Prone position in ARDS patients: why, when, how and for whom

Inflammatory lung injury is associated with endothelial cell mitochondrial fission and requires the nitration of RhoA and cytoskeletal remodeling

Higher levels of extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a TLR4 agonist, are associated with poor clinical outcomes in sepsis-induced acute lung injury (ALI). Little is known regarding the mechanisms by which eNAMPT is involved in ALI. Our recent work has identified a crucial role for mitochondrial dysfunction in ALI. Thus, this study aimed to determine if eNAMPT-mediated inflammatory injury is associated with the loss of mitochondrial function. Our data show that eNAMPT disrupted mitochondrial bioenergetics. This was associated with cytoskeleton remodeling and the loss of endothelial barrier integrity. These changes were associated with enhanced mitochondrial fission and blocked when Rho-kinase (ROCK) was inhibited. The increases in mitochondrial fission were also associated with the nitration-mediated activation of the small GTPase activator of ROCK, RhoA. Blocking RhoA nitration decreased eNAMPT-mediated mitochondrial fission and endothelial barrier dysfunction. The increase in fission was linked to a RhoA-ROCK mediated increase in Drp1 (dynamin-related protein 1) at serine(S)616. Another TLR4 agonist, lipopolysaccharide (LPS), also increased mitochondrial fission in a Drp1 and RhoA-ROCK-dependent manner. To validate our findings in vivo, we challenged C57BL/6 mice with eNAMPT in the presence and absence of the Drp1 inhibitor, Mdivi-1. Mdivi-1 treatment protected against eNAMPT-induced lung inflammation, edema, and lung injury. These studies demonstrate that mitochondrial fission-dependent disruption of mitochondrial function is essential in TLR4-mediated inflammatory lung injury and identify a key role for RhoA-ROCK signaling. Reducing mitochondrial fission could be a potential therapeutic strategy to improve ARDS outcomes.

Upper limb peripheral nerve injuries in patients with ARDS requiring prone positioning: A systematic review with proportion meta-analysis

OBJECTIVE

To investigate the prevalence of upper limb peripheral nerve injuries (PNI) in adult patients admitted to the intensive care unit (ICU) with acute respiratory distress syndrome (ARDS) undergoing prone positioning.

METHODS

This systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines. Four electronic databases including PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), The Cochrane Library, and EMBASE were searched from inception to January 2024. The quality of the included studies was evaluated according to the Joanna Briggs Institute Critical Appraisal Tools. A proportion meta-analysis was conducted to examine the combined prevalence of upper limb PNI among patients requiring prone positioning.

RESULTS

A total of 8 studies (511 patients) were pooled in the quantitative analysis. All studies had a low or moderate risk of bias in methodological quality. The overall proportion of patients with upper limb PNI was 13% (95%CI: 5% to 29%), with large between-study heterogeneity (I2 = 84.6%, P<0.001). Both ulnar neuropathy and brachial plexopathy were described in 4 studies.

CONCLUSION

During the COVID-19 pandemic, prone positioning has been used extensively. Different approaches among ICU teams and selective reporting by untrained staff may be a factor in interpreting the large variability between studies and the 13% proportion of patients with upper limb PNI found in the present meta-analysis. Therefore, it is paramount to stress the importance of patient assessment both after discharge from the ICU and during subsequent follow-up evaluations.

IMPLICATIONS FOR CLINICAL PRACTICE

Specialized training is essential to ensure safe prone positioning, with careful consideration given to arms and head placement to mitigate potential nerve injuries. Therefore, healthcare protocols should incorporate preventive strategies, with patient assessments conducted by expert multidisciplinary teams.

Longer ICU stay and invasive mechanical ventilation accelerate telomere shortening in COVID-19 patients 1 year after recovery

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes virus-induced-senescence. There is an association between shorter telomere length (TL) in coronavirus disease 2019 (COVID-19) patients and hospitalization, severity, or even death. However, it remains unknown whether virus-induced-senescence is reversible. We aim to evaluate the dynamics of TL in COVID-19 patients 1 year after recovery from intensive care units (ICU). Longitudinal study enrolling 49 patients admitted to ICU due to COVID-19 (August 2020 to April 2021). Relative telomere length (RTL) quantification was carried out in whole blood by monochromatic multiplex real-time quantitative PCR (MMqPCR) assay at hospitalization (baseline) and 1 year after discharge (1-year visit). The association between RTL and ICU length of stay (LOS), invasive mechanical ventilation (IMV), prone position, and pulmonary fibrosis development at 1-year visit was evaluated. The median age was 60 years, 71.4% were males, median ICU-LOS was 12 days, 73.5% required IMV, and 38.8% required a prone position. Patients with longer ICU-LOS or who required IMV showed greater RTL shortening during follow-up. Patients who required pronation had a greater RTL shortening during follow-up. IMV patients who developed pulmonary fibrosis showed greater RTL reduction and shorter RTL at the 1-year visit. Patients with longer ICU-LOS and those who required IMV had a shorter RTL in peripheral blood, as observed 1 year after hospital discharge. Additionally, patients who required IMV and developed pulmonary fibrosis had greater telomere shortening, showing shorter telomeres at the 1-year visit. These patients may be more prone to develop cellular senescence and lung-related complications; therefore, closer monitoring may be needed.

Effects of sitting position on ventilation distribution determined by electrical impedance tomography in ventilated ARDS patients

OBJECTIVE

The study aimed to evaluate the improvements in pulmonary ventilation following a sitting position in ventilated ARDS patients using electrical impedance tomography.

METHODOLOGY

A total of 17 patients with ARDS under mechanical ventilation participated in this study, including 8 with moderate ARDS and 9 with severe ARDS. Each patient was initially placed in the supine position (S1), transitioned to sitting position (SP) for 30 min, and then returned to the supine position (S2). Patients were monitored for each period, with parameters recorded.

MAIN OUTCOME MEASURES

The primary outcome included the spatial distribution parameters of EIT, regional of interest (ROI), end-expiratory lung impedance (ΔEELI), and parameters of respiratory mechanics.

RESULTS

Compared to S1, the SP significantly altered the distribution in ROI1 (11.29 ± 4.70 vs 14.88 ± 5.00 %, p = 0.003) and ROI2 (35.59 ± 8.99 vs 44.65 ± 6.97 %, p ＜ 0.001), showing reductions, while ROI3 (39.71 ± 11.49 vs 33.06 ± 6.34 %, p = 0.009), ROI4 (13.35 ± 8.76 vs 7.24 ± 5.23 %, p ＜ 0.001), along with peak inspiratory pressure (29.24 ± 3.96 vs 27.71 ± 4.00 cmH2O, p = 0.036), showed increases. ΔEELI decreased significantly ventrally (168.3 (40.33 - 189.5), p ＜ 0.0001) and increased significantly dorsally (461.7 (297.5 - 683.7), p ＜ 0.0001). The PaO2/FiO2 ratio saw significant improvement in S2 compared to S1 after 30 min in the seated position (108 (73 - 130) vs 96 (57 - 129) mmHg, p = 0.03).

CONCLUSIONS

The sitting position is associated with enhanced compliance, improved oxygenation, and more homogenous ventilation in patients with ventilated ARDS compared to the supine position.

IMPLICATIONS FOR CLINICAL PRACTICE

It is important to know the impact of postural changes on patient pulmonary ventilation in order to standardize safe practices in critically ill patients. It may be helpful in the management among ventilated patients.

Duration of the first prone positioning maneuver and its association with 90-day mortality in patients with acute respiratory failure due to COVID-19: A retrospective study of time terciles

OBJECTIVE

To investigate the association between the duration of the first prone positioning maneuver (PPM) and 90-day mortality in patients with C-ARDS.

DESIGN

Retrospective, observational, and analytical study.

SETTING

COVID-19 ICU of a tertiary hospital.

