Background/Objectives: Attaining adequate oxygenation in critically ill patients undergoing invasive ventilation necessitates intense monitoring through pulse oximetry (SpO2) and frequent manual adjustments of ventilator settings like the fraction of inspired oxygen (FiO2) and the level of positive end-expiratory pressure (PEEP). Our aim was to compare the quality of oxygenation with the use of automated ventilation provided by INTELLiVENT-Adaptive Support Ventilation (ASV) vs. ventilation that is not automated, i.e., conventional pressure-controlled or pressure support ventilation. Methods: A substudy within a randomized crossover clinical trial in critically ill patients under invasive ventilation. The primary endpoint was the percentage of breaths in an optimal oxygenation zone, defined by predetermined levels of SpO2, FiO2, and PEEP. Secondary endpoints were the percentage of breaths in acceptable or critical oxygenation zones, the percentage of time spent in optimal, acceptable, and critical oxygenation zones, the number of manual interventions at the ventilator, and the number and duration of ventilator alarms related to oxygenation. Results: Of the 96 patients included in the parent study, 53 were eligible for this current subanalysis. Among them, 31 patients were randomized to start with automated ventilation, while 22 patients began with conventional ventilation. No significant differences were found in the percentage of breaths within the optimal zone between the two ventilation modes (median percentage of breaths during automated ventilation 19.4 [0.1-99.9]% vs. 25.3 [0.0-100.0]%; p = 0.963). Similarly, there were no differences in the percentage of breaths within the acceptable and critical zones, nor in the time spent in the three predefined oxygenation zones. Although the number of manual interventions was lower with automated ventilation, the number and duration of ventilator alarms were fewer with conventional ventilation. Conclusions: The quality of oxygenation with automated ventilation is not different from that with conventional ventilation. However, while automated ventilation comes with fewer manual interventions at the ventilator, it also comes with more ventilator alarms.

Abstract Background Ventilation management may differ between COVID–19 ARDS (COVID–ARDS) patients and patients with pre–COVID ARDS (CLASSIC–ARDS); it is uncertain whether associations of ventilation management with outcomes for CLASSIC–ARDS also exist in COVID–ARDS. Methods Individual patient data analysis of COVID–ARDS and CLASSIC–ARDS patients in six observational studies of ventilation, four in the COVID–19 pandemic and two pre–pandemic. Descriptive statistics were used to compare epidemiology and ventilation characteristics. The primary endpoint were key ventilation parameters; other outcomes included mortality and ventilator–free days and alive (VFD–60) at day 60. Results This analysis included 6702 COVID–ARDS patients and 1415 CLASSIC–ARDS patients. COVID–ARDS patients received lower median VT (6.6 [6.0 to 7.4] vs 7.3 [6.4 to 8.5] ml/kg PBW; p < 0.001) and higher median PEEP (12.0 [10.0 to 14.0] vs 8.0 [6.0 to 10.0] cm H2O; p < 0.001), at lower median ΔP (13.0 [10.0 to 15.0] vs 16.0 [IQR 12.0 to 20.0] cm H2O; p < 0.001) and higher median Crs (33.5 [26.6 to 42.1] vs 28.1 [21.6 to 38.4] mL/cm H2O; p < 0.001). Following multivariable adjustment, higher ΔP had an independent association with higher 60–day mortality and less VFD–60 in both groups. Higher PEEP had an association with less VFD–60, but only in COVID–ARDS patients. Conclusions Our findings show important differences in key ventilation parameters and associations thereof with outcomes between COVID–ARDS and CLASSIC–ARDS. Trial registration Clinicaltrials.gov (identifier NCT05650957), December 14, 2022.

Epidemiology, ventilator management, and outcomes in patients with acute respiratory distress syndrome (ARDS) because of coronavirus disease 2019 (COVID-19) have been described extensively but have never been compared between countries. We performed an individual patient data analysis of four observational studies to compare epidemiology, ventilator management, and outcomes. We used propensity score weighting to control for confounding factors. The analysis included 6,702 patients: 1,500 from Argentina, 844 from Brazil, 975 from the Netherlands, and 3,383 from Spain. There were substantial differences in baseline characteristics between countries. There were small differences in ventilation management. Intensive care unit mortality was higher in Argentina and Brazil compared with the Netherlands and Spain (59.6% and 56.6% versus 32.1% and 34.7%; P <0.001). The median number of days free from ventilation and alive at day 28 was equally low (0 [0-7], 0 [0-18], 1 [0-16], and 0 [0-16] days, respectively; P = 0.03), and the median number of days free from ventilation and alive at day 60 was higher in the Netherlands and Spain (0 [0-37], 0 [0-50], 33 [0-48], and 26 [0-48] days, respectively; P <0.001). Propensity score matching confirmed the outcome differences. Thus, the outcome of COVID-19 ARDS patients in Argentina and Brazil was substantially worse compared with that of patients in the Netherlands and Spain. It is unlikely that this results from differences in case mix or ventilation management.

