Impact of exposure time in awake prone positioning on clinical outcomes of patients with COVID-19-related acute respiratory failure treated with high-flow nasal oxygen: a multicenter cohort study

Efficacy and Safety of Dexmedetomidine in the Prone Position in Elderly Patients with Pneumonia: A Prospective, Double-Blind, Randomized Controlled Study

PURPOSE

We aimed to identify a safe and effective method to assist older adults with pneumonia in tolerating the prone position for a longer duration.

METHODS

This was a randomized, controlled, double-blinded study performed at the Shanghai Fourth People's Hospital. Eighty patients with pneumonia aged ≥ 65 years were included. The patients were able to spontaneous breath in the prone position and were administered intravenous dexmedetomidine or an isotonic sodium chloride solution. The cumulative daily durations of prone positioning for all patients in the two groups were recorded. The primary outcome was the percentage of patients who completed ≥ 9 h/day in the prone position. The secondary outcomes included the incidence of complications in the prone position and patient outcomes.

RESULTS

Eighty patients were included (average age: 79.6 ± 8.9 years). The percentage of patients who completed ≥ 9 h/day in the prone position was significantly higher in the dexmedetomidine group than in the placebo group (P = 0.011). The percentage of patients who completed ≥ 12 h/day in the prone position was also significantly greater in the dexmedetomidine group than in the placebo group (P = 0.008). There were no significant differences in other variables between the two groups.

CONCLUSIONS

The results of this study demonstrate that intravenous dexmedetomidine injection can significantly prolong the duration of spontaneous breathing in the prone position in elderly pneumonia patients without obvious adverse events. We provide a safe and effective method to help patients with pneumonia, especially those with delirium or cognitive impairment, who cannot tolerate the length of time needed for spontaneous breathing in the prone position to be effective.

TRIAL REGISTRATION

The study was registered with the Chinese Clinical Trial Center (registration number: ChiCRT2300067383) on 2023-01-05.

Dose-response relationship between awake prone-positioning duration and PaO2/FiO2 changes and risk of disease aggravation in patients with severe COVID-19: A prospective cohort study

BACKGROUND

Patients not mechanically ventilated often fail to achieve the recommended duration of awake prone positioning due to treatment interruption and discomfort. Few studies have investigated the link between treatment outcome and prone-positioning duration, the inability to accurately guide patients to perform awake prone positioning.

OBJECTIVES

The aim of this study was to characterise and explore the relationship between awake prone-positioning duration with the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2 [P/F]) changes and the risk of disease aggravation.

METHODS

A prospective cohort study; dose-response relationship was used. Awake prone positioning was performed on patients with severe Corona Virus Disease 2019 (COVID-19) for 5 consecutive days from 1 February to 21 March 2023. Linear and logistic regression models were utilised to assess the association between prone-positioning duration with P/F changes and risk of disease aggravation, respectively. Meanwhile, the restricted cubic spline was used to evaluate the dose-response relationships.

RESULTS

A total of 408 patients with severe COVID-19 were analysed. The daily prone positioning duration was 4.57 ± 2.74 h/d, and the changes in P/F were 67.63 ± 69.17 mmHg. On the sixth day of hospitalisation, the condition of 52 (12.8%) patients deteriorated. There was a positive, nonlinear dose-response relationship (Poverall < 0.001, Pnonlinearity = 0.041) and a strong, significant positive correlation (β = 29.286, t = 4.302, P < 0.001) between the prone-positioning duration and P/F changes. The risk of disease aggravation gradually decreases with the increase of prone-positioning duration. Nonetheless, the prone-positioning duration was not statistically associated with disease aggravation (odds ratio = 0.986, 95% confidence interval: 0.514-1.895).

CONCLUSIONS

Awake prone positioning for ≥4 h/d is effective on oxygenation (not mortality/intubation) and is achievable for patients with severe COVID-19. Prolonged prone positioning is promising in improving patients' oxygenation but does not alleviate their risk of disease aggravation.

Guideline on positioning and early mobilisation in the critically ill by an expert panel

A scientific panel was created consisting of 23 interdisciplinary and interprofessional experts in intensive care medicine, physiotherapy, nursing care, surgery, rehabilitative medicine, and pneumology delegated from scientific societies together with a patient representative and a delegate from the Association of the Scientific Medical Societies who advised methodological implementation. The guideline was created according to the German Association of the Scientific Medical Societies (AWMF), based on The Appraisal of Guidelines for Research and Evaluation (AGREE) II. The topics of (early) mobilisation, neuromuscular electrical stimulation, assist devices for mobilisation, and positioning, including prone positioning, were identified as areas to be addressed and assigned to specialist expert groups, taking conflicts of interest into account. The panel formulated PICO questions (addressing the population, intervention, comparison or control group as well as the resulting outcomes), conducted a systematic literature review with abstract screening and full-text analysis and created summary tables. This was followed by grading the evidence according to the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence and a risk of bias assessment. The recommendations were finalized according to GRADE and voted using an online Delphi process followed by a final hybrid consensus conference. The German long version of the guideline was approved by the professional associations. For this English version an update of the systematic review was conducted until April 2024 and recommendation adapted based on new evidence in systematic reviews and randomized controlled trials. In total, 46 recommendations were developed and research gaps addressed.

