Extracorporeal membrane oxygenation for COVID-19-related acute respiratory distress syndrome: a narrative review

Increasing risk of postlung transplant hospitalizations for infection: An analysis of recent trends

Background

Despite advancements in lung transplantation (LT), infection remains a major cause of morbidity and mortality following LT. We examined trends in hospitalizations for infection in the first year after LT.

Methods

We identified adult LT recipients in the United States (March 1, 2018-March 9, 2023) using the Organ Procurement and Transplantation Network database. We categorized transplants into 3 eras to account for the Composite Allocation Score allocation policy change and coronavirus disease 2019: March 2018 to March 2020, March 2020 to March 2022, and March 2022 to March 9, 2023. One-year post-LT survival was compared using Kaplan-Meier survival analysis and Cox proportional hazards regression. Hospitalizations for infection were compared using multivariable logistic regression, adjusted for era and donor and recipient characteristics.

Results

Of 12,388 LT recipients (median age = 62, male = 61.2%), hospitalization for infection in the first-year post transplant was 5.2% for patients transplanted from March 2018 to March 2020 (N = 5,031), 7.6% from March 2020 to March 2022 (N = 4,659), and 13.2% post-March 2022 (N = 3,640) (p < 0.001). Compared to March 2018 to March 2020, patients transplanted from March 2020 to March 2022 (adjusted aoods ratio [aOR] = 1.50, 95% confidence interval [CI] = 1.26-1.79) and post-March 2022 (aOR = 2.89, 95% CI = 2.29-3.65) were more likely to be hospitalized for an infection. After adjustment, we found no significant difference in risk of death following LT for recipients transplanted between March 2020 and March 2022 (aHR = 1.09, 95% CI = 0.96-1.23, p = 0.175) compared to March 2018 and March 2020. Post-March 2022 risk of death was elevated (aHR = 1.21, 95% CI = 1.04, 1.40, p = 0.014).

Conclusions

Odds of hospitalization for infection in the first year after LT performed between March 2020 and March 2022 and post-March 2022 were 1.50 and 2.89 times as high, respectively, as LT performed between March 2018 and March 2020.

IRB NUMBERS

IRB00352819.

Effect of Respiratory Support Type and Total Duration on Weaning From Venovenous Extracorporeal Membrane Oxygenation in COVID-19 Patients

Background: We evaluated the impact of noninvasive respiratory support (NRS) and invasive mechanical ventilation duration before venovenous extracorporeal membrane oxygenation (VV-ECMO) on weaning from venovenous ECMO and survival. Methods: In a retrospective single-center study, we studied subjects with COVID-19 ARDS treated with VV-ECMO. The subjects were divided and analyzed according to the cut-off of NRS, invasive ventilation, and total duration of respiratory support. Results: We identified a cut-off of NRS duration of 4 days, invasive ventilation duration of 5 days, and total respiratory support duration of 8 days. Weaning from VV-ECMO was observed in 63% (15/24) of subjects with NRS duration ≤ 4 days and in 16% (4/25) of subjects with NRS > 4 days (P = .001), in 50% (17/34) of subjects with invasive ventilation duration ≤ 5 days, in 13% (2/15) of subjects with invasive ventilation duration > 5 days (P = .02), in 68% (13/19) of subjects with total support duration < 8 days, and in 20% (6/30) of subjects with total support duration > 8 days (P = .001). The survival probability at 200 days demonstrated a statistically significant difference in NRS and total support duration comparison (P = .001 and P = .004, respectively). We did not find a statistically significant survival difference according to invasive ventilation duration (P = .13). Conclusions: In our population, the increase in NRS and total support days before ECMO could hamper weaning from VV-ECMO support. However, due to the pandemic, the small sample size, and the lack of precise data on ventilation settings, caution should be exercised in universalizing these results.

Extracorporeal Membrane Oxygenation Outcomes: COVID-19 Pneumonia vs Non-COVID-19 Pneumonia

BACKGROUND

COVID-19 can cause severe acute respiratory distress syndrome or myocardial dysfunction requiring extracorporeal membrane oxygenation (ECMO). Whether comorbidities or sociodemographic factors influence outcomes in these patients is unclear.

