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).

A New Global Definition of Acute Respiratory Distress Syndrome

Background: Since publication of the 2012 Berlin definition of acute respiratory distress syndrome (ARDS), several developments have supported the need for an expansion of the definition, including the use of high-flow nasal oxygen, the expansion of the use of pulse oximetry in place of arterial blood gases, the use of ultrasound for chest imaging, and the need for applicability in resource-limited settings. Methods: A consensus conference of 32 critical care ARDS experts was convened, had six virtual meetings (June 2021 to March 2022), and subsequently obtained input from members of several critical care societies. The goal was to develop a definition that would 1) identify patients with the currently accepted conceptual framework for ARDS, 2) facilitate rapid ARDS diagnosis for clinical care and research, 3) be applicable in resource-limited settings, 4) be useful for testing specific therapies, and 5) be practical for communication to patients and caregivers. Results: The committee made four main recommendations: 1) include high-flow nasal oxygen with a minimum flow rate of ⩾30 L/min; 2) use PaO2:FiO2 ⩽ 300 mm Hg or oxygen saturation as measured by pulse oximetry SpO2:FiO2 ⩽ 315 (if oxygen saturation as measured by pulse oximetry is ⩽97%) to identify hypoxemia; 3) retain bilateral opacities for imaging criteria but add ultrasound as an imaging modality, especially in resource-limited areas; and 4) in resource-limited settings, do not require positive end-expiratory pressure, oxygen flow rate, or specific respiratory support devices. Conclusions: We propose a new global definition of ARDS that builds on the Berlin definition. The recommendations also identify areas for future research, including the need for prospective assessments of the feasibility, reliability, and prognostic validity of the proposed global definition.

Current knowledge gaps in extracorporeal respiratory support

Extracorporeal life support (ECLS) for acute respiratory failure encompasses veno-venous extracorporeal membrane oxygenation (V-V ECMO) and extracorporeal carbon dioxide removal (ECCO2R). V-V ECMO is primarily used to treat severe acute respiratory distress syndrome (ARDS), characterized by life-threatening hypoxemia or ventilatory insufficiency with conventional protective settings. It employs an artificial lung with high blood flows, and allows improvement in gas exchange, correction of hypoxemia, and reduction of the workload on the native lung. On the other hand, ECCO2R focuses on carbon dioxide removal and ventilatory load reduction ("ultra-protective ventilation") in moderate ARDS, or in avoiding pump failure in acute exacerbated chronic obstructive pulmonary disease. Clinical indications for V-V ECLS are tailored to individual patients, as there are no absolute contraindications. However, determining the ideal timing for initiating extracorporeal respiratory support remains uncertain. Current ECLS equipment faces issues like size and durability. Innovations include intravascular lung assist devices (ILADs) and pumpless devices, though they come with their own challenges. Efficient gas exchange relies on modern oxygenators using hollow fiber designs, but research is exploring microfluidic technology to improve oxygenator size, thrombogenicity, and blood flow capacity. Coagulation management during V-V ECLS is crucial due to common bleeding and thrombosis complications; indeed, anticoagulation strategies and monitoring systems require improvement, while surface coatings and new materials show promise. Moreover, pharmacokinetics during ECLS significantly impact antibiotic therapy, necessitating therapeutic drug monitoring for precise dosing. Managing native lung ventilation during V-V ECMO remains complex, requiring a careful balance between benefits and potential risks for spontaneously breathing patients. Moreover, weaning from V-V ECMO is recognized as an area of relevant uncertainty, requiring further research. In the last decade, the concept of Extracorporeal Organ Support (ECOS) for patients with multiple organ dysfunction has emerged, combining ECLS with other organ support therapies to provide a more holistic approach for critically ill patients. In this review, we aim at providing an in-depth overview of V-V ECMO and ECCO2R, addressing various aspects of their use, challenges, and potential future directions in research and development.

Rethinking Acute Respiratory Distress Syndrome after COVID-19: If a "Better" Definition Is the Answer, What Is the Question?

The definition of acute respiratory distress syndrome (ARDS) has a somewhat controversial history, with some even questioning the need for the term "ARDS." This controversy has been amplified by the coronavirus disease (COVID-19) pandemic given the marked increase in the incidence of ARDS, the relatively new treatment modalities that do not fit neatly with the Berlin definition, and the difficulty of making the diagnosis in resource-limited settings. We propose that attempts to revise the definition of ARDS should apply the framework originally developed by psychologists and social scientists and used by other medical disciplines to generate and assess definitions of clinical syndromes that do not have gold standards. This framework is structured around measures of reliability, feasibility, and validity. Future revisions of the definition of ARDS should contain the purpose, the methodology, and the framework for empirically testing any proposed definition. Attempts to revise critical illness syndromes' definitions usually hope to make them "better"; our recommendation is that future attempts use the same criteria used by other fields in defining what "better" means.

Environmental Contamination by SARS-CoV-2 During Noninvasive Ventilation in COVID-19

BACKGROUND

Environmental contamination by SARS-CoV-2 from patients with COVID-19 undergoing noninvasive ventilation (NIV) in the ICU is still under investigation. This study set out to investigate the presence of SARS-CoV-2 on surfaces near subjects receiving NIV in the ICU under controlled conditions (ie, use of dual-limb circuits, filters, adequate room ventilation).

METHODS

This was a single-center, prospective, observational study in the ICU of a tertiary teaching hospital. Four surface sampling areas, at increasing distance from subject's face, were identified; and each one was sampled at fixed intervals: 6, 12, and 24 h. The presence of SARS-CoV-2 was detected with real-time reverse transcriptase-polymerase-chain-reaction (RT-PCR) test on environmental swabs; the RT-PCR assay targeted the SARS-CoV-2 virus nucleocapsid N1 and N2 genes and the human RNase P gene as internal control.

RESULTS

In a total of 256 collected samples, none were positive for SARS-CoV-2 genetic material, whereas 21 samples (8.2%) tested positive for RNase P, thus demonstrating the presence of genetic material unrelated to SARS-CoV-2.

CONCLUSIONS

Our data show that application of NIV in an appropriate environment and with correct precautions leads to no sign of surface environmental contamination. Accordingly, our data support the idea that use of NIV in the ICU is safe both for health care workers and for other patients.