Prolonged vs shorter awake prone positioning for COVID-19 patients with acute respiratory failure: a multicenter, randomised controlled trial

PURPOSE

Awake prone positioning has been reported to reduce endotracheal intubation in patients with coronavirus disease 2019 (COVID-19)-related acute hypoxemic respiratory failure (AHRF). However, it is still unclear whether using the awake prone positioning for longer periods can further improve outcomes.

METHODS

In this randomized, open-label clinical trial conducted at 12 hospitals in China, non-intubated patients with COVID-19-related AHRF were randomly assigned to prolonged awake prone positioning (target > 12 h daily for 7 days) or standard care with a shorter period of awake prone positioning. The primary outcome was endotracheal intubation within 28 days after randomization. The key secondary outcomes included mortality and adverse events.

RESULTS

In total, 409 patients were enrolled and randomly assigned to prolonged awake prone positioning (n = 205) or standard care (n = 204). In the first 7 days after randomization, the median duration of prone positioning was 12 h/d (interquartile range [IQR] 12-14 h/d) in the prolonged awake prone positioning group vs. 5 h/d (IQR 2-8 h/d) in the standard care group. In the intention-to-treat analysis, intubation occurred in 35 (17%) patients assigned to prolonged awake prone positioning and in 56 (27%) patients assigned to standard care (relative risk 0.62 [95% confidence interval (CI) 0.42-0.9]). The hazard ratio (HR) for intubation was 0.56 (0.37-0.86), and for mortality was 0.63 (0.42-0.96) for prolonged awake prone positioning versus standard care, within 28 days. The incidence of pre-specified adverse events was low and similar in both groups.

CONCLUSION

Prolonged awake prone positioning of patients with COVID-19-related AHRF reduces the intubation rate without significant harm. These results support prolonged awake prone positioning of patients with COVID-19-related AHRF.

Conscious prone positioning in nonintubated COVID-19 patients with acute respiratory distress syndrome: systematic review and meta-analysis

OBJECTIVE

To systematically review the effect of the prone position on endotracheal intubation and mortality in nonintubated COVID-19 patients with acute respiratory distress syndrome.

METHODS

We registered the protocol (CRD42021286711) and searched for four databases and gray literature from inception to December 31, 2022. We included observational studies and clinical trials. There was no limit by date or the language of publication. We excluded case reports, case series, studies not available in full text, and those studies that included children < 18-years-old.

RESULTS

We included ten observational studies, eight clinical trials, 3,969 patients, 1,120 endotracheal intubation events, and 843 deaths. All of the studies had a low risk of bias (Newcastle-Ottawa Scale and Risk of Bias 2 tools). We found that the conscious prone position decreased the odds of endotracheal intubation by 44% (OR 0.56; 95%CI 0.40 - 0.78) and mortality by 43% (OR 0.57; 95%CI 0.39 - 0.84) in nonintubated COVID-19 patients with acute respiratory distress syndrome. This protective effect on endotracheal intubation and mortality was more robust in those who spent > 8 hours/day in the conscious prone position (OR 0.43; 95%CI 0.26 - 0.72 and OR 0.38; 95%CI 0.24 - 0.60, respectively). The certainty of the evidence according to the GRADE criteria was moderate.

CONCLUSION

The conscious prone position decreased the odds of endotracheal intubation and mortality, especially when patients spent over 8 hours/day in the conscious prone position and treatment in the intensive care unit. However, our results should be cautiously interpreted due to limitations in evaluating randomized clinical trials, nonrandomized clinical trials and observational studies. However, despite systematic reviews with meta-analyses of randomized clinical trials, we must keep in mind that these studies remain heterogeneous from a clinical and methodological point of view.

Prone positioning in awake patients without ventilatory support does not alter major clinical outcomes in severe COVID-19: results from a retrospective observational cohort study, systematic review and meta-analysis

OBJECTIVES

During the Coronavirus disease (COVID-19) pandemic, clinicians recommended awake-prone positioning (APP) to avoid the worst outcomes. The objectives of this study were to investigate if APP reduces intubation, death rates, and hospital length of stay (HLOS) in acute COVID-19.

