ICU predictive factors of fibrotic changes following COVID-19 related ARDS: a RECOVIDS substudy

Annals of Intensive Care volume 15, Article number: 177 (2025) Published: 04 November 2025

Background

Pulmonary fibrotic changes (FC) following COVID-19-related ARDS represent a significant concern due to the potential respiratory complications. The identification of early predictive factors for FC and the development of predictive tools are needed to optimize patient management and outcomes.

Methods

This observational prospective multicentre study is a substudy of the RECOVIDS study and included 32 centres in France and Belgium. COVID-19 ARDS survivors were included if they met the Berlin ARDS criteria or if they received high flow oxygen therapy (flow ≥ 50 L/min and FiO2 ≥ 50%). Exclusion criteria were non-attendance at follow-up 6 ± 1 months after ICU discharge, lack of baseline or follow-up chest CT, and history of interstitial lung disease. The primary endpoint was presence of FC at follow-up CT. The secondary outcome was to identify predominant radiological patterns.

Results

Among 555 patients included in the RECOVIDS study, 440 were analysed, of whom 162 (36.8%) had FC at follow-up. Predictive factors for FC included older age, body mass index < 30, Charlson comorbidity index ≥ 1, invasive mechanical ventilation, early signs of FC, and greater lung involvement on baseline CT. The nomogram for predicting pulmonary FC yielded an AUC of 80.6% (95%CI (76.4–84.8)). Late organizing pneumonia was the most common pattern overall and 30 (18.5%) of the 162 patients with FC presented mainly anterior fibrosis compatible with post ventilatory changes.

Conclusion

In this large cohort of COVID-19 ARDS survivors, 36.8% exhibited FC at 6 months post-ICU discharge. The key predictors identified here could guide therapeutic and follow-up strategies.

 

 

 

 

Respiratory effects of trunk inclination in obese and non-obese patients mechanically ventilated for ARDS

Critical Care volume 29, Article number: 457 (2025) Published: 28 October 2025

Background

Adjusting trunk inclination in patients with acute respiratory distress syndrome directly affects physiological variables such as respiratory mechanics and PaCO2 levels. These effects may vary according to the body mass index (BMI) due to differences in lung and chest wall mechanics, highlighting the need for further investigation to clarify the clinical relevance of body position across patient subgroups.

Methods

A secondary analysis compared the physiological effects of increasing trunk inclination angles between mechanically ventilated patients with obesity (BMI ≥ 30 kg/m2) and those without obesity (BMI < 30 kg/m2).

Results

Data from 159 patients collected across seven individual studies were analyzed. The following physiological changes were observed in response to increased trunk inclination: Sixty-five patients with obesity presented a greater decrease in respiratory system compliance (-7.5 [-10; -5] mL/cmH2O; p < 0.001) compared to ninety-four patients without obesity (-3.5 [-7; -0.08] mL/cmH2O; p = 0.045). Lung compliance decreased in obese patients (-7.8 [-12.4; -3.3] mL/cmH2O; p < 0.001), whereas no significant changes were observed in patients without obesity (-5.9 [-14.2; 2.3] mL/cmH2O; p = 0.160). Chest wall compliance decreased by -42.9 [-63.2; -22.6] mL/cmH2O (p < 0.001) in obese patients and by -47.7 [-95.3; -0.15] mL/cmH2O in non-obese patients (p = 0.049). PaCO2 increased in obese patients by 4.6 [1.4; 7.8] mmHg (p = 0.004) but not in patients without obesity (2.5 [-0.6; 5.6] (p = 0.113). No significant differences were observed in PaO2/FIO2 between phases.

Conclusions

Increasing the trunk inclination angle during passive ventilation reduces respiratory system, lung, and chest wall compliance. This effect was more pronounced in obese patients. Moreover, only this population exhibited an increase in PaCO2. We acknowledge the methodological heterogeneity across the included studies, which may have influenced the results. Overall, our results highlight the importance of considering BMI as a significant variable that influences individual physiological responses to changes in bed inclination.

 

Tidal volume and mortality during extracorporeal membrane oxygenation for acute respiratory distress syndrome: a multicenter observational cohort study

Annals of Intensive Care volume 15, Article number: 151 (2025) Published: 06 October 2025

Background

Approximately half of the patients with acute respiratory distress syndrome (ARDS) receiving extracorporeal membrane oxygenation (ECMO) remain ECMO-dependent beyond 14 days after ECMO initiation. The identification of factors associated with mortality during an ECMO run may update prognostic assessment and focus clinical interventions.

