Long-term outcomes in survivors of acute respiratory distress syndrome ventilated in supine or prone position

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.

Acute hypoxaemic respiratory failure after treatment with lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal: long-term outcomes from the REST randomised trial

INTRODUCTION

Lower tidal volume ventilation, facilitated by veno-venous extracorporeal carbon dioxide removal (vv-ECCO2R), does not improve 90-day mortality in patients with acute hypoxaemic respiratory failure (AHRF). The aim of this analysis was to evaluate the effect of this therapeutic strategy on long-term outcomes.

METHODS

This was a prespecified analysis of the REST trial, a UK-wide multicentre randomised clinical trial that compared lower tidal volume ventilation, facilitated by vv-ECCO2R (intervention), with standard care in the treatment of patients with moderate-to-severe AHRF. Mortality to 2 years was assessed, while respiratory function, post-traumatic stress disorder, cognitive function and health-related quality of life were evaluated in survivors at 1 year using standardised questionnaires.

RESULTS

Of 412 patients enrolled into the REST trial, 391 (95%) had 2-year mortality outcome data available. There was no difference in the time to death between intervention and standard care (HR 1.08 (0.81, 1.44); log-rank test p=0.61). 161 patients alive at 1 year provided at least one questionnaire response. There was no difference in respiratory function, post-traumatic stress disorder, cognitive dysfunction or health-related quality of life between patients allocated to intervention or standard care.

CONCLUSION

Lower-tidal volume ventilation facilitated by vv-ECCO2R does not affect 1-year mortality in patients with moderate-to-severe AHRF. Of the patients who provided questionnaire responses, there was no treatment effect on long-term respiratory function, post-traumatic stress disorder, cognitive dysfunction or health-related quality of life.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT02654327.

Long-term complications of prone position ventilation with relevance for acute and postacute rehabilitation: a systematic review of the literature

INTRODUCTION

Prone positioning ventilation (PPV) is an effective treatment for patients with moderate to severe acute respiratory distress syndrome (ARDS). Despite the benefits of PPV, different kinds of short and long-term consequences have been noted. This review summarizes long-term complications of PPV that impact treatment strategies and outcomes in acute and postacute rehabilitation.

EVIDENCE ACQUISITION

PubMed/Medline, Cochrane Library, Cochrane COVID-19 Study Register databases and the Google Scholar search engine were systematically searched for studies investigating long-term complications of PPV. The final search date for all sources/databases was January 31, 2022. For our methodological appraisal, we conducted a systematic review of articles without any restrictions on types of articles or publication dates. Only articles published in English and available as full texts were eligible for inclusion. After the screening process, data of interest were extracted from eligible sources: PPV sequelae and conclusions (i.e. possible effects on the course of rehabilitation and therapy strategies).

EVIDENCE SYNTHESIS

A total of 59 studies are included in this review. Long-term consequences are mainly pressure ulcers and nerve lesions that exist after discharge from the Intensive Care Unit (ICU). Publications rarely recommend treatment strategies for long-term complications after PPV. Due to the quality of the included studies, no robust conclusions as to effective strategies can be drawn.

CONCLUSIONS

Further high-quality research is required, considering the different long-term complications after PPV and their impact on rehabilitation in order to draw conclusions about viable physical therapies. Crucially, however, prone positioning (PP) sequelae pose new challenges to physicians and therapists in acute and postacute rehabilitation medicine as well as follow-up care.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

Trial registration: NCT 02149589; May 29, 2014.

Supplementary Information

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

A Simple-to-Use Web-Based Calculator for Survival Prediction in Acute Respiratory Distress Syndrome

Background: The aim of this study was to construct and validate a simple-to-use model to predict the survival of patients with acute respiratory distress syndrome.

Methods: A total of 197 patients with acute respiratory distress syndrome were selected from the Dryad Digital Repository. All eligible individuals were randomly stratified into the training set (n=133) and the validation set (n=64) as 2: 1 ratio. LASSO regression analysis was used to select the optimal predictors, and receiver operating characteristic and calibration curves were used to evaluate accuracy and discrimination of the model. Clinical usefulness of the model was also assessed using decision curve analysis and Kaplan-Meier analysis.