PATIENTS

Adults over 18 years old, with a confirmed diagnosis of SARS-CoV-2 disease requiring PPM.

INTERVENTIONS

Multivariable analysis of 90-day survival.

MAIN VARIABLES OF INTEREST

Duration of the first PPM, number of PPM sessions, 90-day mortality.

RESULTS

271 patients undergoing PPM were analyzed: first tertile (n = 111), second tertile (n = 95) and third tertile (n = 65). The results indicated that the median duration of PDP was 14 h (95% CI: 10-16 h) in the first tertile, 19 h (95% CI: 18-20 h) in the second tertile and 22 h (95% CI: 21-24 h) in the third tertile. Comparison of survival curves using the Logrank test did not reach statistical significance (p = 0.11). Cox Regression analysis showed an association between the number of pronation sessions (patients receiving between 2 and 5 sessions (HR = 2.19; 95% CI: 1.07-4.49); and those receiving more than 5 sessions (HR = 6.05; 95% CI: 2.78-13.16) and 90-day mortality.

CONCLUSIONS

while the duration of PDP does not appear to significantly influence 90-day mortality, the number of pronation sessions is identified as a significant factor associated with an increased risk of mortality.

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.

Adverse Events during Prone Positioning of Patients with COVID-19 during a Surge in Hospitalizations-Results of an Observational Study

This study aimed to determine the prevalence of adverse events in mechanically ventilated adults with COVID-19 who have undergone prone positioning. A total of 100 patients were included retrospectively; 60% were males, the mean age was 64.8 ± 9.1 years, and hospital mortality was 47%. In all, we recorded 118 removals of catheters and tubes in 66 patients; 29.6% were removals of a nasogastric tube, 18.6% of an arterial line, 14.4% of a urinary catheter, and 12.7% of a central venous catheter. Reintubation or repositioning of a tracheotomy tube was required in 19 patients (16.1%), and cardiopulmonary resuscitation in 2 patients (1.7%). We recorded a total of 184 pressure ulcers in 79 patients (on anterior face in 38.5%, anterior thorax in 23.3% and any extremity anteriorly in 15.2%). We observed that body weight (p = 0.021; β = 0.09 (CI95: 0.01-0.17)) and the cumulative duration of prone positioning (p = 0.005; β = 0.06 (CI95: 0.02-0.11)) were independently associated with the occurrence of any adverse event. The use of prone positioning in our setting was associated with a greater number of adverse events than previously reported. Body weight and cumulative duration of prone positioning were associated with the occurrence of adverse events; however, other factors during a COVID-19 surge, such as working conditions, staffing, and staff education, could also have contributed to a high prevalence of adverse events.

Maternal posture-physiology interactions in human pregnancy: a narrative review

There are several well-known medical conditions in which posture and gravity interact with natural history, including pregnancy. In this review, we provide a comprehensive overview of interactions between maternal posture and maternal physiology and pathophysiology at rest during pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 644 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We present a narrative review of the resulting literature and highlight discrepancies, research gaps, and potential clinical implications. We organize the results by organ system and, commencing with the neurological system, proceed in our synthesis generally in the craniocaudal direction, concluding with the skin. The circulatory system warranted our greatest and closest consideration-literature concerning the dynamic interplay between physiology (heart rate, stroke volume, cardiac output, blood pressure, and systemic vascular resistance), pathophysiology (e.g., hypertension in pregnancy), and postural changes provide an intricate and fascinating example of the importance of the subject of this review. Other organ systems discussed include respiratory, renal, genitourinary, gastrointestinal, abdominal, and endocrine. In addition to summarizing the existing literature on maternal posture-physiology interactions, we also point out gaps and opportunities for further research and clinical developments in this area. Overall, our review provides both insight into and relevance of maternal posture-physiology interactions vis à vis healthcare's mission to improve health and wellness during pregnancy and beyond.

Using the sympathetic system, beta blockers and alpha-2 agonists, to address acute respiratory distress syndrome

Acute Respiratory Distress Syndrome (ARDS) manifests as an acute inflammatory lung injury characterized by persistent hypoxemia, featuring a swift onset, high mortality, and predominantly supportive care as the current therapeutic approach, while effective treatments remain an area of active investigation. Adrenergic receptors (AR) play a pivotal role as stress hormone receptors, extensively participating in various inflammatory processes by initiating downstream signaling pathways. Advancements in molecular biology and pharmacology continually unveil the physiological significance of distinct AR subtypes. Interventions targeting these subtypes have the potential to induce specific alterations in cellular and organismal functions, presenting a promising avenue as a therapeutic target for managing ARDS. This article elucidates the pathogenesis of ARDS and the basic structure and function of AR. It also explores the relationship between AR and ARDS from the perspective of different AR subtypes, aiming to provide new insights for the improvement of ARDS.

Recruitment-to-inflation ratio for bedside PEEP selection in acute respiratory distress syndrome

In acute respiratory distress syndrome, the role of positive end-expiratory pressure (PEEP) to prevent ventilator-induced lung injury is controversial. Randomized trials comparing higher versus lower PEEP strategies failed to demonstrate a clinical benefit. This may depend on the inter-individually variable potential for lung recruitment (i.e. recruitability), which would warrant PEEP individualization to balance alveolar recruitment and the unavoidable baby lung overinflation produced by high pressure. Many techniques have been used to assess recruitability, including lung imaging, multiple pressure-volume curves and lung volume measurement. The Recruitment-to-Inflation ratio (R/I) has been recently proposed to bedside assess recruitability without additional equipment. R/I assessment is a simplified technique based on the multiple pressure-volume curve concept: it is measured by monitoring respiratory mechanics and exhaled tidal volume during a 10-cmH2O one-breath derecruitment maneuver after a short high-PEEP test. R/I scales recruited volume to respiratory system compliance, and normalizes recruitment to a proxy of actual lung size. With modest R/I (<0.3-0.4), setting low PEEP (5-8 cmH2O) may be advisable; with R/I>0.6-0.7, high PEEP (≥15 cmH2O) can be considered, provided that airway and/or transpulmonary plateau pressure do not exceed safety limits. In case of intermediate R/I (≈0.5), a more granular assessment of recruitability may be needed. This could be accomplished with advanced monitoring tools, like sequential lung volume measurement with granular R/I assessment or electrical impedance tomography monitoring during a decremental PEEP trial. In this review, we discuss R/I rationale, applications and limits, providing insights on its clinical use for PEEP selection in moderate-to-severe acute respiratory distress syndrome.

Changes in pulmonary mechanics from supine to prone position measured through esophageal manometry in critically ill patients with COVID-19 severe acute respiratory distress syndrome

OBJECTIVE

To describe changes in pulmonary mechanics when changing from supine position (SP) to prone position (PP) in mechanically ventilated (MV) patients with Acute Respiratory Distress Syndrome (ARDS) due to severe COVID-19.

DESIGN

Retrospective cohort.

SETTING

Intensive Care Unit of the National Institute of Respiratory Diseases (Mexico City).

PATIENTS

COVID-19 patients on MV due to ARDS, with criteria for PP.

INTERVENTION

Measurement of pulmonary mechanics in patients on SP to PP, using esophageal manometry.

MAIN VARIABLES OF INTEREST

Changes in lung and thoracic wall mechanics in SP and PP RESULTS: Nineteen patients were included. Changes during first prone positioning were reported. Reductions in lung stress (10.6 vs 7.7, p=0.02), lung strain (0.74 vs 0.57, p=0.02), lung elastance (p=0.01), chest wall elastance (p=0.003) and relation of respiratory system elastances (p=0.001) were observed between patients when changing from SP to PP. No differences were observed in driving pressure (p=0.19) and transpulmonary pressure during inspiration (p=0.70).

CONCLUSIONS

Changes in pulmonary mechanics were observed when patients were comparing values of supine position with measurements obtained 24h after prone positioning. Esophageal pressure monitoring may facilitate ventilator management despite patient positioning.

