A prospective international observational prevalence study on prone positioning of ARDS patients: the APRONET (ARDS Prone Position Network) study

Comparison of venovenous extracorporeal membrane oxygenation, prone position and supine mechanical ventilation for severely hypoxemic acute respiratory distress syndrome: a network meta-analysis

PURPOSE

Severe acute respiratory distress syndrome (ARDS) with PaO2/FiO2 < 80 mmHg is a life-threatening condition. The optimal management strategy is unclear. The aim of this meta-analysis was to compare the effects of low tidal volumes (Vt), moderate Vt, prone ventilation, and venovenous extracorporeal membrane oxygenation (VV-ECMO) on mortality in severe ARDS.

METHODS

We performed a frequentist network meta-analysis of randomised controlled trials (RCTs) with participants who had severe ARDS and met eligibility criteria for VV-ECMO or had PaO2/FiO2 < 80 mmHg. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to discern the relative effect of interventions on mortality and the certainty of the evidence.

RESULTS

Ten RCTs including 812 participants with severe ARDS were eligible. VV-ECMO reduces mortality compared to low Vt (risk ratio [RR] 0.77, 95% confidence interval [CI] 0.59-0.99, moderate certainty) and compared to moderate Vt (RR 0.75, 95% CI 0.57-0.98, low certainty). Prone ventilation reduces mortality compared to moderate Vt (RR 0.78, 95% CI 0.66-0.93, high certainty) and compared to low Vt (RR 0.81, 95% CI 0.63-1.02, moderate certainty). We found no difference in the network comparison of VV-ECMO compared to prone ventilation (RR 0.95, 95% CI 0.72-1.26), but inferences were based solely on indirect comparisons with very low certainty due to very wide confidence intervals.

CONCLUSIONS

In adults with ARDS and severe hypoxia, both VV-ECMO (low to moderate certainty evidence) and prone ventilation (moderate to high certainty evidence) improve mortality relative to low and moderate Vt strategies. The impact of VV-ECMO versus prone ventilation remains uncertain.

Impact of intensive prone position therapy on outcomes in intubated patients with ARDS related to COVID-19

BACKGROUND

Previous retrospective research has shown that maintaining prone positioning (PP) for an average of 40 h is associated with an increase of survival rates in intubated patients with COVID-19-related acute respiratory distress syndrome (ARDS). This study aims to determine whether a cumulative PP duration of more than 32 h during the first 2 days of intensive care unit (ICU) admission is associated with increased survival compared to a cumulative PP duration of 32 h or less.

METHODS

This study is an ancillary analysis from a previous large international observational study involving intubated patients placed in PP in the first 48 h of ICU admission in 149 ICUs across France, Belgium and Switzerland. Given that PP is recommended for a 16-h daily duration, intensive PP was defined as a cumulated duration of more than 32 h during the first 48 h, whereas standard PP was defined as a duration equal to or less than 32 h. Patients were followed-up for 90 days. The primary outcome was mortality at day 60. An Inverse Probability Censoring Weighting (IPCW) Cox model including a target emulation trial method was used to analyze the data.

RESULTS

Out of 2137 intubated patients, 753 were placed in PP during the first 48 h of ICU admission. The intensive PP group (n = 79) had a median PP duration of 36 h, while standard PP group (n = 674) had a median of 16 h during the first 48 h. Sixty-day mortality rate in the intensive PP group was 39.2% compared to 38.7% in the standard PP group (p = 0.93). Twenty-eight-day and 90-day mortality as well as the ventilator-free days until day 28 were similar in both groups. After IPCW, there was no significant difference in mortality at day 60 between the two-study groups (HR 0.95 [0.52-1.74], p = 0.87 and HR 1.1 [0.77-1.57], p = 0.61 in complete case analysis or in multiple imputation analysis, respectively).

CONCLUSIONS

This secondary analysis of a large multicenter European cohort of intubated patients with ARDS due to COVID-19 found that intensive PP during the first 48 h did not provide a survival benefit compared to standard PP.

Outcomes following additional drainage during veno-venous extracorporeal membrane oxygenation: A single-center retrospective study

Refractory hypoxemia during veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may require an additional cannula (VV-V ECMO) to improve oxygenation. This intervention includes risk of recirculation and other various adverse events (AEs) such as injury to the lung, cannula malpositioning, bleeding, circuit or cannula thrombosis requiring intervention (i.e., clot), or cerebral injury. During the study period, 23 of 142 V-V ECMO patients were converted to VV-V utilizing two separate cannulas for bi-caval drainage with an additional upper extremity cannula placed for return. Of those, 21 had COVID-19. In the first 24 h after conversion, ECMO flow rates were higher (5.96 vs 5.24 L/min, p = .002) with no significant change in pump speed (3764 vs 3630 revolutions per minute [RPMs], p = .42). Arterial oxygenation (PaO2) increased (87 vs 64 mmHg, p < .0001) with comparable pre-oxygenator venous saturation (61 vs 53.3, p = .12). By day 5, flows were similar to pre-conversion values at lower pump speed but with improved PaO2. Unadjusted survival was similar in those converted to VV-V ECMO compared to V-V ECMO alone (70% [16/23] vs 66.4% [79/119], p = .77). In a mixed effect regression model, any incidence of AEs, demonstrated a negative impact on PaO2 in the first 48 h but not at day 5. VV-V ECMO improved oxygenation with increasing flows without a significant difference in AEs or pump speed. AEs transiently impacted oxygenation. VV-V ECMO is effective and feasible strategy for refractory hypoxemia on VV-ECMO allowing for higher flow rate and unchanged pump speed.

Adjunctive Therapies in Acute Respiratory Distress Syndrome

Despite significant advances in understanding acute respiratory distress syndrome (ARDS), mortality rates remain high. The appropriate use of adjunctive therapies can improve outcomes, particularly for patients with moderate to severe hypoxia. In this review, the authors discuss the evidence basis behind prone positioning, recruitment maneuvers, neuromuscular blocking agents, corticosteroids, pulmonary vasodilators, and extracorporeal membrane oxygenation and considerations for their use in individual patients and specific clinical scenarios. Because the heterogeneity of ARDS poses challenges in finding universally effective treatments, an individualized approach and continued research efforts are crucial for optimizing the utilization of adjunctive therapies and improving patient outcomes.

Perceptions and Perceived Barriers regarding Proning among Nurses of a Tertiary Care Center in India

Current study was conducted to assess the perception and barriers regarding proning among nurses. 385 nurses were conveniently surveyed using pre-tested tools. 3.9% of nurses "felt like running away" while providing care to the patients in prone position. 93.5% believed that prone position for COVID-19 patients is beneficial in reducing morbidity and that teamwork is required to be effective (96.6%). 93% nurses believed that inadequate staff-patient ratio is a significant barrier for prone positioning. Other barriers were fear of dislodgement of tubings (91.5%), difficulty in providing routine care (87.3%) and inadequate institutional protocol (83.9%). 12.5% were trained regarding proning.

Recapitulation of human pathophysiology and identification of forensic biomarkers in a translational model of chlorine inhalation injury

Chlorine gas (Cl2) has been repeatedly used as a chemical weapon, first in World War I and most recently in Syria. Life-threatening Cl2 exposures frequently occur in domestic and occupational environments, and in transportation accidents. Modeling the human etiology of Cl2-induced acute lung injury (ALI), forensic biomarkers, and targeted countermeasures development have been hampered by inadequate large animal models. The objective of this study was to develop a translational model of Cl2-induced ALI in swine to understand toxico-pathophysiology and evaluate whether it is suitable for screening potential medical countermeasures and to identify biomarkers useful for forensic analysis. Specific pathogen-free Yorkshire swine (30-40 kg) of either sex were exposed to Cl2 (≤240 ppm for 1 h) or filtered air under anesthesia and controlled mechanical ventilation. Exposure to Cl2 resulted in severe hypoxia and hypoxemia, increased airway resistance and peak inspiratory pressure, and decreased dynamic lung compliance. Cl2 exposure resulted in increased total leucocyte and neutrophil counts in bronchoalveolar lavage fluid, vascular leakage, and pulmonary edema compared with the air-exposed group. The model recapitulated all three key histopathological features of human ALI, such as neutrophilic alveolitis, deposition of hyaline membranes, and formation of microthrombi. Free and lipid-bound 2-chlorofatty acids and chlorotyrosine-modified proteins (3-chloro-l-tyrosine and 3,5-dichloro-l-tyrosine) were detected in plasma and lung tissue after Cl2 exposure. In this study, we developed a translational swine model that recapitulates key features of human Cl2 inhalation injury and is suitable for testing medical countermeasures, and validated chlorinated fatty acids and protein adducts as biomarkers of Cl2 inhalation.NEW & NOTEWORTHY We established a swine model of chlorine gas-induced acute lung injury that exhibits several features of human acute lung injury and is suitable for screening potential medical countermeasures. We validated chlorinated fatty acids and protein adducts in plasma and lung samples as forensic biomarkers of chlorine inhalation.

