Prone Positioning of Nonintubated Patients With Coronavirus Disease 2019-A Systematic Review and Meta-Analysis

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.

A randomised clinical trial of awake prone positioning in COVID-19 suspects with acute hypoxemic respiratory failure

Background

Awake prone position (APP) has been reported to improve oxygenation in patients with COVID-19 disease and to reduce the requirement for invasive mechanical ventilation for patients requiring support with high flow nasal cannula. There is conflicting data for patients requiring lower-level oxygen support.

Research question

Does APP reduce escalation of oxygen support in COVID-19 patients requiring supplementary oxygen?The primary outcome was defined as an escalation of oxygen support from simple supplementary oxygen (NP, HM, NRB) to NIV (CPAP or BiPAP), HFNC or IMV; OR from NIV (CPAP or BiPAP) or HFNC to IMV by day30.

Study design

Two center, prospective, non-blind, randomised controlled trial. Patients with confirmed or suspected COVID-19 pneumonia requiring ≥ 5 liters/min oxygen to maintain saturations ≥ 94 % were randomised to either APP or control group. The APP group received a 3-h APP session three times per day for three days.

Results

Between 9 May and July 13, 2021, 89 adults were screened and 61 enrolled, 31 to awake prone position and 30 controls. There was no difference in the primary outcome, 7 (22.6 %) patients randomised to APP and 9 (30.0 %) controls required escalation of oxygen support (OR 0.68 (0.22-2.14), P = 0.51). There were no differences in any secondary outcomes, in APP did not improve oxygenation.

Interpretation

In COVID-19 patients, the use of APP did not prevent escalation of oxygen support from supplementary to invasive or non-invasive ventilation or improve patient respiratory physiology.

Trial registration

NCT04853979 (clinicaltrials.gov).

Deep learning segmentation and registration-driven lung parenchymal volume and movement CT analysis in prone positioning

PURPOSE

To conduct a volumetric and movement analysis of lung parenchyma in prone positioning using deep neural networks (DNNs).

METHOD

We included patients with suspected interstitial lung abnormalities or disease who underwent full-inspiratory supine and prone chest CT at a single institution between June 2021 and March 2022. A thoracic radiologist visually assessed the fibrosis extent in the total lung (using units of 10%) on supine CT. After preprocessing the images into 192×192×192 resolution, a DNN automatically segmented the whole lung and pulmonary lobes in prone and supine CT images. Affine registration matched the patient's center and location, and the DNN deformably registered prone and supine CT images to calculate the x-, y-, z-axis, and 3D pixel movements.

RESULTS

In total, 108 CT pairs had successful registration. Prone positioning significantly increased the left lower (90.2±69.5 mL, P = 0.000) and right lower lobar volumes (52.5±74.2 mL, P = 0.000). During deformable registration, the average maximum whole-lung pixel movements between the two positions were 1.5, 1.9, 1.6, and 2.8 cm in each axis and 3D plane. Compared to patients with <30% fibrosis, those with ≥30% fibrosis had smaller volume changes (P<0.001) and smaller pixel movements in all axes between the positions (P = 0.000-0.007). Forced vital capacity (FVC) correlated with the left lower lobar volume increase (Spearman correlation coefficient, 0.238) and the maximum whole-lung pixel movements in all axes (coefficients, 0.311 to 0.357).

CONCLUSIONS

Prone positioning led to the preferential expansion of the lower lobes, correlated with FVC, and lung fibrosis limited lung expansion during prone positioning.

Prone positioning effect on tracheal intubation rate, mortality and oxygenation parameters in awake non-intubated severe COVID-19-induced respiratory failure: a review of reviews

BACKGROUND

Prone positioning (PP) is a low-cost method with minimal risk to the patient that improves the oxygenation of patients with acute hypoxic respiratory failure (AHRF) due to COVID-19 pneumonia, thereby reducing their need for tracheal intubation (TI) and transferring to the intensive care unit (ICU). We aimed to overview the results of all previous systematic reviews and meta-analyses to examine the net effect of PP on oxygenation, the rate of TI and mortality in COVID-19 patients.

METHODS

We searched PubMed, Scopus, Web of Science, Google Scholar, and Cochrane Library databases from December 2019 through 2022 without publication language restriction for systematic reviews and meta-analysis studies on PP vs. supine position (SP) in conscious patients with hypoxic respiratory failure COVID-19. After study selection, data were extracted from published meta-analyses and pooled by comprehensive meta-analysis (CMA) software version 2.2.064 to achieve effect sizes. They were analyzed for TI and mortality rates dichotomous variables, and the results were shown as pooled odds ratios (OR) with a 95% confidence interval (CI). Continuous variables such as oxygenation indices (PaO2/FiO2 and SpO2) were also analyzed, and the data were shown as mean differences (MD) with lower and upper CI. The level of statistical significance was set at p ≤ 0.05.