INTRODUCTION:Mechanical power of ventilation, a summary parameter reflecting the energy transferred from the ventilator to the respiratory system, has associations with outcomes. INTELLiVENT-Adaptive Support Ventilation is an automated ventilation mode that changes ventilator settings according to algorithms that target a low work-and force of breathing. The study aims to compare mechanical power between automated ventilation by means of INTELLiVENT-Adaptive Support Ventilation and conventional ventilation in critically ill patients. MATERIALS AND METHODS:International, multicenter, randomized crossover clinical trial in patients that were expected to need invasive ventilation > 24 hours. Patients were randomly assigned to start with a 3-hour period of automated ventilation or conventional ventilation after which the alternate ventilation mode was selected. The primary outcome was mechanical power in passive and active patients; secondary outcomes included key ventilator settings and ventilatory parameters that affect mechanical power. RESULTS:A total of 96 patients were randomized. Median mechanical power was not different between automated and conventional ventilation (15.8 [11.5-21.0] versus 16.1 [10.9-22.6] J/min; mean difference -0.44 (95%-CI -1.17 to 0.29) J/min; P = 0.24). Subgroup analyses showed that mechanical power was lower with automated ventilation in passive patients, 16.9 [12.5-22.1] versus 19.0 [14.1-25.0] J/min; mean difference -1.76 (95%-CI -2.47 to -10.34J/min; P < 0.01), and not in active patients (14.6 [11.0-20.3] vs 14.1 [10.1-21.3] J/min; mean difference 0.81 (95%-CI -2.13 to 0.49) J/min; P = 0.23). CONCLUSIONS:In this cohort of unselected critically ill invasively ventilated patients, automated ventilation by means of INTELLiVENT-Adaptive Support Ventilation did not reduce mechanical power. A reduction in mechanical power was only seen in passive patients. STUDY REGISTRATION:Clinicaltrials.gov (study identifier NCT04827927), April 1, 2021. URL OF TRIAL REGISTRY RECORD:https://clinicaltrials.gov/study/NCT04827927?term=intellipower&rank=1.

Objective: We determined the prevalences of hyperoxemia and excessive oxygen use, and the epidemiology, ventilation characteristics and outcomes associated with hyperoxemia in invasively ventilated patients with coronavirus disease 2019 (COVID-19). Methods: Post hoc analysis of a national, multicentre, observational study in 22 ICUs. Patients were classified in the first two days of invasive ventilation as 'hyperoxemic' or 'normoxemic'. The co-primary endpoints were prevalence of hyperoxemia (PaO2 > 90 mmHg) and prevalence of excessive oxygen use (FiO(2) >= 60% while PaO2 > 90 mmHg or SpO(2) > 92%). Secondary endpoints included ventilator settings and ventilation parameters, duration of ventilation, length of stay (LOS) in ICU and hospital, and mortality in ICU, hospital, and at day 28 and 90. We used propensity matching to control for observed confounding factors that may influence endpoints. Results: Of 851 COVID-19 patients, 225 (26.4%) were classified as hyperoxemic. Excessive oxygen use occurred in 385 (45.2%) patients. Acute respiratory distress syndrome (ARDS) severity was lowest in hyperoxemic patients. Hyperoxemic patients were ventilated with higher positive end-expiratory pressure (PEEP), while rescue therapies for hypoxemia were applied more often in normoxemic patients. Neither in the unmatched nor in the matched analysis were there differences between hyperoxemic and normoxemic patients with regard to any of the clinical outcomes. Conclusion: In this cohort of invasively ventilated COVID-19 patients, hyperoxemia occurred often and so did excessive oxygen use. The main differences between hyperoxemic and normoxemic patients were ARDS severity and use of PEEP. Clinical outcomes were not different between hyperoxemic and normoxemic patients.