Diagnosis and treatment of right ventricular failure secondary to acutely increased right ventricular afterload (acute cor pulmonale): a clinical consensus statement of the Association for Acute CardioVascular Care of the European Society of Cardiology

Acute right ventricular failure secondary to acutely increased right ventricular afterload (acute cor pulmonale) is a life-threatening condition that may arise in different clinical settings. Patients at risk of developing or with manifest acute cor pulmonale usually present with an acute pulmonary disease (e.g. pulmonary embolism, pneumonia, and acute respiratory distress syndrome) and are managed initially in emergency departments and later in intensive care units. According to the clinical setting, other specialties are involved (cardiology, pneumology, internal medicine). As such, coordinated delivery of care is particularly challenging but, as shown during the COVID-19 pandemic, has a major impact on prognosis. A common framework for the management of acute cor pulmonale with inclusion of the perspectives of all involved disciplines is urgently needed.

Prone Positioning and Molecular Biomarkers in COVID and Non-COVID ARDS: A Narrative Review

Prone positioning (PP) represents a therapeutic intervention with the proven capacity of ameliorating gas exchanges and ventilatory mechanics indicated in acute respiratory distress syndrome (ARDS). When PP is selectively applied to moderate-severe cases of ARDS, it sensitively affects clinical outcomes, including mortality. After the COVID-19 outbreak, clinical application of PP peaked worldwide and was applied in 60% of treated cases, according to large reports. Research on this topic has revealed many physiological underpinnings of PP, focusing on regional ventilation redistribution and the reduction of parenchymal stress and strain. However, there is a lack of evidence on biomarkers behavior in different phases and phenotypes of ARDS. Patients response to PP are, to date, decided on PaO2/FiO2 ratio improvement, whereas scarce data exist on biomarker tracking during PP. The purpose of this review is to explore current evidence on the clinical relevance of biomarkers in the setting of moderate-severe ARDS of different etiologies (i.e., COVID and non-COVID-related ARDS). Moreover, this review focuses on how PP may modulate biomarkers and which biomarkers may have a role in outcome prediction in ARDS patients.

Application of prone position ventilation in ventilation strategies for patients with COVID-19

BACKGROUND

Patients with coronavirus disease 2019 (COVID-19) have been shown to die mainly due to disease-induced acute respiratory distress syndrome (ARDS). Prone position ventilation (PPV) is an important ventilation strategy in the management of patients with ARDS.

OBJECTIVE

To investigate the application of PPV in ventilation strategies for patients with COVID-19.

METHODS

Three hundred patients with COVID-19 admitted to the Intensive Care Unit (ICU) of Shanxi Bethune Hospital from January 2020 to June 2021 were retrospectively collected. Based on body position and conscious state, all patients were divided into three groups: intubation prone position group (n= 110), awake prone position group (n= 90) and supine position group (n= 100); The acute physiology and chronic health evaluation II (APACHE-II) scores, blood gas indicators, complications and other relevant clinical indicators were compared among the three groups. One-way ANOVA was used to compare means between multiple groups for quantitative information that conformed to a normal distribution. Repeated measures ANOVA was used for repeated measures data. Component comparisons were made using the Kruskal-Wallis H rank sum test for non-normally distributed quantitative data.

RESULTS

One-way repeated-measures ANOVA main effect analysis showed different effects of different treatments on PaO2 in patients with COVID-19 (F treatment = 256.231, P< 0.05), with the order of awake prone position group > intubation prone position group > supine position group. The effects of the three different treatments on P/F in patients with COVID-19 (F treatment = 311.661, P< 0.05), with the order of awake prone position group > supine position group > intubation prone position group; Moreover, the three treatments had different effects on APACHE II scores in patients with COVID-19 (F treatment = 201.342, P< 0.05), with the order of intubation prone position group > supine position group > awake prone position group.

CONCLUSION

Intubation prone position and awake prone position can improve lung function to some extent in patients with COVID-19, and should be applied as early as possible in patients with COVID-19-induced ARDS.

Designing a Behaviour Change Wheel guided implementation strategy for a hypoxaemic respiratory failure and ARDS care pathway that targets barriers

BACKGROUND

A significant gap exists between ideal evidence-based practice and real-world application of evidence-informed therapies for patients with hypoxaemic respiratory failure (HRF) and acute respiratory distress syndrome (ARDS). Pathways can improve the quality of care provided by helping integrate and organise the use of evidence informed practices, but barriers exist that can influence their adoption and successful implementation. We sought to identify barriers to the implementation of a best practice care pathway for HRF and ARDS and design an implementation science-based strategy targeting these barriers that is tailored to the critical care setting.

METHODS

The intervention assessed was a previously described multidisciplinary, evidence-based, stakeholder-informed, integrated care pathway for HRF and ARDS. A survey questionnaire (12 open text questions) was administered to intensive care unit (ICU) clinicians (physicians, nurses, respiratory therapists) in 17 adult ICUs across Alberta. The Behaviour Change Wheel, capability, opportunity, motivation - behaviour components, and Theoretical Domains Framework (TDF) were used to perform qualitative analysis on open text responses to identify barriers to the use of the pathway. Behaviour change technique (BCT) taxonomy, and Affordability, Practicality, Effectiveness and cost-effectiveness, Acceptability, Side effects and safety and Equity (APEASE) criteria were used to design an implementation science-based strategy specific to the critical care context.

RESULTS

Survey responses (692) resulted in 16 belief statements and 9 themes with 9 relevant TDF domains. Differences in responses between clinician professional group and hospital setting were common. Based on intervention functions linked to each belief statement and its relevant TDF domain, 26 candidate BCTs were identified and evaluated using APEASE criteria. 23 BCTs were selected and grouped to form 8 key components of a final strategy: Audit and feedback, education, training, clinical decision support, site champions, reminders, implementation support and empowerment. The final strategy was described using the template for intervention description and replication framework.

CONCLUSIONS

Barriers to a best practice care pathway were identified and were amenable to the design of an implementation science-based mitigation strategy. Future work will evaluate the ability of this strategy to improve quality of care by assessing clinician behaviour change via better adherence to evidence-based care.

Awake prone positioning in acute hypoxaemic respiratory failure: An international expert guidance

BACKGROUND

Awake prone positioning (APP) of non-intubated patients with acute hypoxaemic respiratory failure (AHRF) has been inconsistently adopted into routine care of patients with COVID-19, likely due to apparent conflicting evidence from recent trials. This short guideline aims to provide evidence-based recommendations for the use of APP in various clinical scenarios.

METHODS

An international multidisciplinary panel, assembled for their expertise and representativeness, and supported by a methodologist, performed a systematic literature search, summarized the available evidence derived from randomized clinical trials, and developed recommendations using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology.

RESULTS

The panel strongly recommends that APP rather than standard supine care be used in patients with COVID-19 receiving advanced respiratory support (high-flow nasal cannula, continuous positive airway pressure or non-invasive ventilation). Due to lack of evidence from randomized controlled trials, the panel provides no recommendation on the use of APP in patients with COVID-19 supported with conventional oxygen therapy, nor in patients with AHRF due to causes other than COVID-19.

CONCLUSION

APP should be routinely implemented in patients with COVID-19 receiving advanced respiratory support.