High-Flow Versus VenturiMask Oxygen Therapy to Prevent Reintubation in Hypoxemic Patients after Extubation: A Multicenter Randomized Clinical Trial

Rationale: When compared with VenturiMask after extubation, high-flow nasal oxygen provides physiological advantages. Objectives: To establish whether high-flow oxygen prevents endotracheal reintubation in hypoxemic patients after extubation, compared with VenturiMask. Methods: In this multicenter randomized trial, 494 patients exhibiting Pa_O2:Fi_O2 ratio ⩽ 300 mm Hg after extubation were randomly assigned to receive high-flow or VenturiMask oxygen, with the possibility to apply rescue noninvasive ventilation before reintubation. High-flow use in the VenturiMask group was not permitted. Measurements and Main Results: The primary outcome was the rate of reintubation within 72 hours according to predefined criteria, which were validated a posteriori by an independent adjudication committee. Main secondary outcomes included reintubation rate at 28 days and the need for rescue noninvasive ventilation according to predefined criteria. After intubation criteria validation (n = 492 patients), 32 patients (13%) in the high-flow group and 27 patients (11%) in the VenturiMask group required reintubation at 72 hours (unadjusted odds ratio, 1.26 [95% confidence interval (CI), 0.70-2.26]; P = 0.49). At 28 days, the rate of reintubation was 21% in the high-flow group and 23% in the VenturiMask group (adjusted hazard ratio, 0.89 [95% CI, 0.60-1.31]; P = 0.55). The need for rescue noninvasive ventilation was significantly lower in the high-flow group than in the VenturiMask group: at 72 hours, 8% versus 17% (adjusted hazard ratio, 0.39 [95% CI, 0.22-0.71]; P = 0.002) and at 28 days, 12% versus 21% (adjusted hazard ratio, 0.52 [95% CI, 0.32-0.83]; P = 0.007). Conclusions: Reintubation rate did not significantly differ between patients treated with VenturiMask or high-flow oxygen after extubation. High-flow oxygen yielded less frequent use of rescue noninvasive ventilation. Clinical trial registered with www.clinicaltrials.gov (NCT02107183).

Increased duration and similar outcomes of V‐V ECLS in patients with Covid‐19 Ards compared to non‐Covid ards: single center experience

BACKGROUND

Veno-venous extracorporeal life support (V-V ECLS or V-V ECMO) has been adopted as a rescue support in severe cases of COVID-19 ARDS. Initial reports on the use of V-V ECLS in COVID-19 patients reported very high mortality rates (57%-94%), but subsequent studies showed much lower rates (30%-40%). The aim of this study is to analyze demographic features, clinical course and outcomes of COVID-19 treated with V-V ECLS during the Italian 'third wave', in which the alpha variant was prevalent in the country.

METHODS

Single-center, retrospective observational study conducted at the ECLS referral center of a teaching hospital in Italy from January 1st, 2021 and October 31st, 2021.

RESULTS

Between January and October 2021, 18 consecutive adult patients who underwent V-V ECLS for severe ARDS due to COVID-19 were enrolled. Thirteen patients (72.2%) were male, and their median age was 50 years; the median P/F ratio before V-V ECLS initiation was 43 mm Hg (IQR, 40; 56), and the median RESP score was 0.5 (IQR, -2.25; 1.0). The mortality rate at 90 days was 55.6, compared to 55.7% in non-COVID patients in our center (p > 0.05); the median duration of ECLS was 29 days (IQR, 11; 32), compared to 10 days (IQR, 8; 15), in non-COVID patients (p = 0.004). Incidence of complications was high.

CONCLUSIONS

In patients with COVID-19 ARDS receiving V-V ECLS, unadjusted mortality was similar to pre-pandemic V-V ECLS cases, while the duration of ECLS was almost three times longer and with frequent complications. This could be partly explained by the selection of very sick patients at the baseline that evolved to multiorgan failure during the course of ECLS.

Modulation of LTCC Pathways by a Melusin Mimetic Increases Ventricular Contractility During LPS-Induced Cardiomyopathy

AIM

Sepsis-induced cardiomyopathy is commonplace and carries an increased risk of death. Melusin, a cardiac muscle-specific chaperone, exerts cardioprotective function under varied stressful conditions through activation of the AKT pathway. The objective of this study was to determine the role of melusin in the pathogenesis of lipopolysaccharide (LPS)-induced cardiac dysfunction and to explore its signaling pathway for the identification of putative therapeutic targets.

METHODS AND RESULTS

Prospective, randomized, controlled experimental study in a research laboratory. Melusin overexpressing (MelOV) and wild-type (MelWT) mice were used. MelOV and MelWT mice were injected intraperitoneally with LPS. Cardiac function was assessed using trans-thoracic echocardiography. Myocardial expression of L-type calcium channel (LTCC), phospho-Akt and phospho-Gsk3-b were also measured. In separate experiments, wild-type mice were treated post-LPS challenge with the allosteric Akt inhibitor Arq092 and a mimetic peptide (R7W-MP) targeting the LTCC. The impact of these therapies on protein-protein interactions, cardiac function, and survival was assessed. MelOV mice had limited derangement in cardiac function after LPS challenge. Protection was associated with higher Akt and Gsk3-b phosphorylation and restored LTCC density. Pharmacological inhibition of Akt activity reversed melusin-dependent cardiac protection. Treatment with R7W-MP preserved cardiac function in wild-type mice after LPS challenge and significantly improved survival.

CONCLUSIONS

This study identifies AKT / Melusin as a key pathway for preserving cardiac function following LPS challenge. The cell-permeable mimetic peptide (R7W-MP) represents a putative therapeutic for sepsis-induced cardiomyopathy.

COVID-19 Vaccination Status Among Adults Admitted to Intensive Care Units in Veneto, Italy

This cohort study examines admissions to intensive care units for COVID-19–associated acute respiratory distress syndrome by COVID-19 vaccination status among adults in the Veneto region of Italy from May to December 2021.

