The intricate physiology of veno-venous extracorporeal membrane oxygenation: an overview for clinicians.

During veno-venous extracorporeal membrane oxygenation (V-V ECMO), blood is drained from the central venous circulation to be oxygenated and decarbonated by an artificial lung. It is then reinfused into the right heart and pulmonary circulation where further gas-exchange occurs. Each of these steps is characterized by a peculiar physiology that this manuscript analyses, with the aim of providing bedside tools for clinical care: we begin by describing the factors that affect the efficiency of blood drainage, such as patient and cannulae position, fluid status, cardiac output and ventilatory strategies. We then dig into the complexity of extracorporeal gas-exchange, with particular reference to the effects of extracorporeal blood-flow (ECBF), fraction of delivered oxygen (FdO2) and sweep gas-flow (SGF) on oxygenation and decarbonation. Subsequently, we focus on the reinfusion of arterialized blood into the right heart, highlighting the effects on recirculation and, more importantly, on right ventricular function. The importance and challenges of haemodynamic monitoring during V-V ECMO are also analysed. Finally, we detail the interdependence between extracorporeal circulation, native lung function and mechanical ventilation in providing adequate arterial blood gases while allowing lung rest. In the absence of evidence-based strategies to care for this particular group of patients, clinical practice is underpinned by a sound knowledge of the intricate physiology of V-V ECMO.

Left ventricular unloading in patients supported with veno-arterial extra corporeal membrane oxygenation; an international EuroELSO survey.

INTRODUCTION: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) improves end-organ perfusion in cardiogenic shock but may increase afterload, which can limit cardiac recovery. Left ventricular (LV) unloading strategies may aid cardiac recovery and prevent complications of increased afterload. However, there is no consensus on when and which unloading strategy should be used. METHODS: An online survey was distributed worldwide via the EuroELSO newsletter mailing list to describe contemporary international practice and evaluate heterogeneity in strategies for LV unloading. RESULTS: Of 192 respondents from 43 countries, 53% routinely use mechanical LV unloading, to promote ventricular recovery and/or to prevent complications. Of those that do not routinely unload, 65% cited risk of complications as the reason. The most common indications for unplanned unloading were reduced arterial line pulsatility (68%), pulmonary edema (64%) and LV dilatation (50%). An intra-aortic balloon pump was the most frequently used device for unloading followed by percutaneous left ventricular assist devices. Echocardiography was the most frequently used method to monitor the response to unloading. CONCLUSIONS: Significant variation exists with respect to international practice of ventricular unloading. Further research is required that compares the efficacy of different unloading strategies and a randomized comparison of routine mechanical unloading versus unplanned unloading.

Extracorporeal Life Support Organization Registry International Report 2022: 100,000 Survivors.

The Extracorporeal Life Support Organization (ELSO) maintains the world's largest extracorporeal membrane oxygenation (ECMO) registry by volume, center participation, and international scope. This 2022 ELSO Registry Report describes the program characteristics of ECMO centers, processes of ECMO care, and reported outcomes. Neonates (0-28 days), children (29 days-17 years), and adults (≥18 years) supported with ECMO from 2009 through 2022 and reported to the ELSO Registry were included. This report describes adjunctive therapies, support modes, treatments, complications, and survival outcomes. Data are presented descriptively as counts and percent or median and interquartile range (IQR) by year, group, or level. Missing values were excluded before calculating descriptive statistics. Complications are reported per 1,000 ECMO hours. From 2009 to 2022, 154,568 ECMO runs were entered into the ELSO Registry. Seven hundred and eighty centers submitted data during this time (557 in 2022). Since 2009, the median annual number of adult ECMO runs per center per year increased from 4 to 15, whereas for pediatric and neonatal runs, the rate decreased from 12 to 7. Over 50% of patients were transferred to the reporting ECMO center; 20% of these patients were transported with ECMO. The use of prone positioning before respiratory ECMO increased from 15% (2019) to 44% (2021) for adults during the coronavirus disease-2019 (COVID-19) pandemic. Survival to hospital discharge was greatest at 68.5% for neonatal respiratory support and lowest at 29.5% for ECPR delivered to adults. By 2022, the Registry had enrolled its 200,000th ECMO patient and 100,000th patient discharged alive. Since its inception, the ELSO Registry has helped centers measure and compare outcomes across its member centers and strategies of care. Continued growth and development of the Registry will aim to bolster its utility to patients and centers.