Results: Age, albumin, platelet count, PaO₂/FiO₂, lactate dehydrogenase, high-resolution computed tomography score, and etiology were identified as independent prognostic factors based on LASSO regression analysis; these factors were integrated for the construction of the nomogram. Results of calibration plots, decision curve analysis, and receiver operating characteristic analysis showed that this model has good predictive ability of patient survival in acute respiratory distress syndrome. Moreover, a significant difference in the 28-day survival was shown between the patients stratified into different risk groups (P < 0.001). For convenient application, we also established a web-based calculator (https://huangl.shinyapps.io/ARDSprognosis/).

Conclusions: We satisfactorily constructed a simple-to-use model based on seven relevant factors to predict survival and prognosis of patients with acute respiratory distress syndrome. This model can aid personalized treatment and clinical decision-making.

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.

Emerging approaches in pediatric mechanical ventilation

INTRODUCTION

The use of mechanical ventilation is an invaluable tool in caring for critically ill patients. Enhancing our capabilities in mechanical ventilation has been instrumental in the ability to support clinical conditions and diseases which were once associated with high mortality. Areas covered: Within this manuscript, we will look to discuss emerging approaches to improving the care of pediatric patients who require mechanical ventilation. After an extensive literature search, we will provide a brief review of the history and pathophysiology of acute respiratory distress syndrome, an assessment of several ventilator settings, a discussion on assisted ventilation, review of therapy used to rescue in severe respiratory failure, methods of monitoring the effects of mechanical ventilation, and nutrition. Expert opinion: As we have advanced in our care, we are seeing children survive illnesses that would have once claimed their lives. Given this knowledge, we must continue to advance the research in pediatric critical care to understand the means in which we can tailor the therapy to the patient in efforts to efficiently liberate them from mechanical ventilation once their illness has resolved.

Six-Minute Walk Distance After Critical Illness: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Impaired physical functioning is common and long lasting after an intensive care unit (ICU) admission. The 6-minute walk test (6MWT) is a validated and widely used test of functional capacity. This systematic review synthesizes existing data in order to: (1) evaluate 6-minute walk distance (6MWD) in meters over longitudinal follow-up after critical illness, (2) compare 6MWD between acute respiratory distress syndrome (ARDS) versus non-ARDS survivors, and (3) evaluate patient- and ICU-related factors associated with 6MWD.

DATA SOURCES

Five databases (PubMed, EMBASE, Cumulative Index of Nursing and Allied Health Literature, PsychINFO, and Cochrane Controlled Trials Registry) were searched to identify studies reporting 6MWT after hospital discharge in survivors from general (ie, nonspeciality) ICUs. The last search was run on February 14, 2018. Databases were accessed via Johns Hopkins University Library.

DATA EXTRACTION AND SYNTHESIS

Pooled mean 6MWD were reported, with separate linear random effects models used to evaluate associations of 6MWD with ARDS status, and patient- and ICU-related variables. Twenty-six eligible articles on 16 unique participant groups were included. The pooled mean (95% confidence interval [CI]) 6MWD results at 3- and 12-months post discharge were 361 (321-401) and 436 (391-481) meters, respectively. There was a significant increase in 6MWD at 12 months compared to 3 months (P = .017). In ARDS versus non-ARDS survivors, the mean (95% CI) 6MWD difference over 3-, 6-, and 12-month follow-up was 73 [13-133] meters lower. Female sex and preexisting comorbidity also were significantly associated with lower 6MWD, with ICU-related variables having no consistent associations.

CONCLUSIONS

Compared to initial assessment at 3 months, significant improvement in 6MWD was reported at 12 months. Female sex, preexisting comorbidity, and ARDS (vs non-ARDS) were associated with lower 6MWT results. Such factors warrant consideration in the design of clinical research studies and in the interpretation of patient status using the 6MWT.

Quality of Life and Lung Function in Survivors of Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Survivors of acute respiratory distress syndrome (ARDS) have long-term impairment of pulmonary function and health-related quality of life, but little is known of outcomes of ARDS survivors treated with extracorporeal membrane oxygenation. The aim of this study was to compare long-term outcomes of ARDS patients treated with or without extracorporeal membrane oxygenation.

Methods

A prospective, observational study of adults with ARDS (January 2013 to December 2015) was conducted at a single center. One year after discharge, survivors underwent pulmonary function tests, computed tomography of the chest, and health-related quality-of-life questionnaires.

