COVID-19-associated pulmonary aspergillosis in mechanically ventilated patients: a prospective, multicentre UK study.

BACKGROUND: Invasive pulmonary aspergillosis is a complication of severe COVID-19, with regional variation in reported incidence and mortality. We describe the incidence, risk factors and mortality associated with COVID-19-associated pulmonary aspergillosis (CAPA) in a prospective, multicentre UK cohort. METHODS: From March 2020 to March 2021, 266 mechanically ventilated adults with COVID-19 were enrolled across 5 UK hospital intensive care units (ICUs). CAPA was defined using European Confederation for Medical Mycology and the International Society for Human and Animal Mycology criteria and fungal diagnostics performed on respiratory and serum samples. RESULTS: Twenty-nine of 266 patients (10.9%) had probable CAPA, 14 (5.2%) possible CAPA and none proven CAPA. Probable CAPA was diagnosed a median of 9 (IQR 7-16) days after ICU admission. Factors associated with probable CAPA after multivariable logistic regression were cumulative steroid dose given within 28 days prior to ICU admission (adjusted OR (aOR) 1.16; 95% CI 1.01 to 1.43 per 100 mg prednisolone-equivalent), receipt of an interleukin (IL)-6 inhibitor (aOR 2.79; 95% CI 1.22 to 6.48) and chronic obstructive pulmonary disease (COPD) (aOR 4.78; 95% CI 1.13 to 18.13). Mortality in patients with probable CAPA was 55%, vs 46% in those without. After adjustment for immortal time bias, CAPA was associated with an increased risk of 90-day mortality (HR 1.85; 95% CI 1.07 to 3.19); however, this association did not remain statistically significant after further adjustment for confounders (adjusted HR 1.57; 95% CI 0.88 to 2.80). There was no difference in mortality between patients with CAPA prescribed antifungals (9 of 17; 53%) and those who were not (7 of 12; 58%) (p=0.77). INTERPRETATION: In this first prospective UK study, probable CAPA was associated with corticosteroid use, receipt of IL-6 inhibitors and pre-existing COPD. CAPA did not impact mortality following adjustment for prognostic variables.

Con: Artificial Intelligence-Derived Algorithms to Guide Perioperative Blood Management Decision Making.

Artificial intelligence has the potential to improve the care that is given to patients; however, the predictive models created are only as good as the base data used in their design. Perioperative blood management presents a complex clinical conundrum in which significant variability and the unstructured nature of the required data make it difficult to develop precise prediction models. There is a potential need for training clinicians to ensure they can interrogate the system and override when errors occur. Current systems created to predict perioperative blood transfusion are not generalizable across clinical settings, and there is a considerable cost implication required to research and develop artificial intelligence systems that would disadvantage resource-poor health systems. In addition, a lack of strong regulation currently means it is difficult to prevent bias.

Mechanisms of Acute Right Ventricular Injury in Cardiothoracic Surgical and Critical Care Settings: Part 2.

The right ventricle (RV) is intricately linked in the clinical presentation of critical illness; however, the basis of this is not well-understood and has not been studied as extensively as the left ventricle. There has been an increased awareness of the need to understand how the RV is affected in different critical illness states. In addition, the increased use of point-of-care echocardiography in the critical care setting has allowed for earlier identification and monitoring of the RV in a patient who is critically ill. The first part of this review describes and characterizes the RV in different perioperative states. This second part of the review discusses and analyzes the complex pathophysiologic relationships between the RV and different critical care states. There is a lack of a universal RV injury definition because it represents a range of abnormal RV biomechanics and phenotypes. The term "RV injury" (RVI) has been used to describe a spectrum of presentations, which includes diastolic dysfunction (early injury), when the RV retains the ability to compensate, to RV failure (late or advanced injury). Understanding the mechanisms leading to functional 'uncoupling' between the RV and the pulmonary circulation may enable perioperative physicians, intensivists, and researchers to identify clinical phenotypes of RVI. This, consequently, may provide the opportunity to test RV-centric hypotheses and potentially individualize therapies.

Impact of major bleeding and thrombosis on 180-day survival in patients with severe COVID-19 supported with veno-venous extracorporeal membrane oxygenation in the United Kingdom: a multicentre observational study.

