A New Global Definition of Acute Respiratory Distress Syndrome.

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

Recovery from Sepsis: Management beyond Acute Care.

Recovery from sepsis is a key global health issue, impacting 38 million sepsis survivors worldwide per year. Sepsis survivors face a wide range of physical, cognitive, and psychosocial sequelae. Readmissions to hospital following sepsis are an important driver of global healthcare utilization and cost. Family members of sepsis survivors also experience significant stressors related to their role as informal caregivers. Increasing recognition of the burdens of sepsis survivorship has led to the development of postsepsis recovery programs to better support survivors and their families, although optimal models of care remain uncertain. The goal of this article is to perform a narrative review of recovery from sepsis from the perspective of patients, families, and health systems.

Wellness and Coping of Physicians Who Worked in ICUs During the Pandemic: A Multicenter Cross-Sectional North American Survey.

OBJECTIVES: Few surveys have focused on physician moral distress, burnout, and professional fulfilment. We assessed physician wellness and coping during the COVID-19 pandemic. DESIGN: Cross-sectional survey using four validated instruments. SETTING: Sixty-two sites in Canada and the United States. SUBJECTS: Attending physicians (adult, pediatric; intensivist, nonintensivist) who worked in North American ICUs. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We analysed 431 questionnaires (43.3% response rate) from 25 states and eight provinces. Respondents were predominantly male (229 [55.6%]) and in practice for 11.8 ± 9.8 years. Compared with prepandemic, respondents reported significant intrapandemic increases in days worked/mo, ICU bed occupancy, and self-reported moral distress (240 [56.9%]) and burnout (259 [63.8%]). Of the 10 top-ranked items that incited moral distress, most pertained to regulatory/organizational ( n = 6) or local/institutional ( n = 2) issues or both ( n = 2). Average moral distress (95.6 ± 66.9), professional fulfilment (6.5 ± 2.1), and burnout scores (3.6 ± 2.0) were moderate with 227 physicians (54.6%) meeting burnout criteria. A significant dose-response existed between COVID-19 patient volume and moral distress scores. Physicians who worked more days/mo and more scheduled in-house nightshifts, especially combined with more unscheduled in-house nightshifts, experienced significantly more moral distress. One in five physicians used at least one maladaptive coping strategy. We identified four coping profiles (active/social, avoidant, mixed/ambivalent, infrequent) that were associated with significant differences across all wellness measures. CONCLUSIONS: Despite moderate intrapandemic moral distress and burnout, physicians experienced moderate professional fulfilment. However, one in five physicians used at least one maladaptive coping strategy. We highlight potentially modifiable factors at individual, institutional, and regulatory levels to enhance physician wellness.

Outcomes of critically ill COVID-19 survivors and caregivers: a case study-centred narrative review.

PURPOSE: Critical illness is a transformative experience for both patients and their family members. For COVID-19 patients admitted to the intensive care unit (ICU), survival may be the start of a long road to recovery. Our knowledge of the post-ICU long-term sequelae of acute respiratory distress syndrome (ARDS) and severe acute respiratory syndrome (SARS) may inform our understanding and management of the long-term effects of COVID-19. SOURCE: We identified international and Canadian epidemiologic data on ICU admissions for COVID-19, COVID-19 pathophysiology, emerging ICU practice patterns, early reports of long-term outcomes, and federal support programs for survivors and their families. Centred around an illustrating case study, we applied relevant literature from ARDS and SARS to contextualize knowledge within emerging COVID-19 research and extrapolate findings to future long-term outcomes. PRINCIPAL FINDINGS: COVID-19 is a multisystem disease with unknown long-term morbidity and mortality. Its pathophysiology is distinct and unique from ARDS, SARS, and critical illness. Nevertheless, based on initial reports of critical care management for COVID-19 and the varied injurious supportive practices employed in the ICU, patients and families are at risk for post-intensive care syndrome. The distinct incremental risk of COVID-19 multiple organ dysfunction is unknown. The risk of mood disorders in family members may be further exacerbated by imposed isolation and stigma. CONCLUSION: Emerging literature on COVID-19 outcomes suggests some similarities with those of ARDS/SARS and prolonged mechanical ventilation. The pathophysiology of COVID-19 is presented here in the context of early outcome data and to inform an agenda for longitudinal research for patients and families.