Results

Eighty-four patients (34 extracorporeal membrane oxygenation, 50 non–extracorporeal membrane oxygenation) were studied; both groups had similar characteristics at baseline, but comorbidity was more common in non–extracorporeal membrane oxygenation (23 of 50 vs. 4 of 34, 46% vs. 12%, P &lt; 0.001), and severity of hypoxemia was greater in extracorporeal membrane oxygenation (median Pao2/Fio2 72 [interquartile range, 50 to 103] vs. 114 [87 to 133] mm Hg, P &lt; 0.001) and respiratory compliance worse. At 1 yr, survival was similar (22/33 vs. 28/47, 66% vs. 59%; P = 0.52), and pulmonary function and computed tomography were almost normal in both groups. Non–extracorporeal membrane oxygenation patients had lower health-related quality-of-life scores and higher rates of posttraumatic stress disorder.

Conclusions

Despite more severe respiratory failure at admission, 1-yr survival of extracorporeal membrane oxygenation patients was not different from that of non–extracorporeal membrane oxygenation patients; each group had almost full recovery of lung function, but non–extracorporeal membrane oxygenation patients had greater impairment of health-related quality of life.

Prognostic values of the Berlin definition criteria, blood lactate level, and fibroproliferative changes on high-resolution computed tomography in ARDS patients

Background

In the Berlin definition, acute respiratory distress syndrome (ARDS) is stratified into three stages according to oxygenation severity at the onset. The relevance between ARDS severity and prognosis varies among published reports and has not been verified, especially in Asian patients.

Methods

In this study, we examined the associations between the Berlin definition criteria and prognosis and clinical parameters, including high-resolution computed tomography (HRCT) scores of fibroproliferative changes of the lungs. One hundred fifty-three patients (45 females; mean age, 67 y/o), who met the Berlin definition and received treatment in our intensive care unit between January 2012 and December 2015, were enrolled.

Results

The severity of ARDS was mild in 42 patients, moderate in 71, and severe in 40. The underlying diseases included pneumonia in 56 patients and aspiration in 43. Forty-two (27.5%) patients were deceased within 30 days, and the 30-day mortality was 10% in mild ARDS, 23% in moderate, and 55% in severe, which were significantly different (P <  0.05). In the non-survivors, APACHE II, SOFA, and SAPS II scores were higher than in the survivors (P <  0.001). Multivariate analyses revealed that elevated blood lactate level (≥ 2.0 mmol/L) and increased HRCT scores were significantly associated with weaning failure and 30-day mortality of the patients with ARDS.

Conclusions

These results suggested that the severity criteria in the Berlin definition might be associated with the prognosis of the patients. Blood lactate levels and HRCT score might be predictive of the outcome of patients with ARDS.

Changes in health-related quality of life after discharge from an intensive care unit: a systematic review

Quality of life after critical illness is becoming increasingly important as survival improves. Various measures have been used to study the quality of life of patients discharged from intensive care. We systematically reviewed validated measures of quality of life and their results. We searched PubMed, CENTRAL, CINAHL, Web of Science and Open Grey for studies of quality of life, measured after discharge from intensive care. We categorised studied populations as: general; restricted to level-3 care or critical care beyond 5 days; and septic patients. We included quality of life measured at any time after hospital discharge. We identified 48 studies. Thirty-one studies used the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and 19 used the EuroQol-5D (EQ-5D); eight used both and nine used alternative validated measures. Follow-up rates ranged from 26-100%. Quality of life after critical care was worse than for age- and sex-matched populations. Quality of life improved for one year after hospital discharge. The aspects of life that improved most were physical function, physical role, vitality and social function. However, these domains were also the least likely to recover to population norms as they were more profoundly affected by critical illness.

Assessment of 1-year Outcomes in Survivors of Severe Acute Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation or Mechanical Ventilation: A Prospective Observational Study

Background:

Little is known about the long-term outcomes of severe acute respiratory distress syndrome (ARDS) patients requiring extracorporeal membrane oxygenation (ECMO). This study aimed to investigate the 1-year outcomes of these patients or patients receiving mechanical ventilation (MV) and compare their health-related quality of life (HRQoL) to the general population.