Methods

In this observational study, data from 1137 patients with COVID-19 ARDS receiving ECMO support in 29 German centers between January 1st 2020 and July 31st 2021 were analyzed. Multivariable stepwise logistic regression analyses were performed to build survival prediction models with day-by-day data during the first 14 days of an ECMO run. The primary endpoint was all-cause mortality in the intensive care unit.

Results

Mortality in this cohort was high (75%). Patients who remained ECMO-dependent on day 14 of their ECMO run showed comparable mortality to all patients receiving ECMO support on day 1. Yet, factors associated with mortality changed during the first 14 days of ECMO support. On day 1 of ECMO support, only patient age and lactate remained in the final mortality prediction model. On day 14 of an ECMO run, tidal volume was independently associated with mortality (adjusted Odds Ratio 0.693 (95%CI 0.564–0.851), p < 0.001 for 1 mL/kg increase in tidal volume per predicted body weight). The adjusted mortality for patients with a tidal volume below 2 mL/kg on day 14 of their ECMO run was above 80% (lower limit of the 95%CI interval). Higher tidal volume was mainly based on higher respiratory system compliance. Yet, the benefit of higher compliance was not observed in some patients who were still ventilated with very low driving pressures despite remaining ECMO-dependent on day 14 of ECMO support.

Conclusions

Mortality predictors change during the course of an ECMO run. In a cohort with high mortality, on day 14 of ECMO support for ARDS, tidal volume may be an independent predictor of mortality. Further analyses on ventilation strategies in patients who remain ECMO-dependent are needed.

 

Comparison of two transpulmonary pressure-based positive end-expiratory pressure titration strategies in acute respiratory distress syndrome: a randomized crossover study

Critical Care volume 29, Article number: 409 (2025) Published: 29 September 2025

Background

Esophageal pressure monitoring, which enables the estimation of transpulmonary pressure, has been proposed to personalize ventilator settings, particularly positive end-expiratory pressure (PEEP), in patients with acute respiratory distress syndrome (ARDS). Two conceptually different transpulmonary pressure-based PEEP titration strategies have thus been described but have never been compared. This study aims to compare the PEEP levels obtained with these two distinct strategies and their physiological effects.

Methods

This was a randomized crossover physiological study. Twenty patients with moderate to severe ARDS (PaO2/FiO2 < 150 mmHg) were included in an academic intensive care unit. The two transpulmonary pressure-based PEEP titration strategies were applied for 45 min each in a randomized order, separated by a 45-minute washout period. In the directly measured expiratory transpulmonary pressure (PL, exp) strategy, PEEP was set to target a PL, exp using a PL, exp/FiO2 table. In the calculated inspiratory transpulmonary pressure (PL, insp) strategy, PEEP was set to maintain PL, insp estimated using the lung/respiratory system elastance ratio between 20 and 22 cmH2O. Gas exchange, hemodynamics and partitioned respiratory mechanics were assessed at the end of each PEEP application period.

Results

Median PEEP levels determined by the two strategies were not different; however, individual values were uncorrelated, with a difference of at least 3 cmH2O in 14 (70%) patients. The PL, insp strategy resulted in higher PEEP levels than the PL, exp strategy in the non-obese patients but not in the obese patients. The effects on gas exchange, hemodynamics, and respiratory mechanics did not differ between the two strategies considering the entire study population or the obese and non-obese patients separately. Recruitment with PEEP (assessed by the recruited lung volume from PEEP 5 cmH2O), PL, insp, transpulmonary driving pressure and lung strain did not differ between the two strategies.

Conclusions

The two transpulmonary pressure-based titration strategies result in different PEEP levels in most patients. Neither strategy is associated with higher recruited lung volume or lower estimated Stress and Strain.

 

 

Role of age as eligibility criterion for ECMO in patients with ARDS: meta-regression analysis

Critical Care volume 28, Article number: 278 (2024) Published: 27 August 2024

Background

Age as an eligibility criterion for V-V ECMO is widely debated and varies among healthcare institutions. We examined how age relates to mortality in patients undergoing V-V ECMO for ARDS.

Methods

Systematic review and meta-regression of clinical studies published between 2015 and June 2024. Studies involving at least 6 ARDS patients treated with V-V ECMO, with specific data on ICU and/or hospital mortality and patient age were included. The search strategy was executed in PubMed, limited to English-language. COVID-19 and non-COVID-19 populations were analyzed separately. Meta-regressions of mortality outcomes on age were performed using gender, BMI, SAPS II, APACHE II, Charlson comorbidity index or SOFA as covariates.