The effect of different bed head angles on the hemodynamic parameters of intensive care patients lying in the supine position: A quasi-experimental study

AIMS

The aim of this study was to research the effect of different bed head angles on the hemodynamic parameters of intensive care patients lying in the supine position.

METHODS

This study was a non-randomized and non-controlled, quasi-experimental repeated measures study. The study was conducted with 50 intensive care patients aged 18 and over in a general surgery intensive care unit in Turkey. With each patient in the supine position, the bed head was raised to an angle of 0°, 20°, 30°, and 45° without a pillow, and the hemodynamic parameters of central venous pressure, systolic and diastolic blood pressure, heart rate, breathing rate, and peripheral oxygen saturation were recorded after 0 and 10 min.

RESULTS

It was found that the mean central venous pressure value measured at min 0 and 10 was higher when the intensive care patients' bed head angle was raised to 45° than when the bed head was at an angle of 0° or 20° (p < .05). It was found that the patients' other hemodynamic parameters were not affected by different bed head angles.

CONCLUSIONS

It was concluded as a result of this research that in intensive care patients in the supine position, only central venous pressure was affected by bed head angle, and that central venous pressure measurement can be reliably made at a bed head angle of 30°.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Carbon Dioxide Targets in Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome

Target values for arterial carbon dioxide tension (PaCO2) in extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) are unknown. We hypothesized that lower PaCO2 values on ECMO would be associated with lighter sedation. We used data from two independent patient cohorts with ARDS spending 1,177 days (discovery cohort, 69 patients) and 516 days (validation cohort, 70 patients) on ECMO and evaluated the associations between daily PaCO2, pH, and bicarbonate (HCO3) with sedation. Median PaCO2 was 41 (interquartile range [IQR] = 37-46) mm Hg and 41 (IQR = 37-45) mm Hg in the discovery and the validation cohort, respectively. Lower PaCO2 and higher pH but not bicarbonate (HCO3) served as significant predictors for reaching a Richmond Agitation Sedation Scale (RASS) target range of -2 to +1 (lightly sedated to restless). After multivariable adjustment for mortality, tracheostomy, prone positioning, vasoactive inotropic score, Simplified Acute Physiology Score (SAPS) II or Sequential Organ Failure Assessment (SOFA) Score and day on ECMO, only PaCO2 remained significantly associated with the RASS target range (adjusted odds ratio 1.1 [95% confidence interval (CI) = 1.01-1.21], p = 0.032 and 1.29 [95% CI = 1.1-1.51], p = 0.001 per mm Hg decrease in PaCO2 for the discovery and the validation cohort, respectively). A PaCO2 ≤40 mm Hg, as determined by the concordance probability method, was associated with a significantly increased probability of a sedation level within the RASS target range in both patient cohorts (adjusted odds ratio = 2.92 [95% CI = 1.17-7.24], p = 0.021 and 6.82 [95% CI = 1.50-31.0], p = 0.013 for the discovery and the validation cohort, respectively).

[Clinical study of prone positioning in invasive respiratory support for neonatal respiratory distress syndrome]

OBJECTIVES

To assess the effectiveness and safety of prone positioning in the treatment of neonatal respiratory distress syndrome (NRDS) using invasive respiratory support.

METHODS

A prospective study was conducted from June 2020 to September 2023 at Suining County People's Hospital, involving 77 preterm infants with gestational ages less than 35 weeks requiring invasive respiratory support for NRDS. The infants were randomly divided into a supine group (37 infants) and a prone group (40 infants). Infants in the prone group were ventilated in the prone position for 6 hours followed by 2 hours in the supine position, continuing in this cycle until weaning from the ventilator. The effectiveness and safety of the two approaches were compared.

RESULTS

At 6 hours after enrollment, the prone group showed lower arterial blood carbon dioxide levels, inspired oxygen concentration, oxygenation index, rates of tracheal intubation bacterial colonization, and Neonatal Pain, Agitation and Sedation Scale scores compared to the supine group (P<0.05). There were no significant differences between the groups in terms of pH, arterial oxygen pressure, positive end-expiratory pressure, duration of mechanical ventilation, accidental extubation, ventilator-associated pneumonia, air leak syndrome, skin pressure sores, feeding intolerance, and grades II-IV intraventricular hemorrhage (P>0.05).

CONCLUSIONS

Compared to supine positioning, prone ventilation effectively improves oxygenation, increases comfort, and reduces tracheal intubation bacterial colonization in neonates requiring mechanical ventilation for NRDS, without significantly increasing adverse reactions.

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).

Real-Time Camera Image-Guided Nasoenteric Tube Placement in Prone COVID-19 ICU Patients: A Single-Center Study

Background & Aims: This study aims to assess the application value of the real-time camera image-guided nasoenteric tube placement in critically ill COVID-19 patients undergoing endotracheal intubation and prone position ventilation therapy. Methods: We enrolled 116 COVID-19 patients receiving endotracheal intubation and prone position ventilation therapy in the intensive care unit (ICU). Patients were randomly divided into the real-time camera image-guided nasoenteric tube placement (n = 58) and bedside blind insertion (n = 58) groups. The success rate, placement time, complications, cost, heart rate, respiratory rate, Glasgow Coma Scale (GCS), and Acute Physiology and Chronic Health Evaluation II (APACHE-II) scores were compared between the 2 groups. Results: For ICU patients with COVID-19 undergoing prone position ventilation therapy, the success rate and cost were significantly higher in the real-time camera image-guided group compared to the bedside blind group (P < .05). The placement time and complication incidence were significantly lower in the real-time camera image-guided group (P < .05). The differences in heart rate, respiratory rate, GCS scores, and APACHE-II scores were insignificant (P > .05). Conclusions: The real-time camera image-guided nasoenteric tube placement system had advantages for ICU COVID-19 patients undergoing prone position ventilation therapy, including a high success rate, short placement time, and no impact on patient position during tube placement. Real-time camera image-guided nasoenteric tube placement can be performed in any position, and demonstrates high efficiency, safety, and accuracy.

The occurrence of pressure injuries and related risk factors in patients undergoing extracorporeal membrane oxygenation for respiratory failure: A retrospective single centre study

INTRODUCTION

Limited data is available regarding the incidence of pressure injuries in patients who have undergone Extracorporeal Membrane Oxygenation (ECMO), a life-saving technique that provides respiratory support for hypoxemia that does not respond to conventional treatment.

AIM

To assess the incidence of pressure injuries and identify the risk factors in Acute Respiratory Distress Syndrome patients receiving ECMO.

METHODS

A retrospective observational study utilizing prospectively collected data was performed in an Italian intensive care unit, between 1 January 2012 and 30 April 2022 enrolling all consecutive patients with Acute Respiratory Distress Syndrome who underwent ECMO.

RESULTS

One hundred patients were included in this study. 67 patients (67%) developed pressure injuries during their intensive care unit stay, with a median of 2 (1-3) sites affected. The subgroup of patients with pressure injuries was more hypoxic before ECMO implementation, received more frequent continuous renal replacement therapy and prone positioning, and showed prolonged ECMO duration, intensive care unit and hospital length of stay compared to patients without pressure injuries. The logistic model demonstrated an independent association between the pO2/FiO2 ratio prior to ECMO initiation, the utilization of the prone positioning during ECMO, and the occurrence of pressure injuries.

CONCLUSIONS

The incidence of pressure injuries was elevated in patients with Adult Respiratory Distress Syndrome who received ECMO. The development of pressure injuries was found to be independently associated with hypoxemia before ECMO initiation and the utilization of prone positioning during ECMO.

IMPLICATIONS FOR CLINICAL PRACTICE

Patients who require ECMO for respiratory failure are at a high risk of developing pressure injuries. To ensure optimal outcomes during ECMO implementation and treatment, it is vital to implement preventive measures and to closely monitor skin health in at-risk areas.