Protocol and statistical analysis plan for the identification and treatment of hypoxemic respiratory failure and acute respiratory distress syndrome with protection, paralysis, and proning: A type-1 hybrid stepped-wedge cluster randomised effectiveness-implementation study

Objective

To describe a study protocol and statistical analysis plan (SAP) for the identification and treatment of hypoxemic respiratory failure (HRF) and acute respiratory distress syndrome (ARDS) with protection, paralysis, and proning (TheraPPP) study prior to completion of recruitment, electronic data retrieval, and analysis of any data.

Design

TheraPPP is a stepped-wedge cluster randomised study evaluating a care pathway for HRF and ARDS patients. This is a type-1 hybrid effectiveness-implementation study design evaluating both intervention effectiveness and implementation; however primarily powered for the effectiveness outcome.

Setting

Seventeen adult intensive care units (ICUs) across Alberta, Canada.

Participants

We estimate a sample size of 18816 mechanically ventilated patients, with 11424 patients preimplementation and 7392 patients postimplementation. We estimate 2688 sustained ARDS patients within our study cohort.

Intervention

An evidence-based, stakeholder-informed, multidisciplinary care pathway called Venting Wisely that standardises diagnosis and treatment of HRF and ARDS patients.

Main outcome measures

The primary outcome is 28-day ventilator-free days (VFDs). The primary analysis will compare the mean 28-day VFDs preimplementation and postimplementation using a mixed-effects linear regression model. Prespecified subgroups include sex, age, HRF, ARDS, COVID-19, cardiac surgery, body mass index, height, illness acuity, and ICU volume.

Results

This protocol and SAP are reported using the Standard Protocol Items: Recommendations for Interventional Trials guidance and the Guidelines for the Content of Statistical Analysis Plans in Clinical Trials. The study received ethics approval and was registered (ClinicalTrials.gov-NCT04744298) prior to patient enrolment.

Conclusions

TheraPPP will evaluate the effectiveness and implementation of an HRF and ARDS care pathway.

Dependency-related skin lesions in the prone critical patient. Incidence study

OBJECTIVE

To determine the incidence of dependence-related skin lesions (DRSL) in patients in prone position (PP) and to identify the predisposing factors.

METHOD

Follow-up study in two polyvalent intensive care units. Patients undergoing invasive mechanical ventilation and PP with no skin lesions on admission were included. We recorded the 3 types of DRSL: (pressure ulcers [PU], moisture-associated skin damage [MASD] and friction injuries [FI]), demographic variables, diagnosis, length of stay, PP episodes, postural changes, APACHE II (Acute Physiology and Chronic Health Disease Classification System), prealbumin level on admission, body mass index (BMI), diabetes, hypertension, smoking, peripheral vascular disease (PVD), vasoactive drugs, Braden scale and mortality. Bivariate analysis: chi-square test, t-test or Mann-Whitney U test. Multivariate analysis: logistic regression.

RESULTS

Forty nine patients were included and 170PP were performed.Forty-one DRSL appeared in 22 patients with a cumulative incidence of 44.9% (95%CI: 31.6-58.7). PU accounted for 63.4% (73.1% facial; 76.9% stage II), 12.2% were MASD (60% inguinal; 60% stage II) and 24.4% were FI (50% thoracic; 70% stage III). The median age of the lesion group (LG) was 66.5 [61.8-71.3] vs. 64 [43-71] years old in the non-lesion group (NLG), p=0.04. Eighty percent of the LG had PVD vs. 20% of the NLG, p=0.03. The median total hours on PP of the LG was 96.9 [56.1-149.4] vs. 38.2 [18.8-57] of the NIG, p<0.001. Multivariate analysis selected total PP hours (OR=1.03; 95%CI:1.01-1.05) and PVD (OR=8.9; 95%CI:1.3-58.9) as predisposing factors for developing DRSL.

CONCLUSIONS

There is a high incidence of skin lesions related to prone decubitus dependence, mostly pressure lesions, although of low severity.The accumulated hours in probe position and peripheral vascular disease favor their development.

[Ventilatory management of SARS-CoV-2 acute respiratory failure]

COVID-19 pneumonia presents several particularities in its clinical presentation (cytokine storm, silent hypoxemia, thrombo-embolic risk) and may lead to a number of acute respiratory distress syndrome (ARDS) phenotypes. While the optimal oxygenation strategy in cases of hypoxemic acute respiratory failure (ARF) is still under debate, ventilatory management of COVID-19-related ARF has confirmed the efficacy of high-flow oxygen therapy and restored interest in other ventilatory approaches such as continuous positive airway pressure (CPAP) and noninvasive ventilation involving a helmet, which due to patient overflow are sometimes implemented outside of critical care units. However, further studies are still needed to determine which patients should be given which oxygenation technique, and under which conditions they require invasive mechanical ventilation, given that delayed initiation potentially burdens prognosis. During invasive mechanical ventilation, ventral decubitus and extracorporeal membrane oxygenation have become increasingly prevalent. While innovative therapies such as awake prone position or lung transplantation have likewise been developed, their indications, modalities and efficacy remain to be determined.

Declining Use of Prone Positioning After High Initial Uptake in COVID-19 Adult Respiratory Distress Syndrome

OBJECTIVES

Prone positioning for acute respiratory distress syndrome (ARDS) has historically been underused, but was widely adopted for COVID-19-associated ARDS early in the pandemic. Whether this successful implementation has been sustained over the first 3 years of the COVID-19 pandemic is unknown. In this study, we characterized proning use in patients with COVID-19 ARDS from March 2020 to December 2022.

DESIGN

Multicenter retrospective observational study.

SETTING

Five-hospital health system in Maryland, USA.

PATIENTS

Adults with COVID-19 supported with invasive mechanical ventilation and with a P ao2 /F io2 ratio of less than or equal to 150 mm Hg while receiving F io2 of greater than or equal to 0.6 within 72 hours of intubation.

INTERVENTIONS

None.

MEASUREMENTS

We extracted demographic, clinical, and positioning data from the electronic medical record. The primary outcome was the initiation of proning within 48 hours of meeting criteria. We compared proning use by year with univariate and multivariate relative risk (RR) regression. Additionally, we evaluated the association of treatment during a COVID-19 surge period and receipt of prone positioning.

MAIN RESULTS

We identified 656 qualifying patients; 341 from 2020, 224 from 2021, and 91 from 2022. More than half (53%) met severe ARDS criteria. Early proning occurred in 56.2% of patients in 2020, 56.7% in 2021, and 27.5% in 2022. This translated to a 51% reduction in use of prone positioning among patients treated in 2022 versus 2020 (RR = 0.49; 95% CI, 0.33-0.72; p < 0.001). This reduction remained significant in adjusted models (adjusted RR = 0.59; 95% CI, 0.42-0.82; p = 0.002). Treatment during COVID-19 surge periods was associated with a 7% increase in proning use (adjusted RR = 1.07; 95% CI, 1.02-1.13; p = 0.01).

CONCLUSIONS

The use of prone positioning for COVID-19 ARDS is declining. Interventions to increase and sustain appropriate use of this evidence-based therapy are warranted.

Clinical Applicability of Electrical Impedance Tomography in Patient-Tailored Ventilation: A Narrative Review

Electrical Impedance Tomography (EIT) is a non-invasive bedside imaging technique that provides real-time lung ventilation information on critically ill patients. EIT can potentially become a valuable tool for optimising mechanical ventilation, especially in patients with acute respiratory distress syndrome (ARDS). In addition, EIT has been shown to improve the understanding of ventilation distribution and lung aeration, which can help tailor ventilatory strategies according to patient needs. Evidence from critically ill patients shows that EIT can reduce the duration of mechanical ventilation and prevent lung injury due to overdistension or collapse. EIT can also identify the presence of lung collapse or recruitment during a recruitment manoeuvre, which may guide further therapy. Despite its potential benefits, EIT has not yet been widely used in clinical practice. This may, in part, be due to the challenges associated with its implementation, including the need for specialised equipment and trained personnel and further validation of its usefulness in clinical settings. Nevertheless, ongoing research focuses on improving mechanical ventilation and clinical outcomes in critically ill patients.