RESULTS

Twelve systematic reviews and meta-analyses with 19,651 patients and six systematic reviews with 2,911 patients were included in this Review of Reviews (total: 22,562). PP treatment significantly reduced the rate of TI (OR = 0.639, %95 CI (0.492, 0.829); P-value = 0.001) and decreased mortality (OR = 0.363, %95 CI (0.240, 0.549), P-value < 0.001). There was no difference in PaO2/FiO2 (MD = 3.591[- 40.881, 48.062]; P-value = 0.874) and SpO2 percent (MD = 1.641[- 4.441, 7.723]; P-value = 0.597).

CONCLUSION

Prone positioning can be recommended in conscious ICU patients with COVID-19 pneumonia to reduce mortality and intubation.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42022326951. Registered 25 April 2022.

Associations of Awake Prone Positioning-Induced Changes in Physiology with Intubation: An International Prospective Observational Study in Patients with Acute Hypoxemic Respiratory Failure Related to COVID-19

INTRODUCTION

Awake prone positioning has the potential to improve oxygenation and decrease respiratory rate, potentially reducing the need for intubation in patients with acute hypoxemic respiratory failure. We investigated awake prone positioning-induced changes in oxygenation and respiratory rate, and the prognostic capacity for intubation in patients with COVID-19 pneumonia.

METHODS

International multicenter prospective observation study in critically ill adult patients with COVID-19 receiving supplemental oxygen. We collected data on oxygenation and respiratory rate at baseline, and at 1 h after being placed in prone positioning. The combined primary outcome was oxygenation and respiratory rate at 1 h. The secondary endpoint was treatment failure, defined as need for intubation within 24 h of start of awake prone positioning.

RESULTS

Between March 27th and November 2020, 101 patients were enrolled of which 99 were fully analyzable. Awake prone positioning lasted mean of 3 [2-4] h. In 77 patients (77.7%), awake prone positioning improved oxygenation, and in 37 patients (54.4%) it decreased respiratory rate. Twenty-nine patients (29.3%) were intubated within 24 h. An increase in SpO2/FiO2 of < 10 (OR 5.1, 95% CI 1.4-18.5, P = 0.01), a failure to increase PaO2/FiO2 to > 116 mmHg (OR 3.6, 95% CI 1.2-10.8, P = 0.02), and a decrease in respiratory rate of < 2 breaths/min (OR 3.6, 95% CI 1.3-9.5, P = 0.01) were independent variables associated with need for intubation. The AUC-ROC curve for intubation using a multivariable model was 0.73 (95% CI 0.62-0.84).

CONCLUSIONS

Awake prone positioning improves oxygenation in the majority of patients, and decreases respiratory rate in more than half of patients with acute hypoxemic respiratory failure caused by COVID-19. One in three patients need intubation within 24 h. Awake prone position-induced changes in oxygenation and respiratory rate have prognostic capacity for intubation within 24 h.

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.

Patient Self-Inflicted Lung Injury-A Narrative Review of Pathophysiology, Early Recognition, and Management Options

Patient self-inflicted lung injury (P-SILI) is a life-threatening condition arising from excessive respiratory effort and work of breathing in patients with lung injury. The pathophysiology of P-SILI involves factors related to the underlying lung pathology and vigorous respiratory effort. P-SILI might develop both during spontaneous breathing and mechanical ventilation with preserved spontaneous respiratory activity. In spontaneously breathing patients, clinical signs of increased work of breathing and scales developed for early detection of potentially harmful effort might help clinicians prevent unnecessary intubation, while, on the contrary, identifying patients who would benefit from early intubation. In mechanically ventilated patients, several simple non-invasive methods for assessing the inspiratory effort exerted by the respiratory muscles were correlated with respiratory muscle pressure. In patients with signs of injurious respiratory effort, therapy aimed to minimize this problem has been demonstrated to prevent aggravation of lung injury and, therefore, improve the outcome of such patients. In this narrative review, we accumulated the current information on pathophysiology and early detection of vigorous respiratory effort. In addition, we proposed a simple algorithm for prevention and treatment of P-SILI that is easily applicable in clinical practice.

Increasing Supportive Care for Patients With COVID-19-Related Respiratory Deterioration in Non-ICU Settings

BACKGROUND

Prepandemic hospital guidelines were unable to support an acute influx of patients with respiratory deterioration. New processes for general care practice were needed to facilitate patient care.

PURPOSE

To develop and evaluate guidelines to safely treat patients with COVID-19 respiratory deterioration in the general care setting.

METHODS

A quality improvement project with 2 PDSA (Plan-Do-Study-Act) cycles was used to develop guidelines for high-flow oxygen and prone positioning, along with frequent monitoring and collaboration with virtual critical care support.

