Extracorporeal Membrane Oxygenation Configuration Research Articles

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

Conventional MRI is incompatible with extracorporeal membrane oxygenation (ECMO) cannulas and pumps. Ultra-low-field portable MRI (ULF-pMRI) with 0.064 Tesla may provide a solution, but its safety and compatibility is unknown. ULF-pMRI does not cause significant displacement and heating of ECMO cannulas and does not affect ECMO pump function. ECMO cannulas in various sizes were tested ex vivo using phantom models to assess displacement force and heating according to the American Society for Testing and Materials criteria. ECMO pump function was assessed by pump flow and power consumption. In vivo studies involved five female domestic pigs (20-42 kg) undergoing different ECMO configurations (peripheral and central cannulation) and types of cannulas with an imaging protocol consisting of T2-weighted, T1-weighted, FLuid-Attenuated Inversion Recovery, and diffusion-weighted imaging sequences. Phantom models demonstrated that ECMO cannulas, both single lumen with various sizes (15-24-Fr) and double lumen cannula, had average displacement force less than gravitational force within 5 gauss safety line of ULF-pMRI and temperature changes less than 1°C over 15 minutes of scanning and ECMO pump maintained stable flow and power consumption immediately outside of the 5 gauss line. All pig models showed no visible motion due to displacement force or heating of the cannulas. ECMO flow and the animals' hemodynamic status maintained stability, with no changes greater than 10%, respectively. ULF-pMRI is safe and feasible for use with standard ECMO configurations, supporting its clinical application as a neuroimaging modality in ECMO patients.

Pneumonectomy following penetrating trauma with ECMO as postoperative support: case report – (Lung trauma and ECMO)

BackgroundPenetrating thoracic injuries have a significant risk of morbi-mortality. Despite the advancements in damage control methods, a subset of patients with severe pulmonary vascular lesions and bronchial injuries persists. In some of these cases, post-traumatic pneumonectomy is required, and perioperative extracorporeal membrane oxygenation (ECMO) support may be required due to right ventricular failure and respiratory failure.Case descriptionA male was brought to the emergency department (ED) with a penetrating thoracic injury, presenting with massive right hemothorax and active bleeding that required ligation of the right pulmonary hilum to control the bleeding. Subsequently, he developed right ventricular dysfunction and ARDS, necessitating a dynamic hybrid ECMO configuration to support his condition and facilitate recovery.ConclusionsPenetrating thoracic injuries with severe pulmonary vascular lesions may need pneumonectomy to control bleeding. ECMO support reduces the associated mortality by decreasing the complications rate. A multidisciplinary team is essential to achieve good outcomes in severe compromised patients.

Prevalence and Neurological Outcomes of Comatose Patients With Extracorporeal Membrane Oxygenation

To investigate prevalence, risk factors, and in-hospital outcomes of comatose extracorporeal membrane oxygenation (ECMO) patients. Retrospective observational. Tertiary academic hospital. Adults received venoarterial (VA) or venovenous (VV) ECMO support between November 2017 and April 022. None. We defined 24-hour off sedation as no sedative infusion (except dexmedetomidine) or paralytics administration over a continuous 24-hour period while on ECMO. Off-sedation coma (comaoff) was defined as a Glasgow Coma Scale score of ≤8 after achieving 24-hour off sedation. On-sedation coma (comaon) was defined as a Glasgow Coma Scale score of ≤8 during the entire ECMO course without off sedation for 24 hours. Neurological outcomes were assessed at discharge using the modified Rankin scale (good, 0-3; poor, 4-6). We included 230 patients (VA-ECMO 143, 65% male); 24-hour off sedation was achieved in 32.2% VA-ECMO and 26.4% VV-ECMO patients. Among all patients off sedation for 24 hours (n = 69), 56.5% VA-ECMO and 52.2% VV-ECMO patients experienced comaoff. Among those unable to be sedation free for 24 hours (n = 161), 50.5% VA-ECMO and 17.2% VV-ECMO had comaon. Comaoff was associated with poor outcomes (p < 0.05) in VA-ECMO and VV-ECMO groups, whereas comaon only impacted the VA-ECMO group outcomes. In a multivariable analysis, requirement of renal replacement therapy was an independent risk factor for comaoff after adjusting for ECMO configuration, after adjusting for ECMO configuration, acute brain injury, pre-ECMO partial pressure of oxygen in arterial blood, partial pressure of carbon dioxide in arterial blood, pH, and bicarbonate level (worst value within 24 hours before cannulation). Comaoff was common and associated with poor outcomes at discharge. Requirement of renal replacement therapy was an independent risk factor.