METHODS

Adult patients from the National Inpatient Sample dataset with COVID-19 pneumonia or non-COVID-19 pneumonia who underwent ECMO between 2016 and 2021 were included. Cohorts were matched in a 1:5 ratio using propensity scores. The primary outcome of interest was inpatient mortality; secondary outcomes included length of stay, total hospitalization costs, need for dialysis, rate of vascular complications, and discharge disposition.

RESULTS

Weighted patient groups (COVID-19 pneumonia, 5680 patients; non-COVID-19 pneumonia, 430 patients) were identified. Mean (SD) age was 46.0 (11.2) years in the COVID-19 group, 45.1 (12.5) years in the non-COVID-19 group. After matching, unweighted groups (COVID-19 pneumonia, 1136 patients; non-COVID-19 pneumonia, 86 patients) were compared. Patients with COVID-19 pneumonia had higher mortality risk (odds ratio [OR], 1.98; 95% CI, 1.11-3.53; P = .02), longer stays (38.0 vs 28.5 days, P < .001), higher costs ($1 278 270 vs $967 866, P = .002), and less likelihood of discharge home (OR, 0.42; 95% CI, 0.21-0.85; P = .02) than patients with non-COVID-19 pneumonia. Vascular complication rate (OR, 0.77; 95% CI, 0.27-2.26; P = .64) and need for dialysis (OR, 1.01; 95% CI, 0.49-2.08; P = .97) did not differ between groups.

CONCLUSIONS

Among patients undergoing ECMO, those with COVID-19 pneumonia had worse outcomes than those with non-COVID-19 pneumonia after adjustment for sociodemographic factors and comorbidities.

Awake veno-venous extracorporeal membrane oxygenation: practical aspects and considerations

Veno-venous extracorporeal membrane oxygenation (ECMO) is a life-saving technique in the armamentarium of critical care medicine. It involves extracorporeal blood circulation outside the body, providing temporary respiratory support while allowing the lungs to heal. Traditionally, patients undergoing ECMO require sedation to minimize discomfort and facilitate mechanical ventilation. The "awake ECMO" concept emerged as a promising strategy to mitigate sedation-related complications and facilitate early mobilization in critically ill patients. In this article, we describe the potential advantages of awake ECMO and its role in preserving respiratory muscle function, enhancing rehabilitation prospects, and improving patient outcomes.

Veno-venous extracorporeal membrane oxygenation for severe COVID-19 associated acute respiratory distress syndrome: A retrospective, nationwide, Danish cohort study

BACKGROUND

Severe acute respiratory syndrome (ARDS) may require veno-venous extracorporeal membrane oxygenation (V-V ECMO). The aim of this study was to provide data on patient selection and outcome in a nationwide cohort study of patients with COVID-19 associated ARDS supported with V-V ECMO.

METHODS

We identified all patients with COVID-19, who were supported with V-V ECMO in Denmark from March 10, 2020, to December 31, 2021, and retrieved data on patients who were referred to- and accepted for ECMO, demographics, outcome data, and complications. Risk factors for mortality were analysed using multivariate Cox regression analysis.

RESULTS

During the study period, 1836 patients were admitted to Danish intensive care units (ICUs). In the same period, there were 197 enquiries for ECMO of whom 118 patients were considered eligible. Overall, 71 patients were cannulated for ECMO; three patients were cannulated for veno-arterial extracorporeal membrane oxygenation (V-A ECMO) due to right sided heart failure and 68 patients were cannulated for V-V ECMO. Two patients accepted for V-V ECMO died during cannulation. The median age was 55 years (IQR 45-60) and 66% were males. The median duration of ECMO support was 13 days (IQR 7-21), mechanical ventilation median 26 days (IQR 14-42), ICU stay median 34 days (IQR 17-46), and length of hospital stay median 41 days (IQR 25-56). Ninety-day mortality was 43%. Age of 60 years or more was associated with an increased risk of mortality. Pre-existing hypertension was associated with a decreased risk of mortality.

CONCLUSION

A nationwide, Danish cohort study of 68 COVID-19 patients supported with V-V ECMO, showed a 90-day survival of 43%, which is in accordance with reports from comparable cohorts. Age of 60 years or more was associated with an increased risk of mortality. Pre-existing hypertension was associated with a decreased risk of mortality.