Early pathophysiology-driven airway pressure release ventilation versus low tidal volume ventilation strategy for patients with moderate-severe ARDS: study protocol for a randomized, multicenter, controlled trial

BACKGROUND

Conventional Mechanical ventilation modes used for individuals suffering from acute respiratory distress syndrome have the potential to exacerbate lung injury through regional alveolar overinflation and/or repetitive alveolar collapse with shearing, known as atelectrauma. Animal studies have demonstrated that airway pressure release ventilation (APRV) offers distinct advantages over conventional mechanical ventilation modes. However, the methodologies for implementing APRV vary widely, and the findings from clinical studies remain controversial. This study (APRVplus trial), aims to assess the impact of an early pathophysiology-driven APRV ventilation approach compared to a low tidal volume ventilation (LTV) strategy on the prognosis of patients with moderate to severe ARDS.

METHODS

The APRVplus trial is a prospective, multicenter, randomized clinical trial, building upon our prior single-center study, to enroll 840 patients from at least 35 hospitals in China. This investigation plans to compare the early pathophysiology-driven APRV ventilation approach with the control intervention of LTV lung-protective ventilation. The primary outcome measure will be all-cause mortality at 28 days after randomization in the intensive care units (ICU). Secondary outcome measures will include assessments of oxygenation, and physiology parameters at baseline, as well as on days 1, 2, and 3. Additionally, clinical outcomes such as ventilator-free days at 28 days, duration of ICU and hospital stay, ICU and hospital mortality, and the occurrence of adverse events will be evaluated.

TRIAL ETHICS AND DISSEMINATION

The research project has obtained approval from the Ethics Committee of West China Hospital of Sichuan University (2019-337). Informed consent is required. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.

TRIAL REGISTRATION

The study was registered at Clinical Trials.gov (NCT03549910) on June 8, 2018.

Effect of Extended Prone Positioning in Intubated COVID-19 Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

INPLASY REGISTRATION NUMBER

INPLASY202390072.

Case report: Prone positioning in the improvement of severe post-operative hypoxia following aortic dissection

Postoperative hypoxemia after aortic dissection surgery presents a considerable clinical challenge, and acute respiratory distress syndrome (ARDS) is a common etiology. Prone positioning treatment has emerged as a potential intervention for improving respiratory function in this context. We report the case of a 27-year-old male who developed severe hypoxemia complicated by pulmonary embolism after aortic dissection surgery. He was diagnosed with postoperative hypoxemia combined with pulmonary embolism following aortic dissection. His respiratory status continued to deteriorate despite receiving standard postoperative care, thereby necessitating an alternative approach. Implementation of prone positioning treatment led to a substantial amelioration in his oxygenation and overall respiratory health, with a consistent hemodynamic state observed throughout the treatment. This technique resulted in significant relief in symptoms and improvement in respiratory parameters, facilitating successful extubation and, ultimately, discharge. This case underlines the possible efficacy of prone positioning therapy in managing severe hypoxia complicated by pulmonary embolism following aortic dissection surgery, warranting more thorough research to explore the potential of this treatment modality.

Multidisciplinary Consensus on the Management of Non-Invasive Respiratory Support in the COVID-19 Patient

Acute respiratory failure due to COVID-19 pneumonia often requires a comprehensive approach that includes non-pharmacological strategies such as non-invasive support (including positive pressure modes, high flow therapy or awake proning) in addition to oxygen therapy, with the primary goal of avoiding endotracheal intubation. Clinical issues such as determining the optimal time to initiate non-invasive support, choosing the most appropriate modality (based not only on the acute clinical picture but also on comorbidities), establishing criteria for recognition of treatment failure and strategies to follow in this setting (including palliative care), or implementing de-escalation procedures when improvement occurs are of paramount importance in the ongoing management of severe COVID-19 cases. Organizational issues, such as the most appropriate setting for management and monitoring of the severe COVID-19 patient or protective measures to prevent virus spread to healthcare workers in the presence of aerosol-generating procedures, should also be considered. While many early clinical guidelines during the pandemic were based on previous experience with acute respiratory distress syndrome, the landscape has evolved since then. Today, we have a wealth of high-quality studies that support evidence-based recommendations to address these complex issues. This document, the result of a collaborative effort between four leading scientific societies (SEDAR, SEMES, SEMICYUC, SEPAR), draws on the experience of 25 experts in the field to synthesize knowledge to address pertinent clinical questions and refine the approach to patient care in the face of the challenges posed by severe COVID-19 infection.

Enhancing prone positioning and skin damage prevention education: A randomized controlled non-inferiority trial comparing a digital education hub (PRONEtect) and a traditional lecture on final-year nursing participants' confidence and knowledge

INTRODUCTION

The incidence of pressure ulcers remains high in patients with moderate to severe acute respiratory distress syndrome, ventilated in the prone position. A digital platform, dedicated to prone positioning and skin/tissue damage education was developed.

OBJECTIVE

To evaluate the impact of the PRONEtect Education Hub versus a traditional lecture on final-year nursing students' confidence levels and knowledge in a non-inferiority study.

DESIGN

A multicenter, non-blinded, parallel-group, non-inferiority study with equal randomization (1:1 allocation) was conducted at two nursing schools in Belgium.

CLINICALTRIALS

gov (NCT05575869).

METHODS

Following baseline assessments, the control group received a 1-h classroom lecture, and the experimental group gained access to the PRONEtect website. Three weeks later, participants completed the knowledge, confidence, and visual knowledge assessment.

RESULTS

At baseline, 67 of the 80 participants completed the assessments and post-intervention, 28 and 27 participants respectively completed the confidence, knowledge, and visual knowledge assessments (dropout rate of 66.25%). Confidence levels: a mean ratio of relative change from baseline = 0.96 (Control (C)/Experimental (E)); 97.5% confidence interval (CI): 0.74 to 1.26; p = 0.74. Knowledge assessment: a mean difference in change from baseline = 1.58 (C-E); 97.5% CI: -0.58 to 3.75; p = 0.1. Although confidence and knowledge scores increased in both groups, the study cannot conclude non-inferiority.

CONCLUSIONS

The trade-off between the inability to conclude efficacy of the impact of the website and the benefit of having an accessible educational platform on prone positioning and skin damage prevention makes the PRONEtect Education Hub an acceptable adjunct to traditional lecturing.

Hemodialysis vascular access in prone position for critically ill patients with ARDS

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is defined in critically ill patients with acute hypoxemia and positive-pressure ventilation in association with several clinical disorders including trauma, pneumonia, sepsis, and aspiration. The prone position has been used for many years and is now recommended for patients with severe or moderate-to-severe ARDS on invasive mechanical ventilation. Acute kidney injury (AKI) is a common complication in patients with ARDS, with up to a 35% incidence rate. Initiation of Kidney Replacement Therapy (KRT) requires wise clinical judgment and collaboration between nephrologists and intensivists. A properly functioning vascular access is critical for an optimized KRT. Our institute is a national referral center for respiratory diseases.

RESULTS

We describe 11 cases of dialysis catheter placement for KRT in critically ill patients with ARDS on mechanical ventilation in prone position. The catheter was placed in the first puncture attempt in nine cases, Blood flows (Qb) achieved were 283.4 ± 20.4 ml/min during the session, in six cases the radiologic tip location was achieved in the peri cavoatrial junction; in four cases was achieved in mid to- deep right atrium. The dialysis quality standards were based on KTV and in URR; in nine cases (81.81%) KTV was in 1.3 and in all cases (100%) URR was >65%, lumen dysfunction was reported only in two cases (18.1%), but these cases did respond to mobilization maneuvers. The procedure time of placement was 29.8 min, no arterial punctures or complications were reported.

CONCLUSIONS

We demonstrate that in our study hemodialysis non-tunneled catheter placement in the prone position is safe and effective. We believe this practice could be frequently used in the near future and represent an opportunity window for the training of interventional nephrologists and related areas.