Methods:

Severe ARDS survivors admitted to two ICUs in China between January 2012 and January 2014 were enrolled. Of the severe ARDS survivors enrolled, 1-year postdischarge, HRQoL assessment using the Short-Form 36 (SF-36) and EuroQol questionnaire dimensions, 6-min walking distance, chest computed tomography scan, pulmonary function, and arterial blood gas analysis were compared for ARDS patients with or without ECMO.

Results:

ARDS patients receiving ECMO had a significantly higher Acute Physiology and Chronic Health Evaluation II score (30.3 ± 6.7 vs. 26.5 ± 7.3, P = 0.036), lung injury score (3.3 ± 0.4 vs. 2.8 ± 0.5, P = 0.000), Sequential Organ Failure Assessment score (10.8 ± 3.5 vs. 7.9 ± 3.1, P = 0.000), lower PaO₂/FiO₂ ratio ([mmHg, 1 mmHg = 0.133 kPa], 68.3 ± 16.1 vs. 84.8 ± 16.5, P = 0.000), and increased extrapulmonary organ failure (2 [1, 3] vs. 1 [1, 1], P = 0.025) compared with patients not receiving ECMO. ECMO and non-ECMO survivors showed similar pulmonary function, morphological abnormalities, resting arterial blood gas values, and 6-min walking distance. Mild pulmonary dysfunction and abnormal morphology were observed in a few survivors. In addition, ECMO and non-ECMO survivors showed a similar quality of life. ECMO survivors showed lower SF-36 physical functioning and role-physical domain scores (minimum clinically significant difference at least 5 points), and non-ECMO survivors had similar outcome.

Conclusions:

One-year posthospital discharge, severe ARDS survivors receiving ECMO or MV demonstrated comparable outcomes. Compared with the general population, ARDS survivors showed reduced HRQoL. Pulmonary function and lung morphology revealed sufficient recovery with minor lung impairment.

Fatigue in chronically critically ill patients following intensive care - reliability and validity of the multidimensional fatigue inventory (MFI-20)

Background

Fatigue often occurs as long-term complication in chronically critically ill (CCI) patients after prolonged intensive care treatment. The Multidimensional Fatigue Inventory (MFI-20) has been established as valid instrument to measure fatigue in a wide range of medical illnesses. Regarding the measurement of fatigue in CCI patients, the psychometric properties of the MFI-20 have not been investigated so far. Thus, the present study examines reliability and validity of the MFI-20 in CCI patients.

Methods

A convenience sample of n = 195 patients with Critical Illness Polyneuropathy (CIP) or Myopathy (CIM) were recruited via personal contact within four weeks (t1) following the transfer from acute care ICU to post-acute ICU at a large rehabilitation hospital. N = 113 (median age 61.1 yrs., 72.6% men) patients were again contacted via telephone three (t2) and six (t3) months following the transfer to post-acute ICU. The MFI-20, the Euro-Quality of Life (EQ-5D-3 L) and the Structured Clinical Interview for the Diagnostic and Statistical Manual of mental disorders DSM-IV (SCID-I) were applied within this prospective cohort study.

Results

The internal consistency Cronbach’s α was adequate for the MFI-total and all but the subscale Reduced Motivation (RM) (range: .50–.91). Item-to-total correlations (range: .22–.80) indicated item redundancy for the subscale RM. Confirmatory Factor analyses (CFAs) revealed poor model fit for the original 5-factor model of the MFI-20 (t2/t3, Confirmatory Fit Index, CFI = .783/ .834; Tucker-Lewis Index, TLI = .751/ .809; Root Mean Square Error of Approximation, RMSEA = .112/ .103). Among the alternative models (1-, 2-, 3-factor models), the data best fit to a 3-factor solution summarizing the highly correlated factors General −/ Physical Fatigue/ Reduced Activity (GF/ PF/ RA) (t2/ t3, CFI = .878/ .896, TLI = .846/ .869, RMSEA = .089/ .085, 90% Confidence Interval .073–.104/ .066–.104). The MFI-total score significantly correlated with the health-related quality of life (range: −.65-(−).66) and the diagnosis of major depression (range: .27–.37).