Angiotensin 1-7 restrains vascular injury of extracorporeal membrane oxygenation by inhibiting ferroptosis

BACKGROUND

Angiotensin 1-7 (Ang1-7) is the classical end product of angiotensin II, which has the effects of dilating blood vessels, protecting endothelial cells, anti-hypertension, improving cardiac function, and inhibiting atherosclerosis. We hypothesize that Ang1-7 inhibits human umbilical vein endothelial cells (HUVEC) ferroptosis through NF-κB/P53 signal pathway, and reduces extracorporeal membrane oxygenation (ECMO) vascular injury.

METHODS

Cultured HUVEC were seeded into 15 wells and randomly divided into five groups: the control group and four experimental groups (erastin, erastin + Ang1-7, erastin + Ang1-7 + Betulinic acid, erastin + Betulinic acid). After stimulation, cell viability, lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) activity were measured. The effects of Ang1-7 on HUVEC microstructure, antioxidant enzymes (ferritin heavy chain 1 (FTH1), cystine/glutamic acid reverse transport solute carrier family 7 members 11 (SLC7A11 or XCT), superoxide dismutase-2 (SOD-2) and glutathione peroxidase 4 (GPX4)), NF-κB, P-NF-κB, P53, and P-P53).

RESULTS

Erastin stimulation promoted HUVEC lipid peroxidation, decreased antioxidant enzyme expression, increased P-NF-κB, P53, and P-P53 expressions, and damaged HUVEC mitochondrial structure. Ang1-7 alleviated the effect of erastin on HUVEC, which was destroyed by Betulinic acid.

CONCLUSION

Angiotensin1-7 pretreatment inhibited vascular endothelial cells' ferroptosis and alleviated ECMO vessel injury through NF-κB /P53 signal pathway.

Survival difference in patients treated with extracorporeal membrane oxygenation in COVID-19 vs. non-COVID ARDS: a systematic review and meta-analysis

INTRODUCTION

The COVID-19 pandemic has emphasized the need for effective management of severe acute respiratory distress syndrome (ARDS) using veno-venous extracorporeal membrane oxygenation (VV-ECMO). This meta-analysis aims to compare the effectiveness and outcomes of ECMO in patients with COVID-19 ARDS versus those with non-COVID ARDS, assessing its role in different respiratory virus infections.

EVIDENCE ACQUISITION

A systematic search was conducted in PubMed, Web of Science, and other relevant databases up to June 30, 2023, to identify studies comparing ECMO use in COVID-19 and non-COVID ARDS cases. This analysis adheres to PRISMA guidelines, with studies rigorously selected based on predefined inclusion and exclusion criteria and assessed for bias using validated tools.

EVIDENCE SYNTHESIS

The meta-analysis included 24 studies with 2,121 patients, revealing that non-COVID ARDS patients treated with ECMO had a lower mortality risk compared to those with COVID-19 ARDS. Specifically, the overall pooled risk difference in survival was -0.11 (95% CI: -0.17 to -0.05, P<0.001), indicating a statistically significant advantage for non-COVID patients. The standardized mean difference for ECMO duration was significantly longer in COVID-19 patients (SMD=0.70, 95% CI: 0.32 to 1.08, P<0.001), reflecting more prolonged treatment needs.

CONCLUSIONS

ECMO serves as a vital intervention in severe ARDS, with differential effectiveness observed between COVID-19 and non-COVID patients. The study's findings underline the need for precise patient selection and tailored ECMO application across different viral etiologies. These insights are crucial for enhancing clinical strategies and resource allocation during ongoing and future pandemics.

