Psychological Relationship of Mechanical Ventilation Power on Mortality of Covid-19 Critically Ill Patients

Introduction: ARDS is a type of lung injury that causes inflammation and makes it harder for oxygen to get into the bloodstream. Some treatments have been suggested, such as using less air with each breath, increasing pressure when breathing out, and using special positions or machines to help the lungs. But it's not clear how much these treatments can improve outcomes for patients with ARDS. So far, no studies have looked specifically at whether using more or less mechanical power to help patients breathe affects their chances of survival or other important measures of health. Objectives: This research aimed to investigate how the use of mechanical ventilation affects the likelihood of death in patients who are severely ill with COVID-19. Methods: This study adopts a cross-sectional design and retrospective analysis, observing critically ill patients who are being treated in the Special Isolation Ward of Dr. Soetomo Hospital's intensive care unit. The population for this study consists of critically ill patients who meet the inclusion and exclusion criteria. The research sample is obtained through randomized sampling, where all eligible individuals meeting the criteria are included in the sample size. Results: The study findings reveal a correlation between mechanical ventilation power and mortality among COVID-19 patients with ARDS. The mechanical power of ventilation is identified as a significant variable in this study, with a cut-off point of 17.4. Patients above this cut-off point are at 3.65 times higher risk of death compared to those below it. Moreover, there is evidence of a relationship between the mechanical power of ventilation variable and the P/F Ratio, as a higher mechanical power is associated with a decrease in the P/F Ratio. Conclusions: The study has identified a correlation between the P/F Ratio variable and mortality in COVID-19 patients with ARDS. On the other hand, there is no evidence of a relationship between the compliance variable and mortality in COVID-19 patients with ARDS. © 2023, Journal for ReAttach Therapy and Developmental Diversities. All Rights Reserved.

[The Bayes factor in the analysis of mechanical power in patients with severe respiratory failure due to SARS-CoV-2]. / El método del factor de Bayes en el análisis de la energía mecánica en pacientes con insuficiencia respiratoria grave por SARS-CoV-2.

Objective: To specify the degree of probative force of the statistical hypotheses in relation to mortality at 28 days and the threshold value of 17 J/min mechanical power (MP) in patients with respiratory failure secondary to SARS-CoV-2. Design: Cohort study, longitudinal, analytical. Setting: Intensive care unit of a third level hospital in Spain. Patients: Patients admitted for SARS-CoV-2 infection with admission to the ICU between March 2020 and March 2022. Interventions: Bayesian analysis with the beta binomial model. Main variables of interest: Bayes factor, mechanical power. Results: A total of 253 patients were analyzed. Baseline respiratory rate (BF10: 3.83 × 106), peak pressure value (BF10: 3.72 × 1013) and neumothorax (BF10: 17,663) were the values most likely to be different between the two groups of patients compared. In the group of patients with MP < 17 J/min, a BF10 of 12.71 and a BF01 of 0.07 were established with an 95%CI of 0.27-0.58. For the group of patients with MP ≥ 17 J/min the BF10 was 36,100 and the BF01 of 2.77e-05 with an 95%CI of 0.42-0.72. Conclusions: A MP ≥ 17 J/min value is associated with extreme evidence with 28-day mortality in patients requiring MV due to respiratory failure secondary to SARS-CoV-2 disease.

The Bayes factor in the analysis of mechanical power in patients with severe respiratory failure due to SARS-CoV-2.

OBJECTIVE: To specify the degree of probative force of the statistical hypotheses in relation to mortality at 28 days and the threshold value of 17 J/min mechanical power (MP) in patients with respiratory failure secondary to SARS-CoV-2. DESIGN: Cohort study, longitudinal, analytical. SETTING: Intensive care unit of a third level hospital in Spain. PATIENTS: Patients admitted for SARS-CoV-2 infection with admission to the ICU between March 2020 and March 2022. INTERVENTIONS: Bayesian analysis with the beta binomial model. MAIN VARIABLES OF INTEREST: Bayes factor, mechanical power. RESULTS: A total of 253 patients were analyzed. Baseline respiratory rate (BF10: 3.83 × 106), peak pressure value (BF10: 3.72 × 1013) and neumothorax (BF10: 17,663) were the values most likely to be different between the two groups of patients compared. In the group of patients with MP < 17 J/min, a BF10 of 12.71 and a BF01 of 0.07 were established with an 95%CI of 0.27-0.58. For the group of patients with MP ≥ 17 J/min the BF10 was 36,100 and the BF01 of 2.77e-05 with an 95%CI of 0.42-0.72. CONCLUSIONS: A MP ≥ 17 J/min value is associated with extreme evidence with 28-day mortality in patients requiring MV due to respiratory failure secondary to SARS-CoV-2 disease.

