Venovenous Extracorporeal Membrane Oxygenation Patients Research Articles

Continuous Monitoring of Cerebral Autoregulation in Adults Supported by Extracorporeal Membrane Oxygenation.

Impaired cerebral autoregulation (CA) is one of several proposed mechanisms of acute brain injury in patients supported by extracorporeal membrane oxygenation (ECMO). The primary aim of this study was to determine the feasibility of continuous CA monitoring in adult ECMO patients. Our secondary aims were to describe changes in cerebral oximetry index (COx) and other metrics of CA over time and in relation to functional neurologic outcomes. This is a single-center prospective observational study. We measured COx, a surrogate measurement of cerebral blood flow measured by near-infrared spectroscopy, which is an index of CA derived from the moving correlation between mean arterial pressure (MAP) and slow waves of regional cerebral oxygen saturation. A COx value that approaches 1 indicates impaired CA. Using COx, we determined the optimal MAP (MAPOPT) and lower and upper limits of autoregulation for individual patients. These measurements were examined in relation to modified Rankin Scale (mRS) scores. Fifteen patients (median age 57years [interquartile range 47-69]) with 150 autoregulation measurements were included for analysis. Eleven were on veno-arterial ECMO (VA-ECMO), and four were on veno-venous ECMO (VV-ECMO). Mean COx was higher on postcannulation day 1 than on day 2 (0.2 vs. 0.09, p < 0.01), indicating improved CA over time. COx was higher in VA-ECMO patients than in VV-ECMO patients (0.12 vs. 0.06, p = 0.04). Median MAPOPT for the entire cohort was highly variable, ranging from 55 to 110mm Hg. Patients with mRS scores 0-3 (good outcome) at 3 and 6months spent less time outside MAPOPT compared with patients with mRS scores 4-6 (poor outcome) (74% vs. 82%, p = 0.01). The percentage of time when observed MAP was outside the limits of autoregulation was higher on postcannulation day 1 than on day 2 (18.2% vs. 3.3%, p < 0.01). In ECMO patients, it is feasible to monitor CA continuously at the bedside. CA improved over time, most significantly between postcannulation days 1 and 2. CA was more impaired in VA-ECMO patients than in VV-ECMO patients. Spending less time outside MAPOPT may be associated with achieving a good neurologic outcome.

Venovenous extracorporeal membrane oxygenation after cardiac arrest for acute respiratory distress syndrome caused by Legionella: a case report

BackgroundLegionella remains underdiagnosed in the intensive care unit and can progress to acute respiratory distress syndrome (ARDS), multiorgan failure and death. In severe cases, venovenous extracorporeal membrane oxygenation (VV-ECMO) allows time for resolution of disease with Legionella-targeted therapy. VV-ECMO outcomes for Legionella are favorable with reported survival greater than 70%. Rapid molecular polymerase chain reaction (PCR) testing of the lower respiratory tract aids in diagnosing Legionella with high sensitivity and specificity. We present a unique case of a patient with a positive COVID-19 test and ARDS who suffered a cardiac arrest. The patient was subsequently cannulated for VV-ECMO, and after lower respiratory tract PCR testing, Legionella was determined to be the cause. She was successfully treated and decannulated from VV-ECMO after eight days.Case presentationA 53-year-old female presented with one week of dyspnea and a positive COVID-19 test. She was hypoxemic, hypotensive and had bilateral infiltrates on imaging. She received supplemental oxygen, intravenous fluids, vasopressors, broad spectrum antibiotics, and was transferred to a tertiary care center. She developed progressive hypoxemia and suffered a cardiac arrest, requiring ten minutes of CPR and endotracheal intubation to achieve return of spontaneous circulation. Despite mechanical ventilation and paralysis, she developed refractory hypoxemia and was cannulated for VV-ECMO. Dexamethasone and remdesivir were given for presumed COVID-19. Bronchoscopy with bronchoalveolar lavage (BAL) performed with PCR testing was positive for Legionella pneumophila and negative for COVID-19. Steroids and remdesivir were discontinued and she was treated with azithromycin. Her lung compliance improved, and she was decannulated after eight days on VV-ECMO. She was discharged home on hospital day 16 breathing room air and neurologically intact.ConclusionsThis case illustrates the utility of rapid PCR testing to diagnose Legionella in patients with respiratory failure and the early use of VV-ECMO in patients with refractory hypoxemia secondary to Legionella infection. Moreover, many patients encountered in the ICU may have prior COVID-19 immunity, and though a positive COVID-19 test may be present, further investigation with lower respiratory tract PCR testing may provide alternative diagnoses. Patients with ARDS should undergo Legionella-specific testing, and if Legionella is determined to be the causative organism, early VV-ECMO should be considered in patients with refractory hypoxemia given reported high survival rates.

Mortality on extracorporeal membrane oxygenation: Evaluation of independent risk factors and causes of death during venoarterial and venovenous support.