Outcomes of Adult Patients With COVID-19 Transitioning From Venovenous to Venoarterial or Hybrid Extracorporeal Membrane Oxygenation in the Extracorporeal Life Support Organization Registry.

This retrospective analysis of the Extracorporeal Life Support Organization (ELSO) registry evaluates the outcomes and identifies risk factors associated with conversion from initial venovenous extracorporeal membrane oxygenation (ECMO) support to venoarterial or hybrid ECMO in patients with coronavirus disease 2019 (COVID-19). We collected deidentified data on all adult patients (≥18 years old) diagnosed with COVID who received venovenous extracorporeal membrane oxygenation between March 2020 and November 2022. Patients initially placed on an ECMO configuration other than venovenous (VV) ECMO were excluded from the analysis. Our analysis included data from 12,850 patients, of which 393 (3.1%) transitioned from VV ECMO to an alternative mode. The primary outcome measure was in-hospital mortality, and the conversion group exhibited a higher in-hospital mortality rate. We also examined baseline variables, including demographic information, biochemical labs, and inotrope requirements. Univariate analysis revealed that pre-ECMO arrest, the need for renal replacement therapy, and the use of inotropic agents, particularly milrinone, were strongly associated with the risk of conversion. Notably, even after implementing a 3:1 propensity score matching, the impact of conversion on both mortality and complications remained substantial. Our study underscores an elevated risk of mortality for COVID-19 patients initially treated with VV ECMO who subsequently require conversion to VA-ECMO or hybrid ECMO.

Developing a generalizable pediatric ECMO emergency checklist for clinical specialist: Progress and challenges.

Extracorporeal membrane oxygenation (ECMO) emergencies require skilled clinical specialist (CS) who manage ECMO circuits. While tools for assessing CS skills have been published, there is significant variation in protocols and circuit design. This study aims to further develop these checklists to produce a generalizable ECMO skill assessment with adequate validity evidence to support its use as a summative evaluation tool. An initial survey determined variation in ECMO circuit components and configurations, and the original checklists and simulations were altered through a modified Delphi process. The finalized checklist and simulation were then assessed for validity and reliability. Three trained raters assessed ten simulations from five subjects at two different institutions using two circuit designs. Data analysis was conducted using a fully crossed subject x rater x circuit generalizability (G) and decision (D) study. The G-study coefficient was 0 with 0% variance across subject and circuit. The greatest variance was among raters (28.7%). Significant variance was also associated with the subject and pump type relationship (27%). Despite the rigorous process used to modify the assessment, generalizability was poor. Lack of familiarity with center-specific circuit design played a key role. Future endeavors in ECMO skill assessment should focus either on developing and validating site-specific tools or standardizing circuit designs.

Outcomes of Lung Transplantation in Patients With Right Ventricular Dysfunction: A Single-Center Retrospective Analysis Comparing ECMO Configurations in a Bridge-to-Transplant Setting

This study aimed to assess the lung transplantation (LT) outcomes of patients with right ventricular dysfunction (RVD), focusing on the impact of various extracorporeal membrane oxygenation (ECMO) configurations. We included adult patients who underwent LT with ECMO as a bridge-to-transplant from 2011 to 2021 at a single center. Among patients with RVD (n = 67), veno-venous (V-V) ECMO was initially applied in 79% (53/67) and maintained until LT in 52% (35/67). Due to the worsening of RVD, the configuration was changed from V-V ECMO to veno-arterial (V-A) ECMO or a right ventricular assist device with an oxygenator (Oxy-RVAD) in 34% (18/67). They showed that lactic acid levels (2–6.1 mmol/L) and vasoactive inotropic score (6.6–22.6) increased. V-A ECMO or Oxy-RVAD was initiated and maintained until LT in 21% (14/67) of cases. There was no significant difference in the survival rates among the three configuration groups (V-V ECMO vs. configuration changed vs. V-A ECMO/Oxy-RVAD). Our findings suggest that the choice of ECMO configuration for LT candidates with RVD should be determined by the patient’s current hemodynamic status. Vital sign stability supports the use of V-V ECMO, while increasing lactic acid levels and vasopressor needs may require a switch to V-A ECMO or Oxy-RVAD.

