be applied to patients with both respiratory and cardio-circulatory failure.

AIM

To describe a computational spreadsheet regarding an ex vivo experimental model of veno-venous arterial extracorporeal membrane oxygenation to determine the return of cannula pairs in a single pump-driven circuit.

METHODS

We developed an ex vivo model of veno-venous arterial extracorporeal membrane oxygenation with a single pump and two outflow cannulas, and a glucose solution was used to mimic the features of blood. We maintained a fixed aortic impedance and physiological pulmonary resistance. Both flow and pressure data were collected while testing different pairs of outflow cannulas. Six simulations of different cannula pairs were performed, and data were analysed by a custom-made spreadsheet, which was able to predict the flow partition at different flow levels.

RESULTS

In all simulations, the flow in the arterial cannula gradually increased differently depending on the cannula pair. The best cannula pair was a 19-Fr/18-cm arterial with a 17-Fr/50-cm venous cannula, where we observed an equal flow split and acceptable flow into the arterial cannula at a lower flow rate of 4 L/min.

CONCLUSION

Our computational spreadsheet identifies the suitable cannula pairing set for correctly splitting the outlet blood flow into the arterial and venous return cannulas in a veno-venous arterial extracorporeal membrane oxygenation configuration without the use of external throttles. Several limitations were reported regarding fixed aortic impedance, central venous pressure and the types of cannulas tested; therefore, further studies are mandatory to confirm our findings.