RéSUMé: OBJECTIF: Les maladies au stade critique constituent une expérience bouleversante tant pour les patients que pour leurs proches. Pour les patients atteints de la COVID-19 admis aux soins intensifs (USI), la survie peut être le début d'un long parcours vers la guérison. Notre connaissance des séquelles à long terme post-USI d'un syndrome de détresse respiratoire aiguë (SDRA) ou d'un syndrome respiratoire aigu sévère (SRAS) pourrait éclairer notre compréhension et notre prise en charge des effets à long terme de la COVID-19. SOURCES: Nous avons identifié des données épidémiologiques internationales et canadiennes sur les admissions aux soins intensifs pour la COVID-19, la physiopathologie de la COVID-19, les schémas de pratique émergents en soins intensifs, les premiers rapports sur les issues à long terme et les programmes de soutien fédéraux pour les survivants et leurs familles. En nous centrant autour d'une étude de cas pour illustrer notre propos, nous avons appliqué la littérature pertinente à propos du SDRA et du SRAS afin de contextualiser les connaissances de la recherche émergente sur la COVID-19 et extrapoler les conclusions aux futures issues à long terme. CONSTATATIONS PRINCIPALES: La COVID-19 est une maladie multisystémique dont la morbidité et la mortalité à long terme sont inconnues. Sa physiopathologie est unique et distincte du SDRA, du SRAS et des maladies graves. Néanmoins, en nous fondant sur les rapports initiaux de prise en charge aux soins intensifs de la COVID-19 et sur les diverses pratiques de support préjudiciables utilisées aux soins intensifs, les patients et les familles sont à risque de syndrome post-soins intensifs. Le risque distinct supplémentaire de dysfonctionnement multiviscéral de la COVID-19 est inconnu. Le risque de troubles de l'humeur chez les proches peut être encore exacerbé par l'isolement imposé et la stigmatisation. CONCLUSION: La littérature émergente sur les issues de la COVID-19 suggère certaines similitudes avec celles du SDRA/SRAS et de la ventilation mécanique prolongée. La physiopathologie de la COVID-19 est présentée ici dans le contexte des premières données sur les issues et pour éclairer un programme de recherche longitudinale pour les patients et leurs familles.

Association of Extracorporeal Membrane Oxygenation With New Mental Health Diagnoses in Adult Survivors of Critical Illness.