Occurrence, predictors, and management of late vascular complications following extracorporeal membrane oxygenation

ObjectiveVascular complications (VCs) associated with extracorporeal membrane oxygenation (ECMO) during index hospitalization are prevalent and associated with increased mortality. Few studies have evaluated late VCs following ECMO; this study aims to assess occurrence and management practices of late VCs following discharge. MethodsA retrospective single-institution review was performed of all patients surviving initial hospitalization after being cannulated for central or peripheral veno-venous (VV) or veno-arterial (VA) ECMO between January 1, 2019, and December 31, 2020. Primary outcomes were to categorize and determine the rate of late VCs. Late VCs were defined as any cannulated vessel injury resulting from ECMO cannulation presenting after discharge from index hospitalization. Analysis was conducted by cannulated vessel and stratified by VV or VA ECMO configurations. ResultsA total of 229 patients were identified, of which 50.6% (n = 116) survived until discharge. Late VCs occurred in 7.8% of the surviving cohort (n = 9/116); with a median time until presentation of 150 days (interquartile range, 83-251 days). The most common late VC was infection (n = 5; 55.6%) followed by progression to limb-threatening ischemia (n = 4; 44.4%). Urgent procedures were required in 55.6% of patients (n = 5), whereas 44.4% (n = 4) were elective interventions. Interventions performed for management of late VCs included lower extremity arterial revascularization (n = 6; 66.7%), major (n = 1; 11.1%) or minor amputation (n = 1; 11.1%), and wound debridement (n = 1; 11.1%). The majority of patients presenting with late VCs had initially been cannulated for peripheral VA ECMO (n = 8; 88.9%), and one patient (11.1%) was cannulated for peripheral VV ECMO. VCs during index hospitalization were seen in 77.8% of patients (n = 7) returning with late VCs. Odds for late VCs were significantly increased in patients that had been cannulated for ECMO as part of extracorporeal cardiopulmonary resuscitation (odds ratio, 8.4; P = .016) and in cases where patients had experienced an index VC during index hospitalization (odds ratio, 19.3; P = .001). ConclusionsLate vascular complications after peripheral ECMO cannulation are not rare, particularly after arterial cannulation. Patients should be followed closely early after surviving ECMO with wound evaluation and formal assessment of perfusion with ankle-branchial indices in the cannulated limb.

Head-to-toe bedside ultrasound for adult patients on extracorporeal membrane oxygenation.

Bedside ultrasound represents a well-suited diagnostic and monitoring tool for patients on extracorporeal membrane oxygenation (ECMO) who may be too unstable for transport to other hospital areas for diagnostic tests. The role of ultrasound, however, starts even before ECMO initiation. Every patient considered for ECMO should have a thorough ultrasonographic assessment of cardiac and valvular function, as well as vascular anatomy without delaying ECMO cannulation. The role of pre-ECMO ultrasound is to confirm the indication for ECMO, identify clinical situations for which ECMO is not indicated, rule out contraindications, and inform the choice of ECMO configuration. During ECMO cannulation, the use of vascular and cardiac ultrasound reduces the risk of complications and ensures adequate cannula positioning. Ultrasound remains key for monitoring during ECMO support and troubleshooting ECMO complications. For instance, ultrasound is helpful in the assessment of drainage insufficiency, hemodynamic instability, biventricular function, persistent hypoxemia, and recirculation on venovenous (VV) ECMO. Lung ultrasound can be used to monitor signs of recovery on VV ECMO. Brain ultrasound provides valuable diagnostic and prognostic information on ECMO. Echocardiography is essential in the assessment of readiness for liberation from venoarterial (VA) ECMO. Lastly, post decannulation ultrasound mainly aims at identifying post decannulation thrombosis and vascular complications. This review will cover the role of head-to-toe ultrasound for the management of adult ECMO patients from decision to initiate ECMO to the post decannulation phase.

Respiratory extracorporeal membrane oxygenation : From rescue therapy to standard tool for treatment of acute respiratory distress syndrome?

The use of extracorporeal membrane oxygenation (ECMO) for patients with acute respiratory distress syndrome (ARDS) has increased substantially. With modern trials supporting its efficacy, ECMO has become an important tool in the management of severe ARDS. The objectives of this paper are to discuss ECMO physiology and configurations used for patients with ARDS, review evidence supporting the use of ECMO for ARDS, and discuss aspects of management during ECMO. Current evidence supports the use of ECMO, combined with an ultra-lung-protective approach to mechanical ventilation, in patients with ARDS who have refractory hypoxemia or hypercapnia with severe respiratory acidosis. Furthermore, data suggest that center volume and experience are important factors in the care of patients receiving ECMO. The use of extracorporeal technologies in expanded patient populations and the optimal management of patients during ECMO remain areas of investigation. This article is freely available.

Physiologic benefits of veno-pulmonary extracorporeal membrane oxygenation for COVID-19 ARDS: A single center experience.