Background: Ventilation with lower positive end–expiratory pressure (PEEP) may cause loss of lung aeration in critically ill invasively ventilated patients. This study investigated whether a systematic lung ultrasound (LUS) scoring system can detect such changes in lung aeration in a study comparing lower versus higher PEEP in invasively ventilated patients without acute respiratory distress syndrome (ARDS). Methods: Single center substudy of a national, multicenter, randomized clinical trial comparing lower versus higher PEEP ventilation strategy. Fifty–seven patients underwent a systematic 12–region LUS examination within 12 h and between 24 to 48 h after start of invasive ventilation, according to randomization. The primary endpoint was a change in the global LUS aeration score, where a higher value indicates a greater impairment in lung aeration. Results: Thirty–three and twenty–four patients received ventilation with lower PEEP (median PEEP 1 (0–5) cm H2O) or higher PEEP (median PEEP 8 (8–8) cm H2O), respectively. Median global LUS aeration scores within 12 h and between 24 and 48 h were 8 (4 to 14) and 9 (4 to 12) (difference 1 (–2 to 3)) in the lower PEEP group, and 7 (2–11) and 6 (1–12) (difference 0 (–2 to 3)) in the higher PEEP group. Neither differences in changes over time nor differences in absolute scores reached statistical significance. Conclusions: In this substudy of a randomized clinical trial comparing lower PEEP versus higher PEEP in patients without ARDS, LUS was unable to detect changes in lung aeration.

ABSTRACT. The COVID–19 pandemic led to local oxygen shortages worldwide. To gain a better understanding of oxygen consumption with different respiratory supportive therapies, we conducted an international multicenter observational study to determine the precise amount of oxygen consumption with high-flow nasal oxygen (HFNO) and with mechanical ventilation. A retrospective observational study was conducted in three intensive care units (ICUs) in the Netherlands and Spain. Patients were classified as HFNO patients or ventilated patients, according to the mode of oxygen supplementation with which a patient started. The primary endpoint was actual oxygen consumption; secondary endpoints were hourly and total oxygen consumption during the first two full calendar days. Of 275 patients, 147 started with HFNO and 128 with mechanical ventilation. Actual oxygen use was 4.9-fold higher in patients who started with HFNO than in patients who started with ventilation (median 14.2 [8.4–18.4] versus 2.9 [1.8–4.1] L/minute; mean difference = 11.3 [95% CI 11.0–11.6] L/minute; P < 0.01). Hourly and total oxygen consumption were 4.8-fold (P < 0.01) and 4.8-fold (P < 0.01) higher. Actual oxygen consumption, hourly oxygen consumption, and total oxygen consumption are substantially higher in patients that start with HFNO compared with patients that start with mechanical ventilation. This information may help hospitals and ICUs predicting oxygen needs during high-demand periods and could guide decisions regarding the source of distribution of medical oxygen.

Objective Invasively ventilated patients with acute respiratory failure related to coronavirus disease 2019 (COVID–19) potentially benefit from tracheostomy. The aim of this study was to determine the practice of tracheostomy during the first wave of the pandemic in 2020 in the Netherlands, to ascertain whether timing of tracheostomy had an association with outcome, and to identify factors that had an association with timing.Methods Secondary analysis of the ‘PRactice of VENTilation in COVID–19’ (PRoVENT–COVID) study, a multicenter observational study, conducted from March 1, 2020 through June 1, 2020 in 22 Dutch intensive care units (ICU) in the Netherlands. The primary endpoint was the proportion of patients receiving tracheostomy; secondary endpoints were timing of tracheostomy, duration of ventilation, length of stay in ICU and hospital, mortality, and factors associated with timing.Results Of 1023 patients, 189 patients (18.5%) received a tracheostomy at median 21 [17 to 28] days from start of ventilation. Timing was similar before and after online publication of an amendment to the Dutch national guidelines on tracheostomy focusing on COVID–19 patients (21 [17–28] vs. 21 [17–26] days). Tracheostomy performed ≤ 21 days was independently associated with shorter duration of ventilation (median 26 [21 to 32] vs. 40 [34 to 47] days) and higher mortality in ICU (22.1% vs. 10.2%), hospital (26.1% vs. 11.9%) and at day 90 (27.6% vs. 14.6%). There were no patient demographics or ventilation characteristics that had an association with timing of tracheostomy.Conclusions Tracheostomy was performed late in COVID–19 patients during the first wave of the pandemic in the Netherlands and timing of tracheostomy possibly had an association with outcome. However, prospective studies are needed to further explore these associations. It remains unknown which factors influenced timing of tracheostomy in COVID–19 patients.