Importance: Extracorporeal membrane oxygenation (ECMO) is used as temporary cardiorespiratory support in critically ill patients, but little is known regarding long-term psychiatric sequelae among survivors after ECMO. Objective: To investigate the association between ECMO survivorship and postdischarge mental health diagnoses among adult survivors of critical illness. Design, Setting, and Participants: Population-based retrospective cohort study in Ontario, Canada, from April 1, 2010, through March 31, 2020. Adult patients (N=4462; age ≥18 years) admitted to the intensive care unit (ICU), and surviving to hospital discharge were included. Exposures: Receipt of ECMO. Main Outcomes and Measures: The primary outcome was a new mental health diagnosis (a composite of mood disorders, anxiety disorders, posttraumatic stress disorder; schizophrenia, other psychotic disorders; other mental health disorders; and social problems) following discharge. There were 8 secondary outcomes including incidence of substance misuse, deliberate self-harm, death by suicide, and individual components of the composite primary outcome. Patients were compared with ICU survivors not receiving ECMO using overlap propensity score-weighted cause-specific proportional hazard models. Results: Among 642 survivors who received ECMO (mean age, 50.7 years; 40.7% female), median length of follow-up was 730 days; among 3820 matched ICU survivors who did not receive ECMO (mean age, 51.0 years; 40.0% female), median length of follow-up was 1390 days. Incidence of new mental health conditions among survivors who received ECMO was 22.1 per 100-person years (95% confidence interval [CI] 19.5-25.1), and 14.5 per 100-person years (95% CI, 13.8-15.2) among non-ECMO ICU survivors (absolute rate difference of 7.6 per 100-person years [95% CI, 4.7-10.5]). Following propensity weighting, ECMO survivorship was significantly associated with an increased risk of new mental health diagnosis (hazard ratio [HR] 1.24 [95% CI, 1.01-1.52]). There were no significant differences between survivors who received ECMO vs ICU survivors who did not receive ECMO in substance misuse (1.6 [95% CI, 1.1 to 2.4] per 100 person-years vs 1.4 [95% CI, 1.2 to 1.6] per 100 person-years; absolute rate difference, 0.2 per 100 person-years [95% CI, -0.4 to 0.8]; HR, 0.86 [95% CI, 0.48 to 1.53]) or deliberate self-harm (0.4 [95% CI, 0.2 to 0.9] per 100 person-years vs 0.3 [95% CI, 0.2 to 0.3] per 100 person-years; absolute rate difference, 0.1 per 100 person-years [95% CI, -0.2 to 0.4]; HR, 0.68 [95% CI, 0.21 to 2.23]). There were fewer than 5 total cases of death by suicide in the entire cohort. Conclusions and Relevance: Among adult survivors of critical illness, receipt of ECMO, compared with ICU hospitalization without ECMO, was significantly associated with a modestly increased risk of new mental health diagnosis or social problem diagnosis after discharge. Further research is necessary to elucidate the potential mechanisms underlying this relationship.

Gender Differences in Authorship of Critical Care Literature.

Rationale: Gender gaps exist in academic leadership positions in critical care. Peer-reviewed publications are crucial to career advancement, and yet little is known regarding gender differences in authorship of critical care research.Objectives: To evaluate gender differences in authorship of critical care literature.Methods: We used a validated database of author gender to analyze authorship of critical care articles indexed in PubMed between 2008 and 2018 in 40 frequently cited journals. High-impact journals were defined as those in the top 5% of all journals. We used mixed-effects logistic regression to evaluate the association of senior author gender with first and middle author gender, as well as association of first author gender with journal impact factor.Measurements and Main Results: Among 18,483 studies, 30.8% had female first authors, and 19.5% had female senior authors. Female authorship rose slightly over the last decade (average annual increases of 0.44% [P < 0.01] and 0.51% [P < 0.01] for female first and senior authors, respectively). When the senior author was female, the odds of female coauthorship rose substantially (first author adjusted odds ratio [aOR], 1.93; 95% confidence interval [CI], 1.71-2.17; middle author aOR, 1.48; 95% CI, 1.29-1.69). Female first authors had higher odds than men of publishing in lower-impact journals (aOR, 1.30; 95% CI, 1.16-1.45).Conclusions: Women comprise less than one-third of first authors and one-fourth of senior authors of critical care research, with minimal increase over the past decade. When the senior author was female, the odds of female coauthorship rose substantially. However, female first authors tend to publish in lower-impact journals. These findings may help explain the underrepresentation of women in critical care academic leadership positions and identify targets for improvement.

Intensive Care Unit-Acquired Weakness: Not just Another Muscle Atrophying Condition.

Intensive care unit-acquired weakness (ICUAW) occurs in critically ill patients stemming from the critical illness itself, and results in sustained disability long after the ICU stay. Weakness can be attributed to muscle wasting, impaired contractility, neuropathy, and major pathways associated with muscle protein degradation such as the ubiquitin proteasome system and dysregulated autophagy. Furthermore, it is characterized by the preferential loss of myosin, a distinct feature of the condition. While many risk factors for ICUAW have been identified, effective interventions to offset these changes remain elusive. In addition, our understanding of the mechanisms underlying the long-term, sustained weakness observed in a subset of patients after discharge is minimal. Herein, we discuss the various proposed pathways involved in the pathophysiology of ICUAW, with a focus on the mechanisms underpinning skeletal muscle wasting and impaired contractility, and the animal models used to study them. Furthermore, we will explore the contributions of inflammation, steroid use, and paralysis to the development of ICUAW and how it pertains to those with the corona virus disease of 2019 (COVID-19). We then elaborate on interventions tested as a means to offset these decrements in muscle function that occur as a result of critical illness, and we propose new strategies to explore the molecular mechanisms of ICUAW, including serum-related biomarkers and 3D human skeletal muscle culture models.