Conclusions

In the present sample of CCI patients, a reliable and valid factor structure of the MFI-20 could not be ascertained. Especially the subscale RM should be revised. Since the factors GF, PF and RA cannot be separated from each other and the unclear factorial structure in the present sample of CCI patients, the MFI-20 is not recommended for use in this context.

Trial registration

German Clinical Trials Registration DRKS00003386. Registered 13 December 2011, retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-0862-6) contains supplementary material, which is available to authorized users.

Fatigue in intensive care survivors one year after discharge

BACKGROUND

Fatigue has not been investigated in long-term Intensive Care Unit (ICU) survivors. This study aimed to assess fatigue through a specific instrument, namely the Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F) scale, in ICU survivors one year after hospital discharge. A secondary aim was to compare the findings of FACIT-F with those of the Vitality domain (VT) of the 36-item Short-Form Health Survey (SF-36).

METHODS

This prospective cohort study was performed on 56 adult patients with a Length Of Stay (LOS) in ICU longer than 72 h. At one year after hospital discharge, FACIT-F and SF-36 questionnaires were administered to consenting patients by direct interview. FACIT-F was measured as raw (range 0-52), and FACIT-F-trans value (range 0-100). Past medical history, and demographic and clinical ICU-related variables were collected.

RESULTS

The patients' median age was 67.5, Simplified Acute Physiology Score II 31, and LOS in ICU 5 days. The median raw FACIT-F of the patients was 41, and Cronbach's α was 0.937. The correlation coefficient between FACIT-F-trans and VT of SF-36 was 0.660 (p < 0.001). Both FACIT-F and VT were related to dyspnoea scale (p = 0.01). A Bland-Altman plot of VT vs FACIT-F-trans showed a bias of -0.8 with 95 % limits of agreement from 35.7 to -34.1. The linear regression between differences and means was 0.639, suggesting a significant proportional bias.

CONCLUSIONS

The 13-item FACIT-F questionnaire is valid to assess fatigue of long-term ICU survivors. VT of SF-36 relates to FACIT-F, but consists of only four items assessing two positive and two negative aspects. FACIT-F grasps the negative aspects of fatigue better than VT. Specific tools assess specific conditions better that general tools.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02684877 .

Can lung ultrasonography predict prone positioning response in acute respiratory distress syndrome patients?

PURPOSE

The purpose was to assess whether lung ultrasonography (L-US) is a useful tool in prediction of prone positioning (PP) oxygenation response in patients with acute respiratory distress syndrome (ARDS).

METHODS

In a prospective study, 19 ARDS patients were included for assessment of PP oxygenation response. The latter was assessed for at least 12 hours 6 different ultrasonography windows were performed on each hemithorax before prone (H0, H2, H12 before return to supine and at H14 (2 hours after return to supine). Patients were classified into 2 groups (responders / non responders) according their oxygenation response to PP. Ultrasonography videos were blindly evaluated by 3 expert clinicians to classify lung regions as "normal", "moderate loss of aeration," "severe loss of aeration," or "lung consolidation." Oxygenation parameters were collected at H0, H2, and H14.

RESULTS

Association of each lung region aspect to PP oxygenation response was compared between the 2 groups. The normal aspect of the anterobasal regions was significantly associated with the oxygenation response (P = .0436), with a positive predictive value equal to or near 100%.

DISCUSSION

Our results demonstrated that a simple and short L-US examination could be a useful tool in prediction of PP oxygenation response in ARDS patients. A normal L-US pattern of both anterobasal lung regions in supine position may predict a significant PaO2/FIO2 ratio improvement.

PEEP titration during prone positioning for acute respiratory distress syndrome

No major trial evaluating prone positioning for acute respiratory distress syndrome (ARDS) has incorporated a high-positive end-expiratory pressure (high-PEEP) strategy despite complementary physiological rationales. We evaluated generalizability of three recent proning trials to patients receiving a high-PEEP strategy. All trials employed a relatively low-PEEP strategy. After protocol ventilator settings were initiated and the patient was positioned per treatment assignment, post-intervention PEEP was not more than 5 cm H₂O in 16.7 % and not more than 10 cm H₂O in 66.0 % of patients. Post-intervention PEEP would have been nearly twice the set PEEP had a high-PEEP strategy been employed. Use of either proning or high-PEEP likely improves survival in moderate-severe ARDS; the role for both concomitantly remains unknown.