Introduction: We analyzed the association of age with ventilation practice and outcomes in critically ill COVID-19 patients requiring invasive ventilation. Methods: Posthoc analysis of the PRoVENT-COVID study, an observational study performed in 22 ICUs in the first 3 months of the national outbreak in the Netherlands. The coprimary endpoint was a set of ventilator parameters, including tidal volume normalized for predicted bodyweight, positive end-expiratory pressure, driving pressure, and respiratory system compliance in the first 4 days of invasive ventilation. Secondary endpoints were other ventilation parameters, the use of rescue therapies, pulmonary and extrapulmonary complications in the first 28 days in the ICU, hospital- and ICU stay, and mortality. Results: 1122 patients were divided into four groups based on age quartiles. No meaningful differences were found in ventilation parameters and in the use of rescue therapies for refractory hypoxemia in the first 4 days of invasive ventilation. Older patients received more often a tracheostomy, developed more frequently acute kidney injury and myocardial infarction, stayed longer in hospital and ICU, and had a higher mortality. Conclusions: In this cohort of invasively ventilated critically ill COVID-19 patients, age had no effect on ventilator management. Higher age was associated with more complications, longer length of stay in ICU and hospital and a higher mortality.

Background INTELLiVENT–Adaptive Support Ventilation (ASV) is a fully automated closed-loop mode of ventilation for use in critically ill patients. Evidence for benefit of INTELLiVENT–ASV in comparison to ventilation that is not fully automated with regard to duration of ventilation and quality of breathing is largely lacking. We test the hypothesis that INTELLiVENT–ASV shortens time spent on a ventilator and improves the quality of breathing. Methods The “Effects of Automated Closed–loop VenTilation versus Conventional Ventilation on Duration and Quality of Ventilation” (ACTiVE) study is an international, multicenter, two-group randomized clinical superiority trial. In total, 1200 intensive care unit (ICU) patients with an anticipated duration of ventilation of > 24 h will be randomly assigned to one of the two ventilation strategies. Investigators screen patients aged 18 years or older at start of invasive ventilation in the ICU. Patients either receive automated ventilation by means of INTELLiVENT–ASV, or ventilation that is not automated by means of a conventional ventilation mode. The primary endpoint is the number of days free from ventilation and alive at day 28; secondary endpoints are quality of breathing using granular breath-by-breath analysis of ventilation parameters and variables in a time frame of 24 h early after the start of invasive ventilation, duration of ventilation in survivors, ICU and hospital length of stay (LOS), and mortality rates in the ICU and hospital, and at 28 and 90 days. Discussion ACTiVE is one of the first randomized clinical trials that is adequately powered to compare the effects of automated closed-loop ventilation versus conventional ventilation on duration of ventilation and quality of breathing in invasively ventilated critically ill patients. The results of ACTiVE will support intensivist in their choices regarding the use of automated ventilation. Trial registration ACTiVE is registered in clinicaltrials.gov (study identifier: NCT04593810 ) on 20 October 2020.

The aim of this study was to investigate whether lower PEEP (positive end-expiratory pressure) had beneficial effects on myocardial function among intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) compared to higher PEEP. In this pre-planned substudy of a randomized controlled trial (RELAx), comparing lower to higher PEEP, 44 patients underwent transthoracic echocardiography. The exclusion criteria were known poor left ventricular function and severe shock requiring high dosages of norepinephrine. To create contrast, we also excluded patients who received PEEP between 2 cmH2O and 7 cmH2O in the two randomization arms of the study. The primary outcome was the right ventricular myocardial performance index (MPI), a measure of systolic and diastolic function. The secondary outcomes included systolic and diastolic function parameters. A total of 20 patients were ventilated with lower PEEP (mean ± SD, 0 ± 1 cmH2O), and 24 patients, with higher PEEP (8 ± 1 cmH2O) (mean difference, −8 cmH2O; 95% CI: −8.1 to −7.9 cmH2O; p = 0.01). The tidal volume size was low in both groups (median (IQR), 7.2 (6.3 to 8.1) versus 7.0 (5.3 to 9.1) ml/kg PBW; p = 0.97). The median right ventricular MPI was 0.32 (IQR, 0.26 to 0.39) in the lower-PEEP group versus 0.38 (0.32 to 0.41) in the higher-PEEP group; the median difference was –0.03; 95% CI: −0.11 to 0.03; p = 0.33. The other systolic and diastolic parameters were similar. In patients without ARDS ventilated with a low tidal volume, a lower PEEP had no beneficial effects on the right ventricular MPI.