One-Year Outcomes in Caregivers of Critically Ill Patients.

BACKGROUND: Few resources are available to support caregivers of patients who have survived critical illness; consequently, the caregivers' own health may suffer. We studied caregiver and patient characteristics to determine which characteristics were associated with caregivers' health outcomes during the first year after patient discharge from an intensive care unit (ICU). METHODS: We prospectively enrolled 280 caregivers of patients who had received 7 or more days of mechanical ventilation in an ICU. Using hospital data and self-administered questionnaires, we collected information on caregiver and patient characteristics, including caregiver depressive symptoms, psychological well-being, health-related quality of life, sense of control over life, and effect of providing care on other activities. Assessments occurred 7 days and 3, 6, and 12 months after ICU discharge. RESULTS: The caregivers' mean age was 53 years, 70% were women, and 61% were caring for a spouse. A large percentage of caregivers (67% initially and 43% at 1 year) reported high levels of depressive symptoms. Depressive symptoms decreased at least partially with time in 84% of the caregivers but did not in 16%. Variables that were significantly associated with worse mental health outcomes in caregivers were younger age, greater effect of patient care on other activities, less social support, less sense of control over life, and less personal growth. No patient variables were consistently associated with caregiver outcomes over time. CONCLUSIONS: In this study, most caregivers of critically ill patients reported high levels of depressive symptoms, which commonly persisted up to 1 year and did not decrease in some caregivers. (Funded by the Canadian Institutes of Health Research and others; ClinicalTrials.gov number, NCT00896220.).

From skeletal muscle weakness to functional outcomes following critical illness: a translational biology perspective.

Intensive care unit acquired weakness (ICUAW) is now a well-known entity complicating critical illness. It increases mortality and in the critical illness survivor it is associated with physical disability, substantially increased health resource utilisation and healthcare costs. Skeletal muscle wasting is a key driver of ICUAW and physical functional outcomes in both the short and long term. To date, there is no intervention that can universally and consistently prevent muscle loss during critical illness, or enhance its recovery following intensive care unit discharge, to improve physical function. Clinical trials of early mobilisation or exercise training, or enhanced nutritional support have generated inconsistent results and we have no effective pharmacological interventions. This review will delineate our current understanding of the mechanisms underpinning the development and persistence of skeletal muscle loss and dysfunction in the critically ill individual, highlighting recent discoveries and clinical observations, and utilisation of this knowledge in the development of novel therapeutics.

Mechanical Ventilation-induced Diaphragm Atrophy Strongly Impacts Clinical Outcomes.