METHODS

We performed a retrospective cohort with non-mechanically ventilated patients hospitalized in a reference center in Manaus, Brazil, 2020. Participants were stratified into APP and awake-not-prone positioning (ANPP) groups. Also, we conducted a systematic review and performed a meta-analysis to understand if this intervention had different outcomes in resource-limited settings (PROSPERO CRD42023422452).

RESULTS

A total of 115 participants were allocated into the groups. There was no statistical difference between both groups regarding time to intubation (HR: 0.861; 95CI: 0.474-1.1562; p=0.622) and time to death (HR: 1.666; 95CI: 0.939-2.951; p=0.081). APP was not significantly associated with reduced HLOS. A total of 86 articles were included in the systematic review, of which 76 (88,3%) show similar findings after APP. Also, low/middle, and high-income countries were similar regarding such outcomes.

CONCLUSION

APP in COVID-19 does not present clinical improvement that affects mortality, intubation rate and HLOS. The lack of a prone position protocol, obtained through a controlled study, is necessary. After 3 years, APP benefits are still inconclusive.

Effectiveness and safety of awake prone positioning in COVID-19-related acute hypoxaemic respiratory failure: an overview of systematic reviews

OBJECTIVE

To evaluate and summarize systematic reviews of the effects and safety of awake prone positioning for COVID-19-related acute hypoxaemic respiratory failure.

METHODS

A comprehensive search was conducted on PubMed, Embase, the Cochrane Library, Web of Science, CNKI, CSPD, CCD and CBM from their inception to March 28, 2023. Systematic reviews (SRs) of awake prone positioning (APP) for COVID-19-related acute hypoxaemic respiratory failure in adults were included. Two reviewers screened the eligible articles, and four reviewers in pairs extracted data and assessed the methodological quality/certainty of the evidence of all included SRs by AMSTAR 2 and GRADE tools. The overlap of primary studies was measured by calculating corrected covered areas. Data from the included reviews were synthesized with a narrative description.

RESULTS

A total of 11 SRs were included. The methodological quality of SRs included 1 "High", 4 "Moderate", 2 "Low" and 4 "Critically low" by AMSTAR 2. With the GRADE system, no high-quality evidence was found, and only 14 outcomes provided moderate-quality evidence. Data synthesis of the included SR outcomes showed that APP reduced the risk of requiring intubation (11 SRs) and improving oxygenation (3 SRs), whereas reduced significant mortality was not found in RCT-based SRs. No significant difference was observed in the incidence of adverse events between groups (8 SRs). The corrected covered area index was 27%, which shows very high overlap among studies.

CONCLUSION

The available SRs suggest that APP has benefits in terms of reducing intubation rates and improving oxygenation for COVID-19-related acute hypoxemic respiratory failure, without an increased risk of adverse events. The conclusion should be treated with caution because of the generally low quality of methodology and evidence.

TRIAL REGISTRATION

The protocol for this review was registered with PROSPERO: CRD42023400986. Registered 15 April 2023.

The Predictive Validity of the Berlin Definition of Acute Respiratory Distress Syndrome for Patients With COVID-19-Related Respiratory Failure Treated With High-Flow Nasal Oxygen: A Multicenter, Prospective Cohort Study

OBJECTIVES

The Berlin definition of acute respiratory distress syndrome (ARDS) was constructed for patients receiving invasive mechanical ventilation (IMV) with consideration given to issues related to reliability, feasibility, and validity. Notwithstanding, patients with acute respiratory failure (ARF) may be treated with high-flow nasal oxygen (HFNO) and may not fall within the scope of the original definition. We aimed to evaluate the predictive validity of the Berlin definition in HFNO-treated patients with COVID-19-related respiratory failure who otherwise met ARDS criteria.

DESIGN

Multicenter, prospective cohort study.

SETTING

Five ICUs of five centers in Argentina from March 2020 to September 2021.

PATIENTS

We consecutively included HFNO-treated patients older than 18 years with confirmed COVID-19-related ARF, a Pa o2 /F io2 of less than 300 mm Hg, bilateral infiltrates on imaging, and worsening respiratory symptoms for less than 1 week.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We evaluated the predictive validity of mortality at day 28 using the area under the receiver operating characteristics curve (AUC), compared the predictive validity across subgroups, and characterized relevant clinical outcomes. We screened 1,231 patients and included 696 ARDS patients [30 (4%) mild, 380 (55%) moderate, and 286 (41%) severe]. For the study cohort, the AUC for mortality at day 28 was 0.606 (95% CI, 0.561-0.651) with the AUC for subgroups being similar to that of the overall cohort. Two hundred fifty-six patients (37%) received IMV. By day 28, 142 patients (21%) had died, of whom 81 (57%) had severe ARDS. Mortality occurred primarily in patients who were transitioned to IMV.

CONCLUSIONS

The predictive validity of the Berlin ARDS definition was similar for HFNO-treated patients as compared with the original population of invasively ventilated patients. Our findings support the extension of the Berlin definition to HFNO-treated patients with ARDS.

