Pulmonary function and health-related quality of life in survivors of acute respiratory distress syndrome

Recruitment and retention of intensive care unit survivors in follow-up studies: A systematic review

BACKGROUND

Engaging intensive care unit survivors in research is challenging. Studies have reported recruitment and attrition rates; details are lacking on retention strategies and attrition.

OBJECTIVE

The aim of this study was to explore barriers and enablers to recruitment and retention in research of people post intensive care discharge.

METHODS

A convergent mixed-method review using the Joanna Briggs Institute (JBI) methodology considered studies that reported on recruitment, retention, and attrition rates of adult post-intensive care survivors in longitudinal studies. CINAHL Ultimate (CINAHL+), PubMed, Excerpta Medica Database (EMBASE), PsycINFO, Scopus, Proquest Health, and Medical Collection were searched in March 2024 using Medical Subject Headings terms and keywords related to post-intensive care survivors, patient selection, and research in peer-reviewed journals or theses published in English. Risk of bias was assessed with JBI's critical appraisal tools. Qualitative data were extracted and themed, and quantitative data were extracted using predefined data fields and qualitised. Synthesis was guided by the JBI mixed-method convergent integrated approach.

RESULTS

A total of 1608 records were identified; 12 high-quality articles were included, with a total of 2551 participants. Studies focussed on outcome measures following hospital discharge to the community. Three superordinate and eight subordinate themes emerged: factors influencing participation/nonengagement, retention strategies, and researcher insights. Attrition was predominantly due to mortality or ill health. Non-health-related themes included transport difficulties, expense, and inconvenience. Challenges included symptoms triggered by participation, being unaware of appointments, and not understanding study requirements. Enabling strategies included reminder calls, letters, cards, and home visits. Researcher insights included the impact of critical illness on survivors' wellbeing, finances, and communication challenges.

DISCUSSION

Recruitment and retention strategies were under-reported. Person-centred approaches considering survivors' challenges may increase recruitment and retention. Retention strategies should be evaluated to determine the impact on engagement or withdrawal from studies. The strong likelihood of attrition should be factored into sample size calculations to reduce risk of bias in longitudinal studies.

REGISTRATION

This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO [CRD42022315688]).

Long-term lung function recovery after ECMO versus non-ECMO management in acute respiratory failure: a systematic review and meta-analysis

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly employed to support lung function in patients with acute respiratory failure (ARF). However, the long-term outcomes of the approach have not been encouraging when compared to those of conventional mechanical ventilation. Further, the long-term effects of ECMO on lung function and recovery are unclear. For this review, we examined the long-term lung function outcomes of patients with ARF treated with and without ECMO.

METHODS

We searched the Embase, CENTRAL, Web of Science, and PubMed sites for studies comparing long-term (≥ 6 months) pulmonary function test results in patients with ARF treated with and without ECMO published until January 2024. We conducted a meta-analysis for percentage predicted values.

RESULTS

We included five studies. Our meta-analysis showed similar values of forced vital capacity (FVC%) (MD, 0.47; 95% CI, -3.56-4.50) and forced expiratory flow in the first second % (MD, 1.79; 95% CI, -2.17-5.75) in patients with ARF treated with or without ECMO. The FEV1/FVC % values were slightly higher in patients treated with ECMO than in those without ECMO (MD, 2.03; 95% CI, 0.01-4.04; p-value = 0.05). According to the meta-analysis, the values for total lung capacity % (MD, -3.20; 95% CI, -8.83-2.44) and carbon monoxide diffusion capacity % (MD, -0.72; 95% CI, -3.83-2.39) were also similar between patients undergoing ECMO and those without it.

CONCLUSION

The meta-analysis of a small number of studies with significant selection bias indicates that patients with ARF treated with ECMO may have comparable long-term pulmonary function recovery to those treated with conventional strategies. Further investigations including a larger number of patients and focusing on the long-term impact of ECMO are needed to supplement the current evidence.

Medium-Term Disability and Long-Term Functional Impairment Persistence in Survivors of Severe COVID-19 ARDS: Clinical and Physiological Insights

BACKGROUND

Although the medium- and long-term sequelae of survivor of acute respiratory distress syndrome (ARDS) of any cause have been documented, little is known about the way in which COVID-19-induced ARDS affects functional disability and exercise components. Our aims were to examine the medium-term disability in severe COVID-19-associated ARDS survivors, delineate pathophysiological changes contributing to their exercise intolerance, and explore its utility in predicting long-term functional impairment persistence.

METHODS

We studied 108 consecutive subjects with severe COVID-19 ARDS who remained alive 6 months after intensive care unit (ICU) discharge. Lung morphology was assessed with chest non-contrast CT scans and CT angiography. Functional evaluation included spirometry, plethysmography, muscle strength, and diffusion capacity, with assessment of gas exchange components through diffusing capacity of nitric oxide. Disability was assessed through an incremental exercise test, and measurements were repeated 12 and 24 months later in patients with functional impairments.

RESULTS

At 6 months after ICU discharge, a notable dissociation between morphological and clinical-functional sequelae was identified. Moderate-severe disability was present in 47% of patients and these subjects had greater limitation of ventilatory mechanics and gas exchange, as well as greater symptomatic perception during exercise and a probable associated cardiac limitation. Female sex, hypothyroidism, reduced membrane diffusion component, lower functional residual capacity, and high-attenuation lung volume were independently associated with the presence of moderate-severe functional disability, which in turn was related to higher frequency and greater intensity of dyspnea and worse quality of life. Out of the 71 patients with reduced lung volumes or diffusion capacity at 6 months post-ICU discharge, only 19 maintained a restrictive disorder associated with gas exchange impairment at 24 months post-discharge. In these patients, 6-month values for diffusion membrane component, maximal oxygen uptake, ventilatory equivalent for CO2, and dead space to tidal volume ratio were identified as independent risk factors for persistence of long-term functional sequelae.

CONCLUSIONS

Less than half of survivors of COVID-19 ARDS have moderate-severe disability in the medium term, identifying several risk factors. In turn, diffusion membrane component and exercise tolerance at 6-month ICU discharge are independently associated with the persistence of long-term functional sequelae.

Six and twelve-month respiratory outcomes in a cohort of severe and critical COVID-19 survivors: A prospective monocentric study in Latin America

Introduction

Severe COVID-19 can result in long-term sequelae known as "chronic COVID," characterized by a wide range of persistent physical and mental symptoms. Chest imaging and pulmonary function test alterations have been observed in recovered patients. Most studies focus on up to a 3-month follow-up after symptom onset or hospital discharge, with few reports on long-term follow-up and limited evidence regarding disease progression in Latin America.

Methods

This study aims to describe the clinical characteristics and changes in pulmonary function, imaging, and quality of life in severe and critical COVID-19 patients requiring ICU admission in a high-complexity hospital in Latin America. A prospective cohort of survivors underwent clinical, radiological, pulmonary function, and quality of life assessments 6 and 12 months post-discharge.

Results

One hundred twelve patients were included, all of whom attended the 6-month follow-up, and 99 returned for the 12-month follow-up. Most subjects had no previous respiratory symptoms or significant medical history. At the end of the follow-up period, 74% of the patients showed interstitial infiltrates in chest tomography and a higher frequency of fibroatelectatic tracts and parenchymal bands. Pulmonary function tests returned to normal ranges, except for carbon monoxide diffusion, but no altered scores were reported in the questionnaires.

Conclusion

Despite residual radiological findings, most parameters studied in severe and critical COVID-19 survivors improved over the 12-month follow-up period. Regardless of the imaging abnormalities, the improvement in variables such as symptomatic relief and normal pulmonary function suggests that these alterations are transient. Carbon monoxide diffusion did not normalize by the end of the follow-up, which is consistent with the abnormalities reported in multiple studies, indicating a potential disease-related pattern.

