Six-month and 12-month patient outcomes based on inflammatory subphenotypes in sepsis-associated ARDS: secondary analysis of SAILS-ALTOS trial

Effect of statins on sepsis and inflammatory factors: A Mendelian randomization study

BACKGROUND

As inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), statins can reduce the synthesis of low-density lipoptrotein cholesterol (LDL-C), and are clinically used as first-line lipid-lowering drugs to prevent cardiovascular diseases. However, the effect of statins on sepsis is controversial. Therefore, we intend to explore the effects of statins on sepsis and inflammatory factors through Mendelian randomization (MR).

METHOD

We obtained sepsis, inflammatory factors, and LDL-C data from open and free genome-wide association study (GWAS) for subsequent analysis. Inverse-variance weighted (IVW) was the main method, MR-Egger, MR-PRESSO and Cochrane's Q-test were used as sensitive analysis to evaluate the robustness of MR results.

RESULTS

Statins were associated with a reduced risk of sepsis under 75 (sepsis in individuals under 75 years old) (OR: .716, 95% CI: .572-.896, p = .003), elevated circulating IL-18 (OR: .762, 95% CI: .643-.903, p = .002) and elevated circulating CCL2 (OR: .416, 95% CI: .279-.620, p = 1.685e-5).

CONCLUSION

Statins may have a protective effect on sepsis and this may provide a new idea for the treatment of sepsis.

Critical illness-associated limb and diaphragmatic weakness

PURPOSE OF REVIEW

In the current review, we aim to highlight the evolving evidence on the diagnosis, prevention and treatment of critical illness weakness (CIW) and critical illness associated diaphragmatic weakness (CIDW).

RECENT FINDINGS

In the ICU, several risk factors can lead to CIW and CIDW. Recent evidence suggests that they have different pathophysiological mechanisms and impact on outcomes, although they share common risk factors and may overlap in several patients. Their diagnosis is challenging, because CIW diagnosis is primarily clinical and, therefore, difficult to obtain in the ICU population, and CIDW diagnosis is complex and not easily performed at the bedside. All of these issues lead to underdiagnosis of CIW and CIDW, which significantly increases the risk of complications and the impact on both short and long term outcomes. Moreover, recent studies have explored promising diagnostic techniques that are may be easily implemented in daily clinical practice. In addition, this review summarizes the latest research aimed at improving how to prevent and treat CIW and CIDW.

SUMMARY

This review aims to clarify some uncertain aspects and provide helpful information on developing monitoring techniques and therapeutic interventions for managing CIW and CIDW.

Illness Weakness, Polyneuropathy and Myopathy: Diagnosis, treatment, and long-term outcomes

BACKGROUND

Severe weakness associated with critical illness (CIW) is common. This narrative review summarizes the latest scientific insights and proposes a guide for clinicians to optimize the diagnosis and management of the CIW during the various stages of the disease from the ICU to the community stage.

MAIN BODY

CIW arises as diffuse, symmetrical weakness after ICU admission, which is an important differentiating factor from other diseases causing non-symmetrical muscle weakness or paralysis. In patients with adequate cognitive function, CIW can be easily diagnosed at the bedside using manual muscle testing, which should be routinely conducted until ICU discharge. In patients with delirium or coma or those with prolonged, severe weakness, specific neurophysiological investigations and, in selected cases, muscle biopsy are recommended. With these exams, CIW can be differentiated into critical illness polyneuropathy or myopathy, which often coexist. On the general ward, CIW is seen in patients with prolonged previous ICU treatment, or in those developing a new sepsis. Respiratory muscle weakness can cause neuromuscular respiratory failure, which needs prompt recognition and rapid treatment to avoid life-threatening situations. Active rehabilitation should be reassessed and tailored to the new patient's condition to reduce the risk of disease progression. CIW is associated with long-term physical, cognitive and mental impairments, which emphasizes the need for a multidisciplinary model of care. Follow-up clinics for patients surviving critical illness may serve this purpose by providing direct clinical support to patients, managing referrals to other specialists and general practitioners, and serving as a platform for research to describe the natural history of post-intensive care syndrome and to identify new therapeutic interventions. This surveillance should include an assessment of the activities of daily living, mood, and functional mobility. Finally, nutritional status should be longitudinally assessed in all ICU survivors and incorporated into a patient-centered nutritional approach guided by a dietician.