High-Flow Nasal Oxygen for Severe COVID-19 Pneumonia in Greek Patients: A Prospective Observational Study

INTRODUCTION

High-flow nasal oxygen (HFNO) and prone positioning may improve outcomes of coronavirus disease 2019 (COVID-19) patients treated in the intensive care unit (ICU). The aim of this study was to describe outcomes following the timely application of HFNO and prone positioning in COVID-19 patients treated in a ward setting.

METHODS

The study included 89 prospectively recruited subjects at the COVID-19 ward unit of the University Hospital of Heraklion, Greece, between March and December 2020.

RESULTS

Seventy-four (83%) of the 89 subjects in the study had severe COVID-19. Of those, 33 (45%) required HFNO treatment and prone positioning and 15 (45%) were transferred to the ICU, with 4 of them being intubated. Severe COVID-19 and HFNO needs were associated with an increased pneumonia severity index (PSI) score on admission and a worse PaO2/FiO2 ratio. In multivariate analysis, PSI was the only independent predictor of subsequent HFNO needs (OR=1.022). Overall intubation and mortality rates were 5.6% and 3.4%, respectively.

CONCLUSION

This study shows that for patients with severe COVID-19 hospitalized in medical wards, standard COVID-19 treatment, along with the timely utilization of HFNO and prone positioning, resulted in excellent outcomes with fewer ICU admission rates.

Prone versus lateral position in acute hypoxemic respiratory failure patients with HFNO therapy: study protocol for a multicentre randomised controlled open-label trial

BACKGROUND

High-flow nasal oxygen (HFNO) therapy is a leading treatment technique for acute hypoxemic respiratory failure (AHRF), but its treatment failure rate remains high. The awake prone position (APP) has been proven to increase oxygenation and reduce the endotracheal intubation rate in patients with COVID-19-induced AHRF. However, the APP is poorly tolerated in patients, and its performance in improving prognoses is controversial. The lateral position has a similar mechanism and effect to the prone position, but it is more tolerable than the prone position. Therefore, it is worth exploring whether the lateral position is better for awake patients with AHRF.

METHODS

This is a protocol for a three-arm parallel-group multicentre randomised controlled open-label exploratory trial. A total of 583 patients from two hospitals in Chongqing, China, will be randomised to take the semi-recumbent position, lateral position, or prone position at a ratio of 1:1:1. Patients are all diagnosed with AHRF secondary to non-COVID-19 pneumonia or lung infection and receiving HFNO therapy. The primary outcome is ventilator-free days in 28 days. The secondary outcomes are the 28-day intubation rate, 28-day all-cause mortality, total position change time, the incidence of adverse events, number of hours using HFNO therapy, length of hospital and intensive care unit (ICU) stay, and others. We will conduct subgroup analyses on the arterial partial pressure of oxygen to the fraction of inspiration oxygen (PaO2/FiO2) ratio (> 200 mmHg or ≤ 200 mmHg), time from admission to intervention implementation (< 24 h or ≥ 24 h), position changing time, and different diagnoses.

DISCUSSION

This trial will explore the prognostic effects of the APP with that of the lateral position in awake patients with non-COVID-19AHRF and compare the differences between them. To provide evidence for clinical decision-making and further research on position management.

TRIAL REGISTRATION

This trial was registered in the Chinese Clinical Trial Registry. The registration number is ChiCTR2200055822 . Registered on January 20, 2022.

Prone Positioning for Patients With COVID-19-Induced Acute Hypoxemic Respiratory Failure: Flipping the Script

During the COVID-19 pandemic, prone positioning (PP) emerged as a widely used supportive therapy for patients with acute hypoxemic respiratory failure caused by COVID-19 infection. In particular, awake PP (APP)-the placement of non-intubated patients in the prone position-has gained popularity and hence is detailed first herein. This review discusses recent publications on the use of PP for non-intubated and intubated subjects with COVID-19, highlighting the physiological responses, clinical outcomes, influential factors affecting treatment success, and strategies to improve adherence with APP. The use of prolonged PP and the use of PP for patients undergoing extracorporeal membrane oxygenation are also presented.

Factors Associated With Prolonged Ventilation in Patients Receiving Prone Positioning Protocol With Muscle Relaxants for Severe COVID-19 Pneumonia

BACKGROUND

Prone positioning and neuromuscular blocking agents (NMBAs) are frequently used to treat severe respiratory failure from COVID-19 pneumonia. Prone positioning has shown to improve mortality, whereas NMBAs are used to prevent ventilator asynchrony and reduce patient self-inflicted lung injury. However, despite the use of lung-protective strategies, high death rates in this patient population have been reported.