INTRODUCTION:It is uncertain whether ventilation in patients with acute respiratory failure related to coronavirus disease 2019 (COVID-19) differs from that in patients with acute respiratory distress syndrome (ARDS) from another origin.AREAS COVERED:We undertook two literature searches in PubMed to identify observational studies reporting on ventilation management--one in patients with acute respiratory failure related to COVID-19, and one in patients with ARDS from another origin. The searches identified 14 studies in patients with acute respiratory failure related to COVID-19, and 8 studies in patients with ARDS from another origin.EXPERT OPINION:In patients with acute respiratory failure related to COVID-19, ventilation management seems to be similar to that of patients with ARDS from another origin. The future lies in studies focused on personalized treatment of ARDS of all origins, including COVID-19.

INTRODUCTION Surrogates for impaired ventilation such as estimated dead-space fractions and the ventilatory ratio are independently associated with an increased risk of mortality in the acute respiratory distress syndrome (ARDS) and small case series of COVID-19 related ARDS. METHODS This study aimed to quantify the dynamics and determine the prognostic value of surrogate markers of impaired ventilation in patients with COVID-19 related ARDS. The present study is a secondary analysis of the PRactice Of VENTilation in COVID-19 patients (PROVENT-COVID) in 22 intensive care unit hospitals in the Netherlands. Surrogates of impaired ventilation such as the estimated dead space fraction (by Harris-Benedict-VD/VT HB and direct method-VD/VT DIR), ventilatory ratio (VR), and end-tidal-to-arterial PCO2 ratio (PETCO2/PaCO2) were used. RESULTS 927 consecutive patients admitted with COVID-19 related ARDS were included in this study. Surrogates of impaired ventilation were significantly higher in non-survivors than survivors at baseline and during the following days of mechanical ventilation (p &lt;0.001). As ARDS severity increased, mortality increased with successive tertiles for VD/VT HB and VD/VT DIR, and VR, and decreased with successive tertiles for PETCO2/PaCO2. Mortality over the first 28 days was higher in patients in the high group of dead space fraction by VD/VT HB (16.4% vs. 12.3%;p = 0.003), but similar in the groups considering the dead space fraction by VD/VT DIR (15.4% vs. 13.3%;p = 0.100), and VR (15.5% vs. 13.2%;p = 0.080) (Figure 2). After adjustment for a base risk model that included chronic comorbidities, ventilation and oxygenation parameters, none of the surrogates of impaired ventilation measured at the start of ventilation or the following days were significantly associated with 28-day mortality. CONCLUSION Surrogate markers for impaired ventilation are abnormal at the start of invasive ventilation in patients with COVID-19 related ARDS and worsen during consequent days. Ventilation impairment seems to be more extensive in non-survivors than in survivors, but they do not yield prognostic information when added to a baseline risk model. In the absence of bedside capnography, surrogates of impaired ventilation may serve as an important tool to assess the severity of COVID-19 related ARDS along with other variables such as oxygenation abnormalities and respiratory mechanics.

BACKGROUND There is uncertainty about how much positive end-expiratory pressure (PEEP) should be used in patients with acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19). OBJECTIVE To investigate whether a higher PEEP strategy is superior to a lower PEEP strategy regarding the number of ventilator-free days (VFDs). DESIGN Multicentre observational study conducted from 1 March to 1 June 2020. SETTING AND PATIENTS Twenty-two ICUs in The Netherlands and 933 invasively ventilated COVID-19 ARDS patients. INTERVENTIONS Patients were categorised retrospectively as having received invasive ventilation with higher (n=259) or lower PEEP (n=674), based on the high and low PEEP/F iO2 tables of the ARDS Network, and using ventilator settings and parameters in the first hour of invasive ventilation, and every 8 h thereafter at fixed time points during the first four calendar days. We also used propensity score matching to control for observed confounding factors that might influence outcomes. MAIN OUTCOMES AND MEASURES The primary outcome was the number of VFDs. Secondary outcomes included distant organ failures including acute kidney injury (AKI) and use of renal replacement therapy (RRT), and mortality. RESULTS In the unmatched cohort, the higher PEEP strategy had no association with the median [IQR] number of VFDs (2.0 [0.0 to 15.0] vs. 0.0 [0.0 to 16.0] days). The median (95% confidence interval) difference was 0.21 (−3.34 to 3.78) days, P = 0.905. In the matched cohort, the higher PEEP group had an association with a lower median number of VFDs (0.0 [0.0 to 14.0] vs. 6.0 [0.0 to 17.0] days) a median difference of −4.65 (−8.92 to −0.39) days, P = 0.032. The higher PEEP strategy had associations with higher incidence of AKI (in the matched cohort) and more use of RRT (in the unmatched and matched cohorts). The higher PEEP strategy had no association with mortality. CONCLUSION In COVID-19 ARDS, use of higher PEEP may be associated with a lower number of VFDs, and may increase the incidence of AKI and need for RRT. TRIAL REGISTRATION Practice of VENTilation in COVID-19 is registered at ClinicalTrials.gov, NCT04346342.