High-Flow Nasal Oxygen for Severe Hypoxemia: Oxygenation Response and Outcome in Patients with COVID-19

Rationale: The "Berlin definition" of acute respiratory distress syndrome (ARDS) does not allow inclusion of patients receiving high-flow nasal oxygen (HFNO). However, several articles have proposed that criteria for defining ARDS should be broadened to allow inclusion of patients receiving HFNO. Objectives: To compare the proportion of patients fulfilling ARDS criteria during HFNO and soon after intubation, and 28-day mortality between patients treated exclusively with HFNO and patients transitioned from HFNO to invasive mechanical ventilation (IMV). Methods: From previously published studies, we analyzed patients with coronavirus disease (COVID-19) who had PaO2/FiO2 of ⩽300 while treated with ⩾40 L/min HFNO, or noninvasive ventilation (NIV) with positive end-expiratory pressure of ⩾5 cm H2O (comparator). In patients transitioned from HFNO/NIV to invasive mechanical ventilation (IMV), we compared ARDS severity during HFNO/NIV and soon after IMV. We compared 28-day mortality in patients treated exclusively with HFNO/NIV versus patients transitioned to IMV. Measurements and Main Results: We analyzed 184 and 131 patients receiving HFNO or NIV, respectively. A total of 112 HFNO and 69 NIV patients transitioned to IMV. Of those, 104 (92.9%) patients on HFNO and 66 (95.7%) on NIV continued to have PaO2/FiO2 ⩽300 under IMV. Twenty-eight-day mortality in patients who remained on HFNO was 4.2% (3/72), whereas in patients transitioned from HFNO to IMV, it was 28.6% (32/112) (P < 0.001). Twenty-eight-day mortality in patients who remained on NIV was 1.6% (1/62), whereas in patients who transitioned from NIV to IMV, it was 44.9% (31/69) (P < 0.001). Overall mortality was 19.0% (35/184) and 24.4% (32/131) for HFNO and NIV, respectively (P = 0.2479). Conclusions: Broadening the ARDS definition to include patients on HFNO with PaO2/FiO2 ⩽300 may identify patients at earlier stages of disease but with lower mortality.

Extracorporeal carbon dioxide removal for treatment of exacerbated chronic obstructive pulmonary disease (ORION): study protocol for a randomised controlled trial

Background

Hypercapnic exacerbations are severe complications of chronic obstructive pulmonary disease (COPD), characterized by negative impact on prognosis, quality of life and healthcare costs. The present standard of care for acute exacerbations of COPD is non-invasive ventilation; when it fails, the use of invasive mechanical ventilation is inevitable, but is associated with extremely poor prognosis. Extracorporeal circuits designed to remove CO₂ (ECCO₂R) may enhance the efficacy of NIV to remove CO₂ and avoid the worsening of respiratory acidosis, which inevitably leads to failure of non-invasive ventilation. Although the use of ECCO₂R for acute exacerbations of COPD is steadily increasing, solid evidence on its efficacy and safety is scarce, thus the need for a randomized controlled trial.

Methods

multicenter randomized controlled unblinded clinical trial including 284 (142 per arm) patients with acute hypercapnic respiratory failure caused by exacerbation of COPD, requiring respiratory support with NIV. The primary outcome is event free survival at 28 days, a composite outcome defined by survival in absence of prolonged mechanical ventilation, severe hypoxemia, septic shock and second episode of COPD exacerbation. Secondary outcomes are incidence of endotracheal intubation and tracheostomy, intensive care and hospital length-of-stay and 90-day mortality.

Discussion

Acute exacerbations of COPD represent a significant burden in terms of prognosis, quality of life and healthcare costs. Lack definite evidence despite increasing use of ECCO₂R justifies a randomized trial to evaluate whether patients with acute hypercapnic acidosis not responsive to NIV should undergo invasive mechanical ventilation (with all serious related risks) or be treated with ECCO₂R to avoid invasive ventilation but be exposed to possible adverse events of ECCO₂R. Owing to its pragmatic nature, sample size and composite primary outcome, this trial aims at providing valuable answers to relevant questions for clinical treatment of acute exacerbations of COPD.

Trial registration

ClinicalTrials.gov, NCT04582799. Registered 12 October 2020, .

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05692-w.

Noninvasive respiratory support outside the intensive care unit for acute respiratory failure related to coronavirus-19 disease: a systematic review and meta-analysis

BACKGROUND

Noninvasive respiratory support (NIRS) has been diffusely employed outside the intensive care unit (ICU) to face the high request of ventilatory support due to the massive influx of patients with acute respiratory failure (ARF) caused by coronavirus-19 disease (COVID-19). We sought to summarize the evidence on clinically relevant outcomes in COVID-19 patients supported by NIV outside the ICU.

METHODS

We searched PUBMED®, EMBASE®, and the Cochrane Controlled Clinical trials register, along with medRxiv and bioRxiv repositories for pre-prints, for observational studies and randomized controlled trials, from inception to the end of February 2021. Two authors independently selected the investigations according to the following criteria: (1) observational study or randomized clinical trials enrolling ≥ 50 hospitalized patients undergoing NIRS outside the ICU, (2) laboratory-confirmed COVID-19, and (3) at least the intra-hospital mortality reported. Preferred Reporting Items for Systematic reviews and Meta-analysis guidelines were followed. Data extraction was independently performed by two authors to assess: investigation features, demographics and clinical characteristics, treatments employed, NIRS regulations, and clinical outcomes. Methodological index for nonrandomized studies tool was applied to determine the quality of the enrolled studies. The primary outcome was to assess the overall intra-hospital mortality of patients under NIRS outside the ICU. The secondary outcomes included the proportions intra-hospital mortalities of patients who underwent invasive mechanical ventilation following NIRS failure and of those with 'do-not-intubate' (DNI) orders.

RESULTS

Seventeen investigations (14 peer-reviewed and 3 pre-prints) were included with a low risk of bias and a high heterogeneity, for a total of 3377 patients. The overall intra-hospital mortality of patients receiving NIRS outside the ICU was 36% [30-41%]. 26% [21-30%] of the patients failed NIRS and required intubation, with an intra-hospital mortality rising to 45% [36-54%]. 23% [15-32%] of the patients received DNI orders with an intra-hospital mortality of 72% [65-78%]. Oxygenation on admission was the main source of between-study heterogeneity.

CONCLUSIONS

During COVID-19 outbreak, delivering NIRS outside the ICU revealed as a feasible strategy to cope with the massive demand of ventilatory assistance.

REGISTRATION

PROSPERO, https://www.crd.york.ac.uk/prospero/ , CRD42020224788, December 11, 2020.