Bleeding and thrombosis are major complications in patients supported with extracorporeal membrane oxygenation (ECMO). In this multicentre observational study of 152 consecutive patients (≥18 years) with severe COVID-19 supported by veno-venous (VV) ECMO in four UK commissioned centres during the first wave of the COVID-19 pandemic (1 March to 31 May 2020), we assessed the incidence of major bleeding and thrombosis and their association with 180-day mortality. Median age (range) was 47 years (23-65) and 75% were male. Overall, the 180-day survival was 70·4% (107/152). The rate of major bleeding was 30·9% (47/152), of which intracranial bleeding (ICH) was 34% (16/47). There were 96 thrombotic events (63·1%) consisting of venous 44·7% [68/152 of which 66·2% were pulmonary embolism (PE)], arterial 18·6% (13/152) and ECMO circuit thrombosis 9·9% (15/152). In multivariate analysis, only raised lactate dehydrogenase (LDH) at the initiation of VV ECMO was associated with an increased risk of thrombosis [hazard ratio (HR) 1·92, 95% CI 1·21-3·03]. Major bleeding and ICH were associated with 3·87-fold (95% CI 2·10-7·23) and 5·97-fold [95% confidence interval (CI) 2·36-15·04] increased risk of mortality and PE with a 2·00-fold (95% CI1·09-3·56) risk of mortality. This highlights the difficult balancing act often encountered when managing coagulopathy in COVID-19 patients supported with ECMO.

Thrombosis and coagulopathy in COVID-19 patients rceiving ECMO: A narrative review of current literature.

Extracorporeal membrane oxygenation (ECMO) is an established part of the treatment algorithm for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome. An intense inflammatory response may cause an imbalance in the coagulation cascade making both thrombosis and bleeding common and notable features of the clinical management of these patients. Large observational and retrospective studies provide a better understanding of the pathophysiology and management of bleeding and thrombosis in COVID-19 patients requiring ECMO. Clinically significant bleeding, including intracerebral hemorrhage, is an independent predictor of mortality, and thrombosis (particularly pulmonary embolism) is associated with mortality, especially if occurring with right ventricular dysfunction. The incidence of heparin-induced thrombocytopenia is higher than the general patient cohort with acute respiratory distress syndrome or other indications for ECMO. The use of laboratory parameters to predict bleeding or thrombosis has a limited role. In this review, the authors discuss the complex pathophysiology of bleeding and thrombosis observed in patients with COVID-19 during ECMO support, and their effects on outcomes.

Gender and the Outcome of Postcardiotomy Veno-arterial Extracorporeal Membrane Oxygenation.

OBJECTIVE: There is a paucity of sex-specific data on patients' postcardiotomy venoarterial extracorporeal membrane oxygenation (VA-ECMO). The present study sought to assess this issue in a multicenter study. DESIGN: Retrospective, propensity score-matched analysis of an international registry. SETTING: Multicenter study, tertiary university hospitals. PARTICIPANTS: Data on adult patients undergoing postcardiotomy VA-ECMO. MEASUREMENTS AND MAIN RESULTS: Between January 2010 and March 2018, patients treated with postcardiotomy VA-ECMO at 17 cardiac surgery centers were analyzed. Index procedures considered were coronary artery bypass graft surgery, isolated valve surgery, their combination, and proximal aortic root surgery. Hospital and five-year mortality constituted the endpoints of interest. Propensity score matching was adopted with logistic regression. A total of 358 patients (mean age: 63.3 ± 12.3 years; 29.6% female) were identified. Among 94 propensity score-matched pairs, women had a higher hospital mortality (70.5% v 56.4%, p = 0.049) compared with men. Logistic regression analysis showed that women (odds ratio [OR], 1.87; 95% confidence interval [CI] 1.10-3.16), age (OR, 1.06; 95%CI 1.04-1.08) and pre-ECMO arterial lactate (OR, 1.09; 95%CI 1.04-1.16) were independent predictors of hospital mortality. No differences between female and male patients were observed for other outcomes. Among propensity score-matched pairs, one-, three-, and five-year mortality were 60.6%, 65.0%, and 65.0% among men, and 71.3%, 71.3%, and 74.0% among women, respectively (p = 0.110, adjusted hazard ratio, 1.27; 95%CI 0.96-1.66). CONCLUSIONS: In postcardiotomy VA-ECMO, female patients demonstrated higher hospital mortality than men. Morbidity and late mortality were similar between the two groups.

Blood Transfusion Threshold in Patients Receiving Extracorporeal Membrane Oxygenation Support for Cardiac and Respiratory Failure-A Systematic Review and Meta-Analysis.