Background: The effects of VT and PEEP on myocardial performance is uncertain in patients without ARDS. We compared lower vs intermediate VT and lower vs higher PEEP on right ventricular function. Methods: Posthoc analysis of one single-center substudy of a RCT comparing lower vs intermediate VT (the ‘PReVENT’ study, JAMA 2018; 320:1872) and one single-center substudy of a RCT comparing lower vs higher PEEP (the ‘RELAx’ study, JAMA 2020; 324: 2509) in invasively ventilated critically ill patients without ARDS. In both substudies, patients underwent transthoracic echocardiography within 24–48 hours after start of invasive ventilation according to randomization. The primary outcome of both substudies was the right ventricular ‘myocardial performance index’ (MPIRV). The MPIRV is a measure of systolic and diastolic function – a lower value indicates a better function. Results: 21 patients were ventilated with lower VT (7 ml/kg PBW) and 20 patients with intermediate VT (10 ml/kg PBW) in the PReVENT study – likewise 20 patients were ventilated with lower PEEP (0 cm H2O) and 24 patients with higher PEEP (8 cm H2O) in the RELAx study. The primary endpoint is presented in the table. Conclusions: In ICU patients without ARDS, lower VT and lower PEEP result in a better performance of right ventricular function compared to intermediate VT and higher PEEP.

Background: It is uncertain how to set PEEP/FiO2 in patients with COVID–19 ARDS. Aims and objective: To determine if higher PEEP/lower FiO2 is superior to lower PEEP/higher FiO2. Methods: Observational study (PRoVENT–COVID, PMID 33169671) in 22 ICUs in The Netherlands. Patients were categorized as having received higher or lower PEEP according to the higher PEEP/lower FiO2 or lower PEEP/higher FiO2 ARDS Network tables. Propensity score matching was used to control for confounding factors. The primary outcome was the number ventilator–free days at day 28 (VFD); secondary outcomes were acute kidney injury (AKI), use of renal replacement therapy (RRT), and mortality. Results: 259 vs 674 patients received higher or lower PEEP; 468 patients were matched. In the higher PEEP group, median number of VFD was lower (0 [0–14] vs 6 [0–17] days; OR –4·65 [95%CI, –8·92 to –·39]; P=.032) (Figure) and AKI (56 vs 46%; OR 1·49 [1·02–2·18]; P=.039) and RRT occurred more often (26 vs 18%; OR 1·58 [1·01–2·46]; P=.045). Mortality rates at 28 (31 vs 27%; OR 1·30 [0·9–1·88]; P=.17; Figure) and 90–days (36 vs 36%; OR 1·15 [0·81–1·64]; P=.43) was not different between the two groups. Conclusion: Compared to ventilation with lower PEEP/higher FiO2, ventilation with higher PEEP/lower FiO2 is associated with a lower number of VFD, a higher incidence of AKI and RRT, and similar mortality rates in COVID–19 ARDS patients.

Introduction: INTELLiVENT-Adaptive Support Ventilation (INTELLiVENT-ASV), an advanced closed-loop ventilation mode for use in intensive care unit (ICU) patients, is equipped with algorithms that automatically adjust settings on the basis of physiologic signals and patient's activity. Here we describe its effectiveness, safety, and efficacy in various types of ICU patients.Areas covered: A systematic search conducted in MEDLINE, EMBASE, the Cochrane Central register of Controlled Trials (CENTRAL), and in Google Scholar identified 10 randomized clinical trials.Expert opinion: Studies suggest INTELLiVENT-ASV to be an effective automated mode with regard to the titrations of tidal volume, airway pressure, and oxygen. INTELLiVENT-ASV is as safe as conventional modes. However, thus far studies have not shown INTELLiVENT-ASV to be superior to conventional modes with regard to duration of ventilation and other patient-centered outcomes. Future studies are needed to test its efficacy.