METHODS

We retrospectively examined the factors affecting prolonged mechanical ventilation in subjects receiving prone positioning plus muscle relaxants. The medical records of 170 patients were reviewed. Subjects were divided into 2 groups according to ventilator-free days (VFDs) at day 28. Whereas subjects with VFDs < 18 d were defined as prolonged mechanical ventilation, subjects with VFDs ≥18 d were defined as short-term mechanical ventilation. Subjects' baseline status, status at ICU admission, therapy before ICU admission, and treatment in the ICU were studied.

RESULTS

Under the proning protocol for COVID-19, the mortality rate in our facility was 11.2%. The prognosis may be improved by avoiding lung injury in the early stages of mechanical ventilation. According to multifactorial logistic regression analysis, persistent SARS-CoV-2 viral shedding in blood (P = .03), higher daily corticosteroid use before ICU admission (P = .007), delayed recovery of lymphocyte count (P < .001), and higher maximal fibrinogen degradation products (P = .039) were associated with prolonged mechanical ventilation. A significant relationship was found between daily corticosteroid use before admission and VFDs by squared regression analysis (y = -0.00008522x2 + 0.01338x + 12.8; x: daily corticosteroids dosage before admission [prednisolone mg/d]; y: VFDs/28 d, R2 = 0.047, P = .02). The peak point of the regression curve was 13.4 d at 78.5 mg/d of the equivalent prednisolone dose, which corresponded to the longest VFDs.

CONCLUSIONS

Persistent SARS-CoV-2 viral shedding in blood, high corticosteroid dose from the onset of symptoms to ICU admission, slow recovery of lymphocyte counts, and high levels of fibrinogen degradation products after admission were associated with prolonged mechanical ventilation in subjects with severe COVID-19 pneumonia.

Awake prone positioning for non-intubated patients with COVID-19-related acute hypoxic respiratory failure: a systematic review based on eight high-quality randomized controlled trials

BACKGROUND

Awake prone positioning has been widely used in non-intubated patients with acute hypoxic respiratory failure (AHRF) due to COVID-19, but the evidence is mostly from observational studies and low-quality randomized controlled trials (RCTs), with conflicting results from published studies. A systematic review of published high-quality RCTs to resolve the controversy over the efficacy and safety of awake prone positioning in non-intubated patients with AHRF due to COVID-19.

METHODS

Candidate studies were identified through searches of PubMed, Web of Science, Cochrane, Embase, Scopus databases from December 1, 2019 to November 1, 2022. Literature screening, data extraction and risk of bias assessment were independently conducted by two researchers.

RESULTS

Eight RCTs involving 2657 patients were included. Meta-analysis of fixed effects models showed that awake prone positioning did not increase mortality(OR = 0.88, 95%CI [0.72, 1.08]), length of stay in ICU (WMD = 1.14, 95%CI [-0.45, 2.72]), total length of stay (WMD = 0.11, 95%CI [-1.02, 1.23]), or incidence of adverse events (OR = 1.02, 95%CI [0.79, 1.31]) compared with usual care, but significantly reduced the intubation rate (OR = 0.72, 95%CI [0.60, 0.86]). Similar results were found in a subgroup analysis of patients who received only high flow nasal cannula (Mortality: OR = 0.86, 95%CI [0.70, 1.05]; Intubation rate: OR = 0.69, 95%CI [0.58, 0.83]). All eight RCTs had high quality of evidence, which ensured the reliability of the meta-analysis results.

CONCLUSIONS

Awake prone positioning is safe and feasible in non-intubated patients with AHRF caused by COVID-19, and can significantly reduce the intubation rate. More studies are needed to explore standardized implementation strategies for the awake prone positioning.

TRIAL REGISTRATION

CRD42023394113.

Prone Positioning for Acute Hypoxemic Respiratory Failure and ARDS: A Review

Prone positioning is an immediately accessible, readily implementable intervention that was proposed initially as a method for improvement in gas exchange > 50 years ago. Initially implemented clinically as an empiric therapy for refractory hypoxemia, multiple clinical trials were performed on the use of prone positioning in various respiratory conditions, cumulating in the landmark Proning Severe ARDS Patients trial, which demonstrated mortality benefit in patients with severe ARDS. After this trial and the corresponding meta-analysis, expert consensus and societal guidelines recommended the use of prone positioning for the management of severe ARDS. The ongoing COVID-19 pandemic has brought prone positioning to the forefront of medicine, including widespread implementation of prone positioning in awake, spontaneously breathing, nonintubated patients with acute hypoxemic respiratory failure. Multiple clinical trials now have been performed to investigate the safety and effectiveness of prone positioning in these patients and have enhanced our understanding of the effects of the prone position in respiratory failure. In this review, we discuss the physiologic features, clinical outcome data, practical considerations, and lingering questions of prone positioning.