A subset of patients with COVID-19 acute respiratory distress syndrome (ARDS) require extracorporeal membrane oxygenation (ECMO). Veno-pulmonary (VP) ECMO provides support to the right ventricle and decreased risk of recirculation. A retrospective analysis of patients with COVID-19 ARDS and VP ECMO was performed. Patients were separated into groups by indication (1) "right ventricular (RV) failure," (2) "refractory hypoxemia," and (3) "recurrent suck-down events (SDEs)." Pre- and post-configuration vasoactive inotropic scores (VIS), fraction of inspired oxygen (FIO2), and resolution of SDEs were reported. A 90-day mortality was computed for all groups. Patients were also compared to those who underwent conventional venovenous (VV) ECMO. Forty-seven patients underwent VP ECMO configuration, 18 in group 1, 16 in group 2, and 8 in group 3. Ninety-day mortality was 66% for the entire cohort and was 77.8%, 81.3% and 37.5% for groups 1, 2, and 3, respectively. Mean VIS decreased in group 1 (8.3 vs 2.9, p = 0.005), while mean FIO2 decreased in the group 2 and was sustained at 72 h (82.5% vs 52.5% and 47.5%, p < 0.001). Six of the eight (75%) of patients with recurrent SDEs had resolution of these events after configuration to VP ECMO. Patients with VP ECMO spent more days on ECMO (33 days compared to 18 days, p = 0.004) with no difference in mortality (66% compared to 55.1%, p = 0.28). VP ECMO in COVID-19 ARDS improves hemodynamics in patients with RV failure, improves oxygenation in patients with refractory hypoxemia and improves the frequency of SDEs.

Successful Extracorporeal Membrane Oxygenation Implementation at a Non-tertiary Medical Center: A Single-Center Experience.

The inexperience and limited resources at non-tertiary medical centers pose unique challenges to the successful development of an extracorporeal membrane oxygenation (ECMO) program. The current literature does not provide a detailed framework that addresses the unique challenges encountered at these facilities. We outline a proactive approach to developing an ECMO program and provide a retrospective analysis of patient demographics, clinical characteristics, ECMO configuration, duration of ECMO support, major adverse events, and survival to hospital discharge. Data are summarized using mean, median, percentages, standard deviation, and interquartile range. Eleven patients were cannulated between December 2021 to March 2023. The age range of the patients who received ECMO varied significantly, with the youngest being 25 years old and the oldest being 69 years old. The mean age was 38 years old, with a standard deviation of 15.9. Hypertension was the most common co-morbid condition occurring in 64% (n=7) of patients. Only one patient had a major adverse event, and survival to hospital discharge was 73% (n=8). Of the patients that survived hospital discharge, seven patients were discharged home and one to a rehabilitation facility. These findings suggest that the safe implementation of an ECMO program at a non-tertiary hospital with inexperienced staff and limited resources is feasible. Adherence to established guidelines is essential for new programs, especially with regard to patient selection. Furthermore, a proactive approach that emphasizes high-yield training techniques, patient management protocols, and strategies that mitigate adverse events may be the key to achieving survival rates that exceed those of larger academic hospitals.

PULM9: Development of a Novel Cannula for Durable Venovenous Extracorporeal Membrane Oxygenation

Background: Fifteen million Americans suffer from chronic obstructive pulmonary disease (COPD). After failed optimal medical therapy, the only definitive treatment is lung transplantation, which is limited due to donor scarcity. Extracorporeal membrane oxygenation (ECMO) can be used in acute exacerbations of COPD or as a bridge to transplant for waitlisted COPD patients, but it is not currently suited for long-term respiratory support. Existing venovenous (VV) ECMO configurations often utilize a dual lumen cannula that is inserted into the jugular vein and is designed for short term use. While effective, dual lumen cannulas are associated with high resistance and malposition which limits blood flow, promotes cavitation, and increases blood trauma. Furthermore, patient ambulation is cumbersome because of the difficulty of securing the dual lumen cannula safely to the patient. A novel ECMO system that provides durable respiratory support could reduce morbidity and mortality in patients and facilitate ambulatory use. To this end, a dual lumen cannula that is attached to the heart and tunneled to a more ergonomic position could provide more durable, long term ECMO support. Here, we describe our initial efforts to develop a durable VV ECMO cannula with reduced resistance. Methods: A novel cannula for long-term VV ECMO support was developed using computer aided design. The cannula is designed for surgical attachment to the right atrium with the cannula’s drainage tip at the cavoatrial junction and the reinfusion port directed towards the tricuspid valve to minimize recirculation. Pressure drop was evaluated for the novel cannula, 28Fr, and 32Fr Crescent cannulas (MC3, Dexter, MI) for comparison (N≥5) in circuits primed with deionized water at ambient temperature. A Rotaflow (Maquet, Wayne, NJ) blood pump was operated at 2700-3625 RPM, and pressure drop was assessed for flow rates between 0.1 – 5 LPM. Porcine hearts were harvested from healthy pigs and utilized for ex vivo cannula fit studies. Water flow through the cannula into the right atrium was evaluated using videography. Results: The novel cannula drainage pressure drop (-12±1.1mmHg) was similar to the 28Fr Crescent (-13± 0.3mmHg) and 32Fr Crescent (-9±0.3mmHg) at 2LPM (Figure 1). Reinfusion pressure drop was similar between the novel cannula (22±1.2mmHg) and the 32Fr Crescent (21±0.4mmHg), and higher for the 28Fr Crescent (43±0.9mmHg) at 2LPM. Total pressure drop was similar between the novel cannula (33.4±1.2mmHg) and 32Fr Crescent (29.4±0.5mmHg) and higher for the 28Fr Crescent (57±1.0mmHg) at 2LPM. In ex-vivo heart studies flow through the novel cannula was directed towards the tricuspid valve and entered the right ventricle. Conclusions: Our novel cannula possesses an excellent pressure-flow profile, comparable to the largest-bore commercially available dual lumen cannulas. This novel cannula will enhance durability and ease of use for patients requiring durable mechanical respiratory support.Figure 1. Pressure Flow Curve for Novel VV ECMO Cannula