RESULTS

Over 6 months, 126 patients with COVID-19 were cared for on general care units. Zero intubations occurred on the general care units, with 211 patient hospital days spent in general care that previously would have required an intensive care unit bed.

CONCLUSIONS

Patients in the general care setting with respiratory decline can safely be managed with appropriate monitoring criteria, oxygen device settings, and nursing support unitizing technology.

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 Lessons Learned: Prone Positioning With and Without Invasive Ventilation

Prone positioning (PP) has been used extensively for patients requiring invasive mechanical ventilation for hypoxemic respiratory failure during the COVID-19 pandemic. Evidence suggests that PP was beneficial during the pandemic, as it improves oxygenation and might improve chances of survival, especially in those with a continuum of positive oxygenation responses to the procedure. Additionally, the pandemic drove innovation regarding PP, as it brought attention to awake PP (APP) and the value of an interdisciplinary team approach to PP during a pandemic. APP appears to be safe and effective at improving oxygenation; APP may also reduce the need for intubation in patients requiring advanced respiratory support like high-flow nasal cannula or noninvasive ventilation. Teams specifically assembled for PP during a pandemic also appear useful and can provide needed assistance to bedside clinicians in the time of crisis. Complications associated with PP can be mitigated, and a multidisciplinary approach to reduce the incidence of complications is recommended.

Characteristics, treatment and delirium incidence of older adults hospitalized with COVID-19: a multicentre retrospective cohort study

BACKGROUND

The COVID-19 pandemic has affected older adults disproportionately, and delirium is a concerning consequence; however, the relationship between delirium and corticosteroid use is uncertain. The objective of the present study was to describe patient characteristics, treatments and outcomes among older adults hospitalized with COVID-19, with a focus on dexamethasone use and delirium incidence.

METHODS

We completed this retrospective cohort study at 7 sites (including acute care, rehabilitation and long-term care settings) in Toronto, Ontario, Canada. We included adults aged 65 years or older, consecutively hospitalized with confirmed SARS-CoV-2 infection, between Mar. 11, 2020, and Apr. 30, 2021. We abstracted patient characteristics and outcomes from charts and analyzed them descriptively. We used a logistic regression model to determine the association between dexamethasone use and delirium incidence.

RESULTS

During the study period, 927 patients were admitted to the acute care hospitals with COVID-19. Patients' median age was 79.0 years (interquartile range [IQR] 72.0-87.0), and 417 (45.0%) were female. Most patients were frail (61.9%), based on a Clinical Frailty Scale score of 5 or greater. The prevalence of delirium was 53.6%, and the incidence was 33.1%. Use of restraints was documented in 20.4% of patients. In rehabilitation and long-term care settings (n = 115), patients' median age was 86.0 years (IQR 78.5-91.0), 72 (62.6%) were female and delirium occurred in 17 patients (14.8%). In patients admitted to acute care during wave 2 of the pandemic (Aug. 1, 2020, to Feb. 20, 2021), dexamethasone use had a nonsignificant association with delirium incidence (adjusted odds ratio 1.38, 95% confidence interval 0.77-2.50). Overall, in-hospital death occurred in 262 (28.4%) patients in acute care settings and 28 (24.3%) patients in rehabilitation or long-term care settings.

INTERPRETATION

In-hospital death, delirium and use of restraints were common in older adults admitted to hospital with COVID-19. Further research should be directed to improving the quality of care for this population with known vulnerabilities during continued waves of the COVID-19 pandemic.

Assessment of Awake Prone Positioning in Hospitalized Adults With COVID-19: A Nonrandomized Controlled Trial

IMPORTANCE

Awake prone positioning may improve hypoxemia among patients with COVID-19, but whether it is associated with improved clinical outcomes remains unknown.

OBJECTIVE

To determine whether the recommendation of awake prone positioning is associated with improved outcomes among patients with COVID-19-related hypoxemia who have not received mechanical ventilation.

DESIGN, SETTING, AND PARTICIPANTS

This pragmatic nonrandomized controlled trial was conducted at 2 academic medical centers (Vanderbilt University Medical Center and NorthShore University HealthSystem) during the COVID-19 pandemic. A total of 501 adult patients with COVID-19-associated hypoxemia who had not received mechanical ventilation were enrolled from May 13 to December 11, 2020.

INTERVENTIONS

Patients were assigned 1:1 to receive either the practitioner-recommended awake prone positioning intervention (intervention group) or usual care (usual care group).

MAIN OUTCOMES AND MEASURES

Primary outcome analyses were performed using a bayesian proportional odds model with covariate adjustment for clinical severity ranking based on the World Health Organization ordinal outcome scale, which was modified to highlight the worst level of hypoxemia on study day 5.