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

Comparison of high-flow nasal therapy, noninvasive ventilation, and continuous positive airway pressure on outcomes in critically ill patients admitted for COVID-19 with acute respiratory failure

BACKGROUND

The optimal first-line noninvasive respiratory support (NIRS) to improve outcome in patients affected by COVID-19 pneumonia admitted to ICU is still debated.

METHODS

We conducted a retrospective study in seven French ICUs, including all adults admitted between July and December 2020 with documented SARS-CoV-2 acute respiratory failure (PaO2/FiO2<300 mmHg), and treated with either high-flow nasal therapy (HFNT) alone, noninvasive ventilation alone or in combination with HFNT (NIV), or continuous positive airway pressure alone or in combination with HFNT (CPAP). The primary outcome was NIRS failure at day 28, defined as the need for endotracheal intubation (ETI) or death without ETI.

RESULTS

Among the 355 patients included, 160 (45%) were treated with HFNT alone, 115 (32%) with NIV and 80 (23%) with CPAP. The primary outcome occurred in 65 (41%), 69 (60%), and 25 (31%) patients among those treated with HFNT alone, NIV, and CPAP, respectively (P<0.001). After univariate analysis, patients treated with CPAP had a trend for a lower incidence of the primary outcome, whereas patients treated with NIV had a significant higher incidence of the primary outcome, both compared to those treated with HFNT alone (unadjusted Hazard ratio 0.67; 95% CI [0.42-1.06], and 1.58; 95% CI [1.12-2.22]; P=0.09 and 0.008, respectively).

CONCLUSIONS

Among ICU patients admitted for severe COVID-19 pneumonia and managed with NIRS, the outcome seems to differ according to the initial chosen strategy. Prospective randomized controlled studies are warranted to identify the optimal strategy.

Efficacy and safety of prone position in COVID-19 patients with respiratory failure: a systematic review and meta-analysis

BACKGROUND

Prone position has already been demonstrated to improve survival in non-COVID acute respiratory distress syndrome and has been widely performed in COVID-19 patients with respiratory failure, both in non-intubated and intubated patients. However, the beneficial effect of the prone position in COVID-19 pneumonia still remains controversial. Therefore, we aimed to evaluate the effectiveness and safety of the prone position compared with the non-prone in non-intubated and intubated COVID-19 patients, respectively.

METHODS

We searched the MEDLINE, EMBASE, and Cochrane databases, as well as one Korean domestic database, on July 9, 2021, and updated the search 9 times to September 14, 2022. Studies that compared prone and non-prone positions in patients with COVID-19 were eligible for inclusion. The primary outcomes were mortality, need for intubation, and adverse events.

RESULTS

Of the 1259 records identified, 9 randomized controlled trials (RCTs) and 23 nonrandomized studies (NRSs) were eligible. In the non-intubated patients, the prone position reduced the intubation rate compared with the non-prone position in 6 RCTs (n = 2156, RR 0.81, P = 0.0002) and in 18 NRSs (n = 3374, RR 0.65, P = 0.002). In the subgroup analysis according to the oxygen delivery method, the results were constant only in the HFNC or NIV subgroup. For mortality, RCTs reported no difference between prone and non-prone groups, but in NRSs, the prone position had a significant advantage in mortality [18 NRSs, n = 3361, relative risk (RR) 0.56, P < 0.00001] regardless of the oxygen delivery methods shown in the subgroup analysis. There was no RCT for intubated patients, and mortality did not differ between the prone and non-prone groups in NRSs. Adverse events reported in both the non-intubated and intubated groups were mild and similar between the prone and non-intubated groups.

CONCLUSION

For non-intubated patients with COVID-19, prone positioning reduced the risk of intubation, particularly in patients requiring a high-flow oxygen system. However, the survival benefit was unclear between the prone and non-prone groups. There was insufficient evidence to support the beneficial effects of prone positioning in intubated patients. Trial registration This study was registered in the Prospective Register of Systematic Reviews on February 16, 2022 (Registration No.: CRD42022311150 ).

Supportive Care in Patients with Critical Coronavirus Disease 2019

Specific therapies for the treatment of coronavirus disease 2019 (COVID-19) have limited efficacy in the event a patient worsens clinically and requires admission to the intensive care unit (ICU). Thus, providing quality supportive care is essential to the overall management of patients with critical COVID-19. Patients with respiratory failure not requiring intubation should be supported with noninvasive positive pressure ventilation, continuous positive airway pressure, or high flow oxygenation. Use of these respiratory modalities may prevent patients from subsequently requiring intubation. Basic components of supportive care for the critically ill should be applied equally to patients with COVID-19 in the ICU.