Long-term ECMO, efficiency and performance of EUROSETS adult A.L.ONE ECMO oxygenator

BackgroundThe management of the oxygenator can be prolonged in the long-term procedures especially during extracorporeal membrane oxygenation (ECMO) for bridge to transplant or bridge to recovery. Long-term use often involves an overrun of the time of use with respect to certification of the oxygenating module of 14 days, for the maintenance of performance and efficiency of the oxygenator. The evaluation of the long-term oxygenator efficiency is complex and depends on the: patient pathology, ECMO configuration, the management of coagulation and anticoagulation, materials selection and circuit components, the structure, design and performance of the oxygenator. In this context we investgated the long-term performance of the A.L.ONE Eurosets ECMO oxygenator in relation to the parameters prodromal to replacement.MethodsWe retrospectively collected eight years data from Anthea Hospital GVM Care & Research, Bari, Italy on the long-term use exceeding 14 days of Eurosets A.L.ONE ECMO Adult oxygenator in Polymetylpentene fiber, for ECMO procedures, including the procedures: Veno Arterial (VA) ECMO post-cardiotomy or not, veno-venous (VV) ECMO. The primary end points were the evaluation of Gas Transfer: oxygen partial pressure (PO2) post oxygenator, Carbon dioxide partial pressure (PCO2) post oxygenator, the oxygen transfer across the oxygenator membrane V′O2, differential CO2 content across oxygenator; Pressure monitoring: oxygenator pressure Drop in relation to Blood flow rate (BFR) (ΔP); Hematologic values: Hemoglobin, Fibrinogen, Platelets, aPTT, D-Dimer, LDH.ResultsNine VA ECMO patients who used the oxygenator for 18.5 days and two VV ECMO patients who used the oxygenators for 17.2 days on the seventeenth days reported average values PaO2 (267 ± 29 mmHg); PaCO2 (34 ± 4 mmHg) with gas blender values set to 3.8 ± 0.6 L/min of air and a FiO2 of 78 ± 5%; the transfer across the oxygenator membrane V′O2 was 189 ± 43 (ml/min/m2). The mean peak of partial pressure of carbon dioxide from the gas exhaust of oxygenator (PECO2) was 38 ± 4 mmHg; differential CO2 across the oxygenator “pre-oxygenator PCO2–post-oxygenator PCO2” (18 ± 6 mmHg); the mean blood flow rate (BFR) 4.5 ± 0.6 (L/minute); the pump revolution per minutes mean maximum rate was 4254 ± 345 (RPM); the mean pressure drop (ΔP) was 76 ± 12 mmHg; the mean peak of d-dimers (DDs) was 23.6 ± 0.8 mg / dL; the mean peak of LDH was 230 ± 55 (mg/dl); fibrinogen mean peak 223 ± 40 (mg/dl).ConclusionsThe performance of the Eurosets A.L.ONE ECMO Adult polymethylpentene fiber oxygenator in our experience has proven efficiency in terms of O2 uptake and CO2 removal, blood fluid dynamics, metabolic compensation and heat exchange in the long-term treatment. The device was safe without iatrogenic problems over a period of 14 days in the patients undergoing ECMO VA and in all patients undergoing VV ECMO with continuous administration of anticoagulation therapy.

Thrombotic Events Develop in 1 Out of 5 Patients Receiving ECMO Support: An 11-Year Referral Centre Experience.