Autoptic Findings in Patients Treated with (VA-ECMO) after Cardiac Arrest

Background: This study examines the results of autopsy examinations specifically aimed at documenting complications arising from the implantation phase and treatment with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in patients with refractory cardiac arrest. ECMO and VA-ECMO in particular are life-saving interventions that, in the case of cardiac arrest, can temporarily replace cardiac pump function. VA-ECMO is, however, a very invasive procedure and is associated with early mechanical, haemorrhagic, and thrombotic events, infections, and late multi-organ dysfunction. Aim: This research aims to evaluate autoptic and histologic findings in patients on VA-ECMO support, providing clinical and forensic evaluation elements with respect to the procedure and clinical settings. Materials and Methods: The study analysed 10 cases, considering variables such as the duration of cardiac arrest, understood as the time between the cardiac arrest event and reperfusion with VA-ECMO, the duration of VA-ECMO support, and any complications detected by clinicians during treatment. Results: The results highlighted the presence of numerous ischemic and haemorrhagic events affecting various organs. Among them, the intestines were particularly vulnerable, even after a short ECMO duration. Conclusions: ECMO was found to accelerate post-mortem decomposition, affecting post-mortem interval estimations, and cardiac damage from reperfusion, underlining the need to meticulously select indications for treatment with VA-ECMO and perform constant clinical evaluations during the treatment itself.

Thrombocytopenia risks in ARDS COVID-19 patients treated with high-dose linezolid during vvECMO therapy: an observational study

Patients treated with ECMO are at great risk of nosocomial infections, and around 10% of isolates are gram-positive pathogens. Linezolid (LZD) is effective in the treatment of these infections but appropriate dosing is challenging. The aim was to evaluate the occurrence of thrombocytopenia during ECMO when treated with LZD. An LZD trough concentration of 8 mg/L was set as the cutoff value for thrombocytopenia occurrence among critically ill patients who received parenteral LZD therapy at a dose of 600 mg every 8 h during ECMO. Eleven patients were included in this prospective observational study. Median LZD trough concentrations were 7.85 (interquartile range (IQR), 1.95-11) mg/L. Thrombocytopenia was found in 81.8% of patients. Based on the median LZD trough concentrations cutoff value, patients were divided into two groups, 1.95 (IQR, 0.91-3.6) and 10.3 (IQR, 9.7-11.7) mg/L, respectively. Median platelet values differed significantly between groups on admission, ECMO day 0, ECMO day 1, and LZD sampling day [194 and 152.5, (p < 0.05)], [113 and 214, (p < 0.05)], [76 and 147.5, (p < 0.01)], and [26 and 96.5, (p < 0.01)], respectively. Duration of LZD therapy was similar between the groups. Significant platelet reduction was observed in both groups, emphasizing the need for closer monitoring to prevent LZD-associated thrombocytopenia.

A systematic review of variability in the reporting of extracorporeal membrane oxygenation-associated infections and recommendations for standardization

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) utilization has surged in recent years, particularly amidst the COVID-19 pandemic, yet standardization of ECMO-associated infection (EAI) reporting remains lacking.

METHODS

This systematic review assessed 60 studies from 2018 to 2023 in PubMed, which used key words related to EAIs. Adherence to reporting data elements that may bias reporting, including the use of standardized rates of infections per 1,000 patient days, describing the use of antimicrobial prophylaxis, infection control, and culture practices, describing the definitions for infection by site, and listing pathogens by infection site were evaluated by study.

RESULTS

Our review revealed considerable heterogeneity in data elements and infection definitions. While 51 (85%) studies reported definition by site, only 17 (28%) reported infection control practices, and only 5 (8%) studies adhered to all the identified essential reporting elements. Variation in infection rates was also evident across the definitions, with studies using their own definition having the greatest variability in reported infection rates. Microbiological differences by geographic region further underscored the need for standardized reporting and challenges with generalizability in the EAI literature.

CONCLUSIONS

Our findings underscore the imperative for consensus on ECMO infection definitions and transparent reporting practices to facilitate meaningful comparisons and advance patient care protocols.