Practice of Awake Prone Positioning in Critically Ill COVID-19 Patients-Insights from the PRoAcT-COVID Study

We describe the incidence, practice and associations with outcomes of awake prone positioning in patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19) in a national multicenter observational cohort study performed in 16 intensive care units in the Netherlands (PRoAcT−COVID-study). Patients were categorized in two groups, based on received treatment of awake prone positioning. The primary endpoint was practice of prone positioning. Secondary endpoint was ‘treatment failure’, a composite of intubation for invasive ventilation and death before day 28. We used propensity matching to control for observed confounding factors. In 546 patients, awake prone positioning was used in 88 (16.1%) patients. Prone positioning started within median 1 (0 to 2) days after ICU admission, sessions summed up to median 12.0 (8.4−14.5) hours for median 1.0 day. In the unmatched analysis (HR, 1.80 (1.41−2.31); p < 0.001), but not in the matched analysis (HR, 1.17 (0.87−1.59); p = 0.30), treatment failure occurred more often in patients that received prone positioning. The findings of this study are that awake prone positioning was used in one in six COVID-19 patients. Prone positioning started early, and sessions lasted long but were often discontinued because of need for intubation.

Clinical Outcomes of Routine Awake Prone Positioning in COVID-19 Patients: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Before coronavirus disease 2019 (COVID-19) emerged, proning had been demonstrated to improve oxygenation in those with acute hypoxic respiratory failure and be performed in non-intensive care settings. This benefit was further exemplified by the COVID-19 pandemic, leading to awake prone positioning (APP). We assessed the efficacy of routine APP versus standard care in preventing death and invasive mechanical ventilation (IMV) in non-intubated hypoxic COVID-19 patients. PubMed, Cochrane Library, Scopus, and medRxiv databases were used from January 1st, 2020, to January 15th, 2022, to identify randomized controlled trials (RCTs). Routine APP group were encouraged to be self-prone, whereas the standard care group received care according to local clinical practice and allowed APP crossover as rescue therapy. We included eight COVID-19 RCTs assessing 809 APP vs. 822 standard care patients. APP group had less IMV requirement (26.5% vs. 30.9%; OR - odds ratio 0.77; P=0.03) than the standard care group, with subgroup analysis showing greater benefit (32.5% vs. 39.1%; OR 0.75; P=0.02) for those mainly requiring oxygen support of non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC). The time to IMV initiation was similar (mean 8.3 vs. 10.0 days; P=0.66) for patients requiring NIMV and HFNC. Patients mainly receiving supplemental oxygen and non-rebreather masks had improved oxygenation parameters, although not statistically significant. Other outcomes involving all-cause hospital mortality, hospital and ICU (intensive care unit) length of stay, and adverse events were comparable. APP appeared to be an important modality for reducing IMV requirements, especially in those requiring NIMV and HFNC.

Awake prone positioning for patients with COVID-19-induced acute hypoxemic respiratory failure

Whereas prone positioning of intubated patients suffering from acute respiratory distress syndrome represents the standard of care, proning non-intubated patients, so-called "awake prone positioning (APP)," has only recently gained popularity and undergone scientific evaluation. In this review, we summarize current evidence on physiological and clinical effects of APP on patients' centered outcomes, such as intubation and mortality, the safety of the technique, factors and predictors of success, practical issues for optimal implementation, and future areas of research. Current evidence supports using APP among patients suffering from acute hypoxemic respiratory failure due to COVID-19 and undergoing advanced respiratory support, such as high-flow nasal cannula, in an intensive care unit setting. Healthcare teams should aim to prone patients at least 8 h daily. Future research should focus on optimizing the tolerance of the technique and comprehensively evaluating benefits in other patient populations.

COVID-19: Opportunities to Improve Prognosis

COVID-19 is characterized by a severe course in approximately 5‒10% of patients, who require admittance to the intensive care unit and mechanical ventilation, which is associated with a very high risk of a poor prognosis. At present, in real clinical practice, in managing severe patients with COVID-19, noninvasive ventilation (NIV) is widely used (in some countries, up to 60% of all methods of respiratory support). In most studies on the effectiveness of NIV in hypoxemic acute respiratory failure in patients with COVID-19, the need for tracheal intubation and hospital mortality with the use of NIV averaged 20-30%, which suggests the rather high efficiency of this method. The COVID-19 pandemic has given a powerful impetus to the widespread use of prone positioning among nonintubated patients with acute respiratory failure caused by COVID-19. Several studies have shown that prone positioning can reduce the need for mechanical ventilation and hospital mortality. Medications that have proven effective in severe forms of COVID-19 include remdesivir, systemic glucocorticoids, tocilizumab, baricitinib, and anticoagulants. Among the new promising areas of drug therapy, noteworthy is the use of thiol-containing drugs (N-acetylcysteine), inhaled surfactant, and inhaled prostacyclin analogues.