RESULTS

A total of 501 patients (mean [SD] age, 61.0 [15.3] years; 284 [56.7%] were male; and most [417 (83.2%)] were self-reported non-Hispanic or non-Latinx) were included. Baseline severity was comparable between the intervention vs usual care groups, with 170 patients (65.9%) vs 162 patients (66.7%) receiving oxygen via standard low-flow nasal cannula, 71 patients (27.5%) vs 62 patients (25.5%) receiving oxygen via high-flow nasal cannula, and 16 patients (6.2%) vs 19 patients (7.8%) receiving noninvasive positive-pressure ventilation. Nursing observations estimated that patients in the intervention group spent a median of 4.2 hours (IQR, 1.8-6.7 hours) in the prone position per day compared with 0 hours (IQR, 0-0.7 hours) per day in the usual care group. On study day 5, the bayesian posterior probability of the intervention group having worse outcomes than the usual care group on the modified World Health Organization ordinal outcome scale was 0.998 (posterior median adjusted odds ratio [aOR], 1.63; 95% credibility interval [CrI], 1.16-2.31). However, on study days 14 and 28, the posterior probabilities of harm were 0.874 (aOR, 1.29; 95% CrI, 0.84-1.99) and 0.673 (aOR, 1.12; 95% CrI, 0.67-1.86), respectively. Exploratory outcomes (progression to mechanical ventilation, length of stay, and 28-day mortality) did not differ between groups.

CONCLUSIONS AND RELEVANCE

In this nonrandomized controlled trial, prone positioning offered no observed clinical benefit among patients with COVID-19-associated hypoxemia who had not received mechanical ventilation. Moreover, there was substantial evidence of worsened clinical outcomes at study day 5 among patients recommended to receive the awake prone positioning intervention, suggesting potential harm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04359797.

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.

Mechanical Ventilation for COVID-19 Patients

Non-invasive ventilation (NIV) or invasive mechanical ventilation (MV) is frequently needed in patients with acute hypoxemic respiratory failure due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. While NIV can be delivered in hospital wards and nonintensive care environments, intubated patients require intensive care unit (ICU) admission and support. Thus, the lack of ICU beds generated by the pandemic has often forced the use of NIV in severely hypoxemic patients treated outside the ICU. In this context, awake prone positioning has been widely adopted to ameliorate oxygenation during noninvasive respiratory support. Still, the incidence of NIV failure and the role of patient self-induced lung injury on hospital outcomes of COVID-19 subjects need to be elucidated. On the other hand, endotracheal intubation is indicated when gas exchange deterioration, muscular exhaustion, and/or neurological impairment ensue. Yet, the best timing for intubation in COVID-19 is still widely debated, as it is the safest use of neuromuscular blocking agents. Not differently from other types of acute respiratory distress syndrome, the aim of MV during COVID-19 is to provide adequate gas exchange while avoiding ventilator-induced lung injury. At the same time, the use of rescue therapies is advocated when standard care is unable to guarantee sufficient organ support. Nevertheless, the general shortage of health care resources experienced during SARS-CoV-2 pandemic might affect the utilization of high-cost, highly specialized, and long-term supports. In this article, we describe the state-of-the-art of NIV and MV setting and their usage for acute hypoxemic respiratory failure of COVID-19 patients.

Variation in the COVID-19 infection-fatality ratio by age, time, and geography during the pre-vaccine era: a systematic analysis

BACKGROUND

The infection-fatality ratio (IFR) is a metric that quantifies the likelihood of an individual dying once infected with a pathogen. Understanding the determinants of IFR variation for COVID-19, the disease caused by the SARS-CoV-2 virus, has direct implications for mitigation efforts with respect to clinical practice, non-pharmaceutical interventions, and the prioritisation of risk groups for targeted vaccine delivery. The IFR is also a crucial parameter in COVID-19 dynamic transmission models, providing a way to convert a population's mortality rate into an estimate of infections.

METHODS

We estimated age-specific and all-age IFR by matching seroprevalence surveys to total COVID-19 mortality rates in a population. The term total COVID-19 mortality refers to an estimate of the total number of deaths directly attributable to COVID-19. After applying exclusion criteria to 5131 seroprevalence surveys, the IFR analyses were informed by 2073 all-age surveys and 718 age-specific surveys (3012 age-specific observations). When seroprevalence was reported by age group, we split total COVID-19 mortality into corresponding age groups using a Bayesian hierarchical model to characterise the non-linear age pattern of reported deaths for a given location. To remove the impact of vaccines on the estimated IFR age pattern, we excluded age-specific observations of seroprevalence and deaths that occurred after vaccines were introduced in a location. We estimated age-specific IFR with a non-linear meta-regression and used the resulting age pattern to standardise all-age IFR observations to the global age distribution. All IFR observations were adjusted for baseline and waning antibody-test sensitivity. We then modelled age-standardised IFR as a function of time, geography, and an ensemble of 100 of the top-performing covariate sets. The covariates included seven clinical predictors (eg, age-standardised obesity prevalence) and two measures of health system performance. Final estimates for 190 countries and territories, as well as subnational locations in 11 countries and territories, were obtained by predicting age-standardised IFR conditional on covariates and reversing the age standardisation.