RATIONALE: Diaphragm dysfunction worsens outcomes in mechanically ventilated patients, but the clinical impact of potentially preventable changes in diaphragm structure and function caused by mechanical ventilation is unknown. OBJECTIVES: To determine whether diaphragm atrophy developing during mechanical ventilation leads to prolonged ventilation. METHODS: Diaphragm thickness was measured daily by ultrasound in adults requiring invasive mechanical ventilation; inspiratory effort was assessed by thickening fraction. The primary outcome was time to liberation from ventilation. Secondary outcomes included complications (reintubation, tracheostomy, prolonged ventilation, or death). Associations were adjusted for age, severity of illness, sepsis, sedation, neuromuscular blockade, and comorbidity. MEASUREMENTS AND MAIN RESULTS: Of 211 patients enrolled, 191 had two or more diaphragm thickness measurements. Thickness decreased more than 10% in 78 patients (41%) by median Day 4 (interquartile range, 3-5). Development of decreased thickness was associated with a lower daily probability of liberation from ventilation (adjusted hazard ratio, 0.69; 95% confidence interval [CI], 0.54-0.87; per 10% decrease), prolonged ICU admission (adjusted duration ratio, 1.71; 95% CI, 1.29-2.27), and a higher risk of complications (adjusted odds ratio, 3.00; 95% CI, 1.34-6.72). Development of increased thickness (n = 47; 24%) also predicted prolonged ventilation (adjusted duration ratio, 1.38; 95% CI, 1.00-1.90). Decreasing thickness was related to abnormally low inspiratory effort; increasing thickness was related to excessive effort. Patients with thickening fraction between 15% and 30% (similar to breathing at rest) during the first 3 days had the shortest duration of ventilation. CONCLUSIONS: Diaphragm atrophy developing during mechanical ventilation strongly impacts clinical outcomes. Targeting an inspiratory effort level similar to that of healthy subjects at rest might accelerate liberation from ventilation.

Veno-venous extracorporeal life support for blastomycosis-associated acute respiratory distress syndrome.

BACKGROUND: Blastomyces is a dimorphic fungus endemic to regions of North America, which can lead to pneumonia and fatal severe acute respiratory diseases syndrome in up to 89% of patients. Extracorporeal life support can provide adequate oxygenation while allowing the lungs to rest and heal, which might be an ideal therapy in this patient group, although long-term clinical and radiological outcomes are not known. CLINICAL FEATURES: We report on five consecutive patients admitted to Toronto General Hospital intensive care unit between January 2012 and September 2016, with progressive respiratory failure requiring veno-venous extracorporeal life support within 24-96 hours following mechanical ventilation. Ultra-lung protective mechanical ventilation was achieved within 24 hours. Recovery was the initial goal in all patients. Extracorporeal life support was provided for a prolonged period (up to 49 days), and four patients were successfully discharged from the intensive care unit. Long-term radiological assessment in three patients showed major improvement within 2 years of follow-up with some persistent disease-related changes (bronchiectasis, fibrosis, and cystic changes). In two patients, long-term functional and neuropsychological outcomes showed similar limitations to what is seen in acute respiratory distress syndrome patients who are not supported with extracorporeal life support and in acute respiratory distress syndrome patients without blastomycosis, but worse pulmonary function outcomes in the form of obstructive and restrictive changes that correlated with the radiological imaging. CONCLUSION: Veno-venous extracorporeal life support can effectively provide prolonged support for patients with blastomycosis-associated acute respiratory distress syndrome that is safe and associated with favorable long-term outcomes.

Fifty Years of Research in ARDS. Long-Term Follow-up after Acute Respiratory Distress Syndrome. Insights for Managing Medical Complexity after Critical Illness.

Critical illness is not a discrete disease state or syndrome. It is the culmination of a multiplicity of heterogeneous disease states and their varied health trajectories leading to extreme illness that requires advanced life support in a distinct geographic location in the hospital. It is a marker of newly acquired or worsened medical complexity and multimorbidities. Fifty years ago, distinguished critical care colleagues identified a syndrome of severe lung injury that united a group of patients with disparate admitting diagnoses. Acute respiratory distress syndrome continues to represent an important, incremental insult and risk modifier of acute and longer-term outcome, but it does not solely define our patients or their outcomes in isolation. Over the next 50 years, our research and clinical agenda needs to sharpen our lens on the fundamental importance of our patients' pre-critical illness health status, their intrinsic susceptibilities to tissue injury, and their innate and varied resiliencies. We need to take responsibility for the contribution that we make to morbidity through our practice in the intensive care unit each day. Engagement in frank and transparent communication with our patients and their caregivers about the very real and morbid consequences of being this sick is essential. We must enforce explicit consent about the morbidity of innovative, experimental, or high-risk medical and surgical procedures and ensure that our ongoing level of treatment aligns with patients' and caregivers' goals and values. Interprofessional and multidisciplinary collaboration is crucial to modify existing complex care pathways for our patients and their families to foster optimal rehabilitation and reintegration into the workplace and community.