Most patients on extracorporeal membrane oxygenation (ECMO) decease during therapy on the system. However, the actual causes of death have not been studied sufficiently. This study analyses the etiology, prevalence, and risk factors for the outcome variable death during ongoing ECMO for all patients and divided according to venoarterial (VA) or venovenous (VV) support. We retrospectively analysed all patients receiving ECMO support at our institution between March 2006 to January 2021. Only the patients deceased during ongoing support were included. 2016 patients were placed on VA (n = 1168; 58%) or VV (n = 848; 42%) ECMO; 759 patients (37.7%) deceased on support. The causes of death differed between the support types: VA ECMO patients mostly died from cerebral ischemia (34%), low-cardiac output (LCO; 24.1%) and multi-organ failure (MOF; 21.6%), whereas in VV ECMO cases, refractory respiratory failure (28.2%), and sepsis (20.4%) dominated. Multivariate regression analysis revealed cardiopulmonary resuscitation (CPR) and acidosis prior to ECMO as risk factors for dying on VA ECMO, while high inotropic doses pre-ECMO, a high fraction of inspired oxygen on day 1, elevated lactate dehydrogenase, and international normalized ratio levels lead to an unfavourable outcome in VV ECMO patients. Even in highly experienced centers, ECMO mortality remains high and occurs mainly on support or 24h after its termination. The causes of death differ between VV and VA ECMO, depending on the underlying diseases responsible for the need of extracorporeal support.

Autopsy Histopathologic Lung Findings in Patients Treated With Extracorporeal Membrane Oxygenation

Context.— Extracorporeal membrane oxygenation (ECMO) is increasingly used in the treatment of respiratory and cardiac failure, but data describing lung histopathology in ECMO recipients are limited. Objective.— To examine pulmonary histopathologic findings in patients who underwent venovenous (VV) ECMO for pulmonary reasons, or venoarterial (VA) ECMO for cardiac indications shortly before death, and to determine if the pulmonary changes provided insights into therapy that may prevent complications and improve outcome. Design.— We conducted a retrospective study of lung autopsies, from VV and VA ECMO recipients and patients with acute respiratory distress syndrome (ARDS) and non-ECMO treatment, between 2008 and 2020 in Silesia Center for Heart Diseases in Zabrze, Poland. Results.— Among 83 ECMO patients (42–64 years; male, 57 [68.7%]), the most common histopathologic findings were bronchopneumonia (44 [53.0%]), interstitial edema (40 [48.2%]), diffuse alveolar damage (DAD; 32 [38.6%]), hemorrhagic infarct (28 [33.7%]), and pulmonary hemorrhage (25 [30.1%]). DAD was associated with longer ECMO treatment and longer hospital stay. The use of VV ECMO was a predictor of DAD in patients with ARDS and undergoing ECMO, but it also occurred in 21 of 65 patients (32.3%) in the VA ECMO group, even though VA ECMO was used for heart failure. Conclusions.— Although DAD was significantly more common in lung autopsies of VV ECMO patients, one-third of VA ECMO patients had histopathologic changes characteristic of ARDS. The presence of DAD in lung autopsies of patients treated with VA ECMO indicates that in these patients, protective lung ventilation should be considered.

Days spent on non-invasive ventilation support: can it determine when to initiate VV- ECMO? Observational study in a cohort of Covid-19 patients

BackgroundThe study evaluates the impact of the time between commencing non-invasive ventilation (NIV) support and initiation of venovenous extracorporeal membrane oxygenation (VV-ECMO) in a cohort of critically ill patients with coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS).MethodsProspective observational study design in an intensive Care Unit (ICU) of a tertiary hospital in Barcelona (Spain). All patients requiring VV-ECMO support due to COVID-19 associated ARDS between March 2020 and January 2022 were analysed. Survival outcome was determined at 90 days after VV-ECMO initiation. Demographic data, comorbidities at ICU admission, RESP (respiratory ECMO survival prediction) score, antiviral and immunomodulatory treatments received, inflammatory biomarkers, the need for vasopressors, the thromboprophylaxis regimen received, and respiratory parameters including the length of intubation previous to ECMO and the length of each NIV support (high-flow nasal cannula, continuous positive airway pressure and bi-level positive airway pressure), were also collated in order to assess risk factors for day-90 mortality. The effect of the time lapse between NIV support and VV-ECMO on survival was evaluated using logistic regression and adjusting the association with all factors that were significant in the univariate analysis.ResultsSeventy-two patients finally received VV-ECMO support. At 90 days after commencing VV-ECMO 35 patients (48%) had died and 37 patients (52%) were alive. Multivariable analysis showed that at VV-ECMO initiation, age (p = 0.02), lactate (p = 0.001), and days from initiation of NIV support to starting VV-ECMO (p = 0.04) were all associated with day-90 mortality.ConclusionsIn our small cohort of VV-ECMO patients with COVID-19 associated ARDS, the time spent between initiation of NIV support and VV-ECMO (together with age and lactate) appeared to be a better predictor of mortality than the time between intubation and VV-ECMO.