Extracorporeal Carbon Dioxide Removal to Avoid Invasive Ventilation During Exacerbations of Chronic Obstructive Pulmonary Disease: VENT-AVOID Trial - A Randomized Clinical Trial.

Rationale: It is unclear whether extracorporeal CO2 removal (ECCO2R) can reduce the rate of intubation or the total time on invasive mechanical ventilation (IMV) in adults experiencing an exacerbation of chronic obstructive pulmonary disease (COPD). Objectives: To determine whether ECCO2R increases the number of ventilator-free days within the first 5 days postrandomization (VFD-5) in exacerbation of COPD in patients who are either failing noninvasive ventilation (NIV) or who are failing to wean from IMV. Methods: This randomized clinical trial was conducted in 41 U.S. institutions (2018-2022) (ClinicalTrials.gov ID: NCT03255057). Subjects were randomized to receive either standard care with venovenous ECCO2R (NIV stratum: n = 26; IMV stratum: n = 32) or standard care alone (NIV stratum: n = 22; IMV stratum: n = 33). Measurements and Main Results: The trial was stopped early because of slow enrollment and enrolled 113 subjects of the planned sample size of 180. There was no significant difference in the median VFD-5 between the arms controlled by strata (P = 0.36). In the NIV stratum, the median VFD-5 for both arms was 5 days (median shift = 0.0; 95% confidence interval [CI]: 0.0-0.0). In the IMV stratum, the median VFD-5 in the standard care and ECCO2R arms were 0.25 and 2 days, respectively; median shift = 0.00 (95% confidence interval: 0.00-1.25). In the NIV stratum, all-cause in-hospital mortality was significantly higher in the ECCO2R arm (22% vs. 0%, P = 0.02) with no difference in the IMV stratum (17% vs. 15%, P = 0.73). Conclusions: In subjects with exacerbation of COPD, the use of ECCO2R compared with standard care did not improve VFD-5. Clinical trial registered with www.clinicaltrials.gov (NCT03255057).

The Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal Compared With Conventional Lung Protective Ventilation on Cardiac Function.

OBJECTIVES: Lower tidal volume ventilation (targeting 3 mL/kg predicted body weight, PBW) facilitated by extracorporeal carbon dioxide removal (ECCO2R) has been investigated as a potential therapy for acute hypoxemic respiratory failure (AHRF) in the pRotective vEntilation with veno-venouS lung assisT in respiratory failure (REST) trial. We investigated the effect of this strategy on cardiac function, and in particular the right ventricle. DESIGN: Substudy of the REST trial. SETTING: Nine U.K. ICUs. PATIENTS: Patients with AHRF (Pao2/Fio2 < 150 mm Hg [20 kPa]). INTERVENTION: Transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements were collected at baseline and postrandomization in patients randomized to ECCO2R or usual care. MEASUREMENTS: The primary outcome measures were a difference in tricuspid annular plane systolic excursion (TAPSE) on postrandomization echocardiogram and difference in NT-proBNP postrandomization. RESULTS: There were 21 patients included in the echocardiography cohort (ECCO2R, n = 13; usual care, n = 8). Patient characteristics were similar in both groups at baseline. Median (interquartile range) tidal volumes were lower in the ECCO2R group compared with the usual care group postrandomization; 3.6 (3.1-4.2) mL/kg PBW versus 5.2 (4.9-5.7) mL/kg PBW, respectively (p = 0.01). There was no difference in the primary outcome measure of mean (sd) TAPSE in the ECCO2R and usual care groups postrandomization; 21.3 (5.4) mm versus 20.1 (3.2) mm, respectively (p = 0.60). There were 75 patients included in the NT-proBNP cohort (ECCO2R, n = 36; usual care, n = 39). Patient characteristics were similar in both groups at baseline. Median (interquartile range [IQR]) tidal volumes were lower in the ECCO2R group than the usual care group postrandomization; 3.8 (3.3-4.2) mL/kg PBW versus 6.7 (5.8-8.1) mL/kg PBW, respectively (p < 0.0001). There was no difference in median (IQR) NT-proBNP postrandomization; 1121 (241-5370) pg/mL versus 1393 (723-4332) pg/mL in the ECCO2R and usual care groups, respectively (p = 0.30). CONCLUSIONS: In patients with AHRF, a reduction in tidal volume facilitated by ECCO2R, did not modify cardiac function.