Static compliance and driving pressure are associated with ICU mortality in intubated COVID-19 ARDS

Background

Pathophysiological features of coronavirus disease 2019-associated acute respiratory distress syndrome (COVID-19 ARDS) were indicated to be somewhat different from those described in nonCOVID-19 ARDS, because of relatively preserved compliance of the respiratory system despite marked hypoxemia. We aim ascertaining whether respiratory system static compliance (Crs), driving pressure (DP), and tidal volume normalized for ideal body weight (VT/kg IBW) at the 1st day of controlled mechanical ventilation are associated with intensive care unit (ICU) mortality in COVID-19 ARDS.

Methods

Observational multicenter cohort study. All consecutive COVID-19 adult patients admitted to 25 ICUs belonging to the COVID-19 VENETO ICU network (February 28th–April 28th, 2020), who received controlled mechanical ventilation, were screened. Only patients fulfilling ARDS criteria and with complete records of Crs, DP and VT/kg IBW within the 1st day of controlled mechanical ventilation were included. Crs, DP and VT/kg IBW were collected in sedated, paralyzed and supine patients.

Results

A total of 704 COVID-19 patients were screened and 241 enrolled. Seventy-one patients (29%) died in ICU. The logistic regression analysis showed that: (1) Crs was not linearly associated with ICU mortality (p value for nonlinearity = 0.01), with a greater risk of death for values < 48 ml/cmH₂O; (2) the association between DP and ICU mortality was linear (p value for nonlinearity = 0.68), and increasing DP from 10 to 14 cmH₂O caused significant higher odds of in-ICU death (OR 1.45, 95% CI 1.06–1.99); (3) VT/kg IBW was not associated with a significant increase of the risk of death (OR 0.92, 95% CI 0.55–1.52). Multivariable analysis confirmed these findings.

Conclusions

Crs < 48 ml/cmH₂O was associated with ICU mortality, while DP was linearly associated with mortality. DP should be kept as low as possible, even in the case of relatively preserved Crs, irrespective of VT/kg IBW, to reduce the risk of death.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03667-6.

Effect of Helmet Noninvasive Ventilation vs High-Flow Nasal Oxygen on Days Free of Respiratory Support in Patients With COVID-19 and Moderate to Severe Hypoxemic Respiratory Failure: The HENIVOT Randomized Clinical Trial

IMPORTANCE

High-flow nasal oxygen is recommended as initial treatment for acute hypoxemic respiratory failure and is widely applied in patients with COVID-19.

OBJECTIVE

To assess whether helmet noninvasive ventilation can increase the days free of respiratory support in patients with COVID-19 compared with high-flow nasal oxygen alone.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter randomized clinical trial in 4 intensive care units (ICUs) in Italy between October and December 2020, end of follow-up February 11, 2021, including 109 patients with COVID-19 and moderate to severe hypoxemic respiratory failure (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen ≤200).

INTERVENTIONS

Participants were randomly assigned to receive continuous treatment with helmet noninvasive ventilation (positive end-expiratory pressure, 10-12 cm H2O; pressure support, 10-12 cm H2O) for at least 48 hours eventually followed by high-flow nasal oxygen (n = 54) or high-flow oxygen alone (60 L/min) (n = 55).

MAIN OUTCOMES AND MEASURES

The primary outcome was the number of days free of respiratory support within 28 days after enrollment. Secondary outcomes included the proportion of patients who required endotracheal intubation within 28 days from study enrollment, the number of days free of invasive mechanical ventilation at day 28, the number of days free of invasive mechanical ventilation at day 60, in-ICU mortality, in-hospital mortality, 28-day mortality, 60-day mortality, ICU length of stay, and hospital length of stay.

RESULTS

Among 110 patients who were randomized, 109 (99%) completed the trial (median age, 65 years [interquartile range {IQR}, 55-70]; 21 women [19%]). The median days free of respiratory support within 28 days after randomization were 20 (IQR, 0-25) in the helmet group and 18 (IQR, 0-22) in the high-flow nasal oxygen group, a difference that was not statistically significant (mean difference, 2 days [95% CI, -2 to 6]; P = .26). Of 9 prespecified secondary outcomes reported, 7 showed no significant difference. The rate of endotracheal intubation was significantly lower in the helmet group than in the high-flow nasal oxygen group (30% vs 51%; difference, -21% [95% CI, -38% to -3%]; P = .03). The median number of days free of invasive mechanical ventilation within 28 days was significantly higher in the helmet group than in the high-flow nasal oxygen group (28 [IQR, 13-28] vs 25 [IQR 4-28]; mean difference, 3 days [95% CI, 0-7]; P = .04). The rate of in-hospital mortality was 24% in the helmet group and 25% in the high-flow nasal oxygen group (absolute difference, -1% [95% CI, -17% to 15%]; P > .99).

CONCLUSIONS AND RELEVANCE

Among patients with COVID-19 and moderate to severe hypoxemia, treatment with helmet noninvasive ventilation, compared with high-flow nasal oxygen, resulted in no significant difference in the number of days free of respiratory support within 28 days. Further research is warranted to determine effects on other outcomes, including the need for endotracheal intubation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04502576.

Addressing gender imbalance in intensive care

There is a large gender gap in critical care medicine with women underrepresented, particularly in positions of leadership. Yet gender diversity better reflects the current critical care community and has multiple beneficial effects at individual and societal levels. In this Viewpoint, we discuss some of the reasons for the persistent gender imbalance in critical care medicine, and suggest some possible strategies to help achieve greater equity and inclusion. An explicit and consistent focus on eliminating gender inequity is needed until gender diversity and inclusion become the norms in critical care medicine.

Clinical performance of lung ultrasound in predicting ARDS morphology

Background

To assess diagnostic performance of lung ultrasound (LUS) in identifying ARDS morphology (focal vs non-focal), compared with the gold standard computed tomography.

Methods

Mechanically ventilated ARDS patients undergoing lung computed tomography and ultrasound were enrolled. Twelve fields, were evaluated. LUS score was graded from 0 (normal) to 3 (consolidation) according to B-lines extent. Total and regional LUS score as the sum of the four ventral (LUS_V), intermediate (LUS_I) or dorsal (LUS_D) fields, were calculated. Based on lung CT, ARDS morphology was defined as (1) focal (loss of aeration with lobar distribution); (2) non-focal (widespread loss of aeration or segmental loss of aeration distribution associated with uneven lung attenuation areas), and diagnostic accuracy of LUS in discriminating ARDS morphology was determined by AU-ROC in training and validation set of patients.