Pronation Reveals a Heterogeneous Response of Global and Regional Respiratory Mechanics in Patients With Acute Hypoxemic Respiratory Failure

OBJECTIVES

Experimental models suggest that prone position and positive end-expiratory pressure (PEEP) homogenize ventral-dorsal ventilation distribution and regional respiratory compliance. However, this response still needs confirmation on humans. Therefore, this study aimed to assess the changes in global and regional respiratory mechanics in supine and prone positions over a range of PEEP levels in acute respiratory distress syndrome (ARDS) patients.

DESIGN

A prospective cohort study.

PATIENTS

Twenty-two intubated patients with ARDS caused by COVID-19 pneumonia.

INTERVENTIONS

Electrical impedance tomography and esophageal manometry were applied during PEEP titrations from 20 cm H2O to 6 cm H2O in supine and prone positions.

MEASUREMENTS

Global respiratory system compliance (Crs), chest wall compliance, regional lung compliance, ventilation distribution in supine and prone positions.

MAIN RESULTS

Compared with supine position, the maximum level of Crs changed after prone position in 59% of ARDS patients (n = 13), of which the Crs decreased in 32% (n = 7) and increased in 27% (n = 6). To reach maximum Crs after pronation, PEEP was changed in 45% of the patients by at least 4 cm H2O. After pronation, the ventilation and compliance of the dorsal region did not consistently change in the entire sample of patients, increasing specifically in a subgroup of patients who showed a positive change in Crs when transitioning from supine to prone position. These combined changes in ventilation and compliance suggest dorsal recruitment postpronation. In addition, the subgroup with increased Crs postpronation demonstrated the most pronounced difference between dorsal and ventral ventilation distribution from supine to prone position (p = 0.01), indicating heterogeneous ventilation distribution in prone position.

CONCLUSIONS

Prone position modifies global respiratory compliance in most patients with ARDS. Only a subgroup of patients with a positive change in Crs postpronation presented a consistent improvement in dorsal ventilation and compliance. These data suggest that the response to pronation on global and regional mechanics can vary among ARDS patients, with some patients presenting more dorsal lung recruitment than others.

Adaptation and Uncertainty: A Qualitative Examination of Provider Experiences With Prone Positioning for Intubated Patients With COVID-19 ARDS

BACKGROUND

Prone positioning was widely adopted for use in patients with ARDS from COVID-19. However, proning was also delivered in ways that differed from historical evidence and practice. In implementation research, these changes are referred to as adaptations, and they occur constantly as evidence-based interventions are used in real-world practice. Adaptations can alter the delivered intervention, impacting patient and implementation outcomes.

RESEARCH QUESTION

How have clinicians adapted prone positioning to COVID-19 ARDS, and what uncertainties remain regarding optimal proning use?

STUDY DESIGN AND METHODS

We conducted a qualitative study using semi-structured interviews with ICU clinicians from two hospitals in Baltimore, MD, from February to July 2021. We interviewed physicians (MDs), registered nurses (RNs), respiratory therapists (RTs), advanced practice providers (APPs), and physical therapists (PTs) involved with proning mechanically ventilated patients with COVID-19 ARDS. We used thematic analysis of interviews to classify proning adaptations and clinician uncertainties about best practice for prone positioning.

RESULTS

Forty ICU clinicians (12 MDs, 4 APPs, 12 RNs, 7 RTs, and 5 PTs) were interviewed. Clinicians described several adaptations to the practice of prone positioning, including earlier proning initiation, extended duration of proning sessions, and less use of concomitant neuromuscular blockade. Clinicians expressed uncertainty regarding the optimal timing of initiation and duration of prone positioning. This uncertainty was viewed as a driver of practice variation. Although prescribers intended to use less deep sedation and paralysis in proned patients compared with historical evidence and practice, this raised concerns regarding patient comfort and safety amongst RNs and RTs.

INTERPRETATION

Prone positioning in patients with COVID-19 ARDS has been adapted from historically described practice. Understanding the impact of these adaptations on patient and implementation outcomes and addressing clinician uncertainties are priority areas for future research to optimize the use of prone positioning.

Mechanical ventilation in patients with acute respiratory distress syndrome: current status and future perspectives

INTRODUCTION

Although there has been extensive research on mechanical ventilation for acute respiratory distress syndrome (ARDS), treatment remains mainly supportive. Recent studies and new ventilatory modes have been proposed to manage patients with ARDS; however, the clinical impact of these strategies remains uncertain and not clearly supported by guidelines. The aim of this narrative review is to provide an overview and update on ventilatory management for patients with ARDS.

AREAS COVERED

This article reviews the literature regarding mechanical ventilation in ARDS. A comprehensive overview of the principal settings for the ventilator parameters involved is provided as well as a report on the differences between controlled and assisted ventilation. Additionally, new modes of assisted ventilation are presented and discussed. The evidence concerning rescue strategies, including recruitment maneuvers and extracorporeal membrane oxygenation support, is analyzed. PubMed, EBSCO, and the Cochrane Library were searched up until June 2023, for relevant literature.

EXPERT OPINION

Available evidence for mechanical ventilation in cases of ARDS suggests the use of a personalized mechanical ventilation strategy. Although promising, new modes of assisted mechanical ventilation are still under investigation and guidelines do not recommend rescue strategies as the standard of care. Further research on this topic is required.

Differences in clinical characteristics and outcomes between COVID-19 and influenza in critically ill adult patients: a national database study

OBJECTIVE

Prior to the coronavirus disease 2019 (COVID-19) pandemic, influenza was the most frequent cause of viral respiratory pneumonia requiring intensive care unit (ICU) admission. Few studies have compared the characteristics and outcomes of critically ill patients with COVID-19 and influenza.

METHODS

This was a French nationwide study comparing COVID-19 (March 1, 2020-June 30, 2021) and influenza patients (January 1, 2014-December 31, 2019) admitted to an ICU during pre-vaccination era. Primary outcome was in-hospital death. Secondary outcome was need for mechanical ventilation.

RESULTS

105,979 COVID-19 patients were compared to 18,763 influenza patients. Critically ill patients with COVID-19 were more likely to be men with more comorbidities. Patients with influenza required more invasive mechanical ventilation (47 vs. 34%, p<0·001), vasopressors (40% vs. 27, p<0·001) and renal-replacement therapy (22 vs. 7%, p<0·001). Hospital mortality was 25 and 21% (p<0·001) in patients with COVID-19 and influenza, respectively. In the subgroup of patients receiving invasive mechanical ventilation, ICU length of stay was significantly longer in patients with COVID-19 (18 [10-32] vs. 15 [8-26] days, p<0·001). Adjusting for age, gender, comorbidities, and modified SAPS II score, in-hospital death was higher in COVID-19 patients (adjusted sub-distribution hazard ratio [aSHR]=1.69; 95%CI=1.63-1.75) compared with influenza patients. COVID-19 was also associated with less invasive mechanical ventilation (aSHR=0.87; 95%CI=0.85-0.89) and a higher likelihood of death without invasive mechanical ventilation (aSHR=2.40; 95%CI=2.24-2.57).

CONCLUSION

Despite younger age and lower SAPS II score, critically ill COVID-19 patients had a longer hospital stay and higher mortality than patients with influenza.

Hemodynamic Implications of Prone Positioning in Patients with ARDS

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

Vloga izvajalcev zdravstvene nege pri pronaciji in supinaciji intubiranega pacienta s hudim akutnim respiratornim sindromom koronavirus-2

Uvod: Hud akutni respiratorni sindrom koronavirus-2 je s svojo intenzivnostjo močno vplival na razmere in delo v enotah intenzivne terapije. Pri vse več intubiranih pacientih z akutnim respiratornim distresnim sindromom se je pokazala potreba po pronaciji (obrat na trebuh). Namen raziskave je bil preučiti vlogo izvajalcev zdravstvene nege pri pronaciji in supinaciji (obrat na hrbet) pacienta ter ugotoviti najpogostejše zaplete, ki se ob tem lahko pojavijo.Metode: Uporabljen je bil pregled znanstvene in strokovne literature. Iskanje literature je potekalo v podatkovnih bazah PubMed, Sage in ScienceDirect ter Google Scholar. Vključene so bile raziskave od januarja 2020 do decembra 2021. Izvedena je bila vsebinska analiza raziskav.Rezultati: Skupno je bilo identificiranih 993 člankov. Dodanih je bilo še deset člankov, najdenih s prostoročnim iskanjem v Google Scholar. Izmed 1.003 identificiranih zadetkov je bilo v končno analizo vključenih osem člankov. Izpostavljena so bila tri glavna vsebinska področja: (1) vloga izvajalcev zdravstvene nege pred pronacijo intubiranega pacienta; (2) vloga izvajalcev zdravstvene nege med pronacijo intubiranega pacienta in (3) vloga izvajalcev zdravstvene nege pri supinaciji intubiranega pacienta.Diskusija in zaključek: Pronacija in supinacija intubiranega pacienta predstavljata velik izziv za celoten zdravstveni tim, ki je v času epidemije okrnjen tako številčno kot tudi glede na stopnjo usposobljenosti. Izvajalec zdravstvene nege mora ob teh intervencijah zagotoviti hemodinamsko stabilnost, pravilno pozicioniranje pacienta, preprečiti ekstubacijo in izpade različnih katetrov, zaščititi kožo in vseskozi izvajati potrebne aktivnosti zdravstvene nege.