Gender Parity in Critical Care Medicine.

Clinical practice guidelines are systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances. These documents inform and shape patient care around the world. In this Perspective we discuss the importance of diversity on guideline panels, the disproportionately low representation of women on critical care guideline panels, and existing initiatives to increase the representation of women in corporations, universities, and government. We propose five strategies to ensure gender parity within critical care medicine.

The RECOVER Program: Disability Risk Groups and 1-Year Outcome after 7 or More Days of Mechanical Ventilation.

RATIONALE: Disability risk groups and 1-year outcome after greater than or equal to 7 days of mechanical ventilation (MV) in medical/surgical intensive care unit (ICU) patients are unknown and may inform education, prognostication, rehabilitation, and study design. OBJECTIVES: To stratify patients for post-ICU disability and recovery to 1 year after critical illness. METHODS: We evaluated a multicenter cohort of 391 medical/surgical ICU patients who received greater than or equal to 1 week of MV at 7 days and 3, 6, and 12 months after ICU discharge. Disability risk groups were identified using recursive partitioning modeling. MEASUREMENTS AND MAIN RESULTS: The 7-day post-ICU Functional Independence Measure (FIM) determined the recovery trajectory to 1-year after ICU discharge and was an independent risk factor for 1-year mortality. The 7-day post-ICU FIM was predicted by age and ICU length of stay. By 2 weeks of MV, ICU patients could be stratified into four disability groups characterized by increasing risk for post ICU disability, ICU and post-ICU healthcare use, and disposition. Patients less than 42 years with ICU length of stay less than 2 weeks had the best function and fewest deaths at 1 year compared with patients greater than 66 years with ICU length of stay greater than 2 weeks who sustained the worst disability and 40% 1-year mortality. Depressive symptoms (17%) and post-traumatic stress disorder (18%) persisted at 1 year. CONCLUSIONS: ICU survivors of greater than or equal to 1 week of MV may be stratified into four disability groups based on age and ICU length of stay. These groups determine 1-year recovery and healthcare use and are independent of admitting diagnosis and illness severity. Clinical trial registered with www.clinicaltrials.gov (NCT 00896220).

Evolution of Diaphragm Thickness during Mechanical Ventilation. Impact of Inspiratory Effort.

RATIONALE: Diaphragm atrophy and dysfunction have been reported in humans during mechanical ventilation, but the prevalence, causes, and functional impact of changes in diaphragm thickness during routine mechanical ventilation for critically ill patients are unknown. OBJECTIVES: To describe the evolution of diaphragm thickness over time during mechanical ventilation, its impact on diaphragm function, and the influence of inspiratory effort on this phenomenon. METHODS: In three academic intensive care units, 107 patients were enrolled shortly after initiating ventilation along with 10 nonventilated intensive care unit patients (control subjects). Diaphragm thickness and contractile activity (quantified by the inspiratory thickening fraction) were measured daily by ultrasound. MEASUREMENTS AND MAIN RESULTS: Over the first week of ventilation, diaphragm thickness decreased by more than 10% in 47 (44%), was unchanged in 47 (44%), and increased by more than 10% in 13 (12%). Thickness did not vary over time following extubation or in nonventilated patients. Low diaphragm contractile activity was associated with rapid decreases in diaphragm thickness, whereas high contractile activity was associated with increases in diaphragm thickness (P = 0.002). Contractile activity decreased with increasing ventilator driving pressure (P = 0.01) and controlled ventilator modes (P = 0.02). Maximal thickening fraction (a measure of diaphragm function) was lower in patients with decreased or increased diaphragm thickness (n = 10) compared with patients with unchanged thickness (n = 10; P = 0.05 for comparison). CONCLUSIONS: Changes in diaphragm thickness are common during mechanical ventilation and may be associated with diaphragmatic weakness. Titrating ventilatory support to maintain normal levels of inspiratory effort may prevent changes in diaphragm configuration associated with mechanical ventilation.