The use of extracorporeal membrane oxygenation (ECMO) for critically ill patients is growing rapidly given recent developments in technology. However, adverse events are frequently reported that have potentially devastating impacts on patient outcomes. The information on predictors and risk factors for thrombotic events, especially that focusing on the comparison of veno-arterial and veno-venous ECMO configurations, are still inconsistent and sparse; therefore, we aimed to close this gap. We performed a retrospective analysis of all patients on extracorporeal life support admitted to the intensive care units of a tertiary university center in Europe. From 645 patients, 417 who received extracorporeal life support due to cardiogenic shock (290, 70%), respiratory failure (116, 28%) or hypothermia (11, 3%) were included. In total, 22% (92) of the patients experienced thrombotic events with a similar incidence in both ECMO configurations. Anticoagulation consisted of unfractionated heparin (296, 71%) and argatroban (70, 17%). Univariate Cox analyses identified hemoconcentration and increased maximal clot firmness (thromboelastometry) as risk factors for thrombosis. Moreover, the patients experiencing thrombosis had longer ECMO duration and intensive care stays. ECMO is a specialized life-support modality with a high risk of complications. A longer ECMO duration is associated with thrombosis occurrence in patients receiving ECMO support. Following hemorrhage, thromboembolic complications are common adverse events. However, in contrast to major bleeding, no impact on mortality was observed. The question arises if a protocol with less anticoagulation may have a role to play in the future.

Patient-Specific Computational Modeling of Different Cannulation Strategies for Extracorporeal Membrane Oxygenation.

Institution of extracorporeal membrane oxygenation (ECMO) results in unique blood flow characteristics to the end-organ vascular beds. We studied the interplay between cardiac-driven and extracorporeal membrane oxygenation (ECMO)-driven flow to vascular beds in different ECMO configurations using a patient-specific computational fluid dynamics (CFD) analysis. A computational ECMO model (femoral artery cannulation [FAC]) was constructed using patient-specific imaging and hemodynamic data. Following model calibration, we augmented the 3D geometrical model to represent alternative ECMO configurations (ascending aorta cannulation [AAC] and subclavian artery cannulation [SAC]). We performed CFD analyses, including a novel virtual color-dye analysis to compare global and regional blood flow and pressure characteristics as well as contributions of cardiac and ECMO-derived flow to the various vascular beds. Flow waveforms at all the aortic branch vessels were pulsatile, despite low cardiac output and predominant nonpulsatile ECMO-driven hemodynamics. Virtual color-dye analysis revealed differential contribution of cardiac and ECMO-derived flow to the end-organ vascular beds in the FAC model, while this was more evenly distributed in the AAC and SAC models. While global hemodynamics were relatively similar between various ECMO configurations, several distinct hemodynamic indices, in particular wall shear stress and oscillatory shear patterns, as well as differential contribution of ECMO-derived flow to various vascular beds, showed remarkable differences. The clinical impact of this study highlighting the relevance of CFD modeling in assessment of complex hemodynamics in ECMO warrants further evaluation.

Successful treatment with femoro-femoral venovenous extracorporeal membrane oxygenation in traumatic tracheal injury: a case report

BackgroundTraumatic tracheal injury is a rare type of trauma. In this type of injury, catastrophes may occur owing to a failure to secure the patient's airway. Extracorporeal membrane oxygenation (ECMO) is rescue therapy available for the treatment of urgent cardiorespiratory distress until the patient's vital signs have stabilized. The various applications of ECMO configurations have expanded the scope for this therapy.Case presentationWe describe the case of a 66-year-old man with tracheal rupture with thyroid cartilage fracture due to cultivator handle who was treated with veno-venous ECMO. This case reflects the role and limitations of veno-venous ECMO, in which patient survival was possible with a bi-femoral configuration while also ensuring a clear airway.ConclusionWe shared our experience with bi-femoral veno-venous ECMO as a therapeutic option to contribute to choosing an appropriate approach. Based on our review of the literature, the present case was an uncommon report of survival after tracheal rupture due to trauma without other complications.

Recirculation in single lumen cannula venovenous extracorporeal membrane oxygenation: A non-randomized bi-centric trial.