FINDINGS

We report IFR estimates for April 15, 2020, to January 1, 2021, the period before the introduction of vaccines and widespread evolution of variants. We found substantial heterogeneity in the IFR by age, location, and time. Age-specific IFR estimates form a J shape, with the lowest IFR occurring at age 7 years (0·0023%, 95% uncertainty interval [UI] 0·0015-0·0039) and increasing exponentially through ages 30 years (0·0573%, 0·0418-0·0870), 60 years (1·0035%, 0·7002-1·5727), and 90 years (20·3292%, 14·6888-28·9754). The countries with the highest IFR on July 15, 2020, were Portugal (2·085%, 0·946-4·395), Monaco (1·778%, 1·265-2·915), Japan (1·750%, 1·302-2·690), Spain (1·710%, 0·991-2·718), and Greece (1·637%, 1·155-2·678). All-age IFR varied by a factor of more than 30 among 190 countries and territories. After age standardisation, the countries with the highest IFR on July 15, 2020, were Peru (0·911%, 0·636-1·538), Portugal (0·850%, 0·386-1·793), Oman (0·762%, 0·381-1·399), Spain (0·751%, 0·435-1·193), and Mexico (0·717%, 0·426-1·404). Subnational locations with high IFRs also included hotspots in the UK and southern and eastern states of the USA. Sub-Saharan African countries and Asian countries generally had the lowest all-age and age-standardised IFRs. Population age structure accounted for 74% of logit-scale variation in IFRs estimated for 39 in-sample countries on July 15, 2020. A post-hoc analysis showed that high rates of transmission in the care home population might account for higher IFRs in some locations. Among all countries and territories, we found that the median IFR decreased from 0·466% (interquartile range 0·223-0·840) to 0·314% (0·143-0·551) between April 15, 2020, and Jan 1, 2021.

INTERPRETATION

Estimating the IFR for global populations helps to identify relative vulnerabilities to COVID-19. Information about how IFR varies by age, time, and location informs clinical practice and non-pharmaceutical interventions like physical distancing measures, and underpins vaccine risk stratification. IFR and mortality risk form a J shape with respect to age, which previous research, such as that by Glynn and Moss in 2020, has identified to be a common pattern among infectious diseases. Understanding the experience of a population with COVID-19 mortality requires consideration for local factors; IFRs varied by a factor of more than 30 among 190 countries and territories in this analysis. In particular, the presence of elevated age-standardised IFRs in countries with well resourced health-care systems indicates that factors beyond health-care capacity are important. Potential extenuating circumstances include outbreaks among care home residents, variable burdens of severe cases, and the population prevalence of comorbid conditions that increase the severity of COVID-19 disease. During the pre-vaccine period, the estimated 33% decrease in median IFR over 8 months suggests that treatment for COVID-19 has improved over time. Estimating IFR for the pre-vaccine era provides an important baseline for describing the progression of COVID-19 mortality patterns.

FUNDING

Bill & Melinda Gates Foundation, J Stanton, T Gillespie, and J and E Nordstrom.

Effect of Prone Positioning on Clinical Outcomes of Non-Intubated Subjects With COVID-19

BACKGROUND

Awake prone positioning (APP) has been recently proposed as an adjunctive treatment for non-intubated coronavirus disease 2019 (COVID-19) patients requiring oxygen therapy to improve oxygenation and reduce the risk of intubation. However, the magnitude of the effect of APP on clinical outcomes in these patients remains uncertain. We performed a comparative systematic review and meta-analysis to evaluate the effectiveness of APP to improve the clinical outcomes in non-intubated subjects with COVID-19.

METHODS

The primary outcomes were the need for endotracheal intubation and mortality. The secondary outcome was hospital length of stay. Pooled risk ratio (RR) and mean difference with the corresponding 95% CI were obtained by the Mantel-Haenszel method within a random-effect model.

RESULTS

A total of 14 studies (5 randomized controlled trials [RCTs] and 9 observational studies) involving 3,324 subjects (1,495 received APP and 1,829 did not) were included. There was a significant reduction in the mortality rate in APP group compared to control (RR 0.68 [95% CI 0.51-0.90]; P = .008, I² = 52%) with no significant effect on intubation (RR 0.85 [95% CI 0.66-1.08]; P = .17, I² = 63%) or hospital length of stay (mean difference -3.09 d [95% CI-10.14-3.96]; P = .39, I² = 97%). Subgroup analysis of RCTs showed significant reduction in intubation rate (RR 0.83 [95% CI 0.72-0.97]; P = .02, I² = 0%).