Prone positioning in COVID-19 patients with acute respiratory distress syndrome and invasive mechanical ventilation

OBJECTIVE

To identify adverse events related to prone positioning in COVID-19 patients with severe disease and acute respiratory distress syndrome, to analyze the risk factors associated with the development of anterior pressure ulcers, to determine whether the recommendation of prone positioning is associated with improved clinical outcomes.

METHODS

Retrospective study performed in 63 consecutive patients with COVID-19 pneumonia admitted to intensive care unit on invasive mechanical ventilation and treated with prone positioning between March and April 2020. Association between prone-related pressure ulcers and selected variables was explored by the means of logistic regression.

RESULTS

A total of 139 proning cycles were performed. The mean number of cycles were 2 [1-3] and the mean duration per cycle was of 22h [15-24]. The prevalence of adverse events this population was 84.9 %, being the physiologic ones (i.e., hypo/hypertension) the most prevalent. 29 out of 63 patients (46%) developed prone-related pressure ulcers. The risk factors for prone-related pressure ulcers were older age, hypertension, levels of pre-albumin <21mg/dl, the number of proning cycles and severe disease. We observed a significant increase in the PaO₂/FiO₂ at different time points during the prone positioning, and a significant decrease after it.

CONCLUSIONS

There is a high incidence of adverse events due to PD, with the physiological type being the most frequent. The identification of the main risk factors for the development of prone-related pressure ulcers will help to prevent the occurrence of these lesions during the prone positioning. Prone positioning offered an improvement in the oxygenation in these patients.

Does prolonged prone position affect intracranial pressure? prospective observational study employing Optic nerve sheath diameter measurements

BACKGROUND

Our aim in this observational prospective study is to determine whether the prone position has an effect on intracranial pressure, by performing ultrasound-guided ONSD (Optic Nerve Sheath Diameter) measurements in patients with acute respiratory distress syndrome (ARDS) ventilated in the prone position.

METHODS

Patients hospitalized in the intensive care unit with a diagnosis of ARDS who were placed in the prone position for 24 h during their treatment were included in the study. Standardized sedation and neuromuscular blockade were applied to all patients in the prone position. Mechanical ventilation settings were standardized. Demographic data and patients' pCO₂, pO₂, PaO₂/FiO₂, SpO₂, right and left ONSD data, and complications were recorded at certain times over 24 h.

RESULTS

The evaluation of 24-hour prone-position data of patients with ARDS showed no significant increase in ONSD. There was no significant difference in pCO₂ values either. PaO₂/FiO₂ and pO₂ values demonstrated significant cumulative increases at all times. Post-prone SPO2 values at the 8th hour and later were significantly higher when compared to baseline (p < 0.001).

CONCLUSION

As a result of this study, it appears that the prone position does not increase intracranial pressure during the first 24 h and can be safely utilized, given the administration of appropriate sedation, neuromuscular blockade, and mechanical ventilation strategy. ONSD measurements may increase the safety of monitoring in patients ventilated in the prone position.

A Framework for Developing a Multidisciplinary Approach to Prone Positioning in Acute Respiratory Distress Syndrome

Prone position ventilation (PPV) is one of the few interventions with a proven mortality benefit in the management of acute respiratory distress syndrome (ARDS), yet it is underutilized as demonstrated by multiple large observational studies. Significant barriers to its consistent application have been identified and studied. But the complex interplay of a multidisciplinary team makes its consistent application challenging. We present a framework of multidisciplinary collaboration that identifies the appropriate patients for this intervention and discuss our institutional experience applying a multidisciplinary team to implement prone position (PP) leading up to and through the current COVID-19 pandemic. We also highlight the role of such multidisciplinary teams in the effective implementation of prone positioning in ARDS throughout a large health care system. We emphasize the importance of proper selection of patients and provide guidance on how a protocolized approach can be utilized for proper patient selection.

Challenges in ARDS Definition, Management, and Identification of Effective Personalized Therapies

Over the last decade, the management of acute respiratory distress syndrome (ARDS) has made considerable progress both regarding supportive and pharmacologic therapies. Lung protective mechanical ventilation is the cornerstone of ARDS management. Current recommendations on mechanical ventilation in ARDS include the use of low tidal volume (V_T) 4-6 mL/kg of predicted body weight, plateau pressure (P_PLAT) < 30 cmH₂O, and driving pressure (∆P) < 14 cmH₂O. Moreover, positive end-expiratory pressure should be individualized. Recently, variables such as mechanical power and transpulmonary pressure seem promising for limiting ventilator-induced lung injury and optimizing ventilator settings. Rescue therapies such as recruitment maneuvers, vasodilators, prone positioning, extracorporeal membrane oxygenation, and extracorporeal carbon dioxide removal have been considered for patients with severe ARDS. Regarding pharmacotherapies, despite more than 50 years of research, no effective treatment has yet been found. However, the identification of ARDS sub-phenotypes has revealed that some pharmacologic therapies that have failed to provide benefits when considering all patients with ARDS can show beneficial effects when these patients were stratified into specific sub-populations; for example, those with hyperinflammation/hypoinflammation. The aim of this narrative review is to provide an overview on current advances in the management of ARDS from mechanical ventilation to pharmacological treatments, including personalized therapy.

Pulmonary Specific Ancillary Treatment for Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

We conducted an updated review of the literature on pulmonary-specific ancillary therapies for pediatric acute respiratory distress syndrome (PARDS) to provide an update to the Pediatric Acute Lung Injury Consensus Conference recommendations and statements about clinical practice and research.

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

Searches were limited to children, PARDS or hypoxic respiratory failure and overlap with pulmonary-specific ancillary therapies.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize evidence and develop recommendations. Twenty-six studies were identified for full-text extraction. Four clinical recommendations were generated, related to use of inhaled nitric oxide, surfactant, prone positioning, and corticosteroids. Two good practice statements were generated on the use of routine endotracheal suctioning and installation of isotonic saline prior to endotracheal suctioning. Three research statements were generated related to: the use of open versus closed suctioning, specific methods of airway clearance, and various other ancillary therapies.

CONCLUSIONS

The evidence to support or refute any of the specific ancillary therapies in children with PARDS remains low. Further investigation, including a focus on specific subpopulations, is needed to better understand the role, if any, of these various ancillary therapies in PARDS.

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.

A descriptive evaluation of causes of death in venovenous extracorporeal membrane oxygenation

Veno-venous extracorporeal membrane oxygenation (VV ECMO) has become an important support modality for patients with acute respiratory failure refractory to optimal medical therapy, such as low tidal volume mechanical ventilator support, early paralytic infusion, and early prone positioning. The objective of this cohort study was to investigate the causes and timing of in-hospital mortality in patients on VV ECMO. All patients, excluding trauma and bridge to lung transplant, admitted 8/2014-6/2019 to a specialty ICU for VV ECMO were reviewed. Two hundred twenty-five patients were included. In-hospital mortality was 24.4% (n = 55). Most non-survivors (46/55, 84%) died prior to lung recovery and decannulation from VV ECMO. Most common cause of death (COD) for patients who died on VV ECMO was removal of life sustaining therapy (LST) in setting of multisystem organ failure (MSOF) (n = 24). Nine patients died a median of 9 days [6, 11] after decannulation. Most common COD in these patients was palliative withdrawal of LST due to poor prognosis (n = 3). Non-survivors were older and had worse predictive mortality scores than survivors. We found that death in patients supported with VV ECMO in our study most often occurs prior to decannulation and lung recovery. This study demonstrated that the most common cause of death in patients supported with VV ECMO was removal of LST due MSOF. Acute hemorrhage (systemic or intracranial) was not found to be a common cause of death in our patient population.