Pushing the Survival Bar Higher: Two Decades of Innovation in Lung Transplantation

Survival after lung transplantation has significantly improved during the last two decades. The refinement of the already existing extracorporeal life support (ECLS) systems, such as extracorporeal membrane oxygenation (ECMO), and the introduction of new techniques for donor lung optimization, such as ex vivo lung perfusion (EVLP), have allowed the extension of transplant indication to patients with end-stage lung failure after acute respiratory distress syndrome (ARDS) and the expansion of the donor organ pool, due to the better evaluation and optimization of extended-criteria donor (ECD) lungs and of donors after circulatory death (DCD). The close monitoring of anti-HLA donor-specific antibodies (DSAs) has allowed the early recognition of pulmonary antibody-mediated rejection (AMR), which requires a completely different treatment and has a worse prognosis than acute cellular rejection (ACR). As such, the standardization of patient selection and post-transplant management has significantly contributed to this positive trend, especially at high-volume centers. This review focuses on lung transplantation after ARDS, on the role of EVLP in lung donor expansion, on ECMO as a principal cardiopulmonary support system in lung transplantation, and on the diagnosis and therapy of pulmonary AMR.

Use of Extracorporeal Membrane Oxygenation for Patients with Coronavirus Disease 2019 Infection

The coronavirus disease 2019 (COVID-19) pandemic was a cataclysmic event that infected over 772 million and killed over 6.9 million people worldwide. The pandemic pushed hospitals and society to their limits and resulted in incredibly severe respiratory disease in millions of people. This severe respiratory disease often necessitated maximum medical therapy, including the use of extracorporeal membrane oxygenation. While our understanding of COVID-19 and its treatment continue to evolve, we review the current evidence to guide the care of patients with severe COVID-19 infection.

FOT Technique Applied for Monitoring of COVID-19 Pneumonia Reveals Small Airways Involvement

The fact that some SARS-CoV-2 pneumonia patients benefit from changing body position, and some from continuous positive airways pressure (CPAP), indicates the functional character of hypoxia. We hypothesize that such effects could be explained by the closure of small airways. To prove the hypothesis, we evaluated the patency of small airways in 30 oxygen-dependent, spontaneously breathing patients with SARS-CoV-2 pneumonia during their hospital stay using the FOT method and then compared the results with data obtained three months later. During the acute period, total resistance (R5) and peripheral resistance (R5-20) rose above the upper limit of normal (ULN) in 28% and 50% of all patients, respectively. Reactance indices X5, AX and Fres exceeded ULN in 55%, 68% and 66% of cases. Significant correlations were observed between PaO2/FiO2, the time spent in the hospital and R5, X5, AX and Fres. After 3 months, 18 patients were re-examined. During the hospital stay, 11 of them had risen above the upper limit of normal (ULN), for both resistance (R5-20) and reactance (X5, AX) values. Three months later, ULN for R5-20 was exceeded in only four individuals, but ULN for X5 and AX was exceeded in five individuals. Lung function examination revealed a combined restrictive/obstructive ventilatory failure and reduced CO transfer factor. We interpret these changes as lung tissue remodeling due to the process of fibrosis. We conclude that during acute period of SARS-CoV-2 pneumonia, dilated pulmonary blood vessels and parenchymal oedema induce functional closure of small airways, which in turn induce atelectasis with pulmonary right-to-left shunting, followed by the resulting hypoxemia.

Anti-SARS-CoV-2 Viral Activity of Sweet Potato Trypsin Inhibitor via Downregulation of TMPRSS2 Activity and ACE2 Expression In Vitro and In Vivo

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. Known as COVID-19, it has affected billions of people worldwide, claiming millions of lives and posing a continuing threat to humanity. This is considered one of the most extensive pandemics ever recorded in human history, causing significant losses to both life and economies globally. However, the available evidence is currently insufficient to establish the effectiveness and safety of antiviral drugs or vaccines. The entry of the virus into host cells involves binding to angiotensin-converting enzyme 2 (ACE2), a cell surface receptor, via its spike protein. Meanwhile, transmembrane protease serine 2 (TMPRSS2), a host surface protease, cleaves and activates the virus's S protein, thus promoting viral infection. Plant protease inhibitors play a crucial role in protecting plants against insects and/or microorganisms. The major storage proteins in sweet potato roots include sweet potato trypsin inhibitor (SWTI), which accounts for approximately 60% of the total water-soluble protein and has been found to possess a variety of health-promoting properties, including antioxidant, anti-inflammatory, ACE-inhibitory, and anticancer functions. Our study found that SWTI caused a significant reduction in the expression of the ACE2 and TMPRSS2 proteins, without any adverse effects on cells. Therefore, our findings suggest that the ACE2 and TMPRSS2 axis can be targeted via SWTI to potentially inhibit SARS-CoV-2 infection.