Efficacy of respiratory rehabilitation in patients with COVID-19: a retrospective study

OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic has resulted in millions of confirmed cases and deaths globally. The purpose of this study was to investigate the therapeutic effect of airway clearance technology combined with prone ventilation on patients infected with COVID-19.

METHODS

38 patients with COVID-19 (severe) who were treated in the intensive rehabilitation group of Shengli Oilfield Central Hospital. They were randomly divided into a control group and an observation group. The control group received prone position ventilation intervention, and the observation group received airway clearance technology combined with prone position ventilation intervention. The changes of oxygen and index, procalcitonin (PCT), interleukin-6 (IL-6) and chest X-ray image indexes were compared between the two groups.

RESULT

There was no significant difference in age, gender and other general data between the control group and the observation group. The results showed that oxygen index, PCT, IL-6 and chest X-ray image index in the observation group were better than that indexes in the control group.

CONCLUSION

Airway clearance technology combined with prone ventilation intervention in patients with COVID-19 can improve the total effective rate and oxygenation index, improve the inflammatory indicators and respiratory function of patients. And it may be widely promoted and used in the treatment of patients with COVID-19 (severe).

The Respiratory Mechanics of COVID-19 Acute Respiratory Distress Syndrome-Lessons Learned?

Acute respiratory distress syndrome (ARDS) is a well-defined clinical entity characterized by the acute onset of diffuse pulmonary injury and hypoxemia not explained by fluid overload. The COVID-19 pandemic brought about an unprecedented volume of patients with ARDS and challenged our understanding and clinical approach to treatment of this clinical syndrome. Unique to COVID-19 ARDS is the disruption and dysregulation of the pulmonary vascular compartment caused by the SARS-CoV-2 virus, which is a significant cause of hypoxemia in these patients. As a result, gas exchange does not necessarily correlate with respiratory system compliance and mechanics in COVID-19 ARDS as it does with other etiologies. The purpose of this review is to relate the mechanics of COVID-19 ARDS to its underlying pathophysiologic mechanisms and outline the lessons we have learned in the management of this clinic syndrome.

Effects of prone positioning on lung mechanical power components in patients with acute respiratory distress syndrome: a physiologic study

BACKGROUND

Prone positioning (PP) homogenizes ventilation distribution and may limit ventilator-induced lung injury (VILI) in patients with moderate to severe acute respiratory distress syndrome (ARDS). The static and dynamic components of ventilation that may cause VILI have been aggregated in mechanical power, considered a unifying driver of VILI. PP may affect mechanical power components differently due to changes in respiratory mechanics; however, the effects of PP on lung mechanical power components are unclear. This study aimed to compare the following parameters during supine positioning (SP) and PP: lung total elastic power and its components (elastic static power and elastic dynamic power) and these variables normalized to end-expiratory lung volume (EELV).

METHODS

This prospective physiologic study included 55 patients with moderate to severe ARDS. Lung total elastic power and its static and dynamic components were compared during SP and PP using an esophageal pressure-guided ventilation strategy. In SP, the esophageal pressure-guided ventilation strategy was further compared with an oxygenation-guided ventilation strategy defined as baseline SP. The primary endpoint was the effect of PP on lung total elastic power non-normalized and normalized to EELV. Secondary endpoints were the effects of PP and ventilation strategies on lung elastic static and dynamic power components non-normalized and normalized to EELV, respiratory mechanics, gas exchange, and hemodynamic parameters.

RESULTS

Lung total elastic power (median [interquartile range]) was lower during PP compared with SP (6.7 [4.9-10.6] versus 11.0 [6.6-14.8] J/min; P < 0.001) non-normalized and normalized to EELV (3.2 [2.1-5.0] versus 5.3 [3.3-7.5] J/min/L; P < 0.001). Comparing PP with SP, transpulmonary pressures and EELV did not significantly differ despite lower positive end-expiratory pressure and plateau airway pressure, thereby reducing non-normalized and normalized lung elastic static power in PP. PP improved gas exchange, cardiac output, and increased oxygen delivery compared with SP.

CONCLUSIONS

In patients with moderate to severe ARDS, PP reduced lung total elastic and elastic static power compared with SP regardless of EELV normalization because comparable transpulmonary pressures and EELV were achieved at lower airway pressures. This resulted in improved gas exchange, hemodynamics, and oxygen delivery.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS00017449). Registered June 27, 2019. https://drks.de/search/en/trial/DRKS00017449.

Characteristics and risk factors associated with mortality during the first cycle of prone secondary to ARDS due to SARS-CoV-2 pneumonia

OBJECTIVE

To analyze characteristics, changes in oxygenation, and pulmonary mechanics, in mechanically ventilated patients with ARDS due to SARS-CoV-2 treated with prone position and evaluate the response to this maneuver.

DESIGN

Cohort study including patients with PaO2/FiO2 <150mmHg requiring prone position over 18 months. We classified patients according to PaO2/FiO2 changes from basal to 24h after the first prone cycle as: 1) no increase 2) increase <25%, 3) 25%-50% increase 4) increase >50%.

SETTING

33-bed medical-surgical Intensive Care Unit (ICU) in Argentina.

PATIENTS

273 patients.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Epidemiological characteristics, respiratory mechanics and oxygenation were compared between survivors and non-survivors. Independent factors associated with in-hospital mortality were identified.

RESULTS

Baseline PaO2/FiO2 was 116 [97-135]mmHg (115 [94-136] in survivors vs. 117 [98-134] in non-survivors; p=0.50). After prone positioning, 22 patients (8%) had similar PaO2/FiO2 values; 46(16%) increased PaO2/FiO2 ≤25%; 55 (21%) increased it 25%-50%; and 150 (55%), >50%. Mortality was 86%, 87%, 72% and 50% respectively (p<0.001). Baseline PaO2/FiO2, <100mmHg did not imply that patients were refractory to prone position. Factors independently associated with mortality were age, percentage increase in PaO2/FiO2 after 24h being in prone, and number of prone cycles.

CONCLUSIONS

Older patients unable to improve PaO2/FiO2 after 24h in prone position and who require >1 cycle might early receive additional treatments for refractory hypoxemia. After the first 24h in the prone position, a low percentage of PaO2/FiO2 increase over baseline, beyond the initial value, was independently associated with higher mortality.

A Comprehensive Review of Prone Ventilation in the Intensive Care Unit: Challenges and Solutions

This comprehensive review explores the intricate landscape of prone ventilation in the intensive care unit (ICU), spanning physiological rationale, challenges in implementation, psychosocial impacts, technological innovations, economic considerations, barriers to adoption, and implications for clinical practice. The physiological benefits of prone positioning, including improved oxygenation and lung compliance, are discussed alongside the challenges of patient selection and technical complexities. The psychosocial impact on patients and caregivers, as well as the economic implications for healthcare systems, adds a crucial dimension to the analysis. The review also delves into innovative technologies, such as advanced monitoring and automation, shaping the landscape of prone ventilation. Moreover, it addresses the barriers to widespread adoption and outlines strategies to overcome resistance, emphasizing the need for a comprehensive and collaborative approach. The implications for clinical practice underscore the importance of evidence-based guidelines, ongoing education, and a holistic patient-centered care approach. The conclusion highlights the call to action for further research to refine protocols and technology, ultimately optimizing the application of prone ventilation in critical care settings.

Predictive performance of the variation rate of the driving pressure on the outcome of invasive mechanical ventilation in patients with acute respiratory distress syndrome

PURPOSE

To assess the value of the driving pressure variation rate (ΔP%) in predicting the outcome of weaning from invasive mechanical ventilation in patients with acute respiratory distress syndrome.