The Etiological and Drug Resistance Characteristics of Multidrug-Resistant Pathogens in Patients Requiring Extracorporeal Membrane Oxygenation: A Retrospective Cohort Study.

Infections induced by multidrug-resistant (MDR) pathogens are one of the most common and serious complications in extracorporeal membrane oxygenation (ECMO) patients. However, there is currently little research about "ECMO and MDR bacteria". The purpose of our study was to clarify the epidemiological characteristics of MDR bacteria and provide references for empiric antibiotic treatments according to the drug susceptibility tests for ECMO patients. There were 104 patients admitted to our department and receiving ECMO treatments between January 2014 and December 2022. Altogether, 61 veno-arterial ECMO (VA-ECMO) and 29 veno-venous ECMO (VV-ECMO) patients enrolled. The data on other intensive care unit (ICU) patients in our department in the same period are summarized. A total of 82 MDR bacteria were detected from ECMO patients, and most of these were MDR Gram-negative bacteria (MDR-GNB). There were also 5559 MDR-GNB collected from other patients in our department in the same period. We found that the distribution of MDR-GNB in ECMO patients was different from other critical patients. The proportion of Klebsiella pneumoniae (MDR-KP) in VV-ECMO patients was higher than other critical patients (35.1% and 21.3%, respectively). Moreover, the proportions of MDR Acinetobacter baumannii (MDR-AB) of VA-ECMO and VV-ECMO were higher than other critical patients (54.6%, 43.2% and 30.5%, respectively). In addition, MDR-AB and MDR-KP in ECMO patients exhibited higher percentages of drug resistance to possibly appropriate antibiotics for other critical patients, but showed better sensitivity to colistin. Infections induced by MDR-GNB in ECMO patients were serious and exhibited higher degrees of drug resistance compared with other ICU patients. Colistin might be an option to consider if there is no medical contraindication. However, widespread use of broad spectrum antibiotics is something that should be discouraged, and alternative options are being explored.

Effects of adding the second drainage cannula in severely hypoxemic patients supported with VV ECMO due to COVID-19-associated ARDS.

Extracorporeal membrane oxygenation (ECMO) is a recognized method of support in patients with severe and refractory acute respiratory distress syndrome (ARDS) caused by SARS-CoV-2 infection. While veno-venous (VV) ECMO is the most common type, some patients with severe hypoxemia may require modifications to the ECMO circuit. In this study, we aimed to investigate the effects of adding a second drainage cannula to the circuit in patients with refractory hypoxemia, on their gas exchange, mechanical ventilation, ECMO settings, and clinical outcomes. We conducted an observational retrospective study based on a single-center institutional registry including all consecutive cases of COVID-19 patients requiring ECMO admitted to the Centre of Extracorporeal Therapies in Warsaw between March 1, 2020 and March 1, 2022. We selected patients who had an additional drainage cannula inserted. Changes in ECMO and ventilator settings, blood oxygenation, and hemodynamic parameters, as well as clinical outcomes were assessed. Of 138 VV ECMO patients, 12 (9%) patients met the inclusion criteria. Ten patients (83%) were men, and mean age was 42.2 ± 6.8. An addition of drainage cannula resulted in a significant raise in ECMO blood flow (4.77 ± 0.44 to 5.94 ± 0.81 [L/min]; p = 0.001), and the ratio of ECMO blood flow to ECMO pump rotations per minute (RPM), whereas the raise in ECMO RPM alone was not statistically significant (3432 ± 258 to 3673 ± 340 [1/min]; p = 0.064). We observed a significant drop in ventilator FiO2 and a raise in PaO2 to FiO2 ratio, while blood lactates did not change significantly. Nine patients died in hospital, one was referred to lung transplantation center, two were discharged uneventfully. The use of an additional drainage cannula in severe ARDS associated with COVID-19 allows for an increased ECMO blood flow and improved oxygenation. However, we observed no further improvement in lung-protective ventilation and poor survival.