Results

Forty-seven patients with ARDS (25 training set and 22 validation set) were enrolled. LUS_TOT, LUS_V and LUS_I but not LUS_D score were significantly lower in focal than in non-focal ARDS morphologies (p < .01). The AU-ROC curve of LUS_TOT, LUS_V, LUS_I and LUS_D for identification of non-focal ARDS morphology were 0.890, 0.958, 0.884 and 0.421, respectively. LUS_V value ≥ 3 had the best predictive value (sensitivity = 0.95, specificity = 1.00) in identifying non-focal ARDS morphology. In the validation set, an LUS_V score ≥ 3 confirmed to be highly predictive of non-focal ARDS morphology, with a sensitivity and a specificity of 94% and 100%.

Conclusions

LUS had a valuable performance in distinguishing ARDS morphology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00837-1.

Temporal changes in the epidemiology, management, and outcome from acute respiratory distress syndrome in European intensive care units: a comparison of two large cohorts

Background

Mortality rates for patients with ARDS remain high. We assessed temporal changes in the epidemiology and management of ARDS patients requiring invasive mechanical ventilation in European ICUs. We also investigated the association between ventilatory settings and outcome in these patients.

Methods

This was a post hoc analysis of two cohorts of adult ICU patients admitted between May 1–15, 2002 (SOAP study, n = 3147), and May 8–18, 2012 (ICON audit, n = 4601 admitted to ICUs in the same 24 countries as the SOAP study). ARDS was defined retrospectively using the Berlin definitions. Values of tidal volume, PEEP, plateau pressure, and FiO₂ corresponding to the most abnormal value of arterial PO₂ were recorded prospectively every 24 h. In both studies, patients were followed for outcome until death, hospital discharge or for 60 days.

Results

The frequency of ARDS requiring mechanical ventilation during the ICU stay was similar in SOAP and ICON (327[10.4%] vs. 494[10.7%], p = 0.793). The diagnosis of ARDS was established at a median of 3 (IQ: 1–7) days after admission in SOAP and 2 (1–6) days in ICON. Within 24 h of diagnosis, ARDS was mild in 244 (29.7%), moderate in 388 (47.3%), and severe in 189 (23.0%) patients. In patients with ARDS, tidal volumes were lower in the later (ICON) than in the earlier (SOAP) cohort. Plateau and driving pressures were also lower in ICON than in SOAP. ICU (134[41.1%] vs 179[36.9%]) and hospital (151[46.2%] vs 212[44.4%]) mortality rates in patients with ARDS were similar in SOAP and ICON. High plateau pressure (> 29 cmH₂O) and driving pressure (> 14 cmH₂O) on the first day of mechanical ventilation but not tidal volume (> 8 ml/kg predicted body weight [PBW]) were independently associated with a higher risk of in-hospital death.

Conclusion

The frequency of and outcome from ARDS remained relatively stable between 2002 and 2012. Plateau pressure > 29 cmH₂O and driving pressure > 14 cmH₂O on the first day of mechanical ventilation but not tidal volume > 8 ml/kg PBW were independently associated with a higher risk of death. These data highlight the continued burden of ARDS and provide hypothesis-generating data for the design of future studies.

Extracorporeal Carbon Dioxide Removal Using a Renal Replacement Therapy Platform to Enhance Lung-Protective Ventilation in Hypercapnic Patients With Coronavirus Disease 2019-Associated Acute Respiratory Distress Syndrome

Coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome (ARDS) is associated with high mortality. Lung-protective ventilation is the current standard of care in patients with ARDS, but it might lead to hypercapnia, which is independently associated with worse outcomes. Extracorporeal carbon dioxide removal (ECCO₂R) has been proposed as an adjuvant therapy to avoid progression of clinical severity and limit further ventilator-induced lung injury, but its use in COVID-19 has not been described yet. Acute kidney injury requiring renal replacement therapy (RRT) is common among critically ill COVID-19 patients. In centers with available dialysis, low-flow ECCO₂R (<500 mL/min) using RRT platforms could be carried out by dialysis specialists and might be an option to efficiently allocate resources during the COVID-19 pandemic for patients with hypercapnia as the main indication. Here, we report the feasibility, safety, and efficacy of ECCO₂R using an RRT platform to provide either standalone ECCO₂R or ECCO₂R combined with RRT in four hypercapnic patients with moderate ARDS. A randomized clinical trial is required to assess the overall benefit and harm.

Clinical Trial Registration:ClinicalTrials.gov. Unique identifier: NCT04351906.

Feasibility and clinical impact of out-of-ICU noninvasive respiratory support in patients with COVID-19-related pneumonia

Introduction

The severe acute respiratory syndrome-coronavirus 2 outbreak spread rapidly in Italy and the lack of intensive care unit (ICU) beds soon became evident, forcing the application of noninvasive respiratory support (NRS) outside the ICU, raising concerns over staff contamination. We aimed to analyse the safety of the hospital staff and the feasibility and outcomes of NRS applied to patients outside the ICU.

Methods

In this observational study, data from 670 consecutive patients with confirmed coronavirus disease 2019 referred to pulmonology units in nine hospitals between March 1 and May 10, 2020 were analysed. Data collected included medication, mode and usage of NRS (i.e. high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), noninvasive ventilation (NIV)), length of stay in hospital, endotracheal intubation (ETI) and deaths.

Results

42 (11.1%) healthcare workers tested positive for infection, but only three of them required hospitalisation. Data are reported for all patients (69.3% male), whose mean±sd age was 68±13 years. The arterial oxygen tension/inspiratory oxygen fraction ratio at baseline was 152±79, and the majority (49.3%) of patients were treated with CPAP. The overall unadjusted 30-day mortality rate was 26.9%, with 16%, 30% and 30% for HFNC, CPAP and NIV, respectively, while the total ETI rate was 27%, with 29%, 25% and 28%, respectively; the relative probability of death was not related to the NRS used after adjustment for confounders. ETI and length of stay were not different among the groups. Mortality rate increased with age and comorbidity class progression.

Conclusions

The application of NRS outside the ICU is feasible and associated with favourable outcomes. Nonetheless, it was associated with a risk of staff contamination.