BackgroundRecirculation is a common problem in venovenous (VV) extracorporeal membrane oxygenation (ECMO). The aims of this study were to compare recirculation fraction (Rf) between femoro-jugular and jugulo-femoral VV ECMO configurations, to identify risk factors for recirculation and to assess the impact on hemolysis.MethodsPatients in the medical intensive care unit (ICU) at the University Medical Center Regensburg, Germany receiving VV ECMO with femoro-jugular, and jugulo-femoral configuration at the ECMO Center Karolinska, Sweden, were included in this non-randomized prospective study. Total ECMO flow (QEC), recirculated flow (QREC), and recirculation fraction Rf = QREC/QEC were determined using ultrasound dilution technology. Effective ECMO flow (QEFF) was defined as QEFF = QEC * (1–Rf). Demographics, cannula specifics, and markers of hemolysis were assessed. Survival was evaluated at discharge from ICU.ResultsThirty-seven patients with femoro-jugular configuration underwent 595 single-point measurements and 18 patients with jugulo-femoral configuration 231 measurements. Rf was lower with femoro-jugular compared to jugulo-femoral configuration [5 (0, 11) vs. 19 (13, 28) %, respectively (p < 0.001)], resulting in similar QEFF [2.80 (2.21, 3.39) vs. 2.79 (2.39, 3.08) L/min (p = 0.225)] despite lower QEC with femoro-jugular configuration compared to jugulo-femoral [3.01 (2.40, 3.70) vs. 3.57 (3.05, 4.06) L/min, respectively (p < 0.001)]. In multivariate regression analysis, the type of configuration, distance between the two cannula tips, ECMO flow, and heart rate were significantly associated with Rf [B (95% CI): 25.8 (17.6, 33.8), p < 0.001; 960.4 (960.7, 960.1), p = 0.009; 4.2 (2.5, 5.9), p < 0.001; 960.1 (960.2, 0.0), p = 0.027]. Hemolysis was similar in subjects with Rf > 8 vs. ≤ 8%. Explorative data on survival showed comparable results in the femoro-jugular and the jugulo-femoral group (81 vs. 72%, p = 0.455).ConclusionVV ECMO with femoro-jugular configuration caused less recirculation. Further risk factors for higher Rf were shorter distance between the two cannula tips, higher ECMO flow, and lower heart rate. Rf did not affect hemolysis.

Carboxyhemoglobin (CO-Hb) Correlates with Hemolysis and Hospital Mortality in Extracorporeal Membrane Oxygenation: A Retrospective Registry.

Background: Patients supported with extracorporeal membrane oxygenation (ECMO) may develop elevated carboxyhemoglobin (CO-Hb), a finding described in the context of hemolysis. Clinical relevance of elevated CO-Hb in ECMO is unclear. We therefore investigated the prognostic relevance of CO-Hb during ECMO support. Methods: Data derives from a retrospective single-center registry study. All ECMO patients in a medical ICU from October 2010 through December 2019 were considered. Peak arterial CO-Hb value during ECMO support and median CO-Hb values determined by point-of-care testing for distinct time intervals were determined. Groups were divided by CO-Hb (<2% or ≥2%). The primary endpoint was hospital survival. Results: A total of 729 patients with 59,694 CO-Hb values met the inclusion criteria. Median age (IQR) was 59 (48–68) years, 221/729 (30.3%) were female, and 278/729 (38.1%) survived until hospital discharge. Initial ECMO configuration was veno-arterial in 431/729 (59.1%) patients and veno-venous in 298/729 (40.9%) patients. Markers for hemolysis (lactate dehydrogenase, bilirubin, hemolysis index, and haptoglobin) all correlated significantly with higher CO-Hb (p < 0.001, respectively). Hospital survival was significantly higher in patients with CO-Hb < 2% compared to CO-Hb ≥ 2%, evaluating time periods 24–48 h (48.6% vs. 35.2%, p = 0.003), 48–72 h (51.5% vs. 36.8%, p = 0.003), or >72 h (56.9% vs. 31.1%, p < 0.001) after ECMO cannulation. Peak CO-Hb was independently associated with lower hospital survival after adjustment for confounders. Conclusions: In ECMO, CO-Hb correlates with hemolysis and hospital survival. If high CO-Hb measured should trigger a therapeutic intervention in order to reduce hemolysis has to be investigated in prospective trials.

The effect of tracheostomy on extracorporeal membrane oxygenation outcomes.

