Ventilatory Variables and Mechanical Power in Patients with Acute Respiratory Distress Syndrome

Background: Different positive end-expiratory pressure (PEEP) strategies are available for subjects with coronavirus disease 2019 (COVID-19)–induced acute respiratory distress syndrome (ARDS) requiring invasive mechanical ventilation. We aimed to evaluate three conventional PEEP strategies on their effects on respiratory mechanics, gas exchanges, and hemodynamics.Methods: This is a prospective, physiologic, multicenter study conducted in China. We recruited 20 intubated subjects with ARDS and confirmed COVID-19. We first set PEEP by the ARDSnet low PEEP–fraction of inspired oxygen (FIO2) table. After a recruitment maneuver, PEEP was set at 15, 10, and 5 cm H2O for 10 min, respectively. Among these three PEEP levels, best-compliance PEEP was the one providing the highest respiratory system compliance; best-oxygenation PEEP was the one providing the highest PaO2 (partial pressure of arterial oxygen)/FIO2.Results: At each PEEP level, we assessed respiratory mechanics, arterial blood gas, and hemodynamics. Among three PEEP levels, plateau pressure, driving pressure, mechanical power, and blood pressure improved with lower PEEP. The ARDSnet low PEEP–FIO2 table and the best-oxygenation strategies provided higher PEEP than the best-compliance strategy (11 ± 6 cm H2O vs. 11 ± 3 cm H2O vs. 6 ± 2 cm H2O, p = 0.001), leading to higher plateau pressure, driving pressure, and mechanical power. The three PEEP strategies were not significantly different in gas exchange. The subgroup analysis showed that three PEEP strategies generated different effects in subjects with moderate or severe ARDS (n = 12) but not in subjects with mild ARDS (n = 8).Conclusions: In our cohort with COVID-19–induced ARDS, the ARDSnet low PEEP/FIO2 table and the best-oxygenation strategies led to higher PEEP and potentially higher risk of ventilator-induced lung injury than the best-compliance strategy.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT04359251.

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Faculty Opinions recommendation of Ventilatory Variables and Mechanical Power in Patients with Acute Respiratory Distress Syndrome.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.739847496.793584853 ◽

2021 ◽

Author(s):

Maximilian Schaefer

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Distress Syndrome ◽

Mechanical Power

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Mechanical power in pediatric acute respiratory distress syndrome: a PARDIE study

Critical Care ◽

10.1186/s13054-021-03853-6 ◽

2022 ◽

Vol 26 (1) ◽

Author(s):

Anoopindar K. Bhalla ◽

Margaret J. Klein ◽

Vicent Modesto I Alapont ◽

Guillaume Emeriaud ◽

Martin C. J. Kneyber ◽

...

Keyword(s):

Mechanical Ventilation ◽

Acute Respiratory Distress Syndrome ◽

Intensive Care ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Distress Syndrome ◽

Mechanical Power ◽

Positive End Expiratory Pressure ◽

Ventilator Management ◽

Ventilation Management

Abstract Background Mechanical power is a composite variable for energy transmitted to the respiratory system over time that may better capture risk for ventilator-induced lung injury than individual ventilator management components. We sought to evaluate if mechanical ventilation management with a high mechanical power is associated with fewer ventilator-free days (VFD) in children with pediatric acute respiratory distress syndrome (PARDS). Methods Retrospective analysis of a prospective observational international cohort study. Results There were 306 children from 55 pediatric intensive care units included. High mechanical power was associated with younger age, higher oxygenation index, a comorbid condition of bronchopulmonary dysplasia, higher tidal volume, higher delta pressure (peak inspiratory pressure—positive end-expiratory pressure), and higher respiratory rate. Higher mechanical power was associated with fewer 28-day VFD after controlling for confounding variables (per 0.1 J·min−1·Kg−1 Subdistribution Hazard Ratio (SHR) 0.93 (0.87, 0.98), p = 0.013). Higher mechanical power was not associated with higher intensive care unit mortality in multivariable analysis in the entire cohort (per 0.1 J·min−1·Kg−1 OR 1.12 [0.94, 1.32], p = 0.20). But was associated with higher mortality when excluding children who died due to neurologic reasons (per 0.1 J·min−1·Kg−1 OR 1.22 [1.01, 1.46], p = 0.036). In subgroup analyses by age, the association between higher mechanical power and fewer 28-day VFD remained only in children < 2-years-old (per 0.1 J·min−1·Kg−1 SHR 0.89 (0.82, 0.96), p = 0.005). Younger children were managed with lower tidal volume, higher delta pressure, higher respiratory rate, lower positive end-expiratory pressure, and higher PCO2 than older children. No individual ventilator management component mediated the effect of mechanical power on 28-day VFD. Conclusions Higher mechanical power is associated with fewer 28-day VFDs in children with PARDS. This association is strongest in children < 2-years-old in whom there are notable differences in mechanical ventilation management. While further validation is needed, these data highlight that ventilator management is associated with outcome in children with PARDS, and there may be subgroups of children with higher potential benefit from strategies to improve lung-protective ventilation. Take Home Message: Higher mechanical power is associated with fewer 28-day ventilator-free days in children with pediatric acute respiratory distress syndrome. This association is strongest in children <2-years-old in whom there are notable differences in mechanical ventilation management.

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Mechanical Power During Extracorporeal Membrane