METHODS

In this case-control study, a total of 35 patients with moderate-severe acute respiratory distress syndrome were admitted to the intensive care unit between January 2022 and December 2022 and received invasive mechanical ventilation for at least 48 h were enrolled. Patients were divided into successful weaning group and failed weaning group depending on whether they could be removed from ventilator support within 14 days. Outcome measures including driving pressure, PaO2:FiO2, and positive end-expiratory pressure, etc. were assessed every 24 h from day 0 to day 14 until successful weaning was achieved. The measurement data of non-normal distribution were presented as median (Q1, Q3), and the differences between groups were compared by Wilcoxon rank sum test. And categorical data use the Chi-square test or Fisher's exact test to compare. The predictive value of ΔP% in predicting the outcome of weaning from the ventilator was analyzed using receiver operating characteristic curves.

RESULTS

Of the total 35 patients included in the study, 17 were successful vs. 18 failed in weaning from a ventilator after 14 days of mechanical ventilation. The cut-off values of the median ΔP% measured by Operator 1 vs. Operator 2 in the first 4 days were ≥ 4.17% and 4.55%, respectively (p < 0.001), with the area under curve of 0.804 (sensitivity of 88.2%, specificity of 64.7%) and 0.770 (sensitivity of 88.2%, specificity of 64.7%), respectively. There was a significant difference in mechanical ventilation duration between the successful weaning group and the failure weaning group (8 (6, 13) vs. 12 (7.5, 17.3), p = 0.043). The incidence of ventilator-associated pneumonia in the successful weaning group was significantly lower than in the failed weaning group (0.2‰ vs. 2.3‰, p = 0.001). There was a significant difference noted between these 2 groups in the 28-day mortality (11.8% vs. 66.7%, p = 0.003).

CONCLUSION

The median ΔP% in the first 4 days of mechanical ventilation showed good predictive performance in predicting the outcome of weaning from mechanical ventilation within 14 days. Further study is needed to confirm this finding.

Peripartum veno-venous extracorporeal membrane oxygenation in patients with severe CoViD-19-related-ARDS

We describe a case series of five pregnant or postpartum women with severe CoViD-19-related ARDS requiring VV ECMO at our centre between Jan 1 and Sep 30, 2021. All patients were cannulated at the referring hospitals by our team before transferring to our centre. None of the women were vaccinated against CoViD-19. All had severe ARDS with Murray's Lung Injury Score of 3-4 and met the severity threshold for ECMO initiation that was used in the EOLIA study. All patients were discharged alive to home, acute rehabilitation, or lung transplant centre. One patient suffered intrauterine death before ECMO initiation and another while on ECMO. VV ECMO for refractory CoViD-19 related ARDS in the peripartum period is safe, and in this small series, it was associated with good maternal survival rates.

Effect of prone positioning on survival in adult patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a prospective multicenter randomized controlled study

Background

Current data supporting the use of prone positioning (PP) during venovenous extracorporeal membrane oxygenation (VV-ECMO) in patients with acute respiratory distress syndrome (ARDS) are limited. This prospective randomized controlled study aimed to determine whether PP implemented within 24 hours of ECMO can improve survival in these patients.

Methods

From June 2021 to July 2023, 97 adult patients receiving VV-ECMO for ARDS in three centers were enrolled and 1:1 randomized into PP (n=49) and control groups (n=48). Patients in the PP group receiving prone positioning, while the control group were maintained in the supine position. The primary outcome was 30-day survival, and secondary outcomes included in-hospital survival and other clinical outcomes.

Results

All 97 patients were included for analysis. Patient characteristics did not significantly differ between the two groups. The median duration of PP was 81 hours, and the median number of PP sessions was 5 times. PP improved oxygenation and ventilator parameters. The incidence of complications during PP was low, with pressure sores being the most frequent (10.2%). The 30-day survival was significantly higher in the PP group (67.3% vs. 45.8%; P=0.033), as was in-hospital survival (61.2% vs. 39.6%; P=0.033). In the PP group, the successful ECMO weaning rate was significantly higher (77.5% vs. 50.0%; P=0.005), and the duration of ECMO support was significantly shorter {10 [8-11] vs. 10 [8-14] days; P=0.038}. However, in subgroup analysis of COVID patients the 30-day survival, in-hospital survival, successful ECMO weaning rate and the duration of ECMO support did not differ between the groups. The duration of mechanical ventilation, length of intensive care unit stay, and length of hospital stay did not significantly differ between the groups.

Conclusions

When initiated within 24 hours of ECMO, PP can improve 30-day survival in patients with ARDS receiving VV-ECMO. In addition, it may improve the successful ECMO weaning rate and reduce the duration of ECMO support. However, considering the limitations, more strictly designed, large sample prospective randomized controlled trials are proposed.

Trial Registration

Chinese Clinical Trial Registry ChiCTR2300075326.

Lung impedance changes during awake prone positioning in COVID-19. A non-randomized cross-over study

BACKGROUND

The effects of awake prone positioning (APP) on respiratory mechanics in patients with COVID-19 are not well characterized. The aim of this study was to investigate changes of global and regional lung volumes during APP compared with the supine position using electrical lung impedance tomography (EIT) in patients with hypoxemic respiratory failure due to COVID-19.

MATERIALS AND METHODS

This exploratory non-randomized cross-over study was conducted at two university hospitals in Sweden between January and May 2021. Patients admitted to the intensive care unit with confirmed COVID-19, an arterial cannula in place, a PaO2/FiO2 ratio <26.6 kPa (<200 mmHg) and high-flow nasal oxygen or non-invasive ventilation were eligible for inclusion. EIT-data were recorded at supine baseline, at 30 and 60 minutes after APP-initiation, and 30 minutes after supine repositioning. The primary outcomes were changes in global and regional tidal impedance variation (TIV), center of ventilation (CoV), global and regional delta end-expiratory lung-impedance (dEELI) and global inhomogeneity (GI) index at the end of APP compared with supine baseline. Data were reported as median (IQR).

RESULTS

All patients (n = 10) were male and age was 64 (47-73) years. There were no changes in global or regional TIV, CoV or GI-index during the intervention. dEELI increased from supine reference value 0 to 1.51 (0.32-3.62) 60 minutes after APP (median difference 1.51 (95% CI 0.19-5.16), p = 0.04) and returned to near baseline values after supine repositioning. Seven patients (70%) showed an increase >0.20 in dEELI during APP. The other EIT-variables did not change during APP compared with baseline.

CONCLUSION

Awake prone positioning was associated with a transient lung recruiting effect without changes in ventilation distribution measured with EIT in patients with hypoxemic respiratory failure due to COVID-19.

Incidence and risk factors of peripheral nerve injuries 3 months after ICU discharge: a retrospective study comparing COVID-19 and non-COVID-19 critically ill survivors

BACKGROUND

Peripheral nerve injuries (PNI) have been associated with prone positioning (PP) in mechanically ventilated (MV) patients with COVID-19 pneumonia. The aims of this retrospective study were to describe PNI prevalence 3 months (M3) after intensive care unit (ICU) discharge, whether patients survived COVID-19 or another critical illness, and to search for risk factors of PNI.

RESULTS

A total of 55 COVID (62 [54-69] years) and 22 non-COVID (61.5 [48-71.5] years) patients were followed at M3, after an ICU stay of respectively 15 [9-26.5] and 13.5 [10-19.8] days. PNI symptoms were reported by 23/55 (42.6%) COVID-19 and 8/22 (36%) non-COVID-19 patients (p = 0.798). As the incidence of PNI was similar in both groups, the entire population was used to determine risk factors. The MV duration predicted PNI occurrence (OR (CI95%) = 1.05 (1.01-1.10), p = 0.028), but not the ICU length of stay, glucocorticoids, or inflammation biomarkers.

CONCLUSION

In the present cohort, PNI symptoms were reported in at least one-third of the ICU survivors, in similar proportion whether patients suffered from severe COVID-19 or not.