CONCLUSIONS

Early ICU mobilization combined with the best evidence-based ICU practices can effectively reduce short-term weakness. Multi-professional collaborations are needed to guarantee a multi-dimensional evaluation and unitary community care programs for survivors of critical illnesses.

Early transthoracic echocardiography and long-term mortality in moderate- to-severe acute respiratory distress syndrome: An analysis of the Medical Information Mart for Intensive Care database

BACKGROUND

The clinical use of transthoracic echocardiography (TTE) in patients with acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) has dramatically increased, its impact on long-term prognosis in these patients has not been studied. This study aimed to explore the effect of early-TTE on long-term mortality in patients with moderate-to-severe ARDS in ICU.

METHODS

A total of 2833 patients with moderate-to-severe ARDS who had or had not received early-TTE were obtained from the Medical Information Mart for Intensive Care (MIMIC-III) database after imputing missing values by a random forest model, patients were divided into early-TTE group and non-early-TTE group according to whether they received TTE examination in ICU. A variety of statistical methods were used to balance 41 covariates and increase the reliability of this study, including propensity score matching, inverse probability of treatment weight, covariate balancing propensity score, multivariable regression, and doubly robust estimation. Chi-Square test and t-tests were used to examine the differences between groups for categorical and continuous data, respectively.

RESULTS

There was a significant improvement in 90-day mortality in the early-TTE group compared to non-early-TTE group (odds ratio  =  0.79, 95% CI: 0.64-0.98, p-value  =  0.036), revealing a beneficial effect of early-TTE. Net-input was significantly decreased in the early-TTE group on the third day of ICU admission and throughout the ICU stay, compared with non-early-TTE group (838.57 vs. 1181.89 mL, p-value  =  0.014; 4542.54 vs. 8025.25 mL, p-value  =  0.05). There was a significant difference in the reduction of serum lactate between the two groups, revealing the beneficial effect of early-TTE (0.59 vs. 0.83, p-value  =  0.009). Furthermore, the reduction in the proportion of acute kidney injury demonstrated a correlation between early-TTE and kidney protection (33% vs. 40%, p-value < 0.001).

CONCLUSIONS

Early application of TTE is beneficial to improve the long-term mortality of patients with moderate-to-severe ARDS.

Clinical Sepsis Phenotypes in Critically Ill Patients

Sepsis, defined as the life-threatening dysregulated host response to an infection leading to organ dysfunction, is considered as one of the leading causes of mortality worldwide, especially in intensive care units (ICU). Moreover, sepsis remains an enigmatic clinical syndrome, with complex pathophysiology incompletely understood and a great heterogeneity both in terms of clinical expression, patient response to currently available therapeutic interventions and outcomes. This heterogeneity proves to be a major obstacle in our quest to deliver improved treatment in septic critical care patients; thus, identification of clinical phenotypes is absolutely necessary. Although this might be seen as an extremely difficult task, nowadays, artificial intelligence and machine learning techniques can be recruited to quantify similarities between individuals within sepsis population and differentiate them into distinct phenotypes regarding not only temperature, hemodynamics or type of organ dysfunction, but also fluid status/responsiveness, trajectories in ICU and outcome. Hopefully, we will eventually manage to determine both the subgroup of septic patients that will benefit from a therapeutic intervention and the correct timing of applying the intervention during the disease process.