Predictors of early mobilization in patients requiring VV ECMO for greater than 7 days: An international cohort study

BackgroundDespite the demonstrated benefits of rehabilitation, active physical therapy and early mobilization are not universally performed during critical illness, especially among patients receiving extracorporeal membrane oxygenation (ECMO), with variation among sites. ObjectiveWhat factors are predictive of physical mobility during venovenous (VV) ECMO support? MethodsWe performed an observational analysis of an international cohort using data from the Extracorporeal Life Support Organization (ELSO) Registry. We analyzed adults (≥18 years) supported with VV ECMO who survived for at least 7 days. Our primary outcome was early mobilization (ICU Mobility Scale score >0) at day 7 of ECMO support. Hierarchical multivariable logistic regression models were utilized to identify factors independently associated with early mobilization at day 7 of ECMO. Results are reported as adjusted odds ratios (aOR) with 95% confidence intervals (95%CI). ResultsAmong 8,160 unique VV ECMO patients, factors independently associated with early mobilization included cannulation for transplantation (aOR 2.86 [95% CI 2.08–3.92]; p<0.001), avoidance of mechanical ventilation (aOR 0.51 [95% CI 0.41–0.64]; p<0.0001), higher center level patient volume (6–20 patients annually: aOR 1.49 [95% CI 1 to 2.23] and >20 patients annually: aOR 2 [95% CI: 1.37 to 2.93]; p<0.0001 for group), and cannulation with a dual-lumen cannula (aOR 1.25 [95% CI 1.08–1.42]; p = 0.0018). Early mobilization was associated with a lower probability of death (29 vs 48%; p<0.0001). ConclusionsHigher levels of early mobilization on ECMO were associated modifiable and non-modifiable patient characteristics, including cannulation with a dual-lumen cannula, and with high center level patient volume.

PEDS8: Continuous Renal Replacement Therapy In Pediatric Extracorporeal Membrane Oxygenation: Life Span And Cost Of Filter Changes With Bivalirudin.

Background: The utilization of additional extracorporeal support devices utilized in conjunction with Extracorporeal Membrane Oxygenation (ECMO) has increased with more complex and sicker patients. The use of Continuous Renal Replacement Therapy (CRRT) has increased five-fold over the past 3 years at our institution after implementing Pediatric Nephrology Stewardship (PNS) on ECMO. Bivalirudin is the primary anticoagulant used for ECMO and CRRT at our institution which has resulted in increased ECMO circuit and CRRT filter life. The Prismalflex HF1000 and HF20 filter has a prime volume of 165 ml and 58 ml, respectively, with prime components which include packed red blood cells (pRBC) and albumin. Manufacturer recommendations for changing the CRRT filter is defined as every 72 hours (3 days). We sought to extend the filter length by augmenting the indication for the CRRT filter change from manufacturer recommendation. Filter changes were determined based on monitoring the filter pressure, transmembrane pressure, and pressure drop to diagnosis clotting/clogging. CRRT filter was also changed out if disconnection from ECMO was warranted due to ECMO circuit change or travel. Methods: Retrospective ECMO and CRRT data was collected for pediatric veno-arterial or veno-venous ECMO patients at a tertiary care hospital from January 2021-December 2022. Results: CRRT was performed on 16% (7/44) of ECMO patients. 100% of the patients received bivalirudin as the anticoagulant. 71% (5/7) were supported by VA ECMO. 43% (3/7) were neonates. Mean ECMO duration was 14 days (3-133). Of the 7 ECMO patients on CRRT, 80% (265/332) of their time on ECMO included CRRT support. There was a total of 41 CRRT filter changes performed during 265 days on CRRT with an average filter change occurring every 6.46 days (table 1). Utilizing cost of CRRT filter set ($358.00) and approximate cost of 1 unit of pRBC ($200.00), there was a savings of $26,226 to the hospital ($22,878 vs. $49,104). Discussion: Utilization of an alternative indication versus manufacturer recommendation for CRRT filter change out prolonged filter length from 3 days to 6.46 days (110% decrease in filter change out). By reducing the number of CRRT filters and blood usage for a filter change, cost to the hospital and patients was significantly reduced even without considering labor for CRRT set up and blood preparation. With careful attention to detail and collaboration with Nephrology and Hematology services, it appears CRRT filter length can be safely extended past manufacturers recommendations.

Transfer of Veno-venous Extracorporeal Membrane Oxygenation Patients With COVID-19 Associated Acute Respiratory Distress Syndrome.

Interhospital transport of acute respiratory distress syndrome (ARDS) patients bears transport-associated risks. It is unknown how interhospital extracorporeal membrane oxygenation (ECMO) transfer of COVID-19 patients by mobile ECMO units affects ARDS mortality. We compared the outcome of 94 COVID-19 patients cannulated in primary care hospitals and retrieved by mobile ECMO-teams to that of 84 patients cannulated at five German ECMO centers. Patients were recruited from March 2020 to November 2021. Twenty-six transports were airborne, 68 were land-based. Age, sex, body-mass-index, Simplified Acute Physiology Score (SAPS) II, days invasively ventilated, and P/F-Ratio before ECMO initiation were similar in both groups. Counting only regional transports (≤250 km), mean transport distance was 139.5 km ± 17.7 km for helicopter (duration 52.5 ± 10.6 minutes) and 69.8 km ± 44.1 km for ambulance or mobile intensive care unit (duration 57.6 ± 29.4 minutes). Overall time of vvECMO support (20.4 ± 15.2 ECMO days for transported patients vs. 21.0 ± 20.5 for control, p = 0.83) and days invasively ventilated (27.9 ± 18.1 days vs. 32.6 ± 25.1 days, p = 0.16) were similar. Overall mortality did not differ between transported patients and controls (57/94 [61%] vs. 51/83 [61%], p = 0.43). COVID-19 patients cannulated and retrieved by mobile ECMO-teams have no excess risk compared with patients receiving vvECMO at experienced ECMO centers. Patients with COVID-19-associated ARDS, limited comorbidities, and no contraindication for ECMO should be referred early to local ECMO centers.