Results

In non-COVID ARDS, the meta-regression of 173 studies with 56,257 participants showed a significant positive association between mean age and ICU/hospital mortality. In COVID-19 ARDS, a significant relationship between mean age and ICU mortality, but not hospital mortality, was found in 103 studies with 21,255 participants. Sensitivity analyses confirmed these findings, highlighting a linear relationship between age and mortality in both groups. For each additional year of mean age, ICU mortality increased by 1.2% in non-COVID ARDS and 1.9% in COVID ARDS.

Conclusions

The relationship between age and ICU mortality is linear and shows no inflection point. Consequently, no age cut-off can be recommended for determining patient eligibility for V-V ECMO.

 

Rapidly improving ARDS differs clinically and biologically from persistent ARDS

 

by Patricia L. Valda Toro, Andrew Willmore, Nelson E. Wu, Kevin L. Delucchi, Alejandra Jauregui, Pratik Sinha, Kathleen D. Liu, Carolyn M. Hendrickson, Aartik Sarma, Lucile P. A. Neyton, Aleksandra Leligdowicz, Charles R. Langelier, Hanjing Zhuo, Chayse Jones, Kirsten N. Kangelaris, Antonio D. Gomez

 

Critical Care volume 28, Article number: 132 Published: 22 April 2024

 

Background

Rapidly improving acute respiratory distress syndrome (RIARDS) is an increasingly appreciated subgroup of ARDS in which hypoxemia improves within 24 h after initiation of mechanical ventilation. Detailed clinical and biological features of RIARDS have not been clearly defined, and it is unknown whether RIARDS is associated with the hypoinflammatory or hyperinflammatory phenotype of ARDS. The purpose of this study was to define the clinical and biological features of RIARDS and its association with inflammatory subphenotypes.

Methods

We analyzed data from 215 patients who met Berlin criteria for ARDS (endotracheally intubated) and were enrolled in a prospective observational cohort conducted at two sites, one tertiary care center and one urban safety net hospital. RIARDS was defined according to previous studies as improvement of hypoxemia defined as (i) PaO2:FiO2 > 300 or (ii) SpO2: FiO2 > 315 on the day following diagnosis of ARDS (day 2) or (iii) unassisted breathing by day 2 and for the next 48 h (defined as absence of endotracheal intubation on day 2 through day 4). Plasma biomarkers were measured on samples collected on the day of study enrollment, and ARDS phenotypes were allocated as previously described.

Results

RIARDS accounted for 21% of all ARDS participants. Patients with RIARDS had better clinical outcomes compared to those with persistent ARDS, with lower hospital mortality (13% vs. 57%; p value < 0.001) and more ICU-free days (median 24 vs. 0; p value < 0.001). Plasma levels of interleukin-6, interleukin-8, and plasminogen activator inhibitor-1 were significantly lower among patients with RIARDS. The hypoinflammatory phenotype of ARDS was more common among patients with RIARDS (78% vs. 51% in persistent ARDS; p value = 0.001).

Conclusions

This study identifies a high prevalence of RIARDS in a multicenter observational cohort and confirms the more benign clinical course of these patients. We report the novel finding that RIARDS is characterized by lower concentrations of plasma biomarkers of inflammation compared to persistent ARDS, and that hypoinflammatory ARDS is more prevalent among patients with RIARDS. Identification and exclusion of RIARDS could potentially improve prognostic and predictive enrichment in clinical trials.

 

 

Improving management of ARDS: uniting acute management and long-term recovery

 

by Nicola Latronico, M. Eikermann, E. W. Ely and D. M. Needham 

 

Critical Care volume 28, Article number: 58 (2024) Published: 23 February 2024

 

Acute Respiratory Distress Syndrome (ARDS) is an important global health issue with high in-hospital mortality. Importantly, the impact of ARDS extends beyond the acute phase, with increased mortality and disability for months to years after hospitalization. These findings underscore the importance of extended follow-up to assess and address the Post-Intensive Care Syndrome (PICS), characterized by persistent impairments in physical, cognitive, and/or mental health status that impair quality of life over the long-term. Persistent muscle weakness is a common physical problem for ARDS survivors, affecting mobility and activities of daily living. Critical illness and related interventions, including prolonged bed rest and overuse of sedatives and neuromuscular blocking agents during mechanical ventilation, are important risk factors for ICU-acquired weakness. Deep sedation also increases the risk of delirium in the ICU, and long-term cognitive impairment. Corticosteroids also may be used during management of ARDS, particularly in the setting of COVID-19. Corticosteroids can be associated with myopathy and muscle weakness, as well as prolonged delirium that increases the risk of long-term cognitive impairment. The optimal duration and dosage of corticosteroids remain uncertain, and there's limited long-term data on their effects on muscle weakness and cognition in ARDS survivors. In addition to physical and cognitive issues, mental health challenges, such as depression, anxiety, and post-traumatic stress disorder, are common in ARDS survivors. Strategies to address these complications emphasize the need for consistent implementation of the evidence-based ABCDEF bundle, which includes daily management of analgesia in concert with early cessation of sedatives, avoidance of benzodiazepines, daily delirium monitoring and management, early mobilization, and incorporation of family at the bedside. In conclusion, ARDS is a complex global health challenge with consequences extending beyond the acute phase. Understanding the links between critical care management and long-term consequences is vital for developing effective therapeutic strategies and improving the quality of life for ARDS survivors.