Impact of COVID-19 on quality of life in survivors with pulmonary sequelae

SARS-CoV-2 respiratory infection is still under study today, mainly because of its long-term effects. This study aims to analyse health status and health-related quality of life (HRQoL) in survivors of coronavirus pneumonia (COVID-19) who have developed pulmonary sequelae. Prospective observational study of patients diagnosed with COVID-19 pneumonia between February and May 2020. Reviews were conducted at 3 and 12 months after hospital discharge. HRQoL was assessed by administration of the SF-36 questionnaire and data related to medical records and physical examination were also collected. In addition, chest X-ray, computed tomography and pulmonary function test were included as additional tests. 305 patients were admitted for COVID-19 pneumonia of which 130 (42.6%) completed follow-up. The mean age of the enrolled group was 55.9 ± 15.9 years. The most prevalent persistent symptoms were dyspnea (37.3%) and asthenia (36.9%). Pulmonary sequelae were detected in 20.8% of participants. The most frequent alteration was ground ground glass opacities (GGO) (88.9%), with mild extension. Fibrotic changes were found in only 2% of cases. When comparing the two groups, at 3 and 12 months of evolution, lower scores in the vitality (VT) and mental health (MH) domains were found only in the group without sequelae. Days of hospitalisation and Charlson index acted as influential factors on HRQoL. Minimal or mild pulmonary sequelae of SARS-CoV-2 do not cause further deterioration of HRQoL. Repeated medical care and pulmonary rehabilitation are effective tools to improve HRQoL.

IL-22 Binding Protein Controls IL-22-Driven Bleomycin-Induced Lung Injury

The high mortality rates of acute lung injury and acute respiratory distress syndrome challenge the field to identify biomarkers and factors that can be exploited for therapeutic approaches. IL-22 is a cytokine that has antibacterial and reparative properties in the lung. However, it also can exacerbate inflammation and requires tight control by the extracellular inhibitory protein known as IL-22 binding protein (IL-22BP) (Il22ra2). This study showed the necessity of IL-22BP in controlling and preventing acute lung injury using IL-22BP knockout mice (Il22ra2-/-) in the bleomycin model of acute lung injury/acute respiratory distress syndrome. Il22ra2-/- mice had greater sensitivity (weight loss and death) and pulmonary inflammation in the acute phase (first 7 days) of the injury compared with wild-type C57Bl/6 controls. The inflammation was driven by excess IL-22 production, inducing the influx of pathogenic IL-17A+ γδ T cells to the lung. Interestingly, this inflammation was initiated in part by the noncanonical IL-22 signaling to macrophages, which express the IL-22 receptor (Il22ra1) in vivo after bleomycin challenge. This study further showed that IL-22 receptor alpha-1+ macrophages can be stimulated by IL-22 to produce a number of IL-17-inducing cytokines such as IL-1β, IL-6, and transforming growth factor-β1. Together, the results suggest that IL-22BP prevents IL-22 signaling to macrophages and reduces bleomycin-mediated lung injury.

Health-Related Quality of Life Improves in Parallel with FEV1 and 6-Minute Walking Distance Test at Between 3 and 12 Months in Critical COVID-19 Survivors

Background

In COVID-19 intensive care unit (ICU)-admitted patients, multiorgan acute complications lead to long-lasting sequelae. The aim of this study was to assess (1) changes in chest CT, pulmonary function test (PFT), functional capacity (6-minute walking distance test (6MWT)), and health-related quality of life (HR-QoL) among ICU COVID-19 survivors at 3, 6, and 12 months after ICU discharge and (2) predictors of persistent impairment/improvement in 6MWT and HR-QoL.

Methods

ICU COVID-19 survivors were prospectively included. Outcomes at 3, 6, and 12 months included PFT, 6MWT, respiratory muscle strength (RMS), HR-QoL (SF-36), Medical Research Council dyspnea scale (mMRC), and post-COVID Functional Status scale.

Results

Eighty-seven survivors were included, from June 3, 2020, to September 2, 2021. At 12 months, 50% of PFT were normal, 46% were restrictive, and 22% showed reduced diffusing capacity for carbon monoxide (DLCO). Impaired DLCO was associated with ICU length of stay and age. In mixed linear model analysis, improvements in RMS and mMRC persisted over time regardless of the adjustments applied (P ≤ .050). SF-36 improved in parallel with FEV1 and 6MWT between 3 and 12 months (P ≤ .044), while increment in DLCO correlated with changes in FEV1 and total lung capacity (TLC) (p ≤ 0.026).

Conclusions

This longitudinal study demonstrated that improvements in SF-36 occur in parallel with improvements in FEV1 and 6MWT between 3 and 12 months post-ICU discharge in a sample of critically ill COVID-19 patients. However, PFT remained, however, abnormal in 50% of patients. Based on continued improvements observed from 3 to 12 months, it is anticipated that COVID-19 ICU patients will continue to recover similarly to ARDS patients.

Long-Term Outcomes of Extracorporeal Life Support in Respiratory Failure

Although extracorporeal life support is an expensive method with serious risks of complications, it is nowadays a well-established and generally accepted method of organ support. In patients with severe respiratory failure, when conventional mechanical ventilation cannot ensure adequate blood gas exchange, veno-venous extracorporeal membrane oxygenation (ECMO) is the method of choice. An improvement in oxygenation or normalization of acid-base balance by itself does not necessarily mean an improvement in the outcome but allows us to prevent potential negative effects of mechanical ventilation, which can be considered a crucial part of complex care leading potentially to an improvement in the outcome. The disconnection from ECMO or discharge from the intensive care unit should not be viewed as the main goal, and the long-term outcome of the ECMO-surviving patients should also be considered. Approximately three-quarters of patients survive the veno-venous ECMO, but various (both physical and psychological) health problems may persist. Despite these, a large proportion of these patients are eventually able to return to everyday life with relatively little limitation of respiratory function. In this review, we summarize the available knowledge on long-term mortality and quality of life of ECMO patients with respiratory failure.

Respiratory sequelae of COVID-19: pulmonary and extrapulmonary origins, and approaches to clinical care and rehabilitation

Although the exact prevalence of post-COVID-19 condition (also known as long COVID) is unknown, more than a third of patients with COVID-19 develop symptoms that persist for more than 3 months after SARS-CoV-2 infection. These sequelae are highly heterogeneous in nature and adversely affect multiple biological systems, although breathlessness is a frequently cited symptom. Specific pulmonary sequelae, including pulmonary fibrosis and thromboembolic disease, need careful assessment and might require particular investigations and treatments. COVID-19 outcomes in people with pre-existing respiratory conditions vary according to the nature and severity of the respiratory disease and how well it is controlled. Extrapulmonary complications such as reduced exercise tolerance and frailty might contribute to breathlessness in post-COVID-19 condition. Non-pharmacological therapeutic options, including adapted pulmonary rehabilitation programmes and physiotherapy techniques for breathing management, might help to attenuate breathlessness in people with post-COVID-19 condition. Further research is needed to understand the origins and course of respiratory symptoms and to develop effective therapeutic and rehabilitative strategies.

[Aftercare of ICU patients: A task for pneumology?]

As the number of patients treated in intensive care medicine increases, so does the number of those who suffer from the long-term consequences of critical illness and the consequences of a stay in an intensive care unit. For this group of patients with a post-intensive care syndrome (PICS), there are currently no specialized outpatient care structures that follow the hospital stay and possible follow-up treatment. A number of studies are researching the effectiveness of intensive care outpatient clinics nationally and internationally.After presenting the PICS and the associated complex need for care, this review article presents various model projects for outpatient follow-up care of critically ill patients. We discuss whether the field of pneumology is particularly suitable for the study of therapy control of complex clinical pictures since it has vast experience in the treatment of intensive care patients and the outpatient care of chronically ill patients.

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.

The functional consequences in severe and critical covid-19 survivors - A pilot study

PURPOSE

To perform pulmonary function tests (PFT) in severe COVID-19 survivors one and five months after hospital discharge in order to assess the lung function, as well to identify clinical characteristics and PFT parameters associated with worse cardiopulmonary exercise testing (CPET).