Prone position: how understanding and clinical application of a technique progress with time

Historical background

The prone position was first proposed on theoretical background in 1974 (more advantageous distribution of mechanical ventilation). The first clinical report on 5 ARDS patients in 1976 showed remarkable improvement of oxygenation after pronation. 

Pathophysiology

The findings in CT scans enhanced the use of prone position in ARDS patients. The main mechanism of the improved gas exchange seen in the prone position is nowadays attributed to a dorsal ventilatory recruitment, with a substantially unchanged distribution of perfusion. Regardless of the gas exchange, the primary effect of the prone position is a more homogenous distribution of ventilation, stress and strain, with similar size of pulmonary units in dorsal and ventral regions. In contrast, in the supine position the ventral regions are more expanded compared with the dorsal regions, which leads to greater ventral stress and strain, induced by mechanical ventilation.

Outcome in ARDS

The number of clinical studies paralleled the evolution of the pathophysiological understanding. The first two clinical trials in 2001 and 2004 were based on the hypothesis that better oxygenation would lead to a better survival and the studies were more focused on gas exchange than on lung mechanics. The equations better oxygenation = better survival was disproved by these and other larger trials (ARMA trial). However, the first studies provided signals that some survival advantages were possible in a more severe ARDS, where both oxygenation and lung mechanics were impaired. The PROSEVA trial finally showed the benefits of prone position on mortality supporting the thesis that the clinical advantages of prone position, instead of improved gas exchange, were mainly due to a less harmful mechanical ventilation and better distribution of stress and strain. In less severe ARDS, in spite of a better gas exchange, reduced mechanical stress and strain, and improved oxygenation, prone position was ineffective on outcome.

Prone position and COVID-19

The mechanisms of oxygenation impairment in early COVID-19 are different than in typical ARDS and relate more on perfusion alteration than on alveolar consolidation/collapse, which are minimal in the early phase. Bronchial shunt may also contribute to the early COVID-19 hypoxemia. Therefore, in this phase, the oxygenation improvement in prone position is due to a better matching of local ventilation and perfusion, primarily caused by the perfusion component. Unfortunately, the conditions for improved outcomes, i.e. a better distribution of stress and strain, are almost absent in this phase of COVID-19 disease, as the lung parenchyma is nearly fully inflated. Due to some contradictory results, further studies are needed to better investigate the effect of prone position on outcome in COVID-19 patients.

Graphical Abstract

Factors Influencing the Implementation of Prone Positioning during the COVID-19 Pandemic: A Qualitative Study

Rationale: The adoption of prone positioning for patients with acute respiratory distress syndrome (ARDS) has historically been poor. However, in mechanically ventilated patients with coronavirus disease (COVID-19) ARDS, proning has increased. Understanding the factors influencing this change is important for further expanding and sustaining the use of prone positioning in appropriate clinical settings. Objectives: To characterize factors influencing the implementation of prone positioning in mechanically ventilated patients with COVID-19 ARDS. Methods: We conducted a qualitative study using semistructured interviews with 40 intensive care unit (ICU) team members (physicians, nurses, advanced practice providers, respiratory therapists, and physical therapists) working at two academic hospitals. We used the Consolidated Framework for Implementation Research, a widely used implementation science framework outlining important features of implementation, to structure the interview guide and thematic analysis of interviews. Results: ICU clinicians reported that during the COVID-19 pandemic, proning was viewed as standard early therapy for COVID-19 ARDS rather than salvage therapy for refractory hypoxemia. By caring for large volumes of proned patients, clinicians gained increased comfort with proning and now view proning as a low-risk, high-benefit intervention. Within ICUs, adequate numbers of trained staff members, increased team agreement around proning, and the availability of specific equipment (e.g., to limit pressure injuries) facilitated greater proning use. Hospital-level supports included proning teams, centralized educational resources specific to the management of COVID-19 (including a recommendation for prone positioning), and an electronic medical record proning order. Important implementation processes included informal dissemination of best practices through on-the-job learning and team interactions during routine bedside care. Conclusions: The implementation of prone positioning for COVID-19 ARDS took place in the context of evolving clinician viewpoints and ICU team cultures. Proning was facilitated by hospital support and buy-in and leadership from bedside clinicians. The successful implementation of prone positioning during the COVID-19 pandemic may serve as a model for the implementation of other evidence-based therapies in critical care.

Diagnostic and Therapeutic Implications of Ex Vivo Lung Perfusion in Lung Transplantation: Potential Benefits and Inherent Limitations

Ex vivo lung perfusion (EVLP), a technique in which isolated lungs are continually ventilated and perfused at normothermic temperature, is emerging as a promising platform to optimize donor lung quality and increase the lung graft pool. Over the past few decades, the EVLP technique has become recognized as a significant achievement and gained much attention in the field of lung transplantation. EVLP has been demonstrated to be an effective platform for various targeted therapies to optimize donor lung function before transplantation. Additionally, some physical parameters during EVLP and biological markers in the EVLP perfusate can be used to evaluate graft function before transplantation and predict posttransplant outcomes. However, despite its advantages, the clinical practice of EVLP continuously encounters multiple challenges associated with both intrinsic and extrinsic limitations. It is of utmost importance to address the advantages and disadvantages of EVLP for its broader clinical usage. Here, the pros and cons of EVLP are comprehensively discussed, with a focus on its benefits and potential approaches for overcoming the remaining limitations. Directions for future research to fully explore the clinical potential of EVLP in lung transplantation are also discussed.

Extended prone positioning duration for COVID-19-related ARDS: benefits and detriments

Background

During the COVID-19 pandemic, many more patients were turned prone than before, resulting in a considerable increase in workload. Whether extending duration of prone position may be beneficial has received little attention. We report here benefits and detriments of a strategy of extended prone positioning duration for COVID-19-related acute respiratory distress syndrome (ARDS).

Methods

A eetrospective, monocentric, study was performed on intensive care unit patients with COVID-19-related ARDS who required tracheal intubation and who have been treated with at least one session of prone position of duration greater or equal to 24 h. When prone positioning sessions were initiated, patients were kept prone for a period that covered two nights. Data regarding the incidence of pressure injury and ventilation parameters were collected retrospectively on medical and nurse files of charts. The primary outcome was the occurrence of pressure injury of stage ≥ II during the ICU stay.

Results

For the 81 patients included, the median duration of prone positioning sessions was 39 h [interquartile range (IQR) 34–42]. The cumulated incidence of stage ≥ II pressure injuries was 26% [95% CI 17–37] and 2.5% [95% CI 0.3–8.8] for stages III/IV pressure injuries. Patients were submitted to a median of 2 sessions [IQR 1–4] and for 213 (94%) prone positioning sessions, patients were turned over to supine position during daytime, i.e., between 9 AM and 6 PM. This increased duration was associated with additional increase in oxygenation after 16 h with the PaO₂/FiO₂ ratio increasing from 150 mmHg [IQR 121–196] at H+ 16 to 162 mmHg [IQR 124–221] before being turned back to supine (p = 0.017).

Conclusion

In patients with extended duration of prone position up to 39 h, cumulative incidence for stage ≥ II pressure injuries was 26%, with 25%, 2.5%, and 0% for stage II, III, and IV, respectively. Oxygenation continued to increase significantly beyond the standard 16-h duration. Our results may have significant impact on intensive care unit staffing and patients’ respiratory conditions.

Trial registration: Institutional review board 00006477 of HUPNVS, Université Paris Cité, APHP, with the reference: CER-2021-102, obtained on October 11th 2021. Registered at Clinicaltrials (NCT05124197).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04081-2.