Practice patterns in extracorporeal life support in tertiary cardiac intensive care units in north america: a survey-based analysis from the critical care cardiology trials network

Abstract Funding Acknowledgements Type of funding sources: None. Background The use of veno-arterial (VA) and veno-venous (VV) extracorporeal membrane oxygenation (ECMO) has significantly increased in the last decade. However, there is substantial variability in practice patterns between institutions. To date, the optimal ECMO program model is unclear and possible differences between ECMO centers in staffing, organization and team structure have been poorly characterized. Purpose Our aim was to describe contemporary practices of care for patients undergoing ECMO in tertiary cardiac centers in North America. Methods An 11-question anonymous survey was sent to all participating sites in the Critical Care Cardiology Trials Network (CCCTN), a prospective registry of advanced cardiac intensive care units (CICUs) in North America, coordinated by the TIMI Study Group. The survey evaluated ECMO staffing models, decision-making processes, cannulation and longitudinal care. Results The response rate was 100% (39/39) across CCCTN centers. The decision to proceed with VA ECMO was made as a team in 79% of the cases and in 58.3% of the VV ECMO cases, rather than by an individual specialty. An ECMO consult service was used in 67% of the centers, and integrated with the cardiogenic shock team in 58%. The most common specialty participating in the ECMO service was cardiothoracic surgery (CTS) (73.1%), followed by heart failure specialists (38.5%), with critical care cardiology (CCC) in only 23.1% of the centers (Figure 1A). In the majority of centers, VA ECMO cannulation was performed by CTS alone (46.2%), Interventional cardiology (IC) and CTS (38.5%), and IC alone (7.7%, Figure 1B). Cannulation for VA ECMO was not performed by intensivists at any center. VV ECMO cannulations were performed by CTS in 51.3%, intensivists in 17.9% and IC in 2.6% of the centers. VA ECMO patients were admitted to the cardiovascular surgical intensive care unit in 64.1% of centers, with 20.5 % admitted to the CICU (Figure 1C). VV ECMO patients were admitted to the cardiovascular surgical intensive care unit in 36.8% of sites, and the medical intensive care unit in 34.2%. The most common ECMO specialist model was having a perfusionist at the bedside, followed by nurse specialist (Figure 1D). Specialty services consulted within 24-48 hours of cannulation included physical therapy in 48.7%, palliative care in 30.8%, and bioethics in only 2.6% of centers. Simulation-based ECMO training is performed in 59% of the centers. Half (51.3%) of the centers perform ECPR, while 17.9% reported plans of developing a program. Conclusions Although there is significant variability in ECMO cannulation, location of care, staffing practices in advanced CICUs in North America, a multidisciplinary team approach is common in ECMO centers, with early involvement of physical therapy and palliative care specialists. Further research to establish the optimal model for ECMO programs is of high importance.

Lower Oxygen Tension and Intracranial Hemorrhage in Veno-venous Extracorporeal Membrane Oxygenation.

We examined the relationship between 24-h pre- and post-cannulation arterial oxygen tension (PaO2) and arterial carbon dioxide tension (PaCO2) and subsequent acute brain injury (ABI) in patients receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) with granular arterial blood gas (ABG) data and institutional standardized neuromonitoring. Eighty-nine patients underwent VV-ECMO (median age = 50, 63% male). Twenty (22%) patients experienced ABI; intracranial hemorrhage (ICH) was the most common diagnosis (n = 14, 16%). Lower post-cannulation PaO2 levels were significantly associated with ICH (66 vs. 81mmHg, p = 0.007) and a post-cannulation PaO2 level < 70mmHg was more frequent in these patients (71% vs. 33%, p = 0.007). PaCO2 parameters were not associated with ABI. By multivariable logistic regression, hypoxemia post-cannulation increased the odds of ICH (OR = 5.06, 95% CI:1.41-18.17; p = 0.01). In summary, lower oxygen tension in the 24-h post-cannulation was associated with ICH development. The precise roles of peri-cannulation ABG changes deserve further investigation, as they may influence the management of VV-ECMO patients.

Same but Different-ECMO in COVID-19 and ARDS of Other Etiologies. Comparison of Survival Outcomes and Management in Different ARDS Groups.