OBJECTIVE: To review studies that have evaluated the effects of liberal or restrictive red cell transfusion thresholds on clinical outcomes in patients requiring extracorporeal membrane oxygenation (ECMO) support for cardiac or respiratory failure. DESIGN: A systematic review and meta-analysis. SETTING AND PARTICIPANTS: The study comprised 1,070 patients from observational studies and randomized controlled trials analyzing transfusion policies in venoarterial (VA) and venovenous (VV) ECMO adult populations. MEASUREMENTS AND MAIN RESULTS: Eligible studies were identified by searching the Cochrane Central Register of Controlled Trials, Medline, and EMBASE until March 4, 2020, using a combination of subject headings and text words. Risk of bias assessment was performed to assess study quality according to the ROBINS-I tool and the case series studies appraisal checklist. There was high risk of bias in the studies analyzed, and none had methodologic adequacy. Three studies analyzed VA ECMO and VV ECMO patients separately. Five datasets were related exclusively or mostly to VA ECMO. Four were retrospective analyses, and one was conducted as a prospective observational study; the median transfusion threshold reported was 8 g/dL, with a mean mortality of 52%. Eight datasets were related either exclusively or mostly to VV ECMO. Six were retrospective and two were prospective observational studies; the median transfusion threshold was 8 g/dL, and the mean mortality rate was 33%. CONCLUSIONS: The present study did not resolve uncertainty as to transfusion management in ECMO, although several studies (most of them in VV ECMO) demonstrated that a restrictive threshold has acceptable outcomes in single-center cohorts.

Six-Month Survival After Extracorporeal Membrane Oxygenation for Severe COVID-19.

OBJECTIVES: The authors evaluated the outcome of adult patients with coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS) requiring the use of extracorporeal membrane oxygenation (ECMO). DESIGN: Multicenter retrospective, observational study. SETTING: Ten tertiary referral university and community hospitals. PARTICIPANTS: Patients with confirmed severe COVID-19-related ARDS. INTERVENTIONS: Venovenous or venoarterial ECMO. MEASUREMENTS AND MAIN RESULTS: One hundred thirty-two patients (mean age 51.1 ± 9.7 years, female 17.4%) were treated with ECMO for confirmed severe COVID-19-related ARDS. Before ECMO, the mean Sequential Organ Failure Assessment score was 10.1 ± 4.4, mean pH was 7.23 ± 0.09, and mean PaO2/fraction of inspired oxygen ratio was 77 ± 50 mmHg. Venovenous ECMO was adopted in 122 patients (92.4%) and venoarterial ECMO in ten patients (7.6%) (mean duration, 14.6 ± 11.0 days). Sixty-three (47.7%) patients died on ECMO and 70 (53.0%) during the index hospitalization. Six-month all-cause mortality was 53.0%. Advanced age (per year, hazard ratio [HR] 1.026, 95% CI 1.000-1-052) and low arterial pH (per unit, HR 0.006, 95% CI 0.000-0.083) before ECMO were the only baseline variables associated with increased risk of six-month mortality. CONCLUSIONS: The present findings suggested that about half of adult patients with severe COVID-19-related ARDS can be managed successfully with ECMO with sustained results at six months. Decreased arterial pH before ECMO was associated significantly with early mortality. Therefore, the authors hypothesized that initiation of ECMO therapy before severe metabolic derangements subset may improve survival rates significantly in these patients. These results should be viewed in the light of a strict patient selection policy and may not be replicated in patients with advanced age or multiple comorbidities. CLINICAL TRIAL REGISTRATION: identifier, NCT04383678.

Outcome of Repeat Venoarterial Extracorporeal Membrane Oxygenation in Postcardiotomy Cardiogenic Shock.