Mechanical power of ventilation and driving pressure: two undervalued parameters for pre extracorporeal membrane oxygenation ventilation and during daily management?

The current ARDS guidelines highly recommend lung protective ventilation which include plateau pressure (Pplat < 30 cm H2O), positive end expiratory pressure (PEEP > 5 cm H2O) and tidal volume (Vt of 6 ml/kg) of predicted body weight. In contrast, the ELSO guidelines suggest the evaluation of an indication of veno-venous extracorporeal membrane oxygenation (ECMO) due to hypoxemic or hypercapnic respiratory failure or as bridge to lung transplantation. Finally, these recommendations remain a wide range of scope of interpretation. However, particularly patients with moderate-severe to severe ARDS might benefit from strict adherence to lung protective ventilation strategies. Subsequently, we discuss whether extended physiological ventilation parameter analysis might be relevant for indication of ECMO support and can be implemented during the daily routine evaluation of ARDS patients. Particularly, this viewpoint focus on driving pressure and mechanical power.

Ventilatory ratio and mechanical power in prolonged mechanically ventilated COVID-19 patients versus respiratory failures of other etiologies.

BACKGROUND: Evidence suggests differences in ventilation efficiency and respiratory mechanics between early COVID-19 pneumonia and classical acute respiratory distress syndrome (ARDS), as measured by established ventilatory indexes, such as the ventilatory ratio (VR; a surrogate of the pulmonary dead-space fraction) or mechanical power (MP; affected, e.g., by changes in lung-thorax compliance). OBJECTIVES: The aim of this study was to evaluate VR and MP in the late stages of the disease when patients are ready to be liberated from the ventilator after recovering from COVID-19 pneumonia compared to respiratory failures of other etiologies. DESIGN: A retrospective observational cohort study of 249 prolonged mechanically ventilated, tracheotomized patients with and without COVID-19-related respiratory failure. METHODS: We analyzed each group's VR and MP distributions and trajectories [repeated-measures analysis of variance (ANOVA)] during weaning. Secondary outcomes included weaning failure rates between groups and the ability of VR and MP to predict weaning outcomes (using logistic regression models). RESULTS: The analysis compared 53 COVID-19 cases with a heterogeneous group of 196 non-COVID-19 subjects. VR and MP decreased across both groups during weaning. COVID-19 patients demonstrated higher values for both indexes throughout weaning: median VR 1.54 versus 1.27 (p < 0.01) and MP 26.0 versus 21.3 Joule/min (p < 0.01) at the start of weaning, and median VR 1.38 versus 1.24 (p < 0.01) and MP 24.2 versus 20.1 Joule/min (p < 0.01) at weaning completion. According to the multivariable analysis, VR was not independently associated with weaning outcomes, and the ability of MP to predict weaning failure or success varied with lung-thorax compliance, with COVID-19 patients demonstrating consistently higher dynamic compliance along with significantly fewer weaning failures (9% versus 30%, p < 0.01). CONCLUSION: COVID-19 patients differed considerably in ventilation efficiency and respiratory mechanics among prolonged ventilated individuals, demonstrating significantly higher VRs and MP. The differences in MP were linked with higher lung-thorax compliance in COVID-19 patients, possibly contributing to the lower rate of weaning failures observed.

New insights in mechanical ventilation and adjunctive therapies in ARDS

Patients with acute respiratory distress syndrome (ARDS) often require mechanical ventilation (MV) and may experience high morbidity and mortality. The ventilatory management of ARDS patients has changed over the years to mitigate the risk of ventilator-induced lung injury (VILI) and improve outcomes. Current recommended MV strategies include the use of low tidal volume (VT) at 4–6 mL/kg of predicted body weight (PBW) and plateau pressure (PP LAT) below 27 cmH2O. Some patients achieve better outcomes with low VT than others, and several strategies have been proposed to individualize VT, including standardization for end-expiratory lung volume or inspiratory capacity. To date, no strategy for individualizing positive-end expiratory pressure (PEEP) based on oxygenation, recruitment, respiratory mechanics, or hemodynamics has proven superior for improving survival. Driving pressure, transpulmonary pressure, and mechanical power have been proposed as markers to quantify risk of VILI and optimize ventilator settings. Several rescue therapies, including neuromuscular blockade, prone positioning, recruitment maneuvers (RMs), vasodilators, and extracorporeal membrane oxygenation (ECMO), may be considered in severe ARDS. New ventilator strategies such as airway pressure release ventilation (APRV) and time-controlled adaptive ventilation (TCAV) have demonstrated potential benefits to reduce VILI, but further studies are required to evaluate their clinical relevance. This review aims to discuss the cornerstones of MV and new insights in ARDS ventilatory management, as well as their rationales, to guide the physician in an individually tailored rather than a fixed, sub-physiological approach. We recommend that MV be individualized based on physiological targets to achieve optimal ventilatory settings for each patient. © 2022 The Author(s). Published by MRE Press.