MATERIAL AND METHODS

A prospective study included 75 patients with severe form of COVID-19. PFT was conducted one and five months after hospital discharge, in addition to CPET in a second assessment. Patients with a previous history of chronic respiratory diseases were excluded from our study.

RESULTS

One month after hospital discharge, all examined patients had diffusion lung capacity for carbon-monoxide(DLco%) below the 80% of predicted values (in mean 58%), with 40% of patients having a restrictive pattern (total lung capacity(TLC) < 80%). In a repeated assessment after five months, pathological DLco% persisted in 40% of patients, while all other PFT parameters were normal. CPET showed reduced maximum oxygen consumption during exercise testing (VO2peak%) values in 80% of patients (in mean 69%), and exercise ventilatory inefficiency in 60%. Patients with VO2peak < 60% had significantly lower values of examined PFT parameters, both one and five months after hospital discharge. Patients with VO2peak% ≥ 60% had a significantly higher increase after the second assessment for Forced expiratory volume in 1st second (FEV1%), Forced expiratory volume in 1st second and forced vital capacity ratio (FEV1/FVC), DLco% and Diffusion lung capacity for carbon monoxide corrected for alveolar volume (DLco/VA).

CONCLUSION

Significant functional abnormalities, according to PFT and CPET, was present both one and five months in severe COVID-19 survivors, thus emphasizing the importance of a comprehensive follow-up including both resting and dynamic functional assessment in these patients.

The Intersection of Health Rehabilitation Services with Quality of Life in Saudi Arabia: Current Status and Future Needs

Quality of life (QoL) is essential for maintaining a healthy, balanced lifestyle, especially among individuals with chronic diseases. Saudi Arabia (SA) launched a health sector transformation program as part of the nationwide Vision 2030 initiative to ensure the sustainable development of efficient healthcare services, aiming to improve health by increasing well-being and QoL. More investigation into the current status of health rehabilitation services provided to individuals with chronic diseases and future needs to optimize services and improve QoL is needed. This was narratively discussed by experts from different health rehabilitation services in SA. Comprehensive health rehabilitation services including orthopedic, occupational, cardiac, pulmonary, critical care, perioperative, hearing and speech, substance use disorders, and vocational rehabilitation services were addressed. Health rehabilitation services in SA, as in other countries, are suboptimal for individuals in health rehabilitation programs. To optimize the QoL of individuals with chronic diseases, health rehabilitation services should be tailored based on the unique requirements of each service and its serving patients. The shared need to improve health rehabilitation services includes the adoption of home-based and telehealth services, the integration of multi-governmental sectors, the empowerment and allocation of health rehabilitation specialists, public awareness campaigns, policy legislation and guideline development, and the implementation of a long-term follow-up system. This review is one of the first to address the intersection of health rehabilitation services and QoL in SA; urgent and holistic actions are paramount to address the pressing need to optimize SA's health rehabilitation services. The experts' recommendations in this study may be applicable to other countries' health systems, as health rehabilitation services are not well optimized globally.

Prospectively Assessed Long-Term Outcomes of Patients with E-Cigarette- or Vaping-associated Lung Injury

Rationale: E-cigarette- or vaping-associated lung injury (EVALI) was first identified in 2019. The long-term respiratory, cognitive, mood disorder, and vaping behavior outcomes of patients with EVALI remain unknown. Objectives: To determine the long-term respiratory, cognitive, mood disorder, and vaping behavior outcomes of patients with EVALI. Methods: We prospectively enrolled patients with EVALI from two health systems. We assessed outcomes at 1 year after onset of EVALI using validated instruments measuring cognitive function, depression, anxiety, post-traumatic stress, respiratory disability, coronavirus disease (COVID-19) infection, pulmonary function, and vaping behaviors. We used multivariable regression to identify risk factors of post-EVALI vaping behaviors and to identify whether admission to the intensive care unit (ICU) was associated with cognitive, respiratory, or mood symptoms. Results: Seventy-three patients completed 12-month follow-up. Most patients were male (66.7%), young (mean age, 31 ± 11 yr), and White (85%) and did not need admission to the ICU (59%). At 12 months, 39% (25 of 64) had cognitive impairment, whereas 48% (30 of 62) reported respiratory limitations. Mood disorders were common, with 59% (38 of 64) reporting anxiety and/or depression and 62% (39 of 63) having post-traumatic stress. Four (6.4%) of 64 reported a history of COVID-19 infection. Despite the history of EVALI, many people continued to vape. Only 38% (24 of 64) reported quitting all vaping and smoking behaviors. Younger age was associated with reduced vaping behavior after EVALI (odds ratio, 0.93; P = 0.02). ICU admission was not associated with cognitive impairment, dyspnea, or mood symptoms. Conclusions: Patients with EVALI, despite their youth, commonly have significant long-term respiratory disability; cognitive impairment; symptoms of depression, anxiety, post-traumatic stress; and persistent vaping.

Long-Term Health Consequences of SARS-CoV-2: Assumptions Based on SARS-CoV-1 and MERS-CoV Infections

Coronavirus Disease-2019 (COVID-19) is one of the worst pandemics in the history of the world. It is the third coronavirus disease that has afflicted humans in a short span of time. The world appears to be recovering from the grasp of this deadly pandemic; still, its post-disease health effects are not clearly understood. It is evident that the vast majority of COVID-19 patients usually recovered over time; however, disease manifestation is reported to still exist in some patients even after complete recovery. The disease is known to have left irreversible damage(s) among some patients and these damages are expected to cause mild or severe degrees of health effects. Apart from the apparent damage to the lungs caused by SARS-CoV-1, MERS-CoV, and SARS-CoV-2 infection, COVID-19-surviving patients display a wide spectrum of dysfunctions in different organ systems that is similar to what occurs with SARS-CoV-1 and MERS diseases. The major long COVID-19 manifestations include the following aspects: (1) central nervous system, (2) cardiovascular, (3) pulmonary, (4) gastrointestinal, (5) hematologic, (6) renal and (7) psycho-social systems. COVID-19 has a disease display manifestation in these organs and its related systems amongst a large number of recovered cases. Our study highlights the expected bodily consequences of the pandemic caused by SARS-CoV-2 infection based on the understanding of the long-term effects of SARS-CoV-1 and MERS-CoV.

ARDS Clinical Practice Guideline 2021

BACKGROUND

The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021.

METHODS

The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method.

RESULTS

Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4-8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO2 (PaO2) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D), we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D), we suggest against routinely implementing NO inhalation therapy (GRADE 2C), and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D).

CONCLUSIONS

This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jsicm.org/publication/guideline.html ). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries.

Chronic critical illness and post-intensive care syndrome: from pathophysiology to clinical challenges

Background

Post‐intensive care syndrome (PICS) encompasses physical, cognition, and mental impairments persisting after intensive care unit (ICU) discharge. Ultimately it significantly impacts the long‐term prognosis, both in functional outcomes and survival. Thus, survivors often develop permanent disabilities, consume a lot of healthcare resources, and may experience prolonged suffering. This review aims to present the multiple facets of the PICS, decipher its underlying mechanisms, and highlight future research directions.

Main text

This review abridges the translational data underlying the multiple facets of chronic critical illness (CCI) and PICS. We focus first on ICU-acquired weakness, a syndrome characterized by impaired contractility, muscle wasting, and persisting muscle atrophy during the recovery phase, which involves anabolic resistance, impaired capacity of regeneration, mitochondrial dysfunction, and abnormalities in calcium homeostasis. Second, we discuss the clinical relevance of post-ICU cognitive impairment and neuropsychological disability, its association with delirium during the ICU stay, and the putative role of low-grade long-lasting inflammation. Third, we describe the profound and persistent qualitative and quantitative alteration of the innate and adaptive response. Fourth, we discuss the biological mechanisms of the progression from acute to chronic kidney injury, opening the field for renoprotective strategies. Fifth, we report long-lasting pulmonary consequences of ARDS and prolonged mechanical ventilation. Finally, we discuss several specificities in children, including the influence of the child’s pre-ICU condition, development, and maturation.