CONCLUSIONS

APP has the potential to reduce the in-hospital mortality rate in COVID-19 subjects with hypoxemia without a significant effect on the need for intubation or length of hospital stay. However, there was a significant decrease in the need for intubation on subgroup analysis of RCTs. More large-scale trials with a standardized protocol for prone positioning are needed to better evaluate its effectiveness in this select population.

Effectiveness of prone position in acute respiratory distress syndrome and moderating factors of obesity class and treatment durations for COVID-19 patients: A Meta-Analysis

Objectives

To examine the effectiveness of prone positioning on COVID-19 patients with acute respiratory distress syndrome with moderating factors in both traditional prone positioning (invasive mechanical ventilation) and awake self-prone positioning patients (non-invasive ventilation).

Research methodology

A comprehensive search was conducted in CINAHL, Cochrane library, Embase, Medline-OVID, NCBI SARS-CoV-2 Resources, ProQuest, Scopus, and Web of Science without language restrictions. All studies with prospective and experimental designs evaluating the effect of prone position patients with COVID-19 related to acute respiratory distress syndrome were included. Pooled standardised mean differences were calculated after prone position for primary (PaO₂/FiO₂) and secondary outcomes (SpO₂ and PaO₂)

Results

A total of 15 articles were eligible and included in the final analysis. Prone position had a statistically significant effect in improving PaO₂/FiO₂ with standardised mean difference of 1.10 (95%CI 0.60–1.59), SpO₂ with standardised mean difference of 3.39 (95% CI 1.30–5.48), and PaO₂ with standardised mean difference of 0.77 (95% CI 0.19–1.35). Patients with higher body mass index and longer duration/day are associated with larger standardised mean difference effect sizes for prone positioning.

Conclusions

Our findings demonstrate that prone position significantly improved oxygen saturation in COVID-19 patients with acute respiratory distress syndrome in both traditional prone positioning and awake self-prone positioning patients. Prone position should be recommended for patients with higher body mass index and longer durations to obtain the maximum effect.

Physiotherapy-assisted prone or modified prone positioning in ward-based patients with COVID-19: a retrospective cohort study

Objectives

To evaluate short-term change in oxygenation and feasibility of physiotherapy-assisted prone or modified prone positioning in awake, ward-based patients with COVID-19.

Design

Retrospective observational cohort study.

Setting

General wards, single-centre tertiary hospital in Australia.

Participants

Patients were included if ≥18 years, had COVID-19, required FiO₂ ≥ 0.28 or oxygen flow rate ≥4 l/minute and consented to positioning. Main outcome measures: Feasibility measures included barriers to therapy, assistance required, and comfort. Short-term change in oxygenation (SpO₂) and oxygen requirements before and 15 minutes after positioning.

Results

Thirteen patients, mean age 75 (SD 14) years; median Clinical Frailty Scale score 6 (IQR 4 to 7) participated in 32 sessions of prone or modified prone positioning from a total of 125 ward-based patients admitted with COVID-19 who received physiotherapy intervention. Nine of thirteen patients (69%) required physiotherapy assistance and modified positions were utilised in 8/13 (62%). SpO2 increased in 27/32 sessions, with a mean increase from 90% (SD 5) pre-positioning to 94% (SD 4) (mean difference 4%; 95%CI 3 to 5%) after 15 minutes. Oxygen requirement decreased in 14/32 sessions, with a mean pre-positioning requirement of 8 l/minute (SD 4) to 7 l/minute (SD 4) (mean difference 2 l/minute; 95%CI 1 to 3 l/minute) after 15 minutes. In three sessions oxygen desaturation and discomfort occurred but resolved immediately by returning supine.

Conclusion

Physiotherapy-assisted prone or modified prone positioning may be a feasible option leading to short-term improvements in oxygenation in awake, ward-based patients with hypoxemia due to COVID-19. Further research exploring longerterm health outcomes and safety is required.

Awake prone positioning in nonintubated spontaneous breathing ICU patients with acute hypoxemic respiratory failure (PRONELIFE)-protocol for a randomized clinical trial

BACKGROUND

It is uncertain whether awake prone positioning can prevent intubation for invasive ventilation in spontaneous breathing critically ill patients with acute hypoxemic respiratory failure. Awake prone positioning could benefit these patients for various reasons, including a reduction in direct harm to lung tissue, and prevention of tracheal intubation-related complications.

DESIGN AND METHODS

The PRONELIFE study is an investigator-initiated, international, multicenter, randomized clinical trial in patients who may need invasive ventilation because of acute hypoxemic respiratory failure. Consecutive patients admitted to participating ICUs are randomly assigned to standard care with awake prone positioning, versus standard care without awake prone positioning. The primary endpoint is a composite of tracheal intubation and all-cause mortality in the first 14 days after enrolment. Secondary endpoints include time to tracheal intubation and effects of awake prone positioning on oxygenation parameters, dyspnea sensation, and complications. Other endpoints are the number of days free from ventilation and alive at 28 days, total duration of use of noninvasive respiratory support, total duration of invasive ventilation, length of stay in ICU and hospital, and mortality in ICU and hospital, and at 28, 60, and 90 days. We will also collect data regarding the tolerance of prone positioning.