Driving pressure-guided ventilation decreases the mechanical power compared to predicted body weight-guided ventilation in the Acute Respiratory Distress Syndrome.

BACKGROUND: Whether targeting the driving pressure (∆P) when adjusting the tidal volume in mechanically ventilated patients with the acute respiratory distress syndrome (ARDS) may decrease the risk of ventilator-induced lung injury remains a matter of research. In this study, we assessed the effect of a ∆P-guided ventilation on the mechanical power. METHODS: We prospectively included adult patients with moderate-to-severe ARDS. Positive end expiratory pressure was set by the attending physician and kept constant during the study. Tidal volume was first adjusted to target 6 ml/kg of predicted body weight (PBW-guided ventilation) and subsequently modified within a range from 4 to 10 ml/kg PBW to target a ∆P between 12 and 14 cm H2O. The respiratory rate was then re-adjusted within a range from 12 to 40 breaths/min until EtCO2 returned to its baseline value (∆P-guided ventilation). Mechanical power was computed at each step. RESULTS: Fifty-one patients were included between December 2019 and May 2021. ∆P-guided ventilation was feasible in all but one patient. The ∆P during PBW-guided ventilation was already within the target range of ∆P-guided ventilation in five (10%) patients, above in nine (18%) and below in 36 (72%). The change from PBW- to ∆P-guided ventilation was thus accompanied by an overall increase in tidal volume from 6.1 mL/kg PBW [5.9-6.2] to 7.7 ml/kg PBW [6.2-8.7], while respiratory rate was decreased from 29 breaths/min [26-32] to 21 breaths/min [16-28] (p < 0.001 for all comparisons). ∆P-guided ventilation was accompanied by a significant decrease in mechanical power from 31.5 J/min [28-35.7] to 28.8 J/min [24.6-32.6] (p < 0.001), representing a relative decrease of 7% [0-16]. With ∆P-guided ventilation, the PaO2/FiO2 ratio increased and the ventilatory ratio decreased. CONCLUSION: As compared to a conventional PBW-guided ventilation, a ∆P-guided ventilation strategy targeting a ∆P between 12 and 14 cm H2O required to change the tidal volume in 90% of the patients. Such ∆P-guided ventilation significantly reduced the mechanical power. Whether this physiological observation could be associated with clinical benefit should be assessed in clinical trials.

Double Hybrid Tailsitter Unmanned Aerial Vehicle with Vertical Takeoff and Landing

We propose a new concept and architectural design for a double hybrid tailsitter unmanned aerial vehicle with vertical takeoff and landing capability. Basically, it consists of a modified flying wing with a single combustion powertrain set and a multirotor with 2 powertrain sets with electric motors. To this end, we have designed, built, and tested a prototype that spends less energy on vertical taking off and landing and also on horizontal flight, for maximizing flight endurance and distance.With electric propellers fixed at the leading wing edge, the tailsitter has two standard surfaces for elevation control and two vertical stabilizers that are used to give the necessary direction on vertical takeoff and landing. Experiments and results show the versatility of our hybrid tailsitter for operations in a restricted field. We performed several tests starting with the aircraft on the ground in vertical positioning. These tests include executing vertical takeoffs and landing, transitions from vertical to horizontal flight modes and transitions back from horizontal to vertical flight modes, and hovering, which were carried out successfully. Transition fourth and back from combustion to multirotor modes are inherent to some of those flight mode transitions, which have been performed smoothly.We also performed tests (in bench) to estimate the flight endurance. Final autonomous flight adjustments were not performed due to the Covid-19 pandemic caused by SARS-CoV-2. To this end the proposed and currently built prototype has proven to be functional as an effective hybrid UAV system. Author

Association of Time-Varying Intensity of Ventilation With Mortality in Patients With COVID-19 ARDS: Secondary Analysis of the PRoVENT-COVID Study.