In patients with SARS-CoV-2 infection and acute respiratory failure, this study demonstrates that the utilisation of noninvasive respiratory support delivered outside the ICU was feasible and effective, but associated with a risk of staff contaminationhttps://bit.ly/33mrJTU

Factors influencing liberation from mechanical ventilation in coronavirus disease 2019: multicenter observational study in fifteen Italian ICUs

BACKGROUND

A large proportion of patients with coronavirus disease 2019 (COVID-19) develop severe respiratory failure requiring admission to the intensive care unit (ICU) and about 80% of them need mechanical ventilation (MV). These patients show great complexity due to multiple organ involvement and a dynamic evolution over time; moreover, few information is available about the risk factors that may contribute to increase the time course of mechanical ventilation.The primary objective of this study is to investigate the risk factors associated with the inability to liberate COVID-19 patients from mechanical ventilation. Due to the complex evolution of the disease, we analyzed both pulmonary variables and occurrence of non-pulmonary complications during mechanical ventilation. The secondary objective of this study was the evaluation of risk factors for ICU mortality.

METHODS

This multicenter prospective observational study enrolled 391 patients from fifteen COVID-19 dedicated Italian ICUs which underwent invasive mechanical ventilation for COVID-19 pneumonia. Clinical and laboratory data, ventilator parameters, occurrence of organ dysfunction, and outcome were recorded. The primary outcome measure was 28 days ventilator-free days and the liberation from MV at 28 days was studied by performing a competing risks regression model on data, according to the method of Fine and Gray; the event death was considered as a competing risk.

RESULTS

Liberation from mechanical ventilation was achieved in 53.2% of the patients (208/391). Competing risks analysis, considering death as a competing event, demonstrated a decreased sub-hazard ratio for liberation from mechanical ventilation (MV) with increasing age and SOFA score at ICU admission, low values of PaO2/FiO2 ratio during the first 5 days of MV, respiratory system compliance (CRS) lower than 40 mL/cmH2O during the first 5 days of MV, need for renal replacement therapy (RRT), late-onset ventilator-associated pneumonia (VAP), and cardiovascular complications.ICU mortality during the observation period was 36.1% (141/391). Similar results were obtained by the multivariate logistic regression analysis using mortality as a dependent variable.

CONCLUSIONS

Age, SOFA score at ICU admission, CRS, PaO2/FiO2, renal and cardiovascular complications, and late-onset VAP were all independent risk factors for prolonged mechanical ventilation in patients with COVID-19.

TRIAL REGISTRATION

NCT04411459.

Use of critical care resources during the first 2 weeks (February 24-March 8, 2020) of the Covid-19 outbreak in Italy

Background

A Covid-19 outbreak developed in Lombardy, Veneto and Emilia-Romagna (Italy) at the end of February 2020. Fear of an imminent saturation of available ICU beds generated the notion that rationing of intensive care resources could have been necessary.

Results

In order to evaluate the impact of Covid-19 on the ICU capacity to manage critically ill patients, we performed a retrospective analysis of the first 2 weeks of the outbreak (February 24–March 8). Data were collected from regional registries and from a case report form sent to participating sites. ICU beds increased from 1545 to 1989 (28.7%), and patients receiving respiratory support outside the ICU increased from 4 (0.6%) to 260 (37.0%). Patients receiving respiratory support outside the ICU were significantly older [65 vs. 77 years], had more cerebrovascular (5.8 vs. 13.1%) and renal (5.3 vs. 10.0%) comorbidities and less obesity (31.4 vs. 15.5%) than patients admitted to the ICU. PaO₂/FiO₂ ratio, respiratory rate and arterial pH were higher [165 vs. 244; 20 vs. 24 breath/min; 7.40 vs. 7.46] and PaCO₂ and base excess were lower [34 vs. 42 mmHg; 0.60 vs. 1.30] in patients receiving respiratory support outside the ICU than in patients admitted to the ICU, respectively.

Conclusions

Increase in ICU beds and use of out-of-ICU respiratory support allowed effective management of the first 14 days of the Covid-19 outbreak, avoiding resource rationing.

The clinical spectrum of pulmonary thromboembolism in patients with coronavirus disease-2019 (COVID-19) pneumonia: A European case series

Purpose

To describe the clinical characteristics and outcomes of coronavirus disease-2019 (COVID-19)-associated pulmonary thromboembolism (PTE).

Materials and methods

A case series of five patients, representing the clinical spectrum of COVID-19 associated PTE. Patients were admitted to four hospitals in Germany, Italy, and France. Infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was confirmed using a real-time reverse transcription polymerase chain reaction test.

Results

The onset of PTE varied from 2 to 4 weeks after the occurrence of the initial symptoms of SARS-CoV-2 infection and led to deterioration of the clinical picture in all cases. PTE was the primary reason for hospital admission after a 2-week period of self-isolation at home (1 patient) and hospital readmission after initial uncomplicated hospital discharge (2 patients). Three of the patients had no past history of clinically relevant risk factors for venous thromboembolism (VTE). Severe disease progression was associated with concomitant increases in IL-6, ferritin, and D-Dimer levels. The outcome from PTE was related to the extent of vascular involvement, and associated complications.

Conclusion

PTE is a potential life-threatening complication, which occurs frequently in patients with COVID-19. Intermediate therapeutic dose of anticoagulants and extend thromboprophylaxis are necessary after meticulous risk-benefit assessment.

•

Pulnonary thromboembolism (PTE) is a frequent life-threatening complication in patients with COVID-19.

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The onset of PTE varies from 2 to 4 weeks after the occurrence of the initial symptoms.

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PTE may occur in patients without past history of risk factors for venous thromboembolism and in those receiving standard prophylactic anticoagulation.

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Intermediate therapeutic dose of anticoagulants and extend thromboprophylaxis are necessary in these patients after meticulous risk-benefit assessment.

Pulmonary embolism in patients with coronavirus disease-2019 (COVID-19) pneumonia: a narrative review

BACKGROUND

Preliminary reports have described significant procoagulant events in patients with coronavirus disease-2019 (COVID-19), including life-threatening pulmonary embolism (PE).

MAIN TEXT

We review the current data on the epidemiology, the possible underlying pathophysiologic mechanisms, and the therapeutic implications of PE in relation to COVID-19. The incidence of PE is reported to be around 2.6-8.9% of COVID-19 in hospitalized patients and up to one-third of those requiring intensive care unit (ICU) admission, despite standard prophylactic anticoagulation. This may be explained by direct and indirect pathologic consequences of COVID-19, complement activation, cytokine release, endothelial dysfunction, and interactions between different types of blood cells.