OBJECTIVE: Data on patients requiring a second run of venoarterial extracorporeal membrane oxygenation (VA-ECMO) support in patients affected by postcardiotomy cardiogenic shock (PCS) are very limited. The authors aimed to investigate the effect of a second run of VA-ECMO on PCS patient survival. DESIGN: Retrospective analysis of an international registry. SETTING: Multicenter study, tertiary university hospitals. PARTICIPANTS: Data on adult PCS patients receiving a second run of VA-ECMO. MEASUREMENTS AND MAIN RESULTS: A total of 674 patients with a mean age of 62.9 ± 12.7 years were analyzed, and 21 (3.1%) patients had a second run of VA-ECMO. None of them required more than two VA-ECMO runs. The median duration of VA-ECMO therapy was 135 hours (interquartile range [IQR] 61-226) in patients who did not require a VA-ECMO rerun. In the rerun VA-ECMO group the median overall duration of VA-ECMO therapy was 183 hours (IQR 107-344), and the median duration of the first run was 114 hours (IQR 66-169). Nine (42.9%) of the patients who required a second run of VA-ECMO died during VA-ECMO therapy, whereas five (23.8%) survived to hospital discharge. No differences between patients treated with single or second VA-ECMO runs were observed in terms of hospital mortality and late survival. In patients requiring a second VA-ECMO run, the actuarial survival estimates at three and 12 months after VA-ECMO weaning were 23.8% ± 9.3% and 19.6% ± 6.4%, respectively. CONCLUSIONS: Repeat VA-ECMO therapy is a valid treatment strategy for PCS patients. Early and late survivals are similar between patients who have undergone a single or second run of VA-ECMO.

Duration of Venoarterial Extracorporeal Membrane Oxygenation and Mortality in Postcardiotomy Cardiogenic Shock.

OBJECTIVE: The optimal duration of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in patients affected by postcardiotomy cardiogenic shock (PCS) remains controversial. The present study was conducted to investigate the effect of VA-ECMO duration on hospital outcomes. DESIGN: Retrospective analysis of an international registry. SETTING: Multicenter study including 19 tertiary university hospitals. PARTICIPANTS: Between January 2010 and March 2018, data on PCS patients receiving VA-ECMO were retrieved from the multicenter PC-ECMO registry. INTERVENTIONS: Patients were stratified according to the following different durations of VA-ECMO therapy: ≤three days, four-to-seven days, eight-to-ten days, and >ten days. MEASUREMENTS AND MAIN RESULTS: A total of 725 patients, with a mean age of 62.9 ± 12.9 years, were included. The mean duration of VA-ECMO was 7.1 ± 6.3 days (range 0-39 d), and 39.4% of patients were supported for ≤three days, 29.1% for four-seven days, 15.3% for eight-ten days, and finally 20.7% for >ten days. A total of 391 (53.9%) patients were weaned from VA-ECMO successfully; however, 134 (34.3%) of those patients died before discharge. Multivariate logistic regression showed that prolonged duration of VA-ECMO therapy (four-seven days: adjusted rate 53.6%, odds ratio [OR] 0.28, 95% confidence interval [CI] 0.18-0.44; eight-ten days: adjusted rate 61.3%, OR 0.51, 95% CI 0.29-0.87; and >ten days: adjusted rate 59.3%, OR 0.49, 95% CI 0.31-0.81) was associated with lower risk of mortality compared with VA-ECMO lasting ≤three days (adjusted rate 78.3%). Patients requiring VA-ECMO therapy for eight-ten days (OR 1.96, 95% CI 1.15-3.33) and >10 days (OR 1.85, 95% CI 1.14-3.02) had significantly greater mortality compared with those on VA-ECMO for 4 to 7 days. CONCLUSIONS: PCS patients weaned from VA-ECMO after four-seven days of support had significantly less mortality compared with those with shorter or longer mechanical support.

The Right Ventricle During Selective Lung Ventilation for Thoracic Surgery.

The right ventricle (RV) has been an area of evolving interest after decades of being ignored and considered less important than the left ventricle. Right ventricular dysfunction/failure is an independent predictor of mortality and morbidity in cardiac surgery; however, very little is known about the incidence or impact of RV dysfunction/failure in thoracic surgery. The pathophysiology of RV dysfunction/failure has been studied in the context of acute respiratory distress syndrome (ARDS), cardiac surgery, pulmonary hypertension, and left ventricular failure, but limited data exist in literature addressing the issue of RV dysfunction/failure in the context of thoracic surgery and one-lung ventilation (OLV). Thoracic surgery and OLV present as a unique situation where the RV is faced with sudden changes in afterload, preload, and contractility throughout the perioperative period. The authors discuss the possible pathophysiologic mechanisms that can affect adversely the RV during OLV and introduce the term RV injury to the myocardium that is affected adversely by the various intraoperative factors, which then makes it predisposed to acute dysfunction. The most important of these mechanisms seems to be the role of intraoperative mechanical ventilation, which potentially could cause both ventilator-induced lung injury leading to ARDS and RV injury. Identification of at-risk patients in the perioperative period using focused imaging, particularly echocardiography, is paramount. The authors also discuss the various RV-protective strategies required to prevent RV dysfunction and management of established RV failure.