Routine Metagenomics Service for ICU Patients with Respiratory Infection.

Rationale: Respiratory metagenomics (RMg) needs evaluation in a pilot service setting to determine utility and inform implementation into routine clinical practice. Objectives: Feasibility, performance, and clinical impacts on antimicrobial prescribing and infection control were recorded during a pilot RMg service. Methods: RMg was performed on 128 samples from 87 patients with suspected lower respiratory tract infection (LRTI) on two general and one specialist respiratory ICUs at Guy's and St Thomas' NHS Foundation Trust, London. Measurements and Main Results: During the first 15 weeks, RMg provided same-day results for 110 samples (86%), with a median turnaround time of 6.7 hours (interquartile range = 6.1-7.5 h). RMg was 93% sensitive and 81% specific for clinically relevant pathogens compared with routine testing. Forty-eight percent of RMg results informed antimicrobial prescribing changes (22% escalation; 26% deescalation) with escalation based on speciation in 20 out of 24 cases and detection of acquired-resistance genes in 4 out of 24 cases. Fastidious or unexpected organisms were reported in 21 samples, including anaerobes (n = 12), Mycobacterium tuberculosis, Tropheryma whipplei, cytomegalovirus, and Legionella pneumophila ST1326, which was subsequently isolated from the bedside water outlet. Application to consecutive severe community-acquired LRTI cases identified Staphylococcus aureus (two with SCCmec and three with luk F/S virulence determinants), Streptococcus pyogenes (emm1-M1uk clone), S. dysgalactiae subspecies equisimilis (STG62647A), and Aspergillus fumigatus with multiple treatments and public health impacts. Conclusions: This pilot study illustrates the potential of RMg testing to provide benefits for antimicrobial treatment, infection control, and public health when provided in a real-world critical care setting. Multicenter studies are now required to inform future translation into routine service.

Bilateral Femoral Cannulation Is Associated With Reduced Severe Limb Ischemia-Related Complications Compared With Unilateral Femoral Cannulation in Adult Peripheral Venoarterial Extracorporeal Membrane Oxygenation: Results From the Extracorporeal Life Support Registry.

OBJECTIVES: Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) with femoral access is obtained through unilateral or bilateral groin cannulation. Whether one cannulation strategy is associated with a lower risk for limb ischemia remains unknown. We aim to assess if one strategy is preferable. DESIGN: A retrospective cohort study based on the Extracorporeal Life Support Organization registry. SETTING: ECMO centers worldwide included in the Extracorporeal Life Support Organization registry. PATIENTS: All adult patients (≥ 18 yr) who received peripheral venoarterial ECMO with femoral access and were included from 2014 to 2020. INTERVENTIONS: Unilateral or bilateral femoral cannulation. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the occurrence of limb ischemia defined as a composite endpoint including the need for a distal perfusion cannula (DPC) after 6 hours from implantation, compartment syndrome/fasciotomy, amputation, revascularization, and thrombectomy. Secondary endpoints included bleeding at the peripheral cannulation site, need for vessel repair, vessel repair after decannulation, and in-hospital death. Propensity score matching was performed to account for confounders. Overall, 19,093 patients underwent peripheral venoarterial ECMO through unilateral ( n = 11,965) or bilateral ( n = 7,128) femoral cannulation. Limb ischemia requiring any intervention was not different between both groups (bilateral vs unilateral: odds ratio [OR], 0.92; 95% CI, 0.82-1.02). However, there was a lower rate of compartment syndrome/fasciotomy in the bilateral group (bilateral vs unilateral: OR, 0.80; 95% CI, 0.66-0.97). Bilateral cannulation was also associated with lower odds of cannulation site bleeding (bilateral vs unilateral: OR, 0.87; 95% CI, 0.76-0.99), vessel repair (bilateral vs unilateral: OR, 0.55; 95% CI, 0.38-0.79), and in-hospital mortality (bilateral vs unilateral: OR, 0.85; 95% CI, 0.81-0.91) compared with unilateral cannulation. These findings were unchanged after propensity matching. CONCLUSIONS: This study showed no risk reduction for overall limb ischemia-related events requiring DPC after 6 hours when comparing bilateral to unilateral femoral cannulation in peripheral venoarterial ECMO. However, bilateral cannulation was associated with a reduced risk for compartment syndrome/fasciotomy, lower rates of bleeding and vessel repair during ECMO, and lower in-hospital mortality.