Prone position for acute respiratory failure in adults

BACKGROUND

Acute hypoxaemia de novo or on a background of chronic hypoxaemia is a common reason for admission to intensive care and for provision of mechanical ventilation. Various refinements of mechanical ventilation or adjuncts are employed to improve patient outcomes. Mortality from acute respiratory distress syndrome, one of the main contributors to the need for mechanical ventilation for hypoxaemia, remains approximately 40%. Ventilation in the prone position may improve lung mechanics and gas exchange and could improve outcomes.

OBJECTIVES

The objectives of this review are (1) to ascertain whether prone ventilation offers a mortality advantage when compared with traditional supine or semi recumbent ventilation in patients with severe acute respiratory failure requiring conventional invasive artificial ventilation, and (2) to supplement previous systematic reviews on prone ventilation for hypoxaemic respiratory failure in an adult population.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 1), Ovid MEDLINE (1950 to 31 January 2014), EMBASE (1980 to 31 January 2014), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 31 January 2014) and Latin American Caribbean Health Sciences Literature (LILACS) (1992 to 31 January 2014) in Ovid MEDLINE for eligible randomized controlled trials. We also searched for studies by handsearching reference lists of relevant articles, by contacting colleagues and by handsearching published proceedings of relevant journals. We applied no language constraints, and we reran the searches in CENTRAL, MEDLINE, EMBASE, CINAHL and LILACS in June 2015. We added five new studies of potential interest to the list of "Studies awaiting classification" and will incorporate them into formal review findings during the review update.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that examined the effects of prone position versus supine/semi recumbent position during conventional mechanical ventilation in adult participants with acute hypoxaemia.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed all trials identified by the search and assessed them for suitability, methods and quality. Two review authors extracted data, and three review authors reviewed the data extracted. We analysed data using Review Manager software and pooled included studies to determine the risk ratio (RR) for mortality and the risk ratio or mean difference (MD) for secondary outcomes; we also performed subgroup analyses and sensitivity analyses.

MAIN RESULTS

We identified nine relevant RCTs, which enrolled a total of 2165 participants (10 publications). All recruited participants suffered from disorders of lung function causing moderate to severe hypoxaemia and requiring mechanical ventilation, so they were fairly comparable, given the heterogeneity of specific disease diagnoses in intensive care. Risk of bias, although acceptable in the view of the review authors, was inevitable: Blinding of participants and carers to treatment allocation was not possible (face-up vs face-down).Primary analyses of short- and longer-term mortality pooled from six trials demonstrated an RR of 0.84 to 0.86 in favour of the prone position (PP), but findings were not statistically significant: In the short term, mortality for those ventilated prone was 33.4% (363/1086) and supine 38.3% (395/1031). This resulted in an RR of 0.84 (95% confidence interval (CI) 0.69 to 1.02) marginally in favour of PP. For longer-term mortality, results showed 41.7% (462/1107) for prone and 47.1% (490/1041) for supine positions, with an RR of 0.86 (95% CI 0.72 to 1.03). The quality of the evidence for both outcomes was rated as low as a result of important potential bias and serious inconsistency.Subgroup analyses for mortality identified three groups consistently favouring PP: those recruited within 48 hours of meeting entry criteria (five trials; 1024 participants showed an RR of 0.75 (95% CI 0.59 to 94)); those treated in the PP for 16 or more hours per day (five trials; 1005 participants showed an RR of 0.77 (95% CI 0.61 to 0.99)); and participants with more severe hypoxaemia at trial entry (six trials; 1108 participants showed an RR of 0.77 (95% CI 0.65 to 0.92)). The quality of the evidence for these outcomes was rated as moderate as a result of potentially important bias.Prone positioning appeared to influence adverse effects: Pressure sores (three trials; 366 participants) with an RR of 1.37 (95% CI 1.05 to 1.79) and tracheal tube obstruction with an RR of 1.78 (95% CI 1.22 to 2.60) were increased with prone ventilation. Reporting of arrhythmias was reduced with PP, with an RR of 0.64 (95% CI 0.47 to 0.87).