Role of aspirin, beta-blocker, statins, and heparin therapy in septic patients under mechanical ventilation: a narrative review

Sepsis is the main cause of death among patients admitted to intensive care units. Management of sepsis includes fluid resuscitation, vasopressors, intravenous antimicrobials, source control, mechanical ventilation, and others. New insights into the potential benefits of non-antimicrobial drugs in sepsis have evolved based on the pathophysiology of the disease and the mechanism of action of some drugs, but the findings are still controversial. In this study, we aimed to evaluate the effect of beta-blockers, aspirin, statins, and heparin as adjunctive treatments in septic patients under mechanical ventilation with non-cardiovascular diseases and their effect on mortality. We searched PubMed with relevant keywords (beta-blockers, aspirin, statins, or heparin, and critically ill or sepsis) for the last 10 years and some personal collection of relevant articles, and then we assessed studies according to prespecified inclusion and exclusion criteria. Our results show that beta-blockers, aspirin, and heparin may have promising feedback on reducing mortality. However, new well-controlled, randomized, multicenter studies are needed to confirm that, and multiple issues regarding their usage need to be addressed. On the other hand, the feedback regarding the effectiveness of statins was not as strong as that of the other drugs studied, and we suggest that further research is needed to confirm these results.

Identifying Comorbid Subtypes of Patients With Acute Respiratory Failure

BACKGROUND

Patients with acute respiratory failure have multiple risk factors for disability following their intensive care unit stay. Interventions to facilitate independence at hospital discharge may be more effective if personalized for patient subtypes.

OBJECTIVES

To identify subtypes of patients with acute respiratory failure requiring mechanical ventilation and compare post-intensive care functional disability and intensive care unit mobility level among subtypes.

METHODS

Latent class analysis was conducted in a cohort of adult medical intensive care unit patients with acute respiratory failure receiving mechanical ventilation who survived to hospital discharge. Demographic and clinical medical record data were collected early in the stay. Clinical characteristics and outcomes were compared among subtypes by using Kruskal-Wallis tests and χ2 tests of independence.

RESULTS

In a cohort of 934 patients, the 6-class model provided the optimal fit. Patients in class 4 (obesity and kidney impairment) had worse functional impairment at hospital discharge than patients in classes 1 through 3. Patients in class 3 (alert patients) had the lowest magnitude of functional impairment (P < .001) and achieved the earliest out-of-bed mobility and highest mobility level of all subtypes (P < .001).

CONCLUSIONS

Acute respiratory failure survivor subtypes identified from clinical data available early in the intensive care unit stay differ in post-intensive care functional disability. Future research should target high-risk patients in early rehabilitation trials in the intensive care unit. Additional investigation of contextual factors and mechanisms of disability is critical to improving quality of life in acute respiratory failure survivors.

ESICM guidelines on acute respiratory distress syndrome: definition, phenotyping and respiratory support strategies

The aim of these guidelines is to update the 2017 clinical practice guideline (CPG) of the European Society of Intensive Care Medicine (ESICM). The scope of this CPG is limited to adult patients and to non-pharmacological respiratory support strategies across different aspects of acute respiratory distress syndrome (ARDS), including ARDS due to coronavirus disease 2019 (COVID-19). These guidelines were formulated by an international panel of clinical experts, one methodologist and patients' representatives on behalf of the ESICM. The review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence and grade recommendations and the quality of reporting of each study based on the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) network guidelines. The CPG addressed 21 questions and formulates 21 recommendations on the following domains: (1) definition; (2) phenotyping, and respiratory support strategies including (3) high-flow nasal cannula oxygen (HFNO); (4) non-invasive ventilation (NIV); (5) tidal volume setting; (6) positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM); (7) prone positioning; (8) neuromuscular blockade, and (9) extracorporeal life support (ECLS). In addition, the CPG includes expert opinion on clinical practice and identifies the areas of future research.

Acute and long-term cognitive impairment following sepsis: mechanism and prevention

INTRODUCTION

Sepsis is a severe host response to infection, which induces both acute and long-term cognitive impairment. Despite its high incidence following sepsis, the underlying mechanisms remain elusive and effective treatments are not available clinically.

AREA COVERED

This review focuses on elucidating the pathological mechanisms underlying cognitive impairment following sepsis. Specifically, the authors discuss the role of systemic inflammation response, blood-brain barrier disruption, neuroinflammation, mitochondrial dysfunction, neuronal dysfunction, and Aβ accumulation and tau phosphorylation in cognitive impairment after sepsis. Additionally, they review current strategies to ameliorate cognitive impairment.