Background: COVID-19 has led to increased numbers of patients in need of venovenous extracorporeal membrane oxygenation (ECMO) support, but knowledge on management in comparison to acute respiratory distress syndrome (ARDS) of other etiologies is still lacking. We analyzed venovenous ECMO management and survival outcomes in patients with COVID-19 in comparison to influenza ARDS and pulmonary ARDS of other origin. Results: Retrospective analysis of prospective venovenous ECMO registry-based data collection was performed. One hundred consecutive venovenous ECMO patients with severe ARDS were included (41 COVID-19, 24 influenza A, 35 ARDS of other etiologies). Patients with COVID-19 had higher BMI (body mass index), lower SOFA (Sequential Organ Failure Assessment) and APACHE II (Acute Physiology and Chronic Health Evaluation II) scores, lower C-reactive protein and procalcitonin levels and less vasoactive support at ECMO initiation. Significantly more patients were mechanically ventilated for more than 7 days prior to ECMO initiation in the COVID-19 group, however they were ventilated with lower tidal volumes and more often received additional rescue therapies prior to and on ECMO. COVID-19 patients had significantly more barotrauma and thrombotic events on ECMO. There were no differences in weaning of ECMO, however duration of ECMO runs and ICU length of stay was significantly longer in the COVID-19 group. The leading cause of death in the COVID-19 group was irreversible respiratory failure, while uncontrolled sepsis and multiorgan failure were leading causes in the other 2 groups. All patients who survived ICU treatment were discharged out of hospital, and there were no differences in survival among groups at 180 days. Conclusions: Survival outcomes of venovenous ECMO patients do not differ between COVID-19 and ARDS of other pulmonary etiologies. ARDS guidelines were in greater proportion adhered to in COVID-19 patients, with, however, longer time to ECMO initiation. COVID-19 ARDS seems specific as a more single-organ disease with longer ECMO duration and irreversible respiratory failure as a main cause of ICU mortality.

Evaluation of urinary cysteinyl leukotrienes as biomarkers of severity and putative therapeutic targets in COVID-19 patients

BackgroundCysteinyl leukotrienes (CysLT) are potent inflammation-promoting mediators, but remain scarcely explored in COVID-19. We evaluated urinary CysLT (U-CysLT) relationship with disease severity and their usefulness for prognostication in hospitalized COVID-19 patients. The impact on U-CysLT of veno-venous extracorporeal membrane oxygenation (VV-ECMO) and of comorbidities such as hypertension and obesity was also assessed.MethodsBlood and spot urine were collected in “severe” (n = 26), “critically ill” (n = 17) and “critically ill on VV-ECMO” (n = 17) patients with COVID-19 at days 1–2 (admission), 3–4, 5–8 and weekly thereafter, and in controls (n = 23) at a single time point. U-CysLT were measured by ELISA. Routine markers, prognostic scores and outcomes were also evaluated.ResultsU-CysLT did not differ between groups at admission, but significantly increased along hospitalization only in critical groups, being markedly higher in VV-ECMO patients, especially in hypertensives. U-CysLT values during the first week were positively associated with ICU and total hospital length of stay in critical groups and showed acceptable area under curve (AUC) for prediction of 30-day mortality (AUC: 0.734, p = 0.001) among all patients.ConclusionsU-CysLT increase during hospitalization in critical COVID-19 patients, especially in hypertensives on VV-ECMO. U-CysLT association with severe outcomes suggests their usefulness for prognostication and as therapeutic targets.

Application of argatroban in patients receiving extracorporeal membrane oxygenation support: a case-control study