Background: High intensity of ventilation has an association with mortality in patients with acute respiratory failure. It is uncertain whether similar associations exist in patients with acute respiratory distress syndrome (ARDS) patients due to coronavirus disease 2019 (COVID-19). We investigated the association of exposure to different levels of driving pressure (ΔP) and mechanical power (MP) with mortality in these patients. Methods: PRoVENT-COVID is a national, retrospective observational study, performed at 22 ICUs in the Netherlands, including COVID-19 patients under invasive ventilation for ARDS. Dynamic ΔP and MP were calculated at fixed time points during the first 4 calendar days of ventilation. The primary endpoint was 28-day mortality. To assess the effects of time-varying exposure, Bayesian joint models adjusted for confounders were used. Results: Of 1,122 patients included in the PRoVENT-COVID study, 734 were eligible for this analysis. In the first 28 days, 29.2% of patients died. A significant increase in the hazard of death was found to be associated with each increment in ΔP (HR 1.04, 95% CrI 1.01-1.07) and in MP (HR 1.12, 95% CrI 1.01-1.36). In sensitivity analyses, cumulative exposure to higher levels of ΔP or MP resulted in increased risks for 28-day mortality. Conclusion: Cumulative exposure to higher intensities of ventilation in COVID-19 patients with ARDS have an association with increased risk of 28-day mortality. Limiting exposure to high ΔP or MP has the potential to improve survival in these patients. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT04346342.

Effect of INTELLiVENT-ASV versus Conventional Ventilation on Ventilation Intensity in Patients with COVID-19 ARDS-An Observational Study.

Driving pressure (ΔP) and mechanical power (MP) are associated with outcomes in critically ill patients, irrespective of the presence of Acute Respiratory Distress Syndrome (ARDS). INTELLiVENT-ASV, a fully automated ventilatory mode, controls the settings that affect ΔP and MP. This study compared the intensity of ventilation (ΔP and MP) with INTELLiVENT-ASV versus conventional ventilation in a cohort of COVID-19 ARDS patients in two intensive care units in the Netherlands. The coprimary endpoints were ΔP and MP before and after converting from conventional ventilation to INTELLiVENT-ASV. Compared to conventional ventilation, INTELLiVENT-ASV delivered ventilation with a lower ΔP and less MP. With conventional ventilation, ΔP was 13 cmH2O, and MP was 21.5 and 24.8 J/min, whereas with INTELLiVENT-ASV, ΔP was 11 and 10 cmH2O (mean difference -2 cm H2O (95 %CI -2.5 to -1.2 cm H2O), p < 0.001) and MP was 18.8 and 17.5 J/min (mean difference -7.3 J/Min (95% CI -8.8 to -5.8 J/min), p < 0.001). Conversion from conventional ventilation to INTELLiVENT-ASV resulted in a lower intensity of ventilation. These findings may favor the use of INTELLiVENT-ASV in COVID-19 ARDS patients, but future studies remain needed to see if the reduction in the intensity of ventilation translates into clinical benefits.

Association of intensity of ventilation with 28-day mortality in COVID-19 patients with acute respiratory failure: insights from the PRoVENT-COVID study.

BACKGROUND: The intensity of ventilation, reflected by driving pressure (ΔP) and mechanical power (MP), has an association with outcome in invasively ventilated patients with or without acute respiratory distress syndrome (ARDS). It is uncertain if a similar association exists in coronavirus disease 2019 (COVID-19) patients with acute respiratory failure. METHODS: We aimed to investigate the impact of intensity of ventilation on patient outcome. The PRoVENT-COVID study is a national multicenter observational study in COVID-19 patients receiving invasive ventilation. Ventilator parameters were collected a fixed time points on the first calendar day of invasive ventilation. Mean dynamic ΔP and MP were calculated for individual patients at time points without evidence of spontaneous breathing. A Cox proportional hazard model, and a double stratification analysis adjusted for confounders were used to estimate the independent associations of ΔP and MP with outcome. The primary endpoint was 28-day mortality. RESULTS: In 825 patients included in this analysis, 28-day mortality was 27.5%. ΔP was not independently associated with mortality (HR 1.02 [95% confidence interval 0.88-1.18]; P = 0.750). MP, however, was independently associated with 28-day mortality (HR 1.17 [95% CI 1.01-1.36]; P = 0.031), and increasing quartiles of MP, stratified on comparable levels of ΔP, had higher risks of 28-day mortality (HR 1.15 [95% CI 1.01-1.30]; P = 0.028). CONCLUSIONS: In this cohort of critically ill invasively ventilated COVID-19 patients with acute respiratory failure, we show an independent association of MP, but not ΔP with 28-day mortality. MP could serve as one prognostic biomarker in addition to ΔP in these patients. Efforts aiming at limiting both ΔP and MP could translate in a better outcome. Trial registration Clinicaltrials.gov (study identifier NCT04346342).