Conclusions

Recent understandings of the biological substratum of the PICS’ distinct features highlight the need to rethink our patient trajectories in the long term. A better knowledge of this syndrome and precipitating factors is necessary to develop protocols and strategies to alleviate the CCI and PICS and ultimately improve patient recovery.

Evaluation of pulmonary function and exercise capacity after COVID-19 pneumonia

BACKGROUND

Individuals who suffer from coronavirus disease 2019 (COVID-19) pneumonia may experience pulmonary dysfunction during the chronic period due to pulmonary parenchymal damage after acute disease.

OBJECTIVES

The aim of the present study was to evaluate the pulmonary function and exercise capacity of patients treated for COVID 19 pneumonia after discharge.

METHODS

In this cross-sectional study, 79 people who were hospitalized with COVID-19 between March and October 2020 were evaluated at least two months after discharge. A pulmonary function test and a six-minute walk test were administered to the individuals included in the study.

RESULTS

Restrictive-type disorder was detected in 21.5% of the individuals who were evaluated at least two months after discharge. The forced expiratory volume in the first second (FEV1) and the forced vital capacity (FVC) values of the pulmonary function tests were significantly lower in the individuals with severe/critical clinical disease compared to those with moderate disease (p = 0.004 and p = 0.001, respectively). Although the six-minute walk test (6MWT) distances were lower in the severe/critical group than in the moderate group, the difference was not statistically significant (p > 0.05).

CONCLUSIONS

Individuals who are discharged after hospitalization for COVID-19 pneumonia may develop a restrictive type of pulmonary dysfunction. Therefore, survivors of COVID-19 pneumonia should be evaluated for pulmonary function and rehabilitation needs and should be provided with treatment as required.

ARDS clinical practice guideline 2021

BACKGROUND

The joint committee of the Japanese Society of Intensive Care Medicine/Japanese Respiratory Society/Japanese Society of Respiratory Care Medicine on ARDS Clinical Practice Guideline has created and released the ARDS Clinical Practice Guideline 2021.

METHODS

The 2016 edition of the Clinical Practice Guideline covered clinical questions (CQs) that targeted only adults, but the present guideline includes 15 CQs for children in addition to 46 CQs for adults. As with the previous edition, we used a systematic review method with the Grading of Recommendations Assessment Development and Evaluation (GRADE) system as well as a degree of recommendation determination method. We also conducted systematic reviews that used meta-analyses of diagnostic accuracy and network meta-analyses as a new method.

RESULTS

Recommendations for adult patients with ARDS are described: we suggest against using serum C-reactive protein and procalcitonin levels to identify bacterial pneumonia as the underlying disease (GRADE 2D); we recommend limiting tidal volume to 4-8 mL/kg for mechanical ventilation (GRADE 1D); we recommend against managements targeting an excessively low SpO₂ (PaO₂) (GRADE 2D); we suggest against using transpulmonary pressure as a routine basis in positive end-expiratory pressure settings (GRADE 2B); we suggest implementing extracorporeal membrane oxygenation for those with severe ARDS (GRADE 2B); we suggest against using high-dose steroids (GRADE 2C); and we recommend using low-dose steroids (GRADE 1B). The recommendations for pediatric patients with ARDS are as follows: we suggest against using non-invasive respiratory support (non-invasive positive pressure ventilation/high-flow nasal cannula oxygen therapy) (GRADE 2D); we suggest placing pediatric patients with moderate ARDS in the prone position (GRADE 2D); we suggest against routinely implementing NO inhalation therapy (GRADE 2C); and we suggest against implementing daily sedation interruption for pediatric patients with respiratory failure (GRADE 2D).

CONCLUSIONS

This article is a translated summary of the full version of the ARDS Clinical Practice Guideline 2021 published in Japanese (URL: https://www.jrs.or.jp/publication/jrs_guidelines/). The original text, which was written for Japanese healthcare professionals, may include different perspectives from healthcare professionals of other countries.

Usefulness of low tidal volume ventilation strategy for patients with acute respiratory distress syndrome: a systematic review and meta-analysis

The effects of lower tidal volume ventilation (LTV) were controversial for patients with acute respiratory distress syndrome (ARDS). This systematic review and meta-analysis aimed to evaluate the use of LTV strategy in patients with ARDS. We performed a literature search on MEDLINE, CENTRAL, EMBASE, CINAHL, "Igaku-Chuo-Zasshi", clinical trial registration sites, and the reference of recent guidelines. We included randomized controlled trials (RCTs) to compare the LTV strategy with the higher tidal volume ventilation (HTV) strategy in patients with ARDS. Two authors independently evaluated the eligibility of studies and extracted the data. The primary outcomes were 28-day mortality. We used the GRADE methodology to assess the certainty of evidence. Among the 19,864 records screened, 13 RCTs that recruited 1874 patients were included in our meta-analysis. When comparing LTV (4-8 ml/kg) versus HTV (> 8 ml/kg), the pooled risk ratio for 28-day mortality was 0.79 (11 studies, 95% confidence interval [CI] 0.66-0.94, I2 = 43%, n = 1795, moderate certainty of evidence). Subgroup-analysis by combined high positive end-expiratory pressure with LTV showed interaction (P = 0.01). Our study indicated that ventilation with LTV was associated with reduced risk of mortality in patients with ARDS when compared with HTV. Trial registration: UMIN-CTR (UMIN000041071).

Elevated plasma levels of epithelial and endothelial cell markers in COVID-19 survivors with reduced lung diffusing capacity six months after hospital discharge

BACKGROUND

Some COVID-19 survivors present lung function abnormalities during follow-up, particularly reduced carbon monoxide lung diffusing capacity (DLCO). To investigate risk factors and underlying pathophysiology, we compared the clinical characteristics and levels of circulating pulmonary epithelial and endothelial markers in COVID-19 survivors with normal or reduced DLCO 6 months after discharge.

METHODS

Prospective, observational study. Clinical characteristics during hospitalization, and spirometry, DLCO and plasma levels of epithelial (surfactant protein (SP) A (SP-A), SP-D, Club cell secretory protein-16 (CC16) and secretory leukocyte protease inhibitor (SLPI)), and endothelial (soluble intercellular adhesion molecule 1 (sICAM-1), soluble E-selectin and Angiopoietin-2) 6 months after hospital discharge were determined in 215 COVID-19 survivors.

RESULTS

DLCO was < 80% ref. in 125 (58%) of patients, who were older, more frequently smokers, had hypertension, suffered more severe COVID-19 during hospitalization and refer persistent dyspnoea 6 months after discharge. Multivariate regression analysis showed that age ≥ 60 years and severity score of the acute episode ≥ 6 were independent risk factors of reduced DLCO 6 months after discharge. Levels of epithelial (SP-A, SP-D and SLPI) and endothelial (sICAM-1 and angiopoietin-2) markers were higher in patients with reduced DLCO, particularly in those with DLCO ≤ 50% ref. Circulating SP-A levels were associated with the occurrence of acute respiratory distress syndrome (ARDS), organizing pneumonia and pulmonary embolisms during hospitalization.

CONCLUSIONS

Reduced DLCO is common in COVID-19 survivors 6 months after hospital discharge, especially in those older than 60 years with very severe acute disease. In these individuals, elevated levels of epithelial and endothelial markers suggest persistent lung damage.