The optimal timing for pursuing tracheostomy in patients with prolonged mechanical ventilation with either veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is a discussion of risk versus benefit. Depending on the etiology, cardiothoracic surgical patients carry some of the highest risk for respiratory failure postprocedure.Given that patients with end-stage cardiopulmonary status may be fraught with substantial comorbidities, it is critically important to manage the risk-benefit profile of performing a tracheostomy procedure on a patient requiring ECMO support.These cohorts have risk factors that may depend on each patient's inflammatory state, lung de-recruitment peri-procedure and postprocedure and bleeding requiring transfusions to name a few.We provide a descriptive analysis of ECMO patients on both VA and VV configurations who survived to hospital discharge receiving tracheostomy either during or after their ECMO course. A retrospective single-institutional study collected all consecutive patients age 18 and above who received any form of ECMO between 2016 and 2020. Five hundred forty-fivepatients were screened based on having received ECMO. Patients with mixed EMCO modality were excluded due to heterogeneity of disease process. A total of 521 patients received either VV or VA ECMO. A total of 54 patients received tracheostomy and had sufficiently clean data for analysis. Tracheostomy patients were compared based on survival to discharge, tracheostomy surgical complications, ECMO duration, ECMO configuration, inotrope and vasopressor use, transfusion rates, total ventilator days, total days on intravenoussedation, and history of cardiotomy or heart transplant were assessed. Baseline characteristics of race, age, gender, and body mass index (BMI) were also collected. A total of 54 patients received tracheostomy. Twenty-nineof those patients received tracheostomy during the course of their ECMO, of whom 13 were on VV ECMO, 16 on VA ECMO. Another 25 patients underwent tracheostomy after successful ECMO explant; 8 of those were VV ECMO with the remaining 17 were on VA ECMO before explantation, with mean delay to tracheostomy, 10 and 19 days after explant between both modalities, respectively. A statistically significantly greater proportion of VV ECMO patients received a tracheostomy at any point versusVA ECMO patients (25.93% vs. 8.35%, p ≤ .0001). No statistically significant difference was noted in timing of tracheostomy when stratified by EMCO modality (VA 51.51% after explant vs. VV 38.10% after explant, p = .33).There was a greater frequency of minor tracheostomy complications in patients who were on ECMO at the time of their tracheostomy (p = .014) than in those who received their tracheostomy after being explanted. However, these minor complications did not contribute to a change in survival to hospital discharge (p = .58). Similarly, the small number of major complications (n = 13) did not impair survival to hospital discharge (p = .84).Finally, mean duration of ECMO was longer in those who received tracheostomy during ECMO versus after ECMO. (488.45 vs. 259.72 h, p < .01). Tracheostomy is known to increase patient mobility, clinical participation, and overall decrease in sedation use. Pursuing tracheostomy during ECMO is feasible, does not result in major bleeding, and is associated with only minor complications that overall do not decrease survival. While there is an increased duration of ECMO support in the tracheostomy cohort, this may be due to existing patient conditions, and may not be causal. Research is needed to further determine the external patient factors and specific timing to optimize both VV and VA ECMO courses. We hope that our analysis will pave the initial pathway for an evidence-based guideline on optimal timing of tracheostomy in ECMO patients, whether initiated during or after ECMO and taking into consideration ECMO configuration, its expected duration, and patient comorbidities.

709 Reconfiguration: Extracorporeal blood purification of a burn patient on ECMO

IntroductionPatients who require extracorporeal membrane oxygenation (ECMO) have a very high mortality if they develop septic shock. Extracorporeal blood purification has been studied as an adjunct to antimicrobials but has yielded mixed or even disappointing results. The Seraph-100 Microbind Affinity Blood Filter (ExThera Medical Corporation, Martinez, CA) is currently undergoing clinical trials. The filter consists of polyethylene beads, coated in heparin sulfate, that irreversibly binds bacteria, fungi, viruses, and toxins. Seraph-100 therapy is traditionally delivered through conventional hemodialysis or continuous renal replacement therapy (CRRT), with the filter being placed in-line with these circuits. We present a case of a burn patient on veno-venous (VV) ECMO in septic shock, who was treated with a Seraph filter by connecting it directly to the ECMO circuit.MethodsWe present a case.ResultsA 34-year-old male presented with 56% thermal burns and grade 1 inhalation injury from a fuel tank explosion. He underwent a large-volume resuscitation for burn shock with lactated Ringer’s and albumin, receiving 18,152 mL (163 mL/kg) in the first 24 hours. He was placed on CRRT for acute kidney injury and underwent escharotomies of the hands and legs. On day 4, he developed bacteremia, septic shock and progressed to acute respiratory distress syndrome requiring VV ECMO. Extracorporeal blood purification was started via the Seraph-100 filter. Due to limitations of blood flow rates on CRRT, the Seraph-100 filter was added directly into the ECMO circuit. Inflow tubing was connected to an existing port on the oxygenator (Fig 1) and returned to the venous drainage by cutting a new port into the drainage tubing (Fig 2). The filter itself did not require any special configuration or orientation (Fig 3). This configuration allowed for pressures generated by the ECMO circuit to drive blood flow through the Seraph-100 filter (Fig 4). After 6 hours of treatment, vasopressor requirements drastically decreased.ConclusionsComplications related to the Seraph-100 filter are rare but may include catheter thrombosis. This is typically due to the type of catheter used and/or the blood-flow rate through the filter rather than the filter itself. This issue was avoided with the ECMO configuration. Similarly, clinicians can avoid transient hypotension, blood loss from a clotted circuit, catheter-site bleeding, and other complications frequently associated with a renal replacement circuit.