Individualized Multimodal Physiologic Approach to Mechanical Ventilation in Patients With Obesity and Severe Acute Respiratory Distress Syndrome Reduced Venovenous Extracorporeal Membrane Oxygenation Utilization.

OBJECTIVE: To investigate whether individualized optimization of mechanical ventilation through the implementation of a lung rescue team could reduce the need for venovenous extracorporeal membrane oxygenation in patients with obesity and acute respiratory distress syndrome and decrease ICU and hospital length of stay and mortality. DESIGN: Single-center, retrospective study at the Massachusetts General Hospital from June 2015 to June 2019. PATIENTS: All patients with obesity and acute respiratory distress syndrome who were referred for venovenous extracorporeal membrane oxygenation evaluation due to hypoxemic respiratory failure. INTERVENTION: Evaluation and individualized optimization of mechanical ventilation by the lung rescue team before the decision to proceed with venovenous extracorporeal membrane oxygenation. The control group was those patients managed according to hospital standard of care without lung rescue team evaluation. MEASUREMENT AND MAIN RESULTS: All 20 patients (100%) allocated in the control group received venovenous extracorporeal membrane oxygenation, whereas 10 of 13 patients (77%) evaluated by the lung rescue team did not receive venovenous extracorporeal membrane oxygenation. Patients who underwent lung rescue team evaluation had a shorter duration of mechanical ventilation (p = 0.03) and shorter ICU length of stay (p = 0.03). There were no differences between groups in in-hospital, 30-day, or 1-year mortality. CONCLUSIONS: In this hypothesis-generating study, individualized optimization of mechanical ventilation of patients with acute respiratory distress syndrome and obesity by a lung rescue team was associated with a decrease in the utilization of venovenous extracorporeal membrane oxygenation, duration of mechanical ventilation, and ICU length of stay. Mortality was not modified by the lung rescue team intervention.

COVID-19 and VILI: developing a mobile app for measurement of mechanical power at a glance.

The COVID-19 pandemic has increased the need for a bedside tool for lung mechanics assessment and ventilator-induced lung injury (VILI) monitoring. Mechanical power is a unifying concept including all the components which can possibly cause VILI (volume, pressures, flow, respiratory rate), but the complexity of its mathematical computation makes it not so feasible in routine practice and limits its clinical use. In this letter, we describe the development of a mobile application that allows to simply measure power associated with mechanical ventilation, identifying each component (respiratory rate, resistance, driving pressure, PEEP volume) as well. The major advantage, according to the authors who developed this mathematical description of mechanical power, is that it enables the quantification of the relative contribution of its different components (tidal volume, driving pressure, respiratory rate, resistance). Considering the potential role of medical apps to improve work efficiency, we developed an open source Progressive Web Application (PWA), named "PowerApp" (freely available at https://mechpower.goodbarber.app ), in order to easily obtain a bedside measurement of mechanical power and its components. It also allows to predict how the modification of ventilatory settings or physiological conditions would affect power and each relative component. The "PowerApp" allows to measure mechanical power at a glance during mechanical ventilation, without complex mathematical computation, and making mechanical power equation useful and feasible for everyday clinical practice.

Lung mechanics in type L CoVID-19 pneumonia: a pseudo-normal ARDS.

BACKGROUND: This study was conceived to provide systematic data about lung mechanics during early phases of CoVID-19 pneumonia, as long as to explore its variations during prone positioning. METHODS: We enrolled four patients hospitalized in the Intensive Care Unit of "M. Bufalini" hospital, Cesena (Italy); after the positioning of an esophageal balloon, we measured mechanical power, respiratory system and transpulmonary parameters and arterial blood gases every 6 hours, just before decubitus change and 1 hour after prono-supination. RESULTS: Both respiratory system and transpulmonary compliance and driving pressure confirmed the pseudo-normal respiratory mechanics of early CoVID-19 pneumonia (respectively, CRS 40.8 ml/cmH2O and DPRS 9.7 cmH2O; CL 53.1 ml/cmH2O and DPL 7.9 cmH2O). Interestingly, prone positioning involved a worsening in respiratory mechanical properties throughout time (CRS,SUP 56.3 ml/cmH2O and CRS,PR 41.5 ml/cmH2O - P 0.37; CL,SUP 80.8 ml/cmH2O and CL,PR 53.2 ml/cmH2O - P 0.23). CONCLUSIONS: Despite the severe ARDS pattern, respiratory system and lung mechanical properties during CoVID-19 pneumonia are pseudo-normal and tend to worsen during pronation. TRIAL REGISTRATION: Restrospectively registered.