To evaluate the safety and efficacy of argatroban applied as alternative anticoagulant in critical illness patients underwent extracorporeal membrane oxygenation (ECMO) with contraindications of unfractionated heparin (UFH), and to further explore the effective dose of argatroban. From July 1, 2013 to February 28, 2022, there were 14 patients who admitted in the respiratory intensive care unit (RICU) of Beijing Chao-Yang Hospital received ECMO and used argatroban for anticoagulation (argatroban group). Two of them received argatroban as the initial anticoagulant. The remaining 12 patients used UFH at first, and then switched to argatroban. UFH group included 28 patients who received UFH for anticoagulation after matching the demographic characteristics. Primary endpoint was the prevalence of ECMO-related thrombotic events. Secondary endpoints included the type of thrombotic events, prevalence of ECMO-related major bleeding events, bleeding sites, ICU mortality, mortality during ECMO, liver and kidney function, thrombelastogram, blood transfusion, dosage of argatroban, the dynamic changes of coagulation variables 4 days before and 7 days after argatroban treatment. In argatroban group, there were 8 patients received veno-venous ECMO (VV-ECMO), 2 patients with veno-arterial ECMO (VA-ECMO), and 4 patients with veno-arterio-venous ECMO (VAV-ECMO). In UFH group, VV-ECMO was applied in 23 patients, VA-ECMO and VAV ECMO was established in 3 patients and 2 patients, respectively. In endpoint events, the incidence of ECMO related thrombotic events in argatroban group was slightly higher than that in UFH group (28.6% vs. 21.4%). The ECMO running time in argatroban group was slightly longer than that in UFH group [days: 16 (7, 21) vs. 13 (8, 17)]. The incidence of ECMO-related bleeding events (28.6% vs. 32.1%) and mortality during ECMO (35.7% vs. 46.4%) in argatroban group were slightly lower than those in UFH group. However, the differences were not statistically significant (all P < 0.05). The platelet transfusion in argatroban group was significantly higher than that in UFH group [U: 7.7 (0, 10.0) vs. 0.8 (0, 1.0)]. The coagulation reaction time (R value) in thrombelastography in argatroban group was significantly longer than that in UFH group [minutes: 9.3 (7.2, 10.8) vs. 8.8 (6.3, 9.7)]. The maximum width value [MA value, mm: 48.4 (40.7, 57.9) vs. 52.6 (45.4, 61.5)] and blood clot generation rate [α-Angle (deg): 54.1 (45.4, 62.0) vs. 57.9 (50.2, 69.0)] in the argatroban group were significantly lower than those in the UFH group (all P < 0.05). The activated partial thromboplastin time (APTT) was prolonged after changing from UFH to argatroban in the argatroban group [seconds: 63.5 (58.4, 70.6) vs. 56.7 (53.1, 60.9)]. The PLT level showed a decreasing trend during UFH anticoagulation therapy, and gradually increased after changing to argatroban. D-dimer level was 19.1 (7.0, 28.7) mg/L after switching to argatroban, and then no longer showed an increasing trend. The level of fibrinogen (FIB) showed a decreasing trend during the anticoagulant therapy of UFH (the lowest was 23.6 g/L), and fluctuated between 16.8 and 26.2 g/L after changing to argatroban. The median initial dose of argatroban was 0.049 (0.029, 0.103) μg×kg-1×min-1, which the highest dose was in VV-ECMO patients of [0.092 (0.049, 0.165) μg×kg-1×min-1]. The initial dose of VAV-ECMO was the lowest [0.026 (0.013, 0.041) μg×kg-1×min-1], but without significant difference (P > 0.05). The maintenance dose of argatroban was 0.033 (0.014, 0.090) μg×kg-1×min-1, VV-ECMO patients was significantly higher than those in VA-ECMO and VAV-ECMO patients [μg×kg-1×min-1: 0.102 (0.059, 0.127) vs. 0.036 (0.026, 0.060), 0.013 (0.004, 0.022), both P < 0.05]. Argatroban appears to be a feasible, effective and safety alternative anticoagulant for patients with contraindications to UFH who undergoing ECMO support.

Nutrition support practices across the care continuum in a single centre critical care unit during the first surge of the COVID-19 pandemic – A comparison of VV-ECMO and non-ECMO patients

Background & aimsCritically ill patients with COVID-19 are at high nutrition risk. This study aimed to describe the nutrition support practices in a single centre critical care unit during the initial surge of the COVID-19 pandemic. Practices were explored from ICU admission to post-ICU follow-up clinic and patients who received veno-venous extra-corporeal membrane oxygenation (VV-ECMO) were compared to those who did not.MethodsThis retrospective observational study included COVID-19 positive, adult ICU patients who were mechanically ventilated for ≥72 hours. Data were collected from ICU admission until the time of post-ICU clinic. For in-ICU data, results are compared between patients who did and did not receive VV-ECMO.Results252 patients were included (VV-ECMO n = 58). Adequate energy and protein was delivered in 193 (76.6%) patients during their ICU admission with no differences between those who did and did not receive VV-ECMO (44 (75.9%) vs. 149 (76.8%)). Parenteral nutrition only being required in 12 (4.8%) patients. Following stepdown to the ward 77 (70%) patients required ongoing enteral nutrition support, and 74 (66.7%) required a texture modified diet or were NBM. Following hospital discharge, nearly a third of ICU survivors (28.4%) were referred for dietetic input. The most common referral reason was loss of weight. Breathlessness and fatigue were the most commonly reported nutrition impact symptoms experienced following hospital discharge.ConclusionResults show it is possible to reach nutritional adequacy for most patients and that neither VV-ECMO nor proning were barriers to nutritional adequacy. Nutritional issues for patients who were critically ill with COVID-19 persist following stepdown to ward level and into the community and strategies to manage this require further investigation.