Maintaining moderate versus lower PEEP after cardiac surgery: a propensity-scored matched analysis

BACKGROUND

Setting positive end-expiratory pressure (PEEP) at around 5 cm H2O in the early postoperative period seems a common practice for most patients. It remains unclear if the routine application of higher levels of PEEP confers any meaningful clinical benefit for cardiac surgical patients. The aim of this study was to compare moderate versus conventional lower PEEP on patient-centered outcomes in the intensive care unit (ICU).

METHODS

This is a single-center retrospective study involving patients receiving cardiac surgery from June 2022 to May 2023. Propensity-score matching (PSM) was used to balance the baseline differences. Primary outcomes were the duration of mechanical ventilation and ICU length of stay. Secondary outcomes included PaO2/FiO2 ratio at 24 h and the need for prone positioning during ICU stay.

RESULTS

A total of 334 patients were included in the study, 102 (31%) of them received moderate PEEP (≥ 7 cm H2O) for the major time in the early postoperative period (12 h). After PSM, 79 pairs of patients were matched with balanced baseline data. The results showed that there was marginal difference in the distribution of mechanical ventilation duration (p = 0.05) and the Moderate PEEP group had a higher extubation rate at the day of T-piece trial (65 [82.3%] vs 52 [65.8%], p = 0.029). Applying moderate PEEP was also associated with better oxygenation. No differences were found regarding ICU length of stay and patients requiring prone positioning between groups.

CONCLUSION

In selective cardiac surgical patients, using moderate PEEP compared with conventional lower PEEP in the early postoperative period correlated to better oxygenation, which may have potential for earlier liberation of mechanical ventilation.

Changes in Driving Pressure vs Oxygenation as Predictor of Mortality in Moderate to Severe Acute Respiratory Distress Syndrome Patients Receiving Prone Position Ventilation

Background

Prone position ventilation (PPV) causes improvement in oxygenation, nevertheless, mortality in severe acute respiratory distress syndrome (ARDS) remains high. The changes in the driving pressure (DP) and its role in predicting mortality in moderate to severe ARDS patients receiving PPV is unexplored.

Methods

A prospective observational study, conducted between September 2020 and February 2023 on moderate-severe ARDS patients requiring PPV. The values of DP and oxygenation (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen [PaO2/FiO2]) before, during, and after PPV were recorded. The aim was to compare the DP and oxygenation before, during and after PPV sessions among moderate- severe ARDS patients, and determine the best predictor of mortality.

Results

Total of 52 patients were included; 28-day mortality was 57%. Among the survivors, DP prior to PPV as compared to post-PPV session reduced significantly, from 16.36 ± 2.57 cmH2O to 13.91 ± 1.74 cmH2O (p-value < 0.001), whereas DP did not reduce in the non-survivors (19.43 ± 3.16 to 19.70 ± 3.15 cmH2O (p-value = 0.318)]. Significant improvement in PaO2/FiO2 before PPV to post-PPV among both the survivors [92.75 [67.5-117.75]) to [205.50 (116.25-244.50)], (p-value < 0.001) and also among the non-survivors [87.90 (67.75-100.75)] to [112 (88.00-146.50)], (p-value < 0.001) was noted. Logistic regression analysis showed DP after PPV session as best predictor of mortality (p-value = 0.044) and its AUROC to predict mortality was 0.939, cut-off ≥16 cmH2O, 90% sensitivity, 82% specificity. The Kaplan-Meier curve of DP after PPV ≥16 cmH2O and <16 cmH2O was significant (Log-rank Mantel-Cox p-value < 0.001).

Conclusion

Prone position ventilation-induced decrease in DP is prognostic marker of survival than the increase in PaO2/FiO2. There is a primacy of DP, rather than oxygenation, in predicting mortality in moderate-severe ARDS. Post-PPV session DP ≥16 cmH2O was an independent predictor of mortality.

How to cite this article

Todur P, Nileshwar A, Chaudhuri S, Shanbhag V, Cherisma C. Changes in Driving Pressure vs Oxygenation as Predictor of Mortality in Moderate to Severe Acute Respiratory Distress Syndrome Patients Receiving Prone Position Ventilation. Indian J Crit Care Med 2024;28(2):134-140.

An appraisal of lung computer tomography in very early anti-inflammatory treatment of two different ovine ARDS phenotypes

Mortality and morbidity of Acute Respiratory Distress Syndrome (ARDS) are largely unaltered. A possible new approach to treatment of ARDS is offered by the discovery of inflammatory subphenotypes. In an ovine model of ARDS phenotypes, matching key features of the human subphenotypes, we provide an imaging characterization using computer tomography (CT). Nine animals were randomized into (a) OA (oleic acid, hypoinflammatory; n = 5) and (b) OA-LPS (oleic acid and lipopolysaccharides, hyperinflammatory; n = 4). 48 h after ARDS induction and anti-inflammatory treatment, CT scans were performed at high (H) and then low (L) airway pressure. After CT, the animals were euthanized and lung tissue was collected. OA-LPS showed a higher air fraction and OA a higher tissue fraction, resulting in more normally aerated lungs in OA-LPS in contrast to more non-aerated lung in OA. The change in lung and air volume between H and L was more accentuated in OA-LPS, indicating a higher recruitment potential. Strain was higher in OA, indicating a higher level of lung damage, while the amount of lung edema and histological lung injury were largely comparable. Anti-inflammatory treatment might be beneficial in terms of overall ventilated lung portion and recruitment potential, especially in the OA-LPS group.

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

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

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.

Pressure ulcers after prone positioning in patients undergoing extracorporeal membrane oxygenation: A cross-sectional study

BACKGROUND

The combination of prone positioning and extracorporeal membrane oxygenation (ECMO) in patients with acute respiratory distress syndrome (ARDS) is recognized as safe but its use has been limited due to potential complications.

AIM

To report the prevalence of pressure ulcers and other complications due to prone positioning in adult patients receiving veno-venous ECMO.

STUDY DESIGN

This cross-sectional study was conducted in a tertiary level intensive care unit (ICU) in Milan (Italy), between January 2015 and December 2019. The study population was critically ill adult patients undergoing veno-venous ECMO. Statistical association between pressure ulcers and the type of body positioning (prone versus supine) was explored fitting a logistic model.

RESULTS

In the study period, 114 patients were treated with veno-venous ECMO and 62 (54.4%) patients were placed prone for a total of 130 prone position cycles. ECMO cannulation was performed via femoro-femoral configuration in the majority of patients (82.4%, 94/114). Pressure ulcers developed in 57.0% of patients (95%CI: 44.0%-72.6%), most often arising on the face and the chin (37.1%, 23/62), particularly in those placed prone. The main reason of prone positioning interruption was the decrease of ECMO blood flow (8.1%, 5/62). The fitted model showed no association between body position during ECMO and occurrence of pressure ulcers (OR 1.3, 95%CI: 0.5-3.6, p = .532).

CONCLUSIONS

Facial pressure ulcers were the most frequent complications of prone positioning. Nurses should plan and implement evidence-based care to prevent such pressure injuries in patients undergoing ECMO.

RELEVANCE TO CLINICAL PRACTICE

The combination of prone positioning and ECMO shows few life-threating complications. This manoeuvre during ECMO is feasible and safe when performed by experienced ICU staff.