State of the art: Monitoring of the respiratory system during veno-venous extracorporeal membrane oxygenation.

Monitoring the patient receiving veno-venous extracorporeal membrane oxygenation (VV ECMO) is challenging due to the complex physiological interplay between native and membrane lung. Understanding these interactions is essential to understand the utility and limitations of different approaches to respiratory monitoring during ECMO. We present a summary of the underlying physiology of native and membrane lung gas exchange and describe different tools for titrating and monitoring gas exchange during ECMO. However, the most important role of VV ECMO in severe respiratory failure is as a means of avoiding further ergotrauma. Although optimal respiratory management during ECMO has not been defined, over the last decade there have been advances in multimodal respiratory assessment which have the potential to guide care. We describe a combination of imaging, ventilator-derived or invasive lung mechanic assessments as a means to individualise management during ECMO.

Behavioural and physiological impacts of low salinity on the sea urchin Echinus esculentus.

Reduced seawater salinity as a result of freshwater input can exert a major influence on the ecophysiology of benthic marine invertebrates, such as echinoderms. While numerous experimental studies have explored the physiological and behavioural effects of short-term, acute exposure to low salinity in echinoids, surprisingly few have investigated the consequences of chronic exposure, or compared the two. In this study, the European sea urchin, Echinus esculentus, was exposed to low salinity over the short term (11‰, 16‰, 21‰, 26‰ and 31‰ for 24 h) and longer term (21, 26 and 31‰ for 25 days). Over the short term, oxygen consumption, activity coefficient and coelomic fluid osmolality were directly correlated with reduced salinity, with 100% survival at ≥21‰ and 0% at ≤16‰. Over the longer term at 21‰ (25 days), oxygen consumption was significantly higher, feeding was significantly reduced and activity coefficient values were significantly lower than at control salinity (31‰). At 26‰, all metrics were comparable to the control by the end of the experiment, suggesting acclimation. Furthermore, beneficial functional resistance (righting ability and metabolic capacity) to acute low salinity was observed at 26‰. Osmolality values were slightly hyperosmotic to the external seawater at all acclimation salinities, while coelomocyte composition and concentration were unaffected by chronic low salinity. Overall, E. esculentus demonstrate phenotypic plasticity that enables acclimation to reduced salinity around 26‰; however, 21‰ represents a lower acclimation threshold, potentially limiting its distribution in coastal areas prone to high freshwater input.

Expert consensus on training and accreditation for extracorporeal cardiopulmonary resuscitation an international, multidisciplinary modified Delphi Study.

BACKGROUND: A multidisciplinary group of stakeholders were used to identify: (1) the core competencies of a training program required to perform in-hospital ECPR initiation (2) additional competencies required to perform pre-hospital ECPR initiation and; (3) the optimal training method and maintenance protocol for delivering an ECPR program. METHODS: A modified Delphi process was undertaken utilising two web based survey rounds and one virtual meeting. Experts rated the importance of different aspects of ECPR training, competency and governance on a 9-point Likert scale. A diverse, representative group was targeted. Consensus was achieved when greater than 70% respondents rated a domain as critical (> or = 7 on the 9 point Likert scale). RESULTS: 35 international ECPR experts from 9 countries formed the expert panel, with a median number of 14 years of ECMO practice (interquartile range 11-38). Participant response rates were 97% (survey round one), 63% (virtual meeting) and 100% (survey round two). After the second round of the survey, 47 consensus statements were formed outlining a core set of competencies required for ECPR provision. We identified key elements required to safely train and perform ECPR including skill pre-requisites, surrogate skill identification, the importance of competency-based assessment over volume of practice and competency requirements for successful ECPR practice and skill maintenance. CONCLUSIONS: We present a series of core competencies, training requirements and ongoing governance protocols to guide safe ECPR implementation. These findings can be used to develop training syllabus and guide minimum standards for competency as the growth of ECPR practitioners continues.