Effect of prone position in patients with acute respiratory distress syndrome supported by venovenous extracorporeal membrane oxygenation: a retrospective cohort study

BackgroundThe application of prone position (PP) in acute respiratory distress syndrome (ARDS) supported by venovenous extracorporeal membrane oxygenation (VV-ECMO) is controversial.ObjectivesTo evaluate the safety and efficacy of application of PP during VV-ECMO in patients with ARDS.MethodsThis was a single-center, retrospective study of patients who met the Berlin definition of ARDS, and were supported with VV-ECMO. We divided the patients into two groups. The prone group included patients who were supported by VV-ECMO, and experienced at least one period of PP, while those without PP during VV-ECMO were defined as the supine group. Propensity score matching (PSM) at a ratio of 1:1 was introduced to minimize potential confounders. The primary outcomes were the complications of PP and the change of arterial oxygen pressure/fraction of the inspiration (PaO2/FiO2) ratio after PP. The secondary outcomes were hospital survival, ICU survival, and ECMO weaning rate.ResultsFrom April 2013 to October 2020, a total of 91 patients met the diagnostic criteria of ARDS who were supported with ECMO. 38 patients (41.8%) received at least one period of PP during ECMO, while 53 patients (58.2%) were maintained in supine position during ECMO. 22 minor complications were reported in the prone group and major complications were not found. The other ECMO-related complications were similar between two groups. The PaO2/FiO2 ratio significantly improved after PP compared with before (174.50 (132.40–228.25) mmHg vs. 158.00 (122.93–210.33) mmHg, p < 0.001). PSM selected 25 pairs of patients with similar characteristics. Hospital survival or ICU survival did not differ between the two groups (40% vs. 28%, p = 0.370; 40% vs. 32%, p = 0.556). Significant difference of ECMO weaning rate between two groups was not found (56% vs. 32%, p = 0.087).ConclusionsPP during VV-ECMO was safe and could improve oxygenation. A large-scale and well-designed RCT is needed in the future.

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.

Major Bleeding and Thromboembolic Events in Veno-Venous Extracorporeal Membrane Oxygenation-Patients With Isolated Respiratory Failure.

Bleeding and thromboembolic events are common during veno-venous extracorporeal membrane oxygenation (vvECMO). It is unknown whether these complications are driven by the ECMO system itself, multiorgan-failure, or both. The aim of this study was to assess the prevalence of bleeding and thromboembolic events in patients with isolated respiratory failure. Patients with vvECMO were retrospectively included from March 2009 to October 2017. Exclusion included any organ failure other than respiratory. Major bleeding was defined as a decrease in hemoglobin ≥2 g/dl per 24 hours, the requirement for transfusion of ≥2 packed red blood cell concentrates per 24 hours, any retroperitoneal, pulmonary, central nervous system bleeding, or bleeding requiring surgery. Thromboembolic events were assessed by duplex sonography or CT scan. Of 601 patients, 123 patients with a mean age of 49 ± 15 years and a median Sepsis-related Organ Failure Assessment score of 8 (7-9) were eligible for the analysis. Major bleeding was observed in 73%; 35% of all bleedings occurred on the day of or after ECMO initiation. A more pronounced decrease of PaCO2 after ECMO initiation was seen in patients with intracranial bleeding (ICB) compared with those without. Thromboembolic events were noted in 30%. The levels of activated prothrombin time, fibrinogen, platelet count, or D-dimers affected neither bleeding nor the prevalence of thromboembolic events.

New-Onset Atrial Arrhythmias Are Independently Associated With In-Hospital Mortality in Veno-Venous Extracorporeal Membrane Oxygenation

To explore if atrial arrhythmias are associated with in-hospital mortality in veno-venous extracorporeal membrane oxygenation (VV-ECMO) patients. Retrospective observational cohort study. Quaternary care academic medical center. Patients with respiratory failure requiring VV-ECMO for >24 hours between January 1, 2016, and January 1, 2019. None, observational study. Two hundred nineteen VV-ECMO patients were included. Patients were stratified by absence or presence of clinically significant atrial arrhythmias during the VV-ECMO run. Atrial arrhythmias were defined as either atrial fibrillation or atrial flutter that occurred during VV-ECMO and required pharmacologic or electrical intervention. The primary outcome was in-hospital mortality. Secondary outcomes included a composite of thrombotic events, which included ischemic stroke and on-pump arterial thrombosis. Other objectives of this analysis included characterization of atrial arrhythmia incidence, risk factors, and management. A total of 67 patients (30.5%) experienced new-onset atrial arrhythmias post-ECMO cannulation. Age, male sex, and norepinephrine use were independently associated with atrial arrhythmia development. In-hospital mortality was significantly higher in the atrial arrhythmia group (38.8% v 19.1%; p=0.003). In the multivariate logistic regression analysis, atrial arrhythmias during VV-ECMO were independently associated with increased odds of in-hospital mortality (odds ratio, 2.21; 95% confidence interval, 1.08-4.55; p=0.03), after controlling for Respiratory Extracorporeal Membrane Oxygenation Survival Prediction score, acute renal failure, total norepinephrine dose, and total cannulation time. New-onset atrial arrhythmias are a frequent complication during VV-ECMO and are independently associated with excessive in-hospital mortality. Thus, their presence may serve as an important prognostic tool in this patient population.