Continuous prolonged prone positioning in COVID-19-related ARDS: a multicenter cohort study from Chile

Background

Prone positioning is currently applied in time-limited daily sessions up to 24 h which determines that most patients require several sessions. Although longer prone sessions have been reported, there is scarce evidence about the feasibility and safety of such approach. We analyzed feasibility and safety of a continuous prolonged prone positioning strategy implemented nationwide, in a large cohort of COVID-19 patients in Chile.

Methods

Retrospective cohort study of mechanically ventilated COVID-19 patients with moderate-to-severe acute respiratory distress syndrome (ARDS), conducted in 15 Intensive Care Units, which adhered to a national protocol of continuous prone sessions  ≥ 48 h and until PaO2:FiO2 increased above 200 mm Hg. The number and extension of prone sessions were registered, along with relevant physiologic data and adverse events related to prone positioning. The cohort was stratified according to the first prone session duration: Group A, 2–3 days; Group B, 4–5 days; and Group C, > 5 days. Multivariable regression analyses were performed to assess whether the duration of prone sessions could impact safety.

Results

We included 417 patients who required a first prone session of 4 (3–5) days, of whom 318 (76.3%) received only one session. During the first prone session the main adverse event was grade 1–2 pressure sores in 97 (23.9%) patients; severe adverse events were infrequent with 17 non-scheduled extubations (4.2%). 90-day mortality was 36.2%. Ninety-eight patients (24%) were classified as group C; they exhibited a more severe ARDS at baseline, as reflected by lower PaO2:FiO2 ratio and higher ventilatory ratio, and had a higher rate of pressure sores (44%) and higher 90-day mortality (48%). However, after adjustment for severity and several relevant confounders, prone session duration was not associated with mortality or pressure sores.

Conclusions

Nationwide implementation of a continuous prolonged prone positioning strategy for COVID-19 ARDS patients was feasible. Minor pressure sores were frequent but within the ranges previously described, while severe adverse events were infrequent. The duration of prone session did not have an adverse effect on safety.

Prognostic value of the novel P/FPE index to classify ARDS severity: A cohort study

OBJECTIVE

To evaluate the impact of the novel P/FP_E index to classify ARDS severity on mortality of patients with ARDS.

DESIGN

A retrospective cohort study.

SETTING

Twelve-bed medical and surgical intensive care unit from January 2018 to December 2020.

PATIENTS

A total of 217 ARDS patients managed with invasive mechanical ventilation >48h.

INTERVENTIONS

None.

VARIABLES

ARDS severity on day 1 and day 3 was measured based on PaO₂/FiO₂ ratio and P/FP_E index [PaO₂/(FiO₂×PEEP)]. Primary outcome was the hospital mortality.

RESULTS

Hospital mortality rate was 59.9%. Relative to PaO₂/FiO₂ ratio, 31.8% of patients on day 1 and 77.0% on day 3 were reclassified into a different category of ARDS severity by P/FP_E index. The level of PEEP was lower by P/FP_E index-based ARDS severity classification than by using PaO₂/FiO₂ ratio. The performance for predicting mortality of P/FP_E index was superior to PaO₂/FiO₂ ratio in term of AROC (day 1: 0.72 vs. 0.62; day 3: 0.87 vs. 0.68) and CORR (day 1: 0.370 vs. 0.213; day 3: 0.634 vs. 0.301). P/FP_E index improved prediction of risk of death compared to PaO₂/FiO₂ ratio as showed by the qNRI (day 1: 72.0%, p<0.0001; day 3: 132.4%, p<0.0001) and IDI (day 1: 0.09, p<0.0001; day 3: 0.31, p<0.0001).

CONCLUSIONS

Assessment of ARDS severity based on P/FP_E index seems better than PaO₂/FiO₂ ratio for predicting mortality. The value of P/FP_E index for clinical decision-making requires confirmation by randomized controlled trials.

The effect of prone positioning on pressure injury incidence in adult intensive care unit patients: A meta-review of systematic reviews

OBJECTIVE

Numerous systematic reviews have examined the impact of prone positioning on outcomes, including pressure injury (PI). The objective of this meta-review was to synthesise the evidence on the effect of prone positioning on the incidence and location of PIs in adult intensive care unit patients.

REVIEW METHOD

This is a meta-review of published systematic reviews. Five databases were searched; data were extracted by three authors and adjudicated by a fourth. The AMSTAR-2 tool was used to quality appraise the selected articles, which was completed by three authors with a fourth adjudicating.

RESULTS

Ten systematic reviews were synthesised. The cumulative incidence of PI in 15,979 adult patients ranged from 25.7% to 48.5%. One study did not report adult numbers. Only one review reported the secondary outcome of PI location. PIs were identified in 13 locations such as the face, chest, iliac crest, and knees. Using the AMSTAR-2, three reviews were assessed as high quality, six as moderate quality, and one as low quality.

CONCLUSION

The high incidence of PI in the prone position highlights the need for targeted preventative strategies. Care bundles may be one approach, given their beneficial effects for the prevention of PI in other populations. This review highlights the need for proactive approaches to limit unintended consequences of the use of the prone position, especially notable in the current COVID-19 pandemic.

Decúbito prono en pacientes COVID-19 con síndrome de distrés respiratorio agudo y ventilación mecánica invasiva

Objetivos: Identificar eventos adversos secundarios al decúbito prono (DP) en pacientes con COVID-19 con síndrome de distrés respiratorio agudo (SDRA) moderado/severo, analizar los factores de riesgo para el desarrollo de úlceras por presión (UPP) en DP y describir la evolución oximétrica de estos pacientes durante el DP.

Método: Estudio descriptivo retrospectivo realizado sobre 63 pacientes ingresados en la UCI de un hospital de segundo nivel, con neumonía por SARS-CoV-2, SDRA moderado/severo, ventilación mecánica invasiva, que precisaron maniobras de DP, durante marzo y abril de 2020. Se usó un muestreo no probabilístico consecutivo y se analizaron las variables seleccionadas a través de una regresión logística.

Resultados: Se realizaron un total de 139 sesiones de pronación. La mediana de sesiones fue de 2 [1-3] y la duración de 22 horas [15-24] por sesión. La aparición de eventos adversos ocurrió en un 84,9% de los casos, siendo las fisiológicas (ej. hiper/hipotensión) las más frecuentes. Al comparar pacientes pronados que mantuvieron la integridad cutánea (34 de 63 pacientes, un 54%) versus los que desarrollaron UPP (29 de 63, un 46%), estos últimos presentaron los siguientes factores de riesgo: mayor edad, ser hipertensos, pre-albúmina <21mg/dl, mayor número de sesiones de prono y mayor gravedad al ingreso. Se observó un incremento significativo entre la PaO₂/FiO₂ previa al DP y en los diferentes cortes temporales durante el prono, además de una caída significativa tras despronar.

Conclusiones: Existe una alta incidencia de eventos adversos debidos al DP, siendo los de tipo fisiológico los más frecuentes. La identificación de varios factores de riesgo para el desarrollo de UPP ayudará a prevenir la aparición de estas lesiones durante la pronación. La terapia de DP en pacientes COVID-19 con SDRA moderado/severo ha demostrado una mejora en los parámetros de oxigenación.

Trends in mortality in septic patients according to the different organ failure during 15 years

Background

The incidence of sepsis can be estimated between 250 and 500 cases/100.000 people per year and is responsible for up to 6% of total hospital admissions. Identified as one of the most relevant global health problems, sepsis is the condition that generates the highest costs in the healthcare system. Important changes in the management of septic patients have been included in recent years; however, there is no information about how changes in the management of sepsis-associated organ failure have contributed to reduce mortality.

Methods

A retrospective analysis was conducted from hospital discharge records from the Minimum Basic Data Set Acute-Care Hospitals (CMBD-HA in Catalan language) for the Catalan Health System (CatSalut). CMBD-HA is a mandatory population-based register of admissions to all public and private acute-care hospitals in Catalonia. Sepsis was defined by the presence of infection and at least one organ dysfunction. Patients hospitalized with sepsis were detected, according ICD-9-CM (since 2005 to 2017) and ICD-10-CM (2018 and 2019) codes used to identify acute organ dysfunction and infectious processes.