Clinical impact of screening computed tomography in extracorporeal membrane oxygenation: a retrospective cohort study.

BACKGROUND: Data on the prevalence and clinical impact of extrapulmonary findings at screening computed tomography (CT) on initiation of veno-venous extracorporeal membrane oxygenation (V-V ECMO) are limited. We aimed to identify the prevalence of extrapulmonary findings on screening CT following V-V ECMO initiation. We hypothesized that extrapulmonary findings would influence clinical management and outcome. METHODS: Retrospective analysis (2011-2021) of admission screening CT including head, abdomen and pelvis with contrast of consecutive patients on initiation of V-V ECMO. CT findings identified by the attending consultant radiologist were extracted. Demographics, admission physiological and laboratory data, clinical decision-making following CT and ECMO ICU mortality were recorded from the electronic medical record. We used multivariable logistic regression and Kaplan-Meier curves to evaluate associations between extrapulmonary findings and ECMO ICU mortality. RESULTS: Of the 833 patients receiving V-V ECMO, 761 underwent routine admission CT (91.4%). ECMO ICU length of stay was 19 days (IQR 12-23); ICU mortality at the ECMO centre was 18.9%. An incidental extrapulmonary finding was reported in 227 patients (29.8%), leading to an invasive procedure in 12/227 cases (5.3%) and a change in medical management (mainly in anticoagulation strategy) in 119/227 (52.4%). Extrapulmonary findings associated with mortality were intracranial haemorrhage (OR 2.34 (95% CI 1.31-4.12), cerebral infarction (OR 3.59 (95% CI 1.26-9.86) and colitis (OR 2.80 (95% CI 1.35-5.67). CONCLUSIONS: Screening CT frequently identifies extrapulmonary findings of clinical significance. Newly detected intracranial haemorrhage, cerebral infarction and colitis were associated with increased ICU mortality.

Prevalence and Indications for Oxygenator Circuit Replacement in Patients Receiving Venovenous Extracorporeal Membrane Oxygenation.

In this retrospective observational cohort study, we aimed to describe the rate of extracorporeal membrane oxygenation (ECMO) circuit change, the associated risk factors and its relationship with patient characteristics and outcome in patients receiving venovenous (VV) ECMO at our center between January 2015 and November 2017. Twenty-seven percent of the patients receiving VV ECMO (n = 224) had at least one circuit change, which was associated with lower ICU survival (68% vs 82% p=0.032) and longer ICU stay (30 vs . 17 days p < 0.001). Circuit duration was similar when stratified by gender, clinical severity, or prior circuit change. Hematological abnormalities and increased transmembrane lung pressure (TMLP) were the most frequent indication for circuit change. The change in transmembrane lung resistance (Δ TMLR) gave better prediction of circuit change than TMLP, TMLR, or ΔTMLP. Low postoxygenator PO 2 was indicated as a reason for one-third of the circuit changes. However, the ECMO oxygen transfer was significantly higher in cases of circuit change with documented "low postoxygenator PO 2 " than those without (244 ± 62 vs. 200 ± 57 ml/min; p = 0.009). The results suggest that circuit change in VV ECMO is associated with worse outcomes, that the Δ TMLR is a better predictor of circuit change than TMLP, and that the postoxygenator PO 2 is an unreliable proxy for the oxygenator function.

Relationship between D-dimers and dead-space on disease severity and mortality in COVID-19 acute respiratory distress syndrome: A retrospective observational cohort study.

BACKGROUND: Despite its diagnostic and prognostic importance, physiologic dead space fraction is not included in the current ARDS definition or severity classification. ARDS caused by COVID-19 (C-ARDS) is characterized by increased physiologic dead space fraction and hypoxemia. Our aim was to investigate the relationship between dead space indices, markers of inflammation, immunothrombosis, severity and intensive care unit (ICU) mortality. RESULTS: Retrospective data including demographics, gas exchange, ventilatory parameters, and respiratory mechanics in the first 24 h of invasive ventilation. Plasma concentrations of D-dimers and ferritin were not significantly different across C-ARDS severity categories. Weak relationships were found between D-dimers and VR (r = 0.07, p = 0.13), PETCO2/PaCO2 (r = -0.1, p = 0.02), or estimated dead space fraction (r = 0.019, p = 0.68). Age, PaO2/FiO2, pH, PETCO2/PaCO2 and ferritin, were independently associated with ICU mortality. We found no association between D-dimers or ferritin and any dead-space indices adjusting for PaO2/FiO2, days of ventilation, tidal volume, and respiratory system compliance. CONCLUSIONS: We report no association between dead space and inflammatory markers in mechanically ventilated patients with C-ARDS. Our results support theories suggesting that multiple mechanisms, in addition to immunothrombosis, play a role in the pathophysiology of respiratory failure and degree of dead space in C-ARDS.