Long-term cognitive and pulmonary functions following a lower versus a higher oxygenation target in the HOT-ICU trial: protocol and statistical analysis plan

BACKGROUND

Although supplemental oxygen can be lifesaving, liberal oxygen administration causing hyperoxaemia may be harmful. The targets for oxygenation in patients with acute hypoxaemic respiratory failure acutely admitted to the intensive care unit (ICU) are strongly debated, and consensus on which targets to recommend has not been reached. The Handling Oxygenation Targets in the ICU (HOT-ICU) trial is a multicentre, randomised, parallel-group trial of a lower oxygenation target (arterial partial pressure of oxygen [PaO₂ ] = 8 kPa) versus a higher oxygenation target (PaO₂  = 12 kPa) in adult ICU patients with acute hypoxaemic respiratory failure. In this study, we aim to evaluate the effects of these targets on long-term cognitive and pulmonary function in Danish patients, enrolled in the HOT-ICU trial and surviving to 1-year follow-up. We hypothesise that a lower oxygenation target throughout the ICU stay may result in cognitive impairment, whereas a higher oxygenation target may result in impaired pulmonary function.

METHODS

All patients enrolled in the HOT-ICU trial at Danish sites and surviving to 1 year after randomisation are eligible to participate. The last patient is expected to be included by November 2021. A Repeatable Battery for the Assessment of Neuropsychological Status and a body plethysmography, including diffusion capacity for carbon monoxide, both pre-planned secondary long-term outcomes of the HOT-ICU trial, will be obtained.

CONCLUSION

This study will provide important information on the long-term effects of a lower versus a higher oxygenation target on cognitive and pulmonary function in adult ICU patients with acute hypoxaemic respiratory failure.

Residual lung damage following ARDS in COVID-19 ICU survivors

BACKGROUND

Coronavirus disease 2019 acute respiratory distress syndrome (COVID-19 ARDS) is a disease that often requires invasive ventilation. Little is known about COVID-19 ARDS sequelae. We assessed the mid-term lung status of COVID-19 survivors and investigated factors associated with pulmonary sequelae.

METHODS

All adult COVID-19 patients admitted to the intensive care unit from 25th February to 27th April 2020 were included. Lung function was evaluated through chest CT scan and pulmonary function tests (PFT). Logistic regression was used to identify predictors of persisting lung alterations.

RESULTS

Forty-nine patients (75%) completed lung assessment. Chest CT scan was performed after a median (interquartile range) time of 97 (89-105) days, whilst PFT after 142 (133-160) days. The median age was 58 (52-65) years and most patients were male (90%). The median duration of mechanical ventilation was 11 (6-16) days. Median tidal volume/ideal body weight (TV/IBW) was 6.8 (5.71-7.67) ml/Kg. 59% and 63% of patients showed radiological and functional lung sequelae, respectively. The diffusion capacity of carbon monoxide (DL_CO ) was reduced by 59%, with a median per cent of predicted DL_CO of 72.1 (57.9-93.9) %. Mean TV/IBW during invasive ventilation emerged as an independent predictor of persistent CT scan abnormalities, whilst the duration of mechanical ventilation was an independent predictor of both CT and PFT abnormalities. The extension of lung involvement at hospital admission (evaluated through Radiographic Assessment of Lung Edema, RALE score) independently predicted the risk of persistent alterations in PFTs.

CONCLUSIONS

Both the extent of lung parenchymal involvement and mechanical ventilation protocols predict morphological and functional lung abnormalities months after COVID-19.

Assessment of 5-year outcomes of life satisfaction in survivors after rehabilitation programs: a multicenter clinical trial

Using a rehabilitation program for the survivors of acute respiratory distress syndrome (ARDS) could be one of the important and fundamental steps to improve the pulmonary function and health-related quality of life (HRQoL) of patients. This study was carried out to evaluate the effect of two rehabilitation techniques (Family-Based Empowerment Model (FECM)/Continuing Care Model (CCM), or both of them) on pulmonary function, and HRQoL in ARDS survivors. From December 2009 to June 2016, ARDS survivors from mixed medical-surgical ICUs at four academic teaching hospitals in Tehran, Iran, were randomly assigned to one of three intervention groups (A, B, or C) or a control group (D). Pre- and post-interventions, pulmonary functions and HRQoL status of patients in all groups were collected 48 times via clinical measurements and various questionnaires during 5 years of follow-up. Significantly improvement was seen in the intervention groups compared to the control group, and the greatest benefit was observed in patients who received mixed of FCEM and CCM rehabilitation techniques. Co-administration of FCEM and CCM can improve pulmonary function as well as the life satisfaction of ARDS survivors. As a result, the execution of the empowerment model by nurses is recommended for ARDS survivors and the participation of their families at the same time.Trial registration: NCT02787720 (ClinicalTrial.gov, 24/05/2016).

Pathophysiology of pulmonary function anomalies in COVID-19 survivors

Coronavirus disease 2019 (COVID-19) is a disease caused by a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-​2), and the predisposing and protecting factors have not been fully elucidated. COVID-19 primarily impacts the respiratory system, and can result in mild illness or serious disease leading to critical illness requiring admission to the intensive care unit due to respiratory failure. After hospital discharge, the more commonly described pulmonary function anomalies are alterations in diffusing capacity and the loss of lung volume. Reduction of inspiratory muscle contraction may also be underestimated. This article will focus on the pathophysiology of pulmonary function anomalies in COVID-19 survivors. We will discuss current advances and provide future directions and also present our perspective on this field.

Long-term COVID-19 effects on pulmonary function, exercise capacity, and health status

BACKGROUND:

The long-term effects of respiratory function and related physiological characteristics of coronavirus disease 2019 (COVID-19) survivors have not yet been studied in depth.

OBJECTIVE:

To examine pulmonary function, exercise capacity, and health-related quality of life among COVID-19 survivors.

METHODS:

Eighty-five survivors with confirmed COVID-19 were evaluated at the end of 3 and 6 months after disease onset. The assessment included lung function, diffusing capacity, 6-min walk distance (6MWD), and health status by the 36-item Short-Form General Health Survey (SF-36) questionnaire.

RESULTS:

Totally 85 survivors, 48 (56.5%) were men. The mean (standard deviation) age was 34.6 (9.9) years. Thirteen patients (15.2%) had medical co-morbidities the mean length of hospitalization was 18.5 (5.6) days. 25 (29.4%) required intensive care unit admission, whereas 6 (7%) of them required invasive mechanical ventilation. No significant differences were observed between lung volume parameters. At 6 months, there was a significant reduction in diffusing capacity for carbon monoxide (DLCO), P = 0.02*. 25 (29.4%) of patients had impaired DLCO ≤80% predicted. Regarding 6MWD, a significant increase was noted in 6MWD from 486 ± 72 m at 3 months to 526 ± 82 m at 6 months (P = 0.001*). The 6MWD was lower than that for normal controls of the same age groups. There was significant impairment of health status assessed by SF-36 questionnaire among COVID-19 survivors at 6 months as compared with controls of the same age groups. There were significant positive correlations between lung function parameters (FVC, VC, FEV1, and DlCO) with several SF-36 domains.

CONCLUSION:

In discharged survivors with COVID-19, 23.5% had significant impairment of diffusion capacity abnormality of lung function. The exercise capacity and health status were considerably lower than that of a normal population after 6 months postinfection.

Good survival rate, moderate overall and good respirator quality of life, near normal pulmonary functions, and good return to work despite catastrophic economic costs 6 months following recovery from Acute Respiratory Distress Syndrome

Introduction:

Long-term quality of life, return to work, economic consequences following Acute Respiratory Distress Syndrome (ARDS) are not well described in India. This study was aimed to address the question.

Methods:

A prospective cohort study of 109 ARDS survivors were followed up for a minimum of 6 months following discharge. Quality of life was assessed using the SF-36 questionnaire. Respiratory quality was assessed using the St Georges Respiratory Questionnaire. Time to return to work was documented. Costs-direct medical, as well as indirect were documented up to 6 months.