Extracorporeal membrane oxygenation for COVID-19-associated severe acute respiratory distress syndrome in Canada: Analysis of data from the Canadian Nosocomial Infection Surveillance Program

Background

Extracorporeal membrane oxygenation (ECMO) for COVID-19 across Canada has not been well-described. We studied trends for patients with COVID-19-related acute respiratory distress syndrome who received ECMO.

Methods

Multicentre retrospective cohort study using data from the Canadian Nosocomial Infection Surveillance Program across four different waves. Surveillance data was collected between March 2020 and June 2022. We reported data stratified by ECMO status and wave.

Results

ECMO recipients comprised 299 (6.8%) of the 4,408 critically ill patients included. ECMO recipients were younger (median age 49 versus 62 years, p < 0.001), less likely to be vaccinated against COVID-19 (Wave 4 data: 5.3% versus 19%; p = 0.002), and had fewer comorbidities compared to patients who did not receive ECMO. Thirty-day all-cause mortality was similar between the ECMO and non-ECMO groups (23% versus 26%; p = 0.25). Among ECMO recipients, mortality tended to decrease across Waves 1 to 4: 48%, 31%, 18%, and 16%, respectively (p = 0.04 for trend). However, this was no longer statistically significant when removing the high mortality during Wave 1 (p = 0.15).

Conclusions

Our findings suggest that critically ill patients in Canadian hospitals who received ECMO had different characteristics from those who did not receive ECMO. We also observed a trend of decreased mortality over the waves for the ECMO group. Possible explanatory factors may include potential delay in ECMO initiation during Wave 1, evolution of the virus, better understanding of COVID-19 disease and ECMO use, and new medical treatments and vaccines available in later waves. These findings may provide insight for future potential pandemics.

Neutrophil-to-Lymphocyte Ratio as a Predictor of Mortality for COVID-19-Related Acute Respiratory Distress Syndrome (ARDS) Patients Requiring Extracorporeal Membrane Oxygenation Therapy

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) has been studied as an indicator of systemic inflammation and as a prognostic tool in multiple areas of medicine. Previous research has suggested that higher NLR and rapid increase to peak NLR are associated with poorer outcomes in patients with coronavirus disease 2019 (COVID-19), particularly in those experiencing acute respiratory distress syndrome (ARDS). Within vascular surgery, there is data to suggest a positive correlation between elevated pre-extracorporeal membrane oxygenation (ECMO) NLR and higher rates of mortality following major procedures. This study explores the prognostic value of peri-ECMO NLR in patients requiring veno-venous ECMO (VV-ECMO) therapy for COVID-19-related ARDS. The objective of this study was to explore the utility of pre-ECMO NLR as an easily accessible prognostic factor for patients suffering from COVID-19-associated ARDS that require VV-ECMO.

METHODS

This was a retrospective cohort study within a tertiary care hospital conducted between April 2020 and January 2021. Patients requiring VV-ECMO therapy for COVID-19-associated ARDS were included. Peri-ECMO NLR values, length of stay (LOS), duration on VV-ECMO, and discharge status were recorded. Receiver operating characteristic (ROC) curve analysis and Youden's J statistics were performed to calculate a cut-off value of 11.005 for pre-ECMO NLR and 17.616 for on-ECMO NLR. Pre-ECMO and on-ECMO Kaplan-Meyer curves were generated for two groups of patients, those above and below NLR cutoff thresholds. Two-sample T-test was performed to test for significant differences in LOS and duration on VV-ECMO.

RESULTS

Twenty-six patients were included in the study for final analyses. There was an overall mortality of 39% (n = 10). ROC curve analysis and Youden's J statistic revealed an optimal cut-off value of pre-ECMO NLR = 11.005 and on-ECMO NLR = 17.616. Results showed that the patient group placed on VV-ECMO with a pre-ECMO NLR less than 11.005 experienced no mortality (n = 7) and a median LOS of 28 days (IQR = 14.5-64.5 days). The patient group on VV-ECMO with a pre-ECMO NLR greater than 11.005 (n = 19) included all mortality (n = 10) and had a median LOS of 49 days (IQR = 25.5-63.5 days). The patient group with on-ECMO NLR less than 17.616 also conferred a survival advantage. There was no significant difference in LOS or duration on VV-ECMO between the two groups, pre-ECMO or on-ECMO.