Effect of Awake Prone Positioning in non-Intubated COVID-19 Patients with Acute Hypoxemic Respiratory Failure: A Systematic Review and Meta-Analysis

Background

Awake prone positioning (APP) has been considered as a feasible treatment for patients with acute hypoxemic respiratory failure in non-intubated coronavirus disease 2019 (COVID-19). However, the efficacy and safety of APP remain uncertain. This meta-analysis aims to assess the effect of APP on intubation rate and mortality in COVID-19 patients with acute respiratory failure.

Methods

Relevant studies published from January 1, 2020, to June 17, 2022, were systematically searched. The primary outcomes were the intubation rate and mortality; the secondary outcome was the incidence of adverse events.

Results

Of 5746 identified publications, 22 were eligible for inclusion in the meta-analysis (N = 5146 patients). In comparison to the non-APP group, APP could decrease the intubation rates (OR 0.64; 95% CI 0.48-0.83; P = .001), particularly in the subgroup of the daily median duration of APP > 8 h and in the subgroup of receiving high flow nasal cannula (HFNC) or non-invasive ventilation (NIV). Patients treated with APP were associated with lower mortality rates (OR 0.61; 95% CI 0.45-0.81; P = .0008), but no mortality benefit was found in the APP group in the subgroup of randomized controlled trials (RCTs). No significant difference was found in the incidence of adverse events between the groups (OR 1.13; 95% CI 0.75-1.71; P = .56).

Conclusion

Our results demonstrated that APP could be an effective strategy to avoid intubation without detrimental effects in non-intubated patients with COVID-19, especially for patients requiring HFNC or NIV, and the daily APP duration with the target of minimally eight hours was suggested. In the subgroup of RCTs, the pooled results did not demonstrate any benefit of APP on mortality. Given the limited number of RCTs, further high-quality RCTs are needed to confirm the results.

INPLASY registration number

INPLASY2021110037.

Awake prone positioning for non-intubated patients with COVID-19-related acute hypoxaemic respiratory failure: a systematic review and meta-analysis

Background

Awake prone positioning has been broadly utilised for non-intubated patients with COVID-19-related acute hypoxaemic respiratory failure, but the results from published randomised controlled trials (RCTs) in the past year are contradictory. We aimed to systematically synthesise the outcomes associated with awake prone positioning, and evaluate these outcomes in relevant subpopulations.

Methods

In this systematic review and meta-analysis, two independent groups of researchers searched MEDLINE, Embase, PubMed, Web of Science, Scopus, MedRxiv, BioRxiv, and ClinicalTrials.gov for RCTs and observational studies (with a control group) of awake prone positioning in patients with COVID-19-related acute hypoxaemic respiratory failure published in English from Jan 1, 2020, to Nov 8, 2021. We excluded trials that included patients intubated before or at enrolment, paediatric patients (ie, younger than 18 years), or trials that did not include the supine position in the control group. The same two independent groups screened studies, extracted the summary data from published reports, and assessed the risk of bias. We used a random-effects meta-analysis to pool individual studies. We used the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the certainty and quality of the evidence. The primary outcome was the reported cumulative intubation risk across RCTs, and effect estimates were calculated as risk ratios (RR;95% CI). The analysis was primarily conducted on RCTs, and observational studies were used for sensitivity analyses. No serious adverse events associated with awake prone positioning were reported. The study protocol was prospectively registered with PROSPERO, CRD42021271285.

Findings

A total of 1243 studies were identified, we assessed 138 full-text articles and received the aggregated results of three unpublished RCTs; therefore, after exclusions, 29 studies were included in the study. Ten were RCTs (1985 patients) and 19 were observational studies (2669 patients). In ten RCTs, awake prone positioning compared with the supine position significantly reduced the need for intubation in the overall population (RR 0·84 [95% CI 0·72–0·97]). A reduced need for intubation was shown among patients who received advanced respiratory support (ie, high-flow nasal cannula or non-invasive ventilation) at enrolment (RR 0·83 [0·71–0·97]) and in intensive care unit (ICU) settings (RR 0·83 [0·71–0·97]) but not in patients receiving conventional oxygen therapy (RR 0·87 [0·45–1·69]) or in non-ICU settings (RR 0·88 [0·44–1·76]). No obvious risk of bias and publication bias was found among the included RCTs for the primary outcome.

Interpretation

In patients with COVID-19-related acute hypoxaemic respiratory failure, awake prone positioning reduced the need for intubation, particularly among those requiring advanced respiratory support and those in ICU settings. Awake prone positioning should be used in patients who have acute hypoxaemic respiratory failure due to COVID-19 and require advanced respiratory support or are treated in the ICU.

Funding

OpenAI, Rice Foundation, National Institute for Health Research, and Oxford Biomedical Research Centre.