Results:

At 6 months, 6/109 (5.5%) had expired. Low energy/vitality and general heath were noted in the SF-36 scores at 6 months; overall a moderate quality of life. Pulmonary function tests had mostly normalized. Six-min walk distance was 77% of predicted. Respiratory quality of life was good. It took at the median of 111 days to go back Interquartile range (55–193.5) to work with 88% of previously employed going back to work. There were no significant differences in the severity of ARDS and any of these outcomes at 6 months. The average total cost from the societal perspective was 231,450 (standard deviation 146,430 -, 387,300). There was a significant difference between the 3-ARDS severity groups and costs (P < 0.01). There were no independent predictors of return to work.

Conclusion:

ARDS survivors have low 6-month mortality. Pulmonary physiology and exercise capacity was mostly normal. Overall, quality of life is average was moderate, while respiratory quality of life was good. Return to work was excellent, while cost of care falls under a catastrophic heath expense.

Long-term outcomes of adults with acute respiratory failure treated with veno-venous extracorporeal membrane oxygenation

Veno-venous extracorporeal membrane oxygenation is increasingly used for severe but potentially reversible acute respiratory failure in adults; however, there are limited data regarding long-term morbidity. At our institution, most patients requiring veno-venous extracorporeal membrane oxygenation have been followed up by a single physician. Our primary aim was to describe the serial long-term morbidity for respiratory, musculoskeletal and psychological functioning.

A retrospective audit of inpatient and outpatient medical records was conducted. A total of 125 patients treated with veno-venous extracorporeal membrane oxygenation for primary respiratory failure were included. The patients were young (mean (standard deviation) age 43.7 (4.1) years), obese (mean (standard deviation) body mass index 30.8 (10.4) kg/m²), and mostly were male (59%). Most patients (60%) had no comorbidities.

The survival rate to discharge was 70%, with body mass index and the number of comorbidities being independent predictors of survival on multiple logistic regression analysis. Over half (57%) of the Australian survivors had regular outpatient follow-up. They had a median of three reviews (range 1-9) over a median of 11.8 months (range 1.5-79) months. Breathlessness and weakness resolved in most within six months, with lung function abnormalities taking longer to resolve. Over half (60%) returned to employment within six months of discharge. Over a quarter (29%) displayed symptoms of anxiety, depression or post-traumatic stress disorder.

Long-term changes in pulmonary function among patients surviving to COVID-19 pneumonia

Purpose

The aim of this study was to assess respiratory function at the time of clinical recovery, 6 weeks, 6 months, and 12 months after discharge in patients surviving to COVID-19 pneumonia.

Methods

Our case series consisted of 13 hospitalized patients with COVID-19 pneumonia.

Results

Baseline pulmonary function tests were 55.7 ± 15.6 for FEV1%, 68.6 ± 16.0 for FVC%, and 1.2 ± 0.1 for FEV1/FVC%. Although pulmonary function showed a small improvement after 6 weeks, patients experienced a more significant improvement after 6 and 12 months in FEV1% (95.4 ± 13.7 and 107.2 ± 16.5, respectively; p < 0.001), FVC% (91.3 ± 14.5, and 105.9 ± 15.6, respectively; p < 0.001), and FEV1/FVC% values (1.04 ± 0.04, and 1.01 ± 0.05, respectively; p < 0.001).

Conclusion

COVID-19 pneumonia may result in significant alterations in lung function, with a mainly restrictive pattern, partly persisting at 6 weeks after recovery from acute phase, but significantly improving during a 12-month follow-up period.

The relationship of tidal volume and driving pressure with mortality in hypoxic patients receiving mechanical ventilation

PURPOSE

To determine whether tidal volume/predicted body weight (TV/PBW) or driving pressure (DP) are associated with mortality in a heterogeneous population of hypoxic mechanically ventilated patients.

METHODS

A retrospective cohort study involving 18 intensive care units included consecutive patients ≥18 years old, receiving mechanical ventilation for ≥3 days, with a PaO2/FiO2 ratio ≤300 mmHg, whether or not they met full criteria for ARDS. The main outcome was hospital mortality. Multiple logistic regression (MLR) incorporated TV/PBW, DP, and potential confounders including age, APACHE IVa® predicted hospital mortality, respiratory system compliance (CRS), and PaO2/FiO2. Predetermined strata of TV/PBW were compared using MLR.

RESULTS

Our cohort comprised 5,167 patients with mean age 61.9 years, APACHE IVa® score 79.3, PaO2/FiO2 166 mmHg and CRS 40.5 ml/cm H2O. Regression analysis revealed that patients receiving DP one standard deviation above the mean or higher (≥19 cmH20) had an adjusted odds ratio for mortality (ORmort) = 1.10 (95% CI: 1.06-1.13, p = 0.009). Regression analysis showed a U-shaped relationship between strata of TV/PBW and adjusted mortality. Using TV/PBW 4-6 ml/kg as the referent group, patients receiving >10 ml/kg had similar adjusted ORmort, but those receiving 6-7, 7-8 and 8-10 ml/kg had lower adjusted ORmort (95%CI) of 0.81 (0.65-1.00), 0.78 (0.63-0.97) and 0.80 0.67-1.01) respectively. The adjusted ORmort in patients receiving 4-6 ml/kg was 1.26 (95%CI: 1.04-1.52) compared to patients receiving 6-10 ml/kg.

CONCLUSIONS

Driving pressures ≥19 cmH2O were associated with increased adjusted mortality. TV/PBW 4-6ml/kg were used in less than 15% of patients and associated with increased adjusted mortality compared to TV/PBW 6-10 ml/kg used in 82% of patients. Prospective clinical trials are needed to prove whether limiting DP or the use of TV/PBW 6-10 ml/kg versus 4-6 ml/kg benefits mortality.

Comparative Effectiveness of Protective Ventilation Strategies for Moderate and Severe Acute Respiratory Distress Syndrome. A Network Meta-Analysis

Rationale: Choosing the best ventilation strategy for acute respiratory distress syndrome (ARDS) is complex, yet it is highly relevant to clinicians during a respiratory pandemic. Objectives: To compare the effects of low Vt, high Vt, high positive end-expiratory pressure (PEEP), prone ventilation, high-frequency oscillation, and venovenous extracorporeal membrane oxygenation (VV ECMO) on mortality in ARDS. Methods: We performed a network meta-analysis of randomized trials. We applied the Grading of Recommendations Assessment, Development and Evaluation methodology to discern the relative effect of interventions on mortality. Measurements and Main Results: We analyzed 34 trials including 9,085 adults with primarily moderate-to-severe ARDS (median baseline Pa_O2/Fi_O2, 118; interquartile range, 110-143). Prone positioning combined with low Vt was the best strategy (risk ratio [RR], 0.74 [95% confidence interval (CI), 0.60-0.92] vs. low Vt; high certainty). VV ECMO was also rated among the best (RR, 0.78 [95% CI, 0.58-1.05] vs. low Vt; RR, 0.66; [95% CI, 0.49-0.88] vs. high Vt) but was rated with lower certainty because VV ECMO was restricted to very severe ARDS (mean baseline Pa_O2/Fi_O2<75). High PEEP combined with low Vt was rated intermediately (RR, 0.91 [95% CI, 0.81-1.03] vs. low Vt; low certainty; RR, 0.77 [95% CI, 0.65-0.91] vs. high Vt; moderate certainty). High Vt was rated worst (RR, 1.19 [95% CI, 1.02-1.37] vs. low Vt; moderate certainty), and we found no support for high-frequency oscillation or high Vt with prone ventilation. Conclusions: These findings suggest that combining low Vt with prone ventilation is associated with the greatest reduction in mortality for critically ill adults with moderate-to-severe ARDS.

How and to What Extent Immunological Responses to SARS-CoV-2 Shape Pulmonary Function in COVID-19 Patients

COVID-19 is a disease caused by a new coronavirus SARS-CoV-2, primarily impacting the respiratory system. COVID-19 can result in mild illness or serious disease leading to critical illness and requires admission to ICU due to respiratory failure. There is intense discussion around potential factors predisposing to and protecting from COVID-19. The immune response and the abnormal respiratory function with a focus on respiratory function testing in COVID-19 patients will be at the center of this Perspective article of the Frontiers in Physiology Series on “The Tribute of Physiology for the Understanding of COVID-19 Disease.” We will discuss current advances and provide future directions and present also our perspective in this field.