Background: The SpO(2)/FiO(2) is a useful oxygenation parameter with prognostic capacity in patients with ARDS. We investigated the prognostic capacity of SpO(2)/FiO(2) for mortality in patients with ARDS due to COVID-19. Methods: This was a post-hoc analysis of a national multicenter cohort study in invasively ventilated patients with ARDS due to COVID-19. The primary endpoint was 28-day mortality. Results: In 869 invasively ventilated patients, 28-day mortality was 30.1%. The SpO(2)/FiO(2) on day 1 had no prognostic value. The SpO(2)/FiO(2) on day 2 and day 3 had prognostic capacity for death, with the best cut-offs being 179 and 199, respectively. Both SpO(2)/FiO(2) on day 2 (OR, 0.66 [95%-CI 0.46-0.96]) and on day 3 (OR, 0.70 [95%-CI 0.51-0.96]) were associated with 28-day mortality in a model corrected for age, pH, lactate levels and kidney dysfunction (AUROC 0.78 [0.76-0.79]). The measured PaO2/FiO(2) and the PaO2/FiO(2) calculated from SpO(2)/FiO(2) were strongly correlated (Spearman's r = 0.79). Conclusions: In this cohort of patients with ARDS due to COVID-19, the SpO(2)/FiO(2) on day 2 and day 3 are independently associated with and have prognostic capacity for 28-day mortality. The SpO(2)/FiO(2) is a useful metric for risk stratification in invasively ventilated COVID-19 patients. (C) 2021 The Authors. Published by Elsevier Inc.

BackgroundLittle is known about the practice of ventilation management in patients with COVID-19. We aimed to describe the practice of ventilation management and to establish outcomes in invasively ventilated patients with COVID-19 in a single country during the first month of the outbreak.MethodsPRoVENT-COVID is a national, multicentre, retrospective observational study done at 18 intensive care units (ICUs) in the Netherlands. Consecutive patients aged at least 18 years were eligible for participation if they had received invasive ventilation for COVID-19 at a participating ICU during the first month of the national outbreak in the Netherlands. The primary outcome was a combination of ventilator variables and parameters over the first 4 calendar days of ventilation: tidal volume, positive end-expiratory pressure (PEEP), respiratory system compliance, and driving pressure. Secondary outcomes included the use of adjunctive treatments for refractory hypoxaemia and ICU complications. Patient-centred outcomes were ventilator-free days at day 28, duration of ventilation, duration of ICU and hospital stay, and mortality. PRoVENT-COVID is registered at ClinicalTrials.gov (NCT04346342).FindingsBetween March 1 and April 1, 2020, 553 patients were included in the study. Median tidal volume was 6·3 mL/kg predicted bodyweight (IQR 5·7–7·1), PEEP was 14·0 cm H2O (IQR 11·0–15·0), and driving pressure was 14·0 cm H2O (11·2–16·0). Median respiratory system compliance was 31·9 mL/cm H2O (26·0–39·9). Of the adjunctive treatments for refractory hypoxaemia, prone positioning was most often used in the first 4 days of ventilation (283 [53%] of 530 patients). The median number of ventilator-free days at day 28 was 0 (IQR 0–15); 186 (35%) of 530 patients had died by day 28. Predictors of 28-day mortality were gender, age, tidal volume, respiratory system compliance, arterial pH, and heart rate on the first day of invasive ventilation.InterpretationIn patients with COVID-19 who were invasively ventilated during the first month of the outbreak in the Netherlands, lung-protective ventilation with low tidal volume and low driving pressure was broadly applied and prone positioning was often used. The applied PEEP varied widely, despite an invariably low respiratory system compliance. The findings of this national study provide a basis for new hypotheses and sample size calculations for future trials of invasive ventilation for COVID-19. These data could also help in the interpretation of findings from other studies of ventilation practice and outcomes in invasively ventilated patients with COVID-19.FundingAmsterdam University Medical Centers, location Academic Medical Center.

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.