Fungal infections in adult patients on extracorporeal life support.

BACKGROUND: Patients on extracorporeal membrane oxygenation (ECMO) are often among the most severely ill in the intensive care unit. They are often receiving broad-spectrum antibiotics; they have multiple entry points for pathogens; and their immune system is impaired by blood circuit interaction. These factors are thought to predispose them to fungal infections. We thus aimed to evaluate the prevalence, risk factors, and prognosis of fungal infections in adults on ECMO. METHODS: We conducted a retrospective cohort study using the Extracorporeal Life Support Organization registry, which compiles data on ECMO use from hundreds of international centers. We included all adult patients from 2006 to 2016 on any mode of ECMO with either a diagnosis of fungal infection or a positive fungal culture. RESULTS: Our study comprised 2129 adult patients (10.8%) with fungal colonization or infection. Aspergillus involvement (colonization or infection) was present in 272 patients (1.4%), of whom 35.7% survived to hospital discharge. There were 245 patients (1.2%) with Candida invasive bloodstream infection, with 35.9% survival. Risk factors for Aspergillus involvement included solid organ transplant (OR 1.83; p = 0.008), respiratory support (OR 2.75; p < 0.001), and influenza infection (OR 2.48; p < 0.001). Risk factors for candidemia included sepsis (OR 1.60; p = 0.005) and renal replacement therapy (OR 1.55; p = 0.007). In multivariable analysis, Aspergillus involvement (OR 0.40; p < 0.001) and candidemia (OR 0.47; p < 0.001) were both independently associated with decreased survival. CONCLUSIONS: The prevalence of Aspergillus involvement and Candida invasive bloodstream infection were not higher in patients on ECMO than what has been reported in the general intensive care population. Both were independently associated with a reduced survival. Aspergillus involvement was strongly associated with ECMO for respiratory support and influenza.

Use of a tracheal dilator for percutaneous insertion of 27F and 31F Avalon© dual-lumen cannulae for veno-venous extracorporeal membrane oxygenation in adults.

Veno-venous extracorporeal membrane oxygenation can be performed either by two cannulae or by a single dual-lumen cannula. The dual-lumen cannulation configuration offers multiple advantages: it avoids the femoral site which may be at greater risk of infection, it improves patient mobility, eases prone positioning and greatly reduces recirculation. The Avalon was the first commercially available dual-lumen cannula for adults. It has gained much popularity, but, for more than a year now, the adult vascular access kit with the 30Fr dilator has been discontinued in the United Kingdom. In this article, we share our experience with an alternative insertion method, using a percutaneous dilatational tracheostomy kit. This off-label use of the tracheostomy dilator appears to be safe. It may allow the continuing use of Avalon dual-lumen cannulae while waiting for a more permanent solution to be provided by the manufacturer.

Right Ventricular Injury Increases Mortality in Patients With Acute Respiratory Distress Syndrome on Veno-Venous Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis.

Right ventricular injury (RVI) in the context of acute respiratory distress syndrome (ARDS) is well recognized as an important determinant risk factor of mortality. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is part of the algorithm for the management of patients with severe ARDS and severely impaired gas exchange. Although VV-ECMO may theoretically protect the RV it is uncertain to what degree RVI persists despite VV-ECMO support, and whether it continues to influence mortality after ECMO initiation. The aim of this systematic review and meta-analysis was to investigate the impact of RVI on mortality in this context, testing the hypothesis that RVI worsens mortality in this cohort. We performed a systematic search that identified seven studies commenting on RVI and mortality in patients with ARDS receiving VV-ECMO. The presence of RVI was associated with greater mortality overall (odds ratios [OR]: 2.72; 95% confidence intervals [CI]: 1.52-4.85; p < 0.00) and across three subgroups (RV dilatational measures: OR: 3.51; 95% CI: 1.51-8.14; p < 0.01, RV functional measures: OR: 1.84; 95% CI: 0.99-3.42; p = 0.05, RV measurements post-ECMO initiation: OR: 1.94; 95% CI: 1.01-3.72; p < 0.05). Prospective studies are needed to investigate the causal relationship between RVI and mortality in this patient group and the best management strategies to reduce mortality.