EXPERT OPINION

Potential interventions to reduce cognitive impairment after sepsis include earlier diagnosis and effective infection control, hemodynamic homeostasis, and adequate brain perfusion. Furthermore, interventions to reduce inflammatory response, reactive oxygen species, blood-brain barrier disruption, mitochondrial dysfunction, neuronal injury or death could be beneficial. Implementing strategies to minimize delirium, sleep disturbance, stress factors, and immobility are also recommended. Furthermore, avoiding neurotoxins and implementing early rehabilitation may also be important for preventing cognitive impairment after sepsis.

Cardiovascular Subphenotypes in ARDS: Diagnostic and Therapeutic Implications and Overlap with Other ARDS Subphenotypes

Acute respiratory distress syndrome (ARDS) is a highly heterogeneous clinical condition. Shock is a poor prognostic sign in ARDS, and heterogeneity in its pathophysiology may be a barrier to its effective treatment. Although right ventricular dysfunction is commonly implicated, there is no consensus definition for its diagnosis, and left ventricular function is neglected. There is a need to identify the homogenous subgroups within ARDS, that have a similar pathobiology, which can then be treated with targeted therapies. Haemodynamic clustering analyses in patients with ARDS have identified two subphenotypes of increasingly severe right ventricular injury, and a further subphenotype of hyperdynamic left ventricular function. In this review, we discuss how phenotyping the cardiovascular system in ARDS may align with haemodynamic pathophysiology, can aid in optimally defining right ventricular dysfunction and can identify tailored therapeutic targets for shock in ARDS. Additionally, clustering analyses of inflammatory, clinical and radiographic data describe other subphenotypes in ARDS. We detail the potential overlap between these and the cardiovascular phenotypes.

Post-intensive care syndrome (PICS): recent updates

An increasing number of patients are surviving critical illness, but some experience new or worsening long-lasting impairments in physical, cognitive and/or mental health, commonly known as post-intensive care syndrome (PICS). The need to better understand and improve PICS has resulted in a growing body of literature exploring its various facets. This narrative review will focus on recent studies evaluating various aspects of PICS, including co-occurrence of specific impairments, subtypes/phenotypes, risk factors/mechanisms, and interventions. In addition, we highlight new aspects of PICS, including long-term fatigue, pain, and unemployment.

A narrative review of progress in the application of artificial intelligence in acute respiratory distress syndrome: subtypes and predictive models

Background and Objective

Acute respiratory distress syndrome (ARDS) occurs in different populations, and it is very challenging to manage heterogeneous patient groups. Artificial intelligence (AI) aids in interpreting complex data of patients with ARDS and can be used to detect adverse events as it can automatically capture complex relationships. This review aimed to explore the application and progress of AI in ARDS (e.g., subgroup classification of patients with ARDS via unsupervised clustering and supervised predictive models for early detection) and identify the current ARDS-related problems that can be solved using AI.

Methods

This comprehensive and narrative review was performed to obtain information about the application of AI in ARDS and summarize its subtypes and predictive models.

Key Content and Findings

The current applications of AI and machine learning in ARDS include ARDS subgroup classification, diagnosis, and survival prediction. In this review, the current problems that should be addressed by AI in ARDS were identified, and our findings may serve as a useful reference for its translational use in the ARDS field.

Conclusions

Owing to the discovery of hyper- and hypoinflammatory subtypes, individualized treatment of ARDS is possible, and diagnosis and survival prediction are essential in disease management and planning. However, prospective studies should clarify the reliability and generalizability of the results using AI and machine learning and performing bedside testing in larger populations to establish a more stable and time-resilient model. Therefore, a consensus on conducting and reporting machine learning studies in medicine should be urgently established.

Personalized medicine targeting different ARDS phenotypes: The future of pharmacotherapy for ARDS?

INTRODUCTION

Acute respiratory distress syndrome (ARDS) still represents a major challenge with high mortality rates and altered quality of life. Many well-designed studies have failed to improve ARDS outcomes. Heterogeneity of etiologies, mechanisms of lung damage, different lung mechanics, and different treatment approaches may explain these failures. At the era of personalized medicine, ARDS phenotyping is not only a field of research, but a bedside consideration when implementing therapy. ARDS has moved from being a simple syndrome to a more complex area of subgrouping. Intensivists must understand these phenotypes and therapies associated with a better outcome.