CONCLUSION

Thromboprophylaxis should be started in all patients with suspected or confirmed COVID-19 admitted to the hospital. The use of an intermediate therapeutic dose of low molecular weight (LMWH) or unfractionated heparin can be considered on an individual basis in patients with multiple risk factors for venous thromboembolism, including critically ill patients admitted to the ICU. Decisions about extending prophylaxis with LMWH after hospital discharge should be made after balancing the reduced risk of venous thromboembolism (VTE) with the risk of increased bleeding events and should be continued for 7-14 days after hospital discharge or in the pre-hospital phase in case of pre-existing or persisting VTE risk factors. Therapeutic anticoagulation is the cornerstone in the management of patients with PE. Selection of an appropriate agent and correct dosing requires consideration of underlying comorbidities.

Pathophysiology of COVID-19-associated acute respiratory distress syndrome: a multicentre prospective observational study

Background

Patients with COVID-19 can develop acute respiratory distress syndrome (ARDS), which is associated with high mortality. The aim of this study was to examine the functional and morphological features of COVID-19-associated ARDS and to compare these with the characteristics of ARDS unrelated to COVID-19.

Methods

This prospective observational study was done at seven hospitals in Italy. We enrolled consecutive, mechanically ventilated patients with laboratory-confirmed COVID-19 and who met Berlin criteria for ARDS, who were admitted to the intensive care unit (ICU) between March 9 and March 22, 2020. All patients were sedated, paralysed, and ventilated in volume-control mode with standard ICU ventilators. Static respiratory system compliance, the ratio of partial pressure of arterial oxygen to fractional concentration of oxygen in inspired air, ventilatory ratio (a surrogate of dead space), and D-dimer concentrations were measured within 24 h of ICU admission. Lung CT scans and CT angiograms were done when clinically indicated. A dataset for ARDS unrelated to COVID-19 was created from previous ARDS studies. Survival to day 28 was assessed.

Findings

Between March 9 and March 22, 2020, 301 patients with COVID-19 met the Berlin criteria for ARDS at participating hospitals. Median static compliance was 41 mL/cm H₂O (33–52), which was 28% higher than in the cohort of patients with ARDS unrelated to COVID-19 (32 mL/cm H₂O [25–43]; p<0·0001). 17 (6%) of 297 patients with COVID-19-associated ARDS had compliances greater than the 95th percentile of the classical ARDS cohort. Total lung weight did not differ between the two cohorts. CT pulmonary angiograms (obtained in 23 [8%] patients with COVID-19-related ARDS) showed that 15 (94%) of 16 patients with D-dimer concentrations greater than the median had bilateral areas of hypoperfusion, consistent with thromboembolic disease. Patients with D-dimer concentrations equal to or less than the median had ventilatory ratios lower than those of patients with D-dimer concentrations greater than the median (1·66 [1·32–1·95] vs 1·90 [1·50–2·33]; p=0·0001). Patients with static compliance equal to or less than the median and D-dimer concentrations greater than the median had markedly increased 28-day mortality compared with other patient subgroups (40 [56%] of 71 with high D-dimers and low compliance vs 18 [27%] of 67 with low D-dimers and high compliance, 13 [22%] of 60 with low D-dimers and low compliance, and 22 [35%] of 63 with high D-dimers and high compliance, all p=0·0001).

Interpretation

Patients with COVID-19-associated ARDS have a form of injury that, in many aspects, is similar to that of those with ARDS unrelated to COVID-19. Notably, patients with COVID-19-related ARDS who have a reduction in respiratory system compliance together with increased D-dimer concentrations have high mortality rates.

Funding

None.

Extracorporeal CO2 removal (ECCO2R) in patients with stable COPD with chronic hypercapnia: a proof-of-concept study

Domiciliary non-invasive ventilation (NIV) effectively reduces arterial carbon dioxide pressure (PaCO2) in patients with stable hypercapnic chronic obstructive pulmonary disease, but a consistent percentage of them may remain hypercapnic. We hypothesised that extracorporeal CO2 removal (ECCO2R) may lower their PaCO2. Ten patients hypercapnic despite ≥6 months of NIV underwent a 24-hour trial of ECCO2R. Six patients completed the ECCO2R-trial with a PaCO2 drop ranging between 23% and 47%. Time to return to baseline after interruption ranged 48–96 hours. In four patients, mechanical events led to ECCO2R premature interruption, despite a decreased in PaCO2. This time window ‘free’ from hypercapnia might allow to propose the concept of ‘CO2 dialysis’.

Effect of Intravenous Interferon β-1a on Death and Days Free From Mechanical Ventilation Among Patients With Moderate to Severe Acute Respiratory Distress Syndrome: A Randomized Clinical Trial

IMPORTANCE

Acute respiratory distress syndrome (ARDS) is associated with high mortality. Interferon (IFN) β-1a may prevent the underlying event of vascular leakage.

OBJECTIVE

To determine the efficacy and adverse events of IFN-β-1a in patients with moderate to severe ARDS.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, randomized, double-blind, parallel-group trial conducted at 74 intensive care units in 8 European countries (December 2015-December 2017) that included 301 adults with moderate to severe ARDS according to the Berlin definition. The radiological and partial pressure of oxygen, arterial (Pao2)/fraction of inspired oxygen (Fio2) criteria for ARDS had to be met within a 24-hour period, and the administration of the first dose of the study drug had to occur within 48 hours of the diagnosis of ARDS. The last patient visit was on March 6, 2018.

INTERVENTIONS

Patients were randomized to receive an intravenous injection of 10 μg of IFN-β-1a (144 patients) or placebo (152 patients) once daily for 6 days.

MAIN OUTCOMES AND MEASURES

The primary outcome was a score combining death and number of ventilator-free days at day 28 (score ranged from -1 for death to 27 if the patient was off ventilator on the first day). There were 16 secondary outcomes, including 28-day mortality, which were tested hierarchically to control type I error.

RESULTS

Among 301 patients who were randomized (mean age, 58 years; 103 women [34.2%]), 296 (98.3%) completed the trial and were included in the primary analysis. At 28 days, the median composite score of death and number of ventilator-free days at day 28 was 10 days (interquartile range, -1 to 20) in the IFN-β-1a group and 8.5 days (interquartile range, 0 to 20) in the placebo group (P = .82). There was no significant difference in 28-day mortality between the IFN-β-1a vs placebo groups (26.4% vs 23.0%; difference, 3.4% [95% CI, -8.1% to 14.8%]; P = .53). Seventy-four patients (25.0%) experienced adverse events considered to be related to treatment during the study (41 patients [28.5%] in the IFN-β-1a group and 33 [21.7%] in the placebo group).