Airway Pressure Release Ventilation in COVID-19-Associated Acute Respiratory Distress Syndrome-A Multicenter Propensity Score-Matched Analysis

Background: There are limited and partially contradictory data on the effects of airway pressure release ventilation (APRV) in COVID-19-associated acute respiratory distress syndrome (CARDS). Therefore, we analyzed the clinical outcome, complications, and longitudinal course of ventilation parameters and laboratory values in patients with CARDS, who were mechanically ventilated using APRV. Methods: Respective data from 4 intensive care units (ICUs) were collected and compared to a matched cohort of patients receiving conventional low tidal volume ventilation (LTV). Propensity score matching was performed based on age, sex, blood gas analysis, and APACHE II score at admission, as well as the implementation of prone positioning. Findings: Forty patients with CARDS, who were mechanically ventilated using APRV, and 40 patients receiving LTV were matched. No significant differences were detected for tidal volumes per predicted body weight, peak pressure values, and blood gas analyses on admission, 6 h post admission as well as on day 3 and day 7. Regarding ICU survival, no significant difference was identified between APRV patients (40%) and LTV patients (42%). Median duration of mechanical ventilation and duration of ICU treatment were comparable in both groups. Similar complication rates with respect to ventilator-associated pneumonia, septic shock, thromboembolic events, barotrauma, as well as the necessity for hemodialysis were detected for both groups. Clinical characteristics that were associated with increased mortality in a Cox proportional hazards regression analysis included age (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.04-1.1; P < .001), severe acute respiratory distress syndrome (HR 2.62, 95% CI 1.02-6.7; P = .046) and the occurrence of septic shock (HR 17.18, 95% CI 2.06-143.2; P = .009), but not the ventilation mode. Interpretation: Intensive care unit survival, duration of mechanical ventilation, and ICU treatment as well as ventilation-associated complication rates were equivalent using APRV compared to conventional LTV in patients with CARDS.

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

The role of awake prone positioning (aPP) in patients with acute hypoxemic respiratory failure is debated. We performed a systematic review and meta-analysis to evaluate the role of aPP in acute respiratory failure related to COronaVIrus Disease-19 (COVID-19). Studies reporting on the clinical course of patients with acute respiratory failure related to COVID-19 treated or not treated by aPP were included in the systematic review and meta-analysis (ProsperoID: CRD42022333211). The primary study outcome was the composite of in-hospital death or orotracheal intubation; the individual components of the primary outcome were secondary study outcomes. The composite of in-hospital death or orotracheal intubation was available for 6 studies (1884 patients), five randomized and one prospective; a significant reduction in the risk of this outcome was observed in patients treated vs. not treated by aPP (33.5% vs. 39.8%; OR 0.73, 95% CI 0.60-0.89; I2 0%). In-hospital death was reported in 34 studies (6808 patients) and occurred in 17.4% vs. 23.5% of patients treated or not treated with aPP (random effect OR 0.60, 95% CI 0.46-0.79; I2 59%); orotracheal intubation was observed in 25.8% vs. 32.7% of patients treated or not treated with aPP (27 studies, 5369 patients; random effect OR 0.85, 95% CI 0.56-1.27; I2 84%). aPP reduces the risk for death or orotracheal intubation in patients with acute respiratory failure related to COVID-19. Further studies should be conducted to confirm the clinical benefit of aPP outside the ICU.Registration Prospero ID: CRD42022333211.

Evaluating the Effects of a General Anesthesia and Prone Position Nursing Checklist and Training Course on Posterior Lumbar Surgery: A Randomized Controlled Trial

BACKGROUND

While general anesthesia in the prone position is one of the most utilized surgical positions, it predisposes to multiple types of complications. Existing studies on this topic are mostly literature reviews or focus on solving one complication, which limits their clinical use.

OBJECTIVE

The aims of the study were to evaluate the effectiveness of a 22-item general anesthesia and prone position nursing checklist and specific training course at preventing complications related to general anesthesia in the prone position.

DESIGN

The study used a randomized controlled trial.

SETTINGS AND PARTICIPANTS

Convenience sampling was used to recruit patients who underwent general anesthesia during posterior lumbar surgery from July 2021 to December 2021 at the Run Run Shaw Hospital, Zhejiang University School of Medicine Hospital.

METHODS

Patients involved in the study were randomly assigned to the control (standard general anesthesia and prone position care) or experimental group (general anesthesia and prone position nursing checklist combined with specific training course in addition to standard general anesthesia and prone position care). Outcomes were pressure injuries, peripheral nerve injuries, ocular complications, and length of stay (LOS). Patient satisfaction, Numeric Pain Rating Scale (NRS) and the Oswestry Disability Scale were also measured.

RESULTS

Compared with the control group, pressure injury, brachial plexus injury, and two ocular findings (foreign body sensation and blurry vision) were significantly less common in the intervention group ( P ≤ 0.01). Participants who received standard general anesthesia and prone position care had lower self-reported satisfaction than those managed with the general anesthesia and prone position nursing checklist plus specific training course ( P = 0.002). The checklist-based intervention also significantly reduced LOS ( P = 0.000) and NRS ( P = 0.000).

CONCLUSIONS

The intervention group had significant fewer general anesthesia in the prone position-related complications, improved satisfaction, reduced LOS, and lower NRS. These findings suggest that a general anesthesia and prone position nursing checklist in addition to a specific training course are beneficial to standardizing prone position nursing care during posterior lumbar surgery.

Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome With COVID-19: A Meta-Analysis

The available literature has furnished substantial evidence indicating the favorable outcomes of prone positioning (PP) on oxygenation parameters among patients afflicted with coronavirus disease 2019 (COVID-19). However, there is a notable disparity in the reported influence of PP on the overall outcomes of COVID-19 patients undergoing venovenous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory distress syndrome (ARDS) across studies. This article has been prepared in adherence with Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. MEDLINE, Embase, and Cochrane databases were utilized for data retrieval. The primary endpoint was to evaluate the cumulative survival rate among COVID-19 patients receiving V-V ECMO, comparing those who received PP to those who did not. Secondary endpoints included the duration of intensive care unit (ICU) stay, ECMO duration, and mechanical ventilation duration. A total of 15 studies involving 2286 patients were analyzed in the meta-analysis. PP significantly improved the cumulative survival rate (0.48, 95% CI: 0.40-0.55); risk ratio (RR) of 1.24 (95% CI: 1.11-1.38).PP during ECMO for COVID-19 patients yielded favorable outcomes in terms of 60-day survival, 90-day survival, ICU survival, and hospital survival. In contrast, patients who underwent PP had longer ECMO duration (8.1 days, 95% CI: 6.2-9.9, p<0.001) and mechanical ventilation duration (9.6 days, 95% CI: 8.0-11.2, p<0.001). PP demonstrated improved survival in COVID-19 patients with ARDS receiving V-V ECMO. However, additional well-designed prospective trials are warranted to further explore the effects of this combination on survival outcomes in COVID-19 patients.

Importance of timing and training to implement awake prone positioning in patients with COVID-19: a single-center prospective observational study

Background

Awake prone positioning (APP) is broadly implemented in patients with severe acute respiratory syndrome coronavirus 2 related disease [coronavirus disease 2019 (COVID-19)] admitted to hospital with severe respiratory distress syndrome. This prospective observational study aimed to explore the factors influencing the implementation of APP in patients with acute respiratory failure due to COVID-19.

Methods

Patients with COVID-19, all hospitalized with positive X-ray findings and oxygen supplementation requirement, in the Respiratory Step-Down Unit of the Peking University Third Hospital between January 6th, 2023, and January 20th, 2023, were included in this study. Data regarding basic information, activities of daily living (ADLs) scores, oxygen therapy, vital signs, and duration of APP were collected to investigate the factors influencing prone positioning.

Results

Among the 134 patients included, 55.2% showed an improvement in oxygen saturation 1 hour after APP. Logistic regression revealed that the pre-APP heart rate (HR) [odds ratio (OR) =1.032; P=0.046] and peripheral oxygen saturation (SpO2) (OR =0.720; P<0.001) were the associated factors of the improvement in SpO2 after treatment. Multiple linear regression revealed that the ADL scores and pre-APP respiratory rate (RR) were the associated factors of the duration of prone positioning (P<0.01). The APP technical steering group effectively improved duration of APP.

Conclusions

Patients with low SpO2 and increased HR before treatment showed greater improvement in oxygen saturation. Patients with lower tolerance to ADL but lower RRs were those to demonstrate a longer duration of prone positioning. This is pointing towards establishing the most favorable time window for APP during the course of COVID-19: after the ADLs have already decreased, but before significant tachypnea has appeared.