CONCLUSIONS

 A pre-ECMO NLR cutoff was identified and offered statistically significant prognostic value in predicting mortality. A lower on-ECMO NLR value also indicated a survival advantage. Future studies should include NLR within multivariate models to better discern the effect of NLR and elucidate how it can be factored into clinical decision-making. Importantly, this data can be expanded to assess the predictive value of NLR pertaining to the COVID-19-induced ARDS population and matched cohorts.

Isavuconazole Exposure in Critically Ill Patients Treated with Extracorporeal Membrane Oxygenation: Two Case Reports and a Narrative Literature Review

Effective dosing of isavuconazole in patients supported by extracorporeal membrane oxygenation (ECMO) is important due to the role of isavuconazole as a first-line treatment in patients with influenza- and COVID-19-associated pulmonary aspergillosis. To date, robust pharmacokinetic data in patients supported by ECMO are limited. Therefore, it is unknown whether ECMO independently impacts isavuconazole exposure. We measured isavuconazole plasma concentrations in two patients supported by ECMO and estimated individual pharmacokinetic parameters using non-compartmental analysis and two previously published population pharmacokinetic models. Furthermore, a narrative literature review on isavuconazole exposure in adult patients receiving ECMO was performed. The 24 h areas under the concentration-time curve and trough concentrations of isavuconazole were lower in both patients compared with exposure values published before. In the literature, highly variable isavuconazole concentrations have been documented in patients with ECMO support. The independent effect of ECMO versus critical illness itself on isavuconazole exposure cannot be deduced from our and previously published (case) reports. Pending additional data, therapeutic drug monitoring is recommended in critically ill patients, regardless of ECMO support.

Expert consensus statement on venovenous extracorporeal membrane oxygenation ECMO for COVID-19 severe ARDS: an international Delphi study

BACKGROUND

The high-quality evidence on managing COVID-19 patients requiring extracorporeal membrane oxygenation (ECMO) support is insufficient. Furthermore, there is little consensus on allocating ECMO resources when scarce. The paucity of evidence and the need for guidance on controversial topics required an international expert consensus statement to understand the role of ECMO in COVID-19 better. Twenty-two international ECMO experts worldwide work together to interpret the most recent findings of the evolving published research, statement formulation, and voting to achieve consensus.

OBJECTIVES

To guide the next generation of ECMO practitioners during future pandemics on tackling controversial topics pertaining to using ECMO for patients with COVID-19-related severe ARDS.

METHODS

The scientific committee was assembled of five chairpersons with more than 5 years of ECMO experience and a critical care background. Their roles were modifying and restructuring the panel's questions and, assisting with statement formulation in addition to expert composition and literature review. Experts are identified based on their clinical experience with ECMO (minimum of 5 years) and previous academic activity on a global scale, with a focus on diversity in gender, geography, area of expertise, and level of seniority. We used the modified Delphi technique rounds and the nominal group technique (NGT) through three face-to-face meetings and the voting on the statement was conducted anonymously. The entire process was planned to be carried out in five phases: identifying the gap of knowledge, validation, statement formulation, voting, and drafting, respectively.

RESULTS

In phase I, the scientific committee obtained 52 questions on controversial topics in ECMO for COVID-19, further reviewed for duplication and redundancy in phase II, resulting in nine domains with 32 questions with a validation rate exceeding 75% (Fig. 1). In phase III, 25 questions were used to formulate 14 statements, and six questions achieved no consensus on the statements. In phase IV, two voting rounds resulted in 14 statements that reached a consensus are included in four domains which are: patient selection, ECMO clinical management, operational and logistics management, and ethics.

CONCLUSION

Three years after the onset of COVID-19, our understanding of the role of ECMO has evolved. However, it is incomplete. Tota14 statements achieved consensus; included in four domains discussing patient selection, clinical ECMO management, operational and logistic ECMO management and ethics to guide next-generation ECMO providers during future pandemic situations.