CONCLUSIONS AND RELEVANCE

Among adults with moderate or severe ARDS, intravenous IFN-β-1a administered for 6 days, compared with placebo, resulted in no significant difference in a composite score that included death and number of ventilator-free days over 28 days. These results do not support the use of IFN-β-1a in the management of ARDS.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02622724.

Surfactant replacement might help recovery of low-compliance lung in severe COVID-19 pneumonia

The reviews of this paper are available via the supplemental material section.

Determinants of the effect of extracorporeal carbon dioxide removal in the SUPERNOVA trial: implications for trial design

PURPOSE

To describe the variability and determinants of the effect of extracorporeal CO₂ removal (ECCO₂R) on tidal volume (V_t), driving pressure (ΔP), and mechanical power (Power_RS) and to determine whether highly responsive patients can be identified for the purpose of predictive enrichment in ECCO₂R trial design.

METHODS

Using data from the SUPERNOVA trial (95 patients with early moderate acute respiratory distress syndrome), the independent effects of alveolar dead space fraction (ADF), respiratory system compliance (Crs), hypoxemia (PaO₂/FiO₂), and device performance (higher vs lower CO₂ extraction) on the magnitude of reduction in V_t, ΔP, and Power_RS permitted by ECCO₂R were assessed by linear regression. Predicted and observed changes in ΔP were compared by Bland-Altman analysis. Hypothetical trials of ECCO₂R, incorporating predictive enrichment and different target CO₂ removal rates, were simulated in the SUPERNOVA study population.

RESULTS

Changes in V_t permitted by ECCO₂R were independently associated with ADF and device performance but not PaO₂/FiO₂. Changes in ΔP and Power_RS were independently associated with ADF, Crs, and device performance but not PaO₂/FiO₂. The change in ΔP predicted from ADF and Crs was moderately correlated with observed change in ΔP (R² 0.32, p < 0.001); limits of agreement between observed and predicted changes in ΔP were ± 3.9 cmH₂O. In simulated trials, restricting enrollment to patients with a larger predicted decrease in ΔP enhanced the average reduction in ΔP, increased predicted mortality benefit, and reduced sample size and screening size requirements. The increase in statistical power obtained by restricting enrollment based on predicted ΔP response varied according to device performance as specified by the target CO₂ removal rate.

CONCLUSIONS

The lung-protective benefits of ECCO₂R increase with higher alveolar dead space fraction, lower respiratory system compliance, and higher device performance. ADF and Crs, rather than severity of hypoxemia, should be the primary factors determining whether to enroll patients in clinical trials of ECCO₂R.

Efficacy and safety of lower versus higher CO2 extraction devices to allow ultraprotective ventilation: secondary analysis of the SUPERNOVA study

Retrospective analysis of the SUPERNOVA trial exploring the hypothesis that efficacy and safety of extracorporeal carbon dioxide removal (ECCO2R) to facilitate reduction of tidal volume (VT) to 4 mL/kg in patients with acute respiratory distress syndrome (ARDS) may differ between systems with lower (area of membrane length 0.59 m2; blood flow 300–500 mL/min) and higher (membrane area 1.30 m2; blood flow between 800 and 1000 mL/min) CO2 extraction capacity. Ninety-five patients with moderate ARDS were included (33 patients treated with lower and 62 patients treated with higher CO2 extraction devices). We found that (1) VT of 4 mL/kg was reached by 55% and 64% of patients with the lower extraction versus 90% and 92% of patients with higher extraction devices at 8 and 24 hours from baseline, respectively (p<0.001), and (2) percentage of patients experiencing episodes of ECCO2R-related haemolysis and bleeding was higher with lower than with higher extraction devices (21% vs 6%, p=0.045% and 27% vs 6%, p=0.010, respectively). Although V T of 4 mL/kg could have been obtained with all devices, this was achieved frequently and with a lower rate of adverse events by devices with higher CO2 extraction capacity.

Comparison of the efficacy and safety of FP-1201-lyo (intravenously administered recombinant human interferon beta-1a) and placebo in the treatment of patients with moderate or severe acute respiratory distress syndrome: study protocol for a randomized controlled trial

Background

Acute respiratory distress syndrome (ARDS) results in vascular leakage, inflammation and respiratory failure. There are currently no approved pharmacological treatments for ARDS and standard of care involves treatment of the underlying cause, and supportive care. The vascular leakage may be related to reduced concentrations of local adenosine, which is involved in maintaining endothelial barrier function. Interferon (IFN) beta-1a up-regulates the cell surface ecto-5′-nucleotidase cluster of differentiation 73 (CD73), which increases adenosine levels, and IFN beta-1 may, therefore, be a potential treatment for ARDS. In a phase I/II, open-label study in 37 patients with acute lung injury (ALI)/ARDS, recombinant human IFN beta-1a was well tolerated and mortality rates were significantly lower in treated than in control patients.

Methods/design

In this phase III, double-blind, randomized, parallel-group trial, the efficacy and safety of recombinant human IFN beta-1a (FP-1201-lyo) will be compared with placebo in adult patients with ARDS. Patients will be randomly assigned to receive 10 μg FP-1201-lyo or placebo administered intravenously once daily for 6 days and will be monitored for 28 days or until discharged from the intensive care unit. Follow-up visits will then take place at days 90, 180 and 360. The primary endpoint is a composite endpoint including any cause of death at 28 days and days free of mechanical ventilation within 28 days among survivors. Secondary endpoints include: all-cause mortality at 28, 90, 180 and 360 days; organ failure-free days; length of hospital stay; pharmacodynamic assessment including measurement of myxovirus resistance protein A concentrations; and measures of quality of life, respiratory and neurological function at 180 and 360 days. The estimated sample size to demonstrate a reduction in the primary outcome between groups from 30% to 15% is 300 patients, and the study will be conducted in 70–80 centers in nine countries across Europe.

Discussion

There are no effective specific treatments for patients with ARDS and mortality rates remain high. The results from this study will provide evidence regarding the efficacy of a potential new therapeutic agent, FP-1201-lyo, in improving the clinical course and outcome for patients with moderate/severe ARDS.

Trial registration

European Union Clinical Trials Register, no: 2014-005260-15. Registered on 15 July 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2234-7) contains supplementary material, which is available to authorized users.