DISCUSSION

The PRONELIFE study is among the first randomized clinical trials investigating the effect of awake prone positioning on intubation rate in ICU patients with acute hypoxemic failure from any cause. The PRONELIFE study is sufficiently sized to determine the effect of awake prone positioning on intubation for invasive ventilation-patients are eligible in case of acute hypoxemic respiratory failure without restrictions regarding etiology. The PRONELIFE study is a pragmatic trial in which blinding is impossible-however, as around 35 ICUs worldwide will participate in this study, its findings will be highly generalizable. The findings of the PRONELIFE study have the potential to change clinical management of patients who may need invasive ventilation because of acute hypoxemic respiratory failure.

TRIAL REGISTRATION

ISRCTN ISRCTN11536318 . Registered on 17 September 2021. The PRONELIFE study is registered at clinicaltrials.gov with reference number NCT04142736 (October, 2019).

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

Background

In patients with COVID-19-related acute respiratory failure (ARF), awake prone positioning (AW-PP) reduces the need for intubation in patients treated with high-flow nasal oxygen (HFNO). However, the effects of different exposure times on clinical outcomes remain unclear. We evaluated the effect of AW-PP on the risk of endotracheal intubation and in-hospital mortality in patients with COVID-19-related ARF treated with HFNO and analyzed the effects of different exposure times to AW-PP.

Methods

This multicenter prospective cohort study in six ICUs of 6 centers in Argentine consecutively included patients > 18 years of age with confirmed COVID-19-related ARF requiring HFNO from June 2020 to January 2021. In the primary analysis, the main exposure was awake prone positioning for at least 6 h/day, compared to non-prone positioning (NON-PP). In the sensitivity analysis, exposure was based on the number of hours receiving AW-PP. Inverse probability weighting–propensity score (IPW-PS) was used to adjust the conditional probability of treatment assignment. The primary outcome was endotracheal intubation (ETI); and the secondary outcome was hospital mortality.

Results

During the study period, 580 patients were screened and 335 were included; 187 (56%) tolerated AW-PP for [median (p25–75)] 12 (9–16) h/day and 148 (44%) served as controls. The IPW–propensity analysis showed standardized differences < 0.1 in all the variables assessed. After adjusting for other confounders, the OR (95% CI) for ETI in the AW-PP group was 0.36 (0.2–0.7), with a progressive reduction in OR as the exposure to AW-PP increased. The adjusted OR (95% CI) for hospital mortality in the AW-PP group ≥ 6 h/day was 0.47 (0.19–1.31). The exposure to prone positioning ≥ 8 h/d resulted in a further reduction in OR [0.37 (0.17–0.8)].

Conclusion

In the study population, AW-PP for ≥ 6 h/day reduced the risk of endotracheal intubation, and exposure ≥ 8 h/d reduced the risk of hospital mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03881-2.

Physiotherapy management for COVID-19 in the acute hospital setting and beyond: an update to clinical practice recommendations

This document provides an update to the recommendations for physiotherapy management for adults with coronavirus disease 2019 (COVID-19) in the acute hospital setting. It includes: physiotherapy workforce planning and preparation; a screening tool for determining requirement for physiotherapy; and recommendations for the use of physiotherapy treatments and personal protective equipment. New advice and recommendations are provided on: workload management; staff health, including vaccination; providing clinical education; personal protective equipment; interventions, including awake proning, mobilisation and rehabilitation in patients with hypoxaemia. Additionally, recommendations for recovery after COVID-19 have been added, including roles that physiotherapy can offer in the management of post-COVID syndrome. The updated guidelines are intended for use by physiotherapists and other relevant stakeholders caring for adult patients with confirmed or suspected COVID-19 in the acute care setting and beyond.

Blood circulation changes associated with switching to non-invasive ventilation in COVID-19 patients

Background. Various methods of respiratory support in combination with prone positioning have been used during the COVID-19 pandemic. The effects of combination of these two factors on hemodynamics are of interest for clinical practitioners.The aim: to evaluate the effect of prone positioning on hemodynamics in COVID-19 patients depending on the method of respiratory support.Materials and methods. The study included 17 patients of both sexes diagnosed with COVID-19-associated community-acquired polysegmental viral and bacterial pneumonia with progressive respiratory failure. The study consisted of two stages. During the first stage, the patients were receiving respiratory support with humidified oxygen (3–7 liters per minute). The second stage was initiated after switching to noninvasive ventilation (NIV). The measurements were performed using a technique of volumetric compression oscillometry on a non-invasive hemodynamic monitoring system KAP CGosm-Globus (Russia).Results. The study showed that prone positioning in patients with severe COVID-19 when switching from oxygen therapy to NIV resulted in a change in the diastolic blood pressure difference module from 2.5 (1.0; 8.2) to 8.0 (5.7; 14.0) (p = 0.016). Escalation of respiratory support led to the changes in the left ventricular outflow tract velocity difference module from 11.5 (9.5; 34.2) to 31.0 (15.7; 42.0) (p = 0.049).Conclusions. Patients with community-acquired polysegmental viral and bacterial pneumonia associated with COVID-19 demonstrated changes in diastolic blood pressure and left ventricular outflow tract velocity as a result of prone positioning following switching from oxygen therapy to NIV.