AUTHORS' CONCLUSIONS

We found no convincing evidence of benefit nor harm from universal application of PP in adults with hypoxaemia mechanically ventilated in intensive care units (ICUs). Three subgroups (early implementation of PP, prolonged adoption of PP and severe hypoxaemia at study entry) suggested that prone positioning may confer a statistically significant mortality advantage. Additional adequately powered studies would be required to confirm or refute these possibilities of subgroup benefit but are unlikely, given results of the most recent study and recommendations derived from several published subgroup analyses. Meta-analysis of individual patient data could be useful for further data exploration in this regard. Complications such as tracheal obstruction are increased with use of prone ventilation. Long-term mortality data (12 months and beyond), as well as functional, neuro-psychological and quality of life data, are required if future studies are to better inform the role of PP in the management of hypoxaemic respiratory failure in the ICU.

Long-term survival in patients with severe acute respiratory distress syndrome and rescue therapies for refractory hypoxemia*

OBJECTIVES

To describe long-term survival in patients with severe acute respiratory distress syndrome and assess differences in patient characteristics and outcomes among those who receive rescue therapies (prone position ventilation, inhaled nitric oxide, or inhaled epoprostenol) versus conventional treatment.

DESIGN

Cohort study of patients with severe hypoxemia.

SETTING

University-affiliated level 1 trauma center.

PATIENTS

Patients diagnosed with severe acute respiratory distress syndrome within 72 hours of ICU admission between January 1, 2008, and December 31, 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data were abstracted from the medical record and included demographic and clinical variables, hospital and ICU length of stay, discharge disposition, and hospital costs. Patient-level data were linked to the Washington State Death Registry. Kaplan-Meier methods and Cox's proportional hazards models were used to estimate survival and hazard ratios. Four hundred twenty-eight patients meeting study inclusion criteria were identified; 62 (14%) were initiated on a rescue therapy. PaO2/FIO2 ratios were comparable at admission between patients treated with a rescue therapy and those treated conventionally but were substantially lower by 72 hours in those who received rescue therapies (54 ± 17 vs 69 ± 17 mm Hg; p < 0.01). For the entire cohort, estimated survival probability at 3 years was 55% (95% CI, 51-61%). Among 280 hospital survivors (65%), 3-year survival was 85% (95% CI, 80-89%). The relative hazard of in-hospital mortality was 68% higher among patients who received rescue therapy compared with patients treated conventionally (95% CI, 8-162%; p = 0.02). For long-term survival, the hazard ratio of death following ICU admission was 1.56 (95% CI, 1.02-2.37; p = 0.04), comparing rescue versus conventional treatment.

CONCLUSIONS

Despite high hospital mortality, severe acute respiratory distress syndrome patients surviving to hospital discharge have relatively good long-term survival. Worsening hypoxemia was associated with initiation of rescue therapy. Patients on rescue therapy had higher in-hospital mortality; however, survivors to hospital discharge had long-term survival that was comparable to other acute respiratory distress syndrome survivors.

Acute respiratory distress syndrome in patients with malignancies

PURPOSE

Little attention has been given to ARDS in cancer patients, despite their high risk for pulmonary complications. We sought to describe outcomes in cancer patients with ARDS meeting the Berlin definition.

METHODS

Data from a cohort of patients admitted to 14 ICUs between 1990 and 2011 were used for a multivariable analysis of risk factors for hospital mortality.

RESULTS

Of 1,004 included patients (86 % with hematological malignancies and 14 % with solid tumors), 444 (44.2 %) had neutropenia. Admission SOFA score was 12 (10-13). Etiological categories were primary infection-related ARDS (n = 662, 65.9 %; 385 bacterial infections, 213 invasive aspergillosis, 64 Pneumocystis pneumonia); extrapulmonary septic shock-related ARDS (n = 225, 22.4 %; 33 % candidemia); noninfectious ARDS (n = 76, 7.6 %); and undetermined cause (n = 41, 4.1 %). Of 387 (38.6 %) patients given noninvasive ventilation (NIV), 276 (71 %) subsequently required endotracheal ventilation. Hospital mortality was 64 % overall. According to the Berlin definition, 252 (25.1 %) patients had mild, 426 (42.4 %) moderate and 326 (32.5 %) severe ARDS; mortality was 59, 63 and 68.5 %, respectively (p = 0.06). Mortality dropped from 89 % in 1990-1995 to 52 % in 2006-2011 (p < 0.0001). Solid tumors, primary ARDS, and later admission period were associated with lower mortality. Risk factors for higher mortality were allogeneic bone-marrow transplantation, modified SOFA, NIV failure, severe ARDS, and invasive fungal infection.