"Bridging the Gap" international ECLS training and simulation - evaluation of the 10th educational corner on EuroELSO congress 2022 in London, United Kingdom.

Introduction: Simulation training offers an authentic team-based learning opportunity without risk to real patients. The Educational Corner at the annual congress of the European Branch of Extracorporeal Life Support Organisation (EuroELSO) provided an opportunity for multiple simulation training sessions facilitated by experts from all over the world.Aim: We aimed to review the educational impact of EuroELSO Educational Corner and whether it provides a quality ECLS training to a wide spectrum of multidisciplinary international attendees utilising high and low fidelity simulation, workshops and hands on sessions.Methods: During the congress, 43 sessions were conducted dedicated to ECLS education with identified educational objectives. The sessions focused on management of adults and children on V-V or V-A ECMO. Adult sessions covered emergencies on mechanical circulatory support with management of LVAD and Impella, managing refractory hypoxemia on V-V ECMO, emergencies on ECMO, renal replacement therapy on ECMO, V-V ECMO, ECPR cannulation and performing perfect simulation. Paediatric sessions covered ECPR neck and central cannulation, renal replacement on ECMO, troubleshooting, cannulation workshop, V-V recirculation, ECMO for single ventricle, PIMS-TS and CDH, ECMO transport and neurological injury.Results: The Educational Corner was attended by more than 400 participants over the two congress days. Majority of responders (88%) reported that training sessions met the set educational goals and objectives and that this would change their current practice. Almost all (94%) reported that they received useful information and 95% would recommend the session to their colleagues.Conclusion: The Educational Corner, as an integral component of the annual EuroELSO congress, achieved the set educational goals and provided quality education based on the recipient survey. Structured multidisciplinary ECLS education with standardised curriculum and feedback is an important key step in delivering quality training to an international audience. Standardisation of European ECLS education remains an important focus of the EuroELSO.

Unloading the Left Ventricle in Venoarterial ECMO: In Whom, When, and How?

Venoarterial extracorporeal membrane oxygenation provides cardiorespiratory support to patients in cardiogenic shock. This comes at the cost of increased left ventricle (LV) afterload that can be partly ascribed to retrograde aortic flow, causing LV distension, and leads to complications including cardiac thrombi, arrhythmias, and pulmonary edema. LV unloading can be achieved by using an additional circulatory support device to mitigate the adverse effects of mechanical overload that may increase the likelihood of myocardial recovery. Observational data suggest that these strategies may improve outcomes, but in whom, when, and how LV unloading should be employed is unclear; all techniques require balancing presumed benefits against known risks of device-related complications. This review summarizes the current evidence related to LV unloading with venoarterial extracorporeal membrane oxygenation.

Extracorporeal Carbon Dioxide Removal With the Hemolung in Patients With Acute Respiratory Failure: A Multicenter Retrospective Cohort Study.

OBJECTIVES: Extracorporeal carbon dioxide removal (ECCO 2 R) devices are effective in reducing hypercapnia and mechanical ventilation support but have not been shown to reduce mortality. This may be due to case selection, device performance, familiarity, or the management. The objective of this study is to investigate the effectiveness and safety of a single ECCO 2 R device (Hemolung) in patients with acute respiratory failure and identify variables associated with survival that could help case selection in clinical practice as well as future research. DESIGN: Multicenter, multinational, retrospective review. SETTING: Data from the Hemolung Registry between April 2013 and June 2021, where 57 ICUs contributed deidentified data. PATIENTS: Patients with acute respiratory failure treated with the Hemolung. The characteristics of patients who survived to ICU discharge were compared with those who died. Multivariable logistical regression analysis was used to identify variables associated with ICU survival. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 159 patients included, 65 (41%) survived to ICU discharge. The survival was highest in status asthmaticus (86%), followed by acute respiratory distress syndrome (ARDS) (52%) and COVID-19 ARDS (31%). All patients had a significant reduction in Pa co2 and improvement in pH with reduction in mechanical ventilation support. Patients who died were older, had a lower Pa o2 :F io2 (P/F) and higher use of adjunctive therapies. There was no difference in the complications between patients who survived to those who died. Multivariable regression analysis showed non-COVID-19 ARDS, age less than 65 years, and P/F at initiation of ECCO 2 R to be independently associated with survival to ICU discharge (P/F 100-200 vs <100: odds ratio, 6.57; 95% CI, 2.03-21.33). CONCLUSIONS: Significant improvement in hypercapnic acidosis along with reduction in ventilation supports was noted within 4 hours of initiating ECCO 2 R. Non-COVID-19 ARDS, age, and P/F at commencement of ECCO 2 R were independently associated with survival.