Results

Of 11.916.974 discharges from all acute-care hospitals during the study period (2005–2019), 296.554 had sepsis (2.49%). The mean annual sepsis incidence in the population was 264.1 per 100.000 inhabitants/year, and it increased every year, going from 144.5 in 2005 to 410.1 in 2019. Multiorgan failure was present in 21.9% and bacteremia in 26.3% of cases. Renal was the most frequent organ failure (56.8%), followed by cardiovascular (24.2%). Hospital mortality during the study period was 19.5%, but decreases continuously from 25.7% in 2005 to 17.9% in 2019 (p < 0.0001). The most important reduction in mortality was observed in cases with cardiovascular failure (from 47.3% in 2005 to 31.2% in 2019) (p < 0.0001). In the same way, mean mortality related to renal and respiratory failure in sepsis was decreased in last years (p < 0.0001).

Conclusions

The incidence of sepsis has been increasing in recent years in our country. However, hospital mortality has been significantly reduced. In septic patients, all organ failures except liver have shown a statistically significant reduction on associated mortality, with cardiovascular failure as the most relevant.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04176-w.

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

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

Prevalence and impact of early prone position on 30-day mortality in mechanically ventilated patients with COVID-19: a nationwide cohort study

Background

COVID-19 ARDS shares features with non-COVID ARDS but also demonstrates distinct physiological differences. Despite a lack of strong evidence, prone positioning has been advocated as a key therapy for COVID-19 ARDS. The effects of prone position in critically ill patients with COVID-19 are not fully understood, nor is the optimal time of initiation defined. In this nationwide cohort study, we aimed to investigate the association between early initiation of prone position and mortality in mechanically ventilated COVID-19 patients with low oxygenation on ICU admission.

Methods

Using the Swedish Intensive Care Registry (SIR), all Swedish ICU patients ≥ 18 years of age with COVID-19 admitted between March 2020, and April 2021 were identified. A study-population of patients with PaO2/FiO2 ratio ≤ 20 kPa on ICU admission and receiving invasive mechanical ventilation within 24 h from ICU admission was generated. In this study-population, the association between early use of prone position (within 24 h from intubation) and 30-day mortality was estimated using univariate and multivariable logistic regression models.

Results

The total study cohort included 6350 ICU patients with COVID-19, of whom 46.4% were treated with prone position ventilation. Overall, 30-day mortality was 24.3%. In the study-population of 1714 patients with lower admission oxygenation (PaO2/FiO2 ratio ≤ 20 kPa), the utilization of early prone increased from 8.5% in March 2020 to 48.1% in April 2021. The crude 30-day mortality was 27.2% compared to 30.2% in patients not receiving early prone positioning. We found no significant association between early use of prone positioning and survival.

Conclusions

During the first three waves of the COVID-19 pandemic, almost half of the patients in Sweden were treated with prone position ventilation. We found no association between early use of prone positioning and survival in patients on mechanical ventilation with severe hypoxemia on ICU admission. To fully elucidate the effect and timing of prone position ventilation in critically ill patients with COVID-19 further studies are desirable.

Advances in Ventilator Management for Patients with Acute Respiratory Distress Syndrome

The ventilatory care of patients with acute respiratory distress syndrome (ARDS) is evolving as our understanding of physiologic mechanisms of respiratory failure improves. Despite several decades of research, the mortality rate for ARDS remains high. Over the years, we continue to expand strategies to identify and mitigate ventilator-induced lung injury. This now includes a greater understanding of the benefits and harms associated with spontaneous breathing.

Nurse-led implementation of awake prone positioning

This article discusses the pathophysiology of COVID-19 acute respiratory distress syndrome (ARDS), the evidence supporting the use of awake prone positioning (APP) for adult patients with COVID-19 ARDS cared for in acute care medical units, and a quality improvement initiative to support a standardized APP process on a COVID-19 medical unit.

Elevated soluble death receptor 5 can predict poor prognosis in patients with acute respiratory distress syndrome

BACKGROUND

: The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its receptor, death receptor 5 (DR5), participate in pulmonary cell apoptosis. This study aimed to investigate the clinical value of soluble DR5 and TRAIL for prognosis assessment in acute respiratory distress syndrome (ARDS).

RESEARCH DESIGN AND METHODS

: Serum and bronchoalveolar lavage fluid (BALF) samples were collected from ARDS patients and controls. Patients were followed-up until death or discharge. Soluble DR5, TRAIL, TNF-α, soluble receptor for advanced glycation end-products (sRAGE), and albumin levels were measured using the Magnetic Luminex or enzyme-linked immunosorbent assays. Data were analyzed according to their distribution and statistical purpose.

RESULTS

: Serum and BALF DR5 levels were elevated in patients with ARDS; TRAIL elevation and reduction was observed in BALF and serum, respectively. Serum DR5 was higher in non-survivors compared to survivors. Serum DR5 was positively correlated with serum TNF-α and critical illness scores and negatively correlated with serum TRAIL. Serum and BALF DR5 was positively correlated with the alveolar epithelial cell damage (sRAGE) and lung fluid leakage indicators. Serum DR5 exhibited potential for predicting mortality in patients with ARDS.

CONCLUSIONS

: Serum soluble DR5 elevation, a valuable prognosis predictor in ARDS, may be associated with alveolar epithelial cell apoptosis.

Prone positioning for mechanically ventilated patients with coronavirus disease 2019: the experience of an Irish regional hospital intensive care unit

Background

The benefits of prone positioning in acute respiratory distress syndrome (ARDS) have been known for many years. While some controversy exists regarding whether coronavirus disease 2019 (COVID-19) pneumonia should be treated with the same therapeutic strategies as for non-COVID ARDS, the Surviving Sepsis Campaign still provide a weak recommendation to utilise prone positioning in this setting.

Aims

The aims of this study are to ascertain if prone positioning improves oxygenation significantly in mechanically ventilated patients with severe COVID-19 ARDS and to describe the feasibility of frequent prone positioning in an Irish regional hospital intensive care unit (ICU) with limited prior experience.

Methods

In this retrospective, observational cohort study, we investigate if the PaO₂/FiO₂ ratio and ventilatory ratio improve during and following prone positioning, and whether this improvement correlates with patient baseline characteristics or survival.

Results

Between March 2020 and 2021, 12 patients underwent prone positioning while mechanically ventilated for severe COVID ARDS. Sixty-six percent were male, mean age 60.9 (± 10.5), mean BMI 33.5 (± 6.74) and median APACHE II score on admission to ICU was 10.5 (7.25–16.3). Further, 83% were proned within 24 h of being intubated due to refractory hypoxaemia. PaO₂/FiO₂ ratio improved from 11.6 kPa (9.80–13.8) to 15.80 kPa (13.1–19.6) while prone, p < 0.0001.

Conclusions

We found prone positioning to be a safe method of significantly improving oxygenation in mechanically ventilated patients with severe COVID-19 ARDS. We did not find a relationship between patient baseline characteristics nor illness severity and degree of PaO₂/FiO₂ ratio improvement, nor did we find a relationship between degree of PaO₂/FiO₂ ratio improvement and survival.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11845-022-03085-9.

Prone Positioning and Neuromuscular Blocking Agents as Adjunctive Therapies in Mechanically Ventilated Patients with Acute Respiratory Distress Syndrome

Neuromuscular blocking agents (NMBAs) and prone position (PP) are two major adjunctive therapies that can improve outcome in moderate-to-severe acute respiratory distress syndrome. NMBA should be used once lung-protective mechanical ventilation has been set, for 48 hours or less and as a continuous intravenous infusion. PP should be used as early as possible for long sessions; in COVID-19 its use has exploded. In nonintubated patients, PP might reduce the rate of intubation but not mortality. The goal of this article is to perform a narrative review on the pathophysiological rationale, the clinical effects, and the clinical use and recommendations of both NMBA and PP.

Comparing Prone Positioning Use in COVID-19 Versus Historic Acute Respiratory Distress Syndrome

Use of prone positioning in patients with acute respiratory distress syndrome (ARDS) from COVID-19 may be greater than in patients treated for ARDS before the pandemic. However, the magnitude of this increase, sources of practice variation, and the extent to which use adheres to guidelines is unknown.