CONCLUSIONS

In cancer patients, 90 % of ARDS cases are infection-related, including one-third due to invasive fungal infections. Mortality has decreased over time. NIV failure is associated with increased mortality. The high mortality associated with invasive fungal infections warrants specific studies of early treatment strategies.

Prone positioning reduces mortality from acute respiratory distress syndrome in the low tidal volume era: a meta-analysis

PURPOSE

Prone positioning for ARDS has been performed for decades without definitive evidence of clinical benefit. A recent multicenter trial demonstrated for the first time significantly reduced mortality with prone positioning. This meta-analysis was performed to integrate these findings with existing literature and test whether differences in tidal volume explain conflicting results among randomized trials.

METHODS

Studies were identified using MEDLINE, EMBASE, Cochrane Register of Controlled Trials, LILACS, and citation review. Included were randomized trials evaluating the effect on mortality of prone versus supine positioning during conventional ventilation for ARDS. The primary outcome was risk ratio of death at 60 days meta-analyzed using random effects models. Analysis stratified by high (>8 ml/kg predicted body weight) or low (≤ 8 ml/kg PBW) mean baseline tidal volume was planned a priori.

RESULTS

Seven trials were identified including 2,119 patients, of whom 1,088 received prone positioning. Overall, prone positioning was not significantly associated with the risk ratio of death (RR 0.83; 95% CI 0.68-1.02; p = 0.073; I (2) = 64%). When stratified by high or low tidal volume, prone positioning was associated with a significant decrease in RR of death only among studies with low baseline tidal volume (RR 0.66; 95% CI 0.50-0.86; p = 0.002; I (2) = 25%). Stratification by tidal volume explained over half the between-study heterogeneity observed in the unstratified analysis.

CONCLUSIONS

Prone positioning is associated with significantly reduced mortality from ARDS in the low tidal volume era. Substantial heterogeneity across studies can be explained by differences in tidal volume.

One-year mortality and predictors of death among hospital survivors of acute respiratory distress syndrome

PURPOSE

Advances in supportive care and ventilator management for acute respiratory distress syndrome (ARDS) have resulted in declines in short-term mortality, but risks of death after survival to hospital discharge have not been well described. Our objective was to quantify the difference between short-term and long-term mortality in ARDS and to identify risk factors for death and causes of death at 1 year among hospital survivors.

METHODS

This multi-intensive care unit, prospective cohort included patients with ARDS enrolled between January 2006 and February 2010. We determined the clinical characteristics associated with in-hospital and 1-year mortality among hospital survivors and utilized death certificate data to identify causes of death.

RESULTS

Of 646 patients hospitalized with ARDS, mortality at 1 year was substantially higher (41 %, 95% CI 37-45%) than in-hospital mortality (24%, 95% CI 21-27%), P < 0.0001. Among 493 patients who survived to hospital discharge, the 110 (22%) who died in the subsequent year were older (P < 0.001) and more likely to have been discharged to a nursing home, other hospital, or hospice compared to patients alive at 1 year (P < 0.001). Important predictors of death among hospital survivors were comorbidities present at the time of ARDS, and not living at home prior to admission. ARDS-related measures of severity of illness did not emerge as independent predictors of mortality in hospital survivors.

CONCLUSIONS

Despite improvements in short-term ARDS outcomes, 1-year mortality is high, mostly because of the large burden of comorbidities, which are prevalent in patients with ARDS.

Clinical review: Lung imaging in acute respiratory distress syndrome patients--an update

Over the past 30 years lung imaging has greatly contributed to the current understanding of the pathophysiology and the management of acute respiratory distress syndrome (ARDS). In the past few years, in addition to chest X-ray and lung computed tomography, newer functional lung imaging techniques, such as lung ultrasound, positron emission tomography, electrical impedance tomography and magnetic resonance, have been gaining a role as diagnostic tools to optimize lung assessment and ventilator management in ARDS patients. Here we provide an updated clinical review of lung imaging in ARDS over the past few years to offer an overview of the literature on the available imaging techniques from a clinical perspective.