 

Sex and gender differences in intensive care medicine

 

Intensive Care Medicine: Narrative Review: Published: 07 September 2023

 

 

Abstract

Despite significant advancements in critical care medicine, limited attention has been given to sex and gender disparities in management and outcomes of patients admitted to the intensive care unit (ICU). While “sex” pertains to biological and physiological characteristics, such as reproductive organs, chromosomes and sex hormones, “gender” refers more to sociocultural roles and human behavior. Unfortunately, data on gender-related topics in the ICU are lacking. Consequently, data on sex and gender-related differences in admission to the ICU, clinical course, length of stay, mortality, and post-ICU burdens, are often inconsistent. Moreover, when examining specific diagnoses in the ICU, variations can be observed in epidemiology, pathophysiology, presentation, severity, and treatment response due to the distinct impact of sex hormones on the immune and cardiovascular systems. In this narrative review, we highlight the influence of sex and gender on the clinical course, management, and outcomes of the most encountered intensive care conditions, in addition to the potential co-existence of unconscious biases which may also impact critical illness. Diagnoses with a known sex predilection will be discussed within the context of underlying sex differences in physiology, anatomy, and pharmacology with the goal of identifying areas where clinical improvement is needed. To optimize patient care and outcomes, it is crucial to comprehend and address sex and gender differences in the ICU setting and personalize management accordingly to ensure equitable, patient-centered care. Future research should focus on elucidating the underlying mechanisms driving sex and gender disparities, as well as exploring targeted interventions to mitigate these disparities and improve outcomes for all critically ill patients.

 

Which severe COVID-19 patients could benefit from high dose dexamethasone? A Bayesian post-hoc reanalysis of the COVIDICUS randomized clinical trial

 

by Chevret Sylvie, Bouadma Lila, Dupuis Claire, Burdet Charles and Timsit Jean-François 

 

Annals of Intensive Care volume 13, Article number: 75 (2023)

 

Background

The respective benefits of high and low doses of dexamethasone (DXM) in patients with severe acute respiratory syndrome coronavirus 2 (SARS-Cov2) and acute respiratory failure (ARF) are controversial, with two large triple-blind RCTs reaching very important difference in the effect-size. In the COVIDICUS trial, no evidence of additional benefit of high-dose dexamethasone (DXM20) was found. We aimed to explore whether some specific patient phenotypes could benefit from DXM20 compared to the standard of care 6 mg dose of DXM (DXMSoC).

Methods

We performed a post hoc exploratory Bayesian analysis of 473 patients who received either DXMSoc or DXM20 in the COVIDICUS trial. The outcome was the 60 day mortality rate of DXM20 over DXMSoC, with treatment effect measured on the hazard ratio (HR) estimated from Cox model. Bayesian analyses allowed to compute the posterior probability of a more than trivial benefit (HR < 0.95), and that of a potential harm (HR > 1.05). Bayesian measures of interaction then quantified the probability of interaction (Pr Interact) that the HR of death differed across the subsets by 20%. Primary analyses used noninformative priors, centred on HR = 1.00. Sensitivity analyses used sceptical and enthusiastic priors, based on null (HR = 1.00) or benefit (HR = 0.95) effects.

Results

Overall, the posterior probability of a more than trivial benefit and potential harm was 29.0 and 51.1%, respectively. There was some evidence of treatment by subset interaction (i) according to age (Pr Interact, 84%), with a 86.5% probability of benefit in patients aged below 70 compared to 22% in those aged above 70; (ii) according to the time since symptoms onset (Pr Interact, 99%), with a 99.9% probability of a more than trivial benefit when lower than 7 days compared to a < 0.1% probability when delayed by 7 days or more; and (iii) according to use of remdesivir (Pr Interact, 91%), with a 90.1% probability of benefit in patients receiving remdesivir compared to 19.1% in those who did not.

Conclusions

In this exploratory post hoc Bayesian analysis, compared with standard-of-care DXM, high-dose DXM may benefit patients aged less than 70 years with severe ARF that occurred less than 7 days after symptoms onset. The use of remdesivir may also favour the benefit of DXM20. Further analysis is needed to confirm these findings.

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

by Ahmed A. Rabie, Alyaa Elhazmi, Mohamed H. Azzam, Akram Abdelbary, Ahmed Labib, Alain Combes, Bishoy Zakhary, Graeme MacLaren, Ryan P. Barbaro, Giles J. Peek, Marta Velia Antonini, Kiran Shekar, Abdulrahman Al‐Fares, Pranay Oza, Yatin Mehta, Huda Alfoudri

Annals of Intensive Care volume 13, Article number: 36 (2023)

 

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.

 A structured diagnostic algorithm for patients with ARDS

by Lieuwe Durk Jacobus Bos, Harm Jan de Grooth and Pieter Roel Tuinman 

Critical Care volume 27, Article number: 94 (2023) Published: 21 March 2023

Abstract

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2023. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2023. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901.

 

Mechanical power of ventilation and driving pressure: two undervalued parameters for pre extracorporeal membrane oxygenation ventilation and during daily management?

by K. Hoppe, E. Khan, P. Meybohm and T. Riese 

Critical Care volume 27, Article number: 111 (2023) Published: 14 March 2023

Abstract

The current ARDS guidelines highly recommend lung protective ventilation which include plateau pressure (Pplat < 30 cm H2O), positive end expiratory pressure (PEEP > 5 cm H2O) and tidal volume (Vt of 6 ml/kg) of predicted body weight. In contrast, the ELSO guidelines suggest the evaluation of an indication of veno-venous extracorporeal membrane oxygenation (ECMO) due to hypoxemic or hypercapnic respiratory failure or as bridge to lung transplantation. Finally, these recommendations remain a wide range of scope of interpretation. However, particularly patients with moderate-severe to severe ARDS might benefit from strict adherence to lung protective ventilation strategies. Subsequently, we discuss whether extended physiological ventilation parameter analysis might be relevant for indication of ECMO support and can be implemented during the daily routine evaluation of ARDS patients. Particularly, this viewpoint focus on driving pressure and mechanical power.

 

Right ventricle-specific therapies in acute respiratory distress syndrome: a scoping review

by Simran Ganeriwal, Gabriele Alves dos Anjos, Mary Schleicher, Maxwell A. Hockstein, Adriano R. Tonelli, Abhijit Duggal and Matthew T. Siuba 

Critical Care volume 27, Article number: 104 (2023) Published: 12 March 2023

Objective

To summarize knowledge and identify gaps in evidence regarding treatment of right ventricular dysfunction (RVD) in acute respiratory distress syndrome (ARDS).

Data sources

We conducted a comprehensive search of MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials.

Study selection

Studies were included if they reported effects of treatments on right ventricular function, whether or not the intent was to modify right ventricular function.

Data extraction

Data extraction was performed independently and in duplicate by two authors. Data items included the study design, patient population, type of intervention, comparison group, and RV-specific outcomes.

Data synthesis

Of 1,430 studies screened, 51 studies reporting on 1,526 patients were included. By frequency, the included studies examined the following interventions: ventilator settings (29.4%), inhaled medications (33.3%), extracorporeal life support (13.7%), intravenous or oral medications (13.7%), and prone positioning (9.8%). The majority of the studies were non-randomized experimental studies (53%), with the next most common being case reports (16%). Only 5.9% of studies were RCTs. In total, 27% of studies were conducted with the goal of modifying RV function.

Conclusions

Given the prevalence of RVD in ARDS and its association with mortality, the dearth of research on this topic is concerning. This review highlights the need for prospective trials aimed at treating RV dysfunction in ARDS.

 

COVID-19 does not influence functional status after ARDS therapy

 

by Alice Bernard, Lina Maria Serna-Higuita, Peter Martus, Valbona Mirakaj, Michael Koeppen, Alexander Zarbock, Gernot Marx, Christian Putensen, Peter Rosenberger and Helene Anna Haeberle 

 

Critical Care volume 27, Article number: 48 (2023) 

 

Rationale

Health-related quality of life after surviving acute respiratory distress syndrome has come into focus in recent years, especially during the coronavirus disease 2019 pandemic.

Objectives

A total of 144 patients with acute respiratory distress syndrome caused by COVID-19 or of other origin were recruited in a randomized multicenter trial.

Methods

Clinical data during intensive care treatment and data up to 180 days after study inclusion were collected. Changes in the Sequential Organ Failure Assessment score were used to quantify disease severity. Disability was assessed using the Barthel index on days 1, 28, 90, and 180.

Measurements

Mortality rate and morbidity after 180 days were compared between patients with and without COVID-19. Independent risk factors associated with high disability were identified using a binary logistic regression.

Main results

The SOFA score at day 5 was an independent risk factor for high disability in both groups, and score dynamic within the first 5 days significantly impacted disability in the non-COVID group. Mortality after 180 days and impairment measured by the Barthel index did not differ between patients with and without COVID-19.

Conclusions

Resolution of organ dysfunction within the first 5 days significantly impacts long-term morbidity. Acute respiratory distress syndrome caused by COVID-19 was not associated with increased mortality or morbidity.

 

Dead space ventilation-related indices: bedside tools to evaluate the ventilation and perfusion relationship in patients with acute respiratory distress syndrome

 

by Mingjia Zheng 

 

Critical Care volume 27, Article number: 46 (2023) 

 

Abstract

Cumulative evidence has demonstrated that the ventilatory ratio closely correlates with mortality in acute respiratory distress syndrome (ARDS), and a primary feature in coronavirus disease 2019 (COVID-19)-ARDS is increased dead space that has been reported recently. Thus, new attention has been given to this group of dead space ventilation-related indices, such as physiological dead space fraction, ventilatory ratio, and end-tidal-to-arterial PCO2 ratio, which, albeit distinctive, are all global indices with which to assess the relationship between ventilation and perfusion. These parameters have already been applied to positive end expiratory pressure titration, prediction of responses to the prone position and the field of extracorporeal life support for patients suffering from ARDS. Dead space ventilation-related indices remain hampered by several deflects; notwithstanding, for this catastrophic syndrome, they may facilitate better stratifications and identifications of subphenotypes, thereby providing therapy tailored to individual needs.

 

Epidemiology and outcomes of early-onset AKI in COVID-19-related ARDS in comparison with non-COVID-19-related ARDS: insights from two prospective global cohort studies

 

by Bairbre A. McNicholas, Emanuele Rezoagli, Andrew J. Simpkin, Sankalp Khanna, Jacky Y. Suen, Pauline Yeung, Daniel Brodie, Gianluigi Li Bassi, Tai Pham, Giacomo Bellani, John F. Fraser and John Laffey 

Critical Care volume 27, Article number: 3 Published: 05 January 2023

Background

Acute kidney injury (AKI) is a frequent and severe complication of both COVID-19-related acute respiratory distress syndrome (ARDS) and non-COVID-19-related ARDS. The COVID-19 Critical Care Consortium (CCCC) has generated a global data set on the demographics, management and outcomes of critically ill COVID-19 patients. The LUNG-SAFE study was an international prospective cohort study of patients with severe respiratory failure, including ARDS, which pre-dated the pandemic.

Methods

The incidence, demographic profile, management and outcomes of early AKI in patients undergoing invasive mechanical ventilation for COVID-19-related ARDS were described and compared with AKI in a non-COVID-19-related ARDS cohort.

Results

Of 18,964 patients in the CCCC data set, 1699 patients with COVID-19-related ARDS required invasive ventilation and had relevant outcome data. Of these, 110 (6.5%) had stage 1, 94 (5.5%) had stage 2, 151 (8.9%) had stage 3 AKI, while 1214 (79.1%) had no AKI within 48 h of initiating invasive mechanical ventilation. Patients developing AKI were older and more likely to have hypertension or chronic cardiac disease. There were geo-economic differences in the incidence of AKI, with lower incidence of stage 3 AKI in European high-income countries and a higher incidence in patients from middle-income countries. Both 28-day and 90-day mortality risk was increased for patients with stage 2 (HR 2.00, p < 0.001) and stage 3 AKI (HR 1.95, p < 0.001). Compared to non-COVID-19 ARDS, the incidence of shock was reduced with lower cardiovascular SOFA score across all patient groups, while hospital mortality was worse in all groups [no AKI (30 vs 50%), Stage 1 (38 vs 58%), Stage 2 (56 vs 74%), and Stage 3 (52 vs 72%), p < 0.001]. The time profile of onset of AKI also differed, with 56% of all AKI occurring in the first 48 h in patients with COVID-19 ARDS compared to 89% in the non-COVID-19 ARDS population.

Conclusion

AKI is a common and serious complication of COVID-19, with a high mortality rate, which differs by geo-economic location. Important differences exist in the profile of AKI in COVID-19 versus non-COVID-19 ARDS in terms of their haemodynamic profile, time of onset and clinical outcomes.

 

Mechanical ventilation variables associated with high pulmonary artery pressures in ARDS patients: a post hoc analysis

 

by Joseph R. Riddell, Benjamin J. Jones, Bruno M. Fernandes, Daniel J. Law, Jackie A. Cooper and Matt P. Wise 

 

Critical Care volume 26, Article number: 396 (2022)

 

Background

The relationship between indices of mechanical ventilation and pulmonary artery pressures remains ill-defined in ARDS. As our understanding of mechanical ventilation has progressed, there is now a greater appreciation of the impact of high driving pressures and mechanical power in perpetuating lung injury. However, the relationship between the newer derived indices of mechanical ventilation and pulmonary artery pressure is unclear. We performed a post hoc analysis of the Fluid and Catheters Treatment Trial (FACTT) trial to investigate the associations between mechanical ventilation indices in ARDS patients and the prevalence of pulmonary hypertension. This may help elucidate future clinical targets for more, right ventricular protective, mechanical ventilation strategies.

Methods

We performed a post hoc analysis of the FACTT database to identify ARDS patients who had a pulmonary artery catheter (PAC) inserted and pulmonary artery pressure readings recorded. We excluded any patient with a PAC inserted who was spontaneously breathing, as driving pressure and mechanical power are not validated in this cohort. Three independent analyses were performed: a univariate analysis, to assess for associations between mPAP and mechanical ventilation parameters using Pearson correlation coefficients, a multivariate analysis, to assess for independent associations with mPAP using a multiple regression model according to Akaike’s information criteria and finally an analysis for nonlinearity, using the best-fitting model according to the Bayesian information criterion (BIC) from linear, quadratic, fractional polynomial and restricted cubic spline models.

Results

All the ventilation parameters demonstrated a significant correlation with mPAP, except tidal volume (once adjusted for respiratory rate) in the univariate analysis. The multivariate analysis demonstrated that the blood pH level, P/F ratio, PaCO2 level, mean airway pressure and the mechanical power indexed to compliance were independently associated with mPAP. In the final nonlinear analysis, associations did not differ from linearity except for 4 variables for which the fractional polynomial was the best-fitting model. These were mechanical power (p = 0.01 compared to the linear model), respiratory rate (p = 0.04), peak pressure (p = 0.03) and mean airway pressure (p = 0.01). Two nonlinear variables associated with mPAP were assessed in more detail, respiratory rate and mechanical power. Inflexion points at a respiratory rate of 16.8 cycles per minute and a mechanical power of 8.8 J/min were demonstrated.

Conclusions

The associations identified between mPAP and mechanical ventilation variables in this analysis would suggest that classical ARDS lung protective strategies, including low tidal volume ventilation and permissive hypercapnia, may negatively impact the management of the subset of ARDS patients with associated right ventricular dysfunction or ACP. Additionally, respiratory rates above 17 cycles per minute show an incremental increase in mPAP. Therefore, increases in tidal volume (within the limitation of driving pressure < 18 cmH20) may represent a more right ventricular protective way to control CO2 and pH.

 

 

 

ARDS: hidden perils of an overburdened diagnosis

 

by Martin J. Tobin 

 

Critical Care volume 26, Article number: 392 (2022)

 

A diagnosis of ARDS serves as a pretext for several perilous clinical practices. Clinical trials demonstrated that tidal volume 12 ml/kg increases patient mortality, but 6 ml/kg has not proven superior to 11 ml/kg or anything in between. Present guidelines recommend 4 ml/kg, which foments severe air hunger, leading to prescription of hazardous (yet ineffective) sedatives, narcotics and paralytic agents. Inappropriate lowering of tidal volume also fosters double triggering, which promotes alveolar overdistention and lung injury. Successive panels have devoted considerable energy to developing a more precise definition of ARDS to homogenize the recruitment of patients into clinical trials. Each of three pillars of the prevailing Berlin definition is extremely flimsy and the source of confusion and unscientific practices. For doctors at the bedside, none of the revisions have enhanced patient care over that using the original 1967 description of Ashbaugh and colleagues. Bedside doctors are better advised to diagnose ARDS on the basis of pattern recognition and instead concentrate their vigilance on resolving the numerous hidden dangers that follow inevitably once a diagnosis has been made…

 

Evaluation of inhaled nitric oxide (iNO) treatment for moderate-to-severe ARDS in critically ill patients with COVID-19: a multicenter cohort study

 

by Khalid Al Sulaiman, Ghazwa B. Korayem, Ali F. Altebainawi, Shmeylan Al Harbi, Abdulrahman Alissa, Abdullah Alharthi, Raed Kensara, Amjaad Alfahed, Ramesh Vishwakarma, Hussain Al Haji, Naif Almohaimid, Omar Al Zumai, Fahad Alrubayan, Abdulmajid Asiri, Nasser Alkahtani, Abdulaziz Alolayan… 

 

Critical Care volume 26, Article number: 304 (2022) 

 

Background

Inhaled nitric oxide (iNO) is used as rescue therapy in patients with refractory hypoxemia due to severe COVID-19 acute respiratory distress syndrome (ARDS) despite the recommendation against the use of this treatment. To date, the effect of iNO on the clinical outcomes of critically ill COVID-19 patients with moderate-to-severe ARDS remains arguable. Therefore, this study aimed to evaluate the use of iNO in critically ill COVID-19 patients with moderate-to-severe ARDS.

Methods

This multicenter, retrospective cohort study included critically ill adult patients with confirmed COVID-19 treated from March 01, 2020, until July 31, 2021. Eligible patients with moderate-to-severe ARDS were subsequently categorized into two groups based on inhaled nitric oxide (iNO) use throughout their ICU stay. The primary endpoint was the improvement in oxygenation parameters 24 h after iNO use. Other outcomes were considered secondary. Propensity score matching (1:2) was used based on the predefined criteria.

Results

A total of 1598 patients were screened, and 815 were included based on the eligibility criteria. Among them, 210 patients were matched based on predefined criteria. Oxygenation parameters (PaO2, FiO2 requirement, P/F ratio, oxygenation index) were significantly improved 24 h after iNO administration within a median of six days of ICU admission. However, the risk of 30-day and in-hospital mortality were found to be similar between the two groups (HR: 1.18; 95% CI: 0.77, 1.82; p = 0.45 and HR: 1.40; 95% CI: 0.94, 2.11; p= 0.10, respectively). On the other hand, ventilator-free days (VFDs) were significantly fewer, and  ICU and hospital LOS were significantly longer in the iNO group. In addition, patients who received iNO had higher odds of acute kidney injury (AKI) (OR (95% CI): 2.35 (1.30, 4.26), p value = 0.005) and hospital/ventilator-acquired pneumonia (OR (95% CI): 3.2 (1.76, 5.83), p value = 0.001).

Conclusion

In critically ill COVID-19 patients with moderate-to-severe ARDS, iNO rescue therapy is associated with improved oxygenation parameters but no mortality benefits. Moreover, iNO use is associated with higher odds of AKI, pneumonia, longer LOS, and fewer VFDs.

 

 

Critical Care Bulletin - September 2022

 

PEEP-FiO2 table versus EIT to titrate PEEP in mechanically ventilated patients with COVID-19-related ARDS

 

by Peter Somhorst, Philip van der Zee, Henrik Endeman and Diederik Gommers 

 

Critical Care volume 26, Article number: 272 (2022)

 

Rationale

It is unknown how to titrate positive end-expiratory pressure (PEEP) in patients with COVID-19-related acute respiratory distress syndrome (ARDS). Guidelines recommend the one-size-fits-all PEEP-FiO2 table. In this retrospective cohort study, an electrical impedance tomography (EIT)-guided PEEP trial was used to titrate PEEP.

Objectives

To compare baseline PEEP according to the high PEEP-FiO2 table and personalized PEEP following an EIT-guided PEEP trial.

Methods

We performed an EIT-guided decremental PEEP trial in patients with moderate-to-severe COVID-19-related ARDS upon intensive care unit admission. PEEP was set at the lowest PEEP above the intersection of curves representing relative alveolar overdistention and collapse. Baseline PEEP was compared with PEEP set according to EIT. We identified patients in whom the EIT-guided PEEP trial resulted in a decrease or increase in PEEP of ≥ 2 cmH2O.

Measurements and main results

We performed a PEEP trial in 75 patients. In 23 (31%) patients, PEEP was decreased ≥ 2 cmH2O, and in 24 (32%) patients, PEEP was increased ≥ 2 cmH2O. Patients in whom PEEP was decreased had improved respiratory mechanics and more overdistention in the non-dependent lung region at higher PEEP levels. These patients also had a lower BMI, longer time between onset of symptoms and intubation, and higher incidence of pulmonary embolism. Oxygenation improved in patients in whom PEEP was increased.

Conclusions

An EIT-guided PEEP trial resulted in a relevant change in PEEP in 63% of patients. These results support the hypothesis that PEEP should be personalized in patients with ARDS.