Enabling a learning healthcare system with automated computer protocols that produce replicable and personalized clinician actions

Clinical decision-making is based on knowledge, expertise, and authority, with clinicians approving almost every intervention-the starting point for delivery of "All the right care, but only the right care," an unachieved healthcare quality improvement goal. Unaided clinicians suffer from human cognitive limitations and biases when decisions are based only on their training, expertise, and experience. Electronic health records (EHRs) could improve healthcare with robust decision-support tools that reduce unwarranted variation of clinician decisions and actions. Current EHRs, focused on results review, documentation, and accounting, are awkward, time-consuming, and contribute to clinician stress and burnout. Decision-support tools could reduce clinician burden and enable replicable clinician decisions and actions that personalize patient care. Most current clinical decision-support tools or aids lack detail and neither reduce burden nor enable replicable actions. Clinicians must provide subjective interpretation and missing logic, thus introducing personal biases and mindless, unwarranted, variation from evidence-based practice. Replicability occurs when different clinicians, with the same patient information and context, come to the same decision and action. We propose a feasible subset of therapeutic decision-support tools based on credible clinical outcome evidence: computer protocols leading to replicable clinician actions (eActions). eActions enable different clinicians to make consistent decisions and actions when faced with the same patient input data. eActions embrace good everyday decision-making informed by evidence, experience, EHR data, and individual patient status. eActions can reduce unwarranted variation, increase quality of clinical care and research, reduce EHR noise, and could enable a learning healthcare system.

A Clinic Blueprint for Post-Coronavirus Disease 2019 RECOVERY: Learning From the Past, Looking to the Future

The severe acute respiratory syndrome coronavirus 2 pandemic poses extraordinary challenges. The tremendous number of coronavirus disease 2019 (COVID-19) cases in the United States has resulted in a large population of survivors with prolonged postinfection symptoms. The creation of multidisciplinary post-COVID-19 clinics to address both persistent symptoms and potential long-term complications requires an understanding of the acute disease and the emerging data regarding COVID-19 outcomes. Experience with severe acute respiratory syndrome and Middle East respiratory syndrome, post-acute respiratory distress syndrome complications, and post-intensive care syndrome also informs anticipated sequelae and clinical program design. Post-COVID-19 clinical programs should be prepared to care for individuals previously hospitalized with COVID-19 (including those who required critical care support), nonhospitalized individuals with persistent respiratory symptoms following COVID-19, and individuals with preexisting lung disease complicated by COVID-19. Effective multidisciplinary collaboration models leverage lessons learned during the early phases of the pandemic to overcome the unique logistical challenges posed by pandemic circumstances. Collaboration between physicians and researchers across disciplines will provide insight into survivorship that may shape the treatment of both acute disease and chronic complications. In this review, we discuss the aims, general principles, elements of design, and challenges of a successful multidisciplinary model to address the needs of COVID-19 survivors.

Non-specialist therapeutic strategies in acute respiratory distress syndrome

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is associated with significant morbidity and mortality. We undertook a meta-analysis of randomized controlled trials (RCTs) to determine the mortality benefit of non-specialist therapeutic interventions for ARDS available to general critical care units.

EVIDENCE ACQUISITION

A systematic search of MEDLINE, Embase, and the Cochrane Central Register for RCTs investigating therapeutic interventions in ARDS including corticosteroids, fluid management strategy, high PEEP, low tidal volume ventilation, neuromuscular blockade, prone position ventilation, or recruitment maneuvers. Data was collected on demographic information, treatment strategy, duration and dose of treatment, and primary (28 or 30-day mortality) and secondary (P<inf>a</inf>O<inf>2</inf>:FiO<inf>2</inf> ratio at 24-48 hours) outcomes.

EVIDENCE SYNTHESIS

No improvement in 28-day mortality could be demonstrated in three RCTs investigating high PEEP (28.0% vs. 30.2% control; risk ratio [confidence interval] 0.93 [0.82-1.06]; eight assessing prone position ventilation (39.3% vs. 44.5%; RR 0.83 [0.68-1.01]; seven investigating neuromuscular blockade (37.8% vs. 42.0%; RR 0.91 [0.81-1.03]); ten investigating recruitment maneuvers (42.4% vs. 42.1%; RR 1.01 [0.91-1.12]); eight investigating steroids (34.8% vs. 41.1%; RR 0.81 [0.59-1.12]); and one investigating conservative fluid strategies (25.4% vs. 28.4%; RR 0.90 [0.73-1.10]). Three studies assessing low tidal volume ventilation (33.1% vs. 41.9%; RR 0.79 (0.68-0.91); P=0.001), and subgroup analyses within studies investigating prone position ventilation greater than 12 hours (33.1% vs. 44.4%; RR 0.75 [0.59-0.95), P=0.02) did reveal outcome benefit.

CONCLUSIONS

Among non-specialist therapeutic strategies available to general critical care units, low tidal volumes and prone position ventilation for greater than 12 hours improve mortality in ARDS.

Mesenchymal Stromal Cell-Derived Extracellular Vesicles in Lung Diseases: Current Status and Perspectives

Extracellular vesicles (EVs) have emerged as a potential therapy for several diseases. These plasma membrane-derived fragments are released constitutively by virtually all cell types-including mesenchymal stromal cells (MSCs)-under stimulation or following cell-to-cell interaction, which leads to activation or inhibition of distinct signaling pathways. Based on their size, intracellular origin, and secretion pathway, EVs have been grouped into three main populations: exosomes, microvesicles (or microparticles), and apoptotic bodies. Several molecules can be found inside MSC-derived EVs, including proteins, lipids, mRNA, microRNAs, DNAs, as well as organelles that can be transferred to damaged recipient cells, thus contributing to the reparative process and promoting relevant anti-inflammatory/resolutive actions. Indeed, the paracrine/endocrine actions induced by MSC-derived EVs have demonstrated therapeutic potential to mitigate or even reverse tissue damage, thus raising interest in the regenerative medicine field, particularly for lung diseases. In this review, we summarize the main features of EVs and the current understanding of the mechanisms of action of MSC-derived EVs in several lung diseases, such as chronic obstructive pulmonary disease (COPD), pulmonary infections [including coronavirus disease 2019 (COVID-19)], asthma, acute respiratory distress syndrome (ARDS), idiopathic pulmonary fibrosis (IPF), and cystic fibrosis (CF), among others. Finally, we list a number of limitations associated with this therapeutic strategy that must be overcome in order to translate effective EV-based therapies into clinical practice.

Post-discharge critical COVID-19 lung function related to severity of radiologic lung involvement at admission

Lung function impairment persists in 55% of critical COVID-19 patients three months after ICU discharge. Patient lung function, exercise capacity, radiologic, and quality of life data suggest impairment is related to radiologic lung involvement at admission.

COVID-19: from an acute to chronic disease? Potential long-term health consequences

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite pulmonary impairments being the most prevalent, extra-pulmonary manifestations of COVID-19 are abundant. Confirmed COVID-19 cases have now surpassed 57.8 million worldwide as of 22 November 2020. With estimated case fatality rates (number of deaths from COVID-19 divided by number of confirmed COVID-19 cases) varying between 1 and 7%, there will be a large population of recovered COVID-19 patients that may acquire a multitude of long-term health consequences. While the multi-organ manifestations of COVID-19 are now well-documented, the potential long-term implications of these manifestations remain to be uncovered. In this review, we turn to previous similar coronaviruses (i.e. SARS-CoV-1 and Middle East respiratory syndrome coronavirus [MERS-CoV]) in combination with known health implications of SARS-CoV-2 infection to predict potential long-term effects of COVID-19, including pulmonary, cardiovascular, hematologic, renal, central nervous system, gastrointestinal, and psychosocial manifestations, in addition to the well-known post-intensive care syndrome. It is necessary to monitor COVID-19 patients after discharge to understand the breadth and severity of long-term effects. This can be accomplished by repurposing or initiating large cohort studies to not only focus on the long-term consequences of SARS-CoV-2 infection, but also on acquired immune function as well as ethno-racial group and household income disparities in COVID-19 cases and hospitalizations. The future for COVID-19 survivors remains uncertain, and if this virus circulates among us for years to come, long-term effects may accumulate exponentially.