Prone positioning for non-intubated hypoxemic patients with COVID-19: cheap, easy, and makes sense, but does it work?

Since the 1970s, prone positioning has been proposed as an inexpensive and physiologically justified management strategy for patients with acute respiratory distress syndrome (ARDS). The physiological rationale for prone positioning in ARDS has been well described [1,2]. Placing a person in the prone position reduces lung compression, which facilitates better ventilation/perfusion matching and leads to improved oxygenation. However, determining whether patients receive clinically meaningful benefit from prone positioning in the form of reduced mortality or time supported on mechanical ventilation has been challenging. Early trials that used prone positioning as a “rescue” therapy or applied relatively small “doses” of prone positioning (i.e. limited duration of time in prone position) did not demonstrate improvements in mortality or ventilator-free days (VFDs) [3–5].

This editorial evaluates a large observational study that identified strong associations between awake prone positioning and decreased mortality in hospitalised patients with COVID-19https://bit.ly/3m3NeAx

Impact of prone position on outcomes of COVID-19 patients with spontaneous breathing

Background

In this study, we explored whether early application of the prone position (PP) can improve severe hypoxemia and respiratory failure in coronavirus disease 2019 (COVID-19) patients with spontaneous breathing.

Methods

This is a prospective observational study of severe, critically ill adult COVID-19 patients admitted to the intensive care unit. All vital parameters were recorded in real time for all patients. Moreover, the results of chest computed tomography (CT), when available, were analyzed.

Results

PP was applied in 21 patients who were breathing spontaneously. The application of PP was associated with a significant increase in oxygen saturation measured by pulse oximetry (SpO₂) from 82%±12% to 96%±3% (P<0.001) 1 hour later. Moreover, PP was associated with a significant reduction in respiratory rate from 31±10 to 21±4 breaths/min (P<0.001). Furthermore, the number of patients who exhibited signs of respiratory distress after PP was reduced from 10 (47%) to 3 (14%) (P=0.04). Early PP application also led to a clear improvement on CT imaging. It was not, however, associated with a reduction in mortality rate or in the use of invasive mechanical ventilation (P>0.05 for both).

Conclusions

Our study confirmed that the early application of PP can improve hypoxemia and tachypnea in COVID-19 patients with spontaneous breathing. Randomized controlled trials are needed to confirm the beneficial effects of PP in COVID-19 patients with spontaneous breathing.

Response of patients with acute respiratory failure caused by COVID-19 to awake-prone position outside the intensive care unit based on pulmonary involvement

OBJECTIVES

Since there are difficulties in establishing effective treatments for COVID-19, a vital way to reduce mortality is an early intervention to prevent disease progression. This study aimed to evaluate the performance of patients with COVID-19 with acute hypoxic respiratory failure according to pulmonary impairment in the awake-prone position, outside of the intensive care unit (ICU).

METHODS

A prospective observational cohort study was conducted on COVID-19 patients under noninvasive respiratory support. Clinical and laboratory data were obtained for each patient before the treatment and after they were placed in the awake-prone position. To identify responders and non-responders after the first prone maneuver, receiver operating characteristic curves with sensitivity and specificity of the PaO2/FiO2 and SpO2/FiO2 indices were analyzed. The maneuver was considered positive if the patient did not require endotracheal intubation for ventilatory assistance.

RESULTS

Forty-eight patients were included, and 64.6% were categorized as responders. The SpO2/FiO2 index was effective for predicting endotracheal intubation in COVID-19 patients regardless of lung parenchymal damage (area under the curve 0.84, cutoff point 165, sensitivity 85%, specificity 75%). Responders had better outcomes with lower hospital mortality (hazard ratio [HR]=0.107, 95% confidence interval [CI]: 0.012-0.93) and a shorter length of stay (median difference 6 days, HR=0.30, 95% CI: 0.13-0.66) after adjusting for age, body mass index, sex, and comorbidities.

CONCLUSIONS

The awake-prone position for COVID-19 patients outside the ICU can improve oxygenation and clinical outcomes regardless of the extent of pulmonary impairment. Furthermore, the SpO2/FiO2 index discriminates responders from non-responders to the prone maneuver predicting endotracheal intubation with a cutoff under or below 165.