Steroid exposure and outcome in COVID-19 pneumonia.

Background: Corticosteroids are used to treat COVID-19 pneumonia. However, the optimal dose is unclear. This study describes the association between corticosteroid exposure with disease severity and outcome in COVID-19 pneumonia. Methods: This is a single-centre retrospective, observational study including adult ICU patients who received systemic corticosteroids for COVID-19 pneumonia between March 2020 and March 2021. We recorded patient characteristics, disease severity, total steroid exposure, respiratory support and gas exchange data, and 90-day mortality. Results: We included 362 patients. We allocated patients to groups with increasing disease severity according to the highest level of respiratory support that they received: high-flow nasal oxygen or continuous positive airway pressure (HFNO/CPAP) in 12.7%, invasive mechanical ventilation (IMV) in 61.6%, and extracorporeal membrane oxygenation (ECMO) in 25.7%. For these three groups, the median (inter-quartile range [IQR]) age was 61 (54-71) vs 58 (50-66) vs 46 (38-53) yr, respectively (P<0.001); median (IQR) APACHE (Acute Physiology and Chronic Health Evaluation) II scores were 12 (9-15) vs 14 (12-18) vs 15 (12-17), respectively (P=0.006); the median (IQR) lowest P a O 2 /FiO2 ratio was 15.1 (11.8-21.7) vs 15.1 (10.7-22.2) vs 9.5 (7.9-10.9) kPa, respectively (P<0.001). Ninety-day mortality was 9% vs 27% vs 37% (P=0.002). Median (IQR) dexamethasone-equivalent exposure was 37 (24-62) vs 174 (86-504) vs 535 (257-1213) mg (P<0.001). 'Pulsed' steroids were administered to 26% of the IMV group and 48% of the ECMO group. Patients with higher disease severity who received pulse steroids had a higher 90-day mortality. Conclusions: Corticosteroid exposure increased with the severity of COVID-19 pneumonia. Pulsed dose steroids were used more frequently in patients receiving greater respiratory support. Future studies should address patient selection and outcomes associated with pulsed dose steroids in patients with severe and deteriorating COVID-19 pneumonia.

Extracorporeal life support provision in COVID-19 patients - An international EuroELSO 2022 update survey.

INTRODUCTION: An analysis on the ECLS use for patients with respiratory or cardiac support in COVID-19 based on an international response to EuroELSO survey, aims to generate a more comprehensive understanding of ECLS role during the recent viral pandemic. METHODS: EuroELSO announced the survey at the 10th annual congress in London, May 2022. The survey covered 26 multiple-choice questions. RESULTS: The survey returned 69 questionnaires from 62 centers across 22 European countries and seven centers across five non-European countries. Most of the centers providing ECLS for COVID-19 patients had more than 30 runs for respiratory support since December 2019. In the same period, at least 31 runs in adult COVID-19 patients have been performed in 48 of 69 centers (69.6%). The reported pediatric data from 18 centers is limited to less than the patients per center. CONCLUSION: Majority of the COVID-19 patients received respiratory ECLS support and adult patients dominated. The indications and contraindications are broadly aligned with available guidelines. Most of the centers considered age >65 or biological age as a relative or absolute contraindication for ECLS in COVID-19. ECLS withdrawal criteria in COVID-19 are controversial because the long-term outcomes after ECLS in COVID-19 and the impact of critical illness and the impact of long-COVID are still not known.