Clinical, Bronchoscopic, and Imaging Findings of e-Cigarette, or Vaping, Product Use-Associated Lung Injury Among Patients Treated at an Academic Medical Center

IMPORTANCE

e-Cigarette, or vaping, product use-associated lung injury (EVALI) has caused more than 2800 illnesses and 68 deaths in the United States. Better characterization of this novel illness is needed to inform diagnosis and management.

OBJECTIVE

To describe the clinical features, bronchoscopic findings, imaging patterns, and outcomes of EVALI.

DESIGN, SETTING, AND PARTICIPANTS

This case series of 31 adult patients diagnosed with EVALI between June 24 and December 10, 2019, took place at an academic medical center in Salt Lake City, Utah.

EXPOSURES

e-Cigarette use, also known as vaping.

MAIN OUTCOMES AND MEASURES

Symptoms, laboratory findings, bronchoscopic results, imaging patterns, and clinical outcomes.

RESULTS

Data from 31 patients (median [interquartile range] age, 24 [21-31] years) were included in the study. Patients were primarily men (24 [77%]) and White individuals (27 [87%]) who used e-cigarette products containing tetrahydrocannabinol (THC) (29 [94%]). Patients presented with respiratory (30 [97%]), constitutional (28 [90%]), and gastrointestinal (28 [90%]) symptoms. Serum inflammatory markers were elevated in all patients. Bronchoscopy was performed in 23 of 28 inpatients (82%) and bronchoalveolar lavage (BAL) revealed the presence of lipid-laden macrophages (LLMs) in 22 of 24 cases (91%). BAL samples tested positive for Pneumocystis jirovecii (3 patients [13%]), rhinovirus (2 patients [8%]), human metapneumovirus and Aspergillus (1 patient each [4%]); all except human metapneumovirus were determined to be false-positives or clinically inconsequential. The exclusive or dominant computed tomography (CT) pattern was organizing pneumonia in 23 of 26 cases (89%). Patients received antibiotics (26 [84%]) and corticosteroids (24 [77%]), and all survived; 20 patients (65%) seen in follow-up showed marked improvement, but residual symptoms (13 [65%]), radiographic opacities (8 [40%]), and abnormal pulmonary function tests (8 of 18 [44%]) were common.

CONCLUSIONS AND RELEVANCE

In this case series, patients with EVALI characteristically presented with a flu-like illness with elevated inflammatory markers, LLMs on BAL samples, and an organizing pneumonia pattern on CT imaging. Bronchoscopic testing for infection had a high incidence of false-positive results. Patients had substantial residual abnormal results at early follow-up. These data suggest a limited role for bronchoscopy in typical presentations of EVALI without risk factors for alternative diagnoses and the need for careful longitudinal follow-up.

Participant Retention in Follow-Up Studies of Acute Respiratory Failure Survivors

BACKGROUND

With an increasing number of follow-up studies of acute respiratory failure survivors, there is need for a better understanding of participant retention and its reporting in this field of research. Hence, our objective was to synthesize participant retention data and associated reporting for this field.

METHODS

Two screeners independently searched for acute respiratory failure survivorship studies within a published scoping review to evaluate subject outcomes after hospital discharge in critical illness survivors.

RESULTS

There were 21 acute respiratory failure studies (n = 4,342 survivors) over 47 follow-up time points. Six-month follow-up (range: 2-60 months) was the most frequently reported time point, in 81% of studies. Only 1 study (5%) reported accounting for loss to follow-up in sample-size calculation. Retention rates could not be calculated for 5 (24%) studies. In 16 studies reporting on retention across all time points, retention ranged from 32% to 100%. Pooled retention rates at 3, 6, 12, and 24 months were 85%, 89%, 82%, and 88%, respectively. Retention rates did not significantly differ by publication year, participant mean age, or when comparing earlier (3 months) versus each later follow-up time point (6, 12, or 24 months).

CONCLUSIONS

Participant retention was generally high but varied greatly across individual studies and time points, with 24% of studies reporting inadequate data to calculate retention rate. High participant retention is possible, but resources for optimizing retention may help studies retain participants. Improved reporting guidelines with greater adherence would be beneficial.

Pulmonary function in patients surviving to COVID-19 pneumonia

Purpose

The aim of our study was to assess respiratory function at the time of clinical recovery and 6 weeks after discharge in patients surviving to COVID-19 pneumonia.

Methods

Our case series consisted of 13 patients with COVID-19 pneumonia.

Results

At the time of clinical recovery, FEV1 (2.07 ± 0.72 L) and FVC (2.25 ± 0.86 L) were lower compared to lower limit of normality (LLN) values (2.56 ± 0.53 L, p = 0.004, and 3.31 ± 0.65 L, p < 0.001, respectively), while FEV1/FVC (0.94 ± 0.07) was higher compared to upper limit of normality (ULN) values (0.89 ± 0.01, p = 0.029). After 6 weeks pulmonary function improved but FVC was still lower than ULN (2.87 ± 0.81, p = 0.014).

Conclusion

These findings suggest that COVID-19 pneumonia may result in clinically relevant alterations in pulmonary function tests, with a mainly restrictive pattern.

Electronic supplementary material

The online version of this article (10.1007/s15010-020-01474-9) contains supplementary material, which is available to authorized users.

Acute respiratory distress syndrome: how do patients fare after the intensive care unit?

Patients with acute respiratory distress syndrome require ventilation strategies that have been shown to be important for reducing short-term mortality, such as protective ventilation and prone position ventilation. However, patients who survive have a prolonged stay in both the intensive care unit and the hospital, and they experience a reduction in overall satisfaction with life (independence, acceptance and positive outlook) as well as decreased mental health (including anxiety, depression and posttraumatic stress disorder symptoms), physical health (impaired physical state and activities of daily living; fatigue and muscle weakness), social health and the ability to participate in social activities (including relationships with friends and family, hobbies and social gatherings).

Surviving Sepsis Campaign: Guidelines on the Management of Critically Ill Adults with Coronavirus Disease 2019 (COVID-19)

BACKGROUND

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, Coronavirus Disease 2019 (COVID-19), affecting thousands of people around the world. Urgent guidance for clinicians caring for the sickest of these patients is needed.

METHODS

We formed a panel of 36 experts from 12 countries. All panel members completed the World Health Organization conflict of interest disclosure form. The panel proposed 53 questions that are relevant to the management of COVID-19 in the ICU. We searched the literature for direct and indirect evidence on the management of COVID-19 in critically ill patients in the ICU. We identified relevant and recent systematic reviews on most questions relating to supportive care. We assessed the certainty in the evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach, then generated recommendations based on the balance between benefit and harm, resource and cost implications, equity, and feasibility. Recommendations were either strong or weak, or in the form of best practice recommendations.

RESULTS

The Surviving Sepsis Campaign COVID-19 panel issued 54 statements, of which four are best practice statements, nine are strong recommendations, and 35 are weak recommendations. No recommendation was provided for six questions. The topics were: 1) infection control, 2) laboratory diagnosis and specimens, 3) hemodynamic support, 4) ventilatory support, and 5) COVID-19 therapy.

CONCLUSION

The Surviving Sepsis Campaign COVID-19 panel issued several recommendations to help support healthcare workers caring for critically ill ICU patients with COVID-19. When available, we will provide new evidence in further releases of these guidelines.