AREAS COVERED

After a brief sum-up of the different type of ARDS phenotypes, we will present some relevant therapy that may be impacted by phenotyping. A focus on pharmacotherapy will be realized before a section on non-pharmaceutical strategies. Eventually, we will highlight the limits of our knowledge of phenotyping and the pitfalls of personalized medicine.

EXPERT OPINION

Biological and morphological ARDS phenotypes are now well studied. The future of ARDS therapy will go through phenotyping that allows a personalized medication for each patient. However, a better assessment of these phenotypes is required, and clinical trials should be conducted with an ad-hoc phenotyping before randomization.

Research Progress on Phenotypic Classification of Acute Respiratory Distress Syndrome: A Narrative Review

Acute respiratory distress syndrome (ARDS) is a clinical syndrome that is characterized by an acute onset and refractory hypoxemia. It remains an important contributor to high mortality in critically ill patients, and the majority of clinical randomized controlled trials on ARDS provide underwhelming findings, which is attributed in large part to its pathophysiological and clinical heterogeneity, among other aspects. It is now widely accepted that ARDS is highly heterogeneous, growing evidences support this. ARDS phenotypic and subphenotypic studies aim to further differentiate and identify ARDS heterogeneity in the hope that clinicians can benefit from it, then can diagnose ARDS faster and more accurately and provide targeted treatments. This review collates and evaluates the major phenotype-related research advances of recent years, with a specific focus on ARDS biomarkers and clinical factors.

Patient and Caregiver-Derived Health Service Improvements for Better Critical Care Recovery

OBJECTIVES

To engage critical care end-users (survivors and caregivers) to describe their emotions and experiences across their recovery trajectory, and elicit their ideas and solutions for health service improvements to improve the ICU recovery experience.

DESIGN

End-user engagement as part of a qualitative design using the Framework Analysis method.

SETTING

The Society of Critical Care Medicine's THRIVE international collaborative sites (follow-up clinics and peer support groups).

SUBJECTS

Patients and caregivers following critical illness and identified through the collaboratives.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eighty-six interviews were conducted. The following themes were identified: 1) Emotions and experiences of patients-"Loss of former self; Experiences of disability and adaptation"; 2) Emotions and experiences of caregivers-"Emotional impacts, adopting new roles, and caregiver burden; Influence of gender roles; Adaptation, adjustment, recalibration"; and 3) Patient and caregiver-generated solutions to improve recovery across the arc of care-"Family-targeted education; Expectation management; Rehabilitation for patients and caregivers; Peer support groups; Reconnecting with ICU post-discharge; Access to community-based supports post-discharge; Psychological support; Education of issues of ICU survivorship for health professionals; Support across recovery trajectory." Themes were mapped to a previously published recovery framework (Timing It Right) that captures patient and caregiver experiences and their support needs across the phases of care from the event/diagnosis to adaptation post-discharge home.

CONCLUSIONS

Patients and caregivers reported a range of emotions and experiences across the recovery trajectory from ICU to home. Through end-user engagement strategies many potential solutions were identified that could be implemented by health services and tested to support the delivery of higher-quality care for ICU survivors and their caregivers that extend from tertiary to primary care settings.

Acute respiratory distress syndrome in adults: diagnosis, outcomes, long-term sequelae, and management

Acute respiratory distress syndrome (ARDS) is characterised by acute hypoxaemic respiratory failure with bilateral infiltrates on chest imaging, which is not fully explained by cardiac failure or fluid overload. ARDS is defined by the Berlin criteria. In this Series paper the diagnosis, management, outcomes, and long-term sequelae of ARDS are reviewed. Potential limitations of the ARDS definition and evidence that could inform future revisions are considered. Guideline recommendations, evidence, and uncertainties in relation to ARDS management are discussed. The future of ARDS strives towards a precision medicine approach, and the framework of treatable traits in ARDS diagnosis and management is explored.

New Insights into Clinical and Mechanistic Heterogeneity of the Acute Respiratory Distress Syndrome: Summary of the Aspen Lung Conference 2021

Clinical and molecular heterogeneity are common features of human disease. Understanding the basis for heterogeneity has led to major advances in therapy for many cancers and pulmonary diseases such as cystic fibrosis and asthma. Although heterogeneity of risk factors, disease severity, and outcomes in survivors are common features of the acute respiratory distress syndrome (ARDS), many challenges exist in understanding the clinical and molecular basis for disease heterogeneity and using heterogeneity to tailor therapy for individual patients. This report summarizes the proceedings of the 2021 Aspen Lung Conference, which was organized to review key issues related to understanding clinical and molecular heterogeneity in ARDS. The goals were to review new information about ARDS phenotypes, to explore multicellular and multisystem mechanisms responsible for heterogeneity, and to review how best to account for clinical and molecular heterogeneity in clinical trial design and assessment of outcomes. The report concludes with recommendations for future research to understand the clinical and basic mechanisms underlying heterogeneity in ARDS to advance the development of new treatments for this life-threatening critical illness.

One-year patient outcomes based on lung morphology in acute respiratory distress syndrome: secondary analysis of LIVE trial

Background

Acute respiratory distress syndrome (ARDS) has different phenotypes and distinct short-term outcomes. Patients with non-focal ARDS have a higher short-term mortality than focal ones. The aim of this study was to assess the impact of the morphological phenotypes of ARDS on long-term outcomes.

Methods

This was a secondary analysis of the LIVE study, a prospective, randomised control trial, assessing the usefulness of a personalised ventilator setting according to lung morphology in moderate-to-severe ARDS. ARDS was classified as focal (consolidations only in the infero-posterior part of the lungs) or non-focal. Outcomes were assessed using mortality and functional scores for quality of life at the 1-year follow-up.

Results

A total of 124 focal ARDS and 236 non-focal ARDS cases were included. The 1-year mortality was higher for non-focal ARDS than for focal ARDS (37% vs. 24%, p = 0.012). Non-focal ARDS (hazard ratio, 3.44; 95% confidence interval, 1.80–6.59; p < 0.001), age, McCabe score, haematological cancers, SAPS II, and renal replacement therapy were independently associated with 1-year mortality. This difference was driven by mortality during the first 90 days (28 vs. 16%, p = 0.010) but not between 90 days and 1 year (7 vs. 6%, p = 0.591), at which point only the McCabe score was independently associated with mortality. Morphological phenotypes had no impact on patient-reported outcomes.

Conclusion

Lung morphologies reflect the acute phase of ARDS and its short-term impact but not long-term outcomes, which seem only influenced by comorbidities.

Trial registration: NCT 02149589; May 29, 2014.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04036-7.

Phenotypes and subphenotypes of delirium: a review of current categorisations and suggestions for progression

Delirium is a clinical syndrome occurring in heterogeneous patient populations. It affects 45-87% of critical care patients and is often associated with adverse outcomes including acquired dementia, institutionalisation, and death. Despite an exponential increase in delirium research in recent years, the pathophysiological mechanisms resulting in the clinical presentation of delirium are still hypotheses. Efforts have been made to categorise the delirium spectrum into clinically meaningful subgroups (subphenotypes), using psychomotor subtypes such as hypoactive, hyperactive, and mixed, for example, and also inflammatory and non-inflammatory delirium. Delirium remains, however, a constellation of symptoms resulting from a variety of risk factors and precipitants with currently no successful targeted pharmacological treatment. Identifying specific clinical and biological subphenotypes will greatly improve understanding of the relationship between the clinical symptoms and the putative pathways and thus risk factors, precipitants, natural history, and biological mechanism. This will facilitate risk factor mitigation, identification of potential methods for interventional studies, and informed patient and family counselling. Here, we review evidence to date and propose a framework to identify subphenotypes. Endotype identification may be done by clustering symptoms with their biological mechanism, which will facilitate research of targeted treatments. In order to achieve identification of delirium subphenotypes, the following steps must be taken: (1) robust records of symptoms must be kept at a clinical level. (2) Global collaboration must facilitate large, heterogeneous research cohorts. (3) Patients must be clustered for identification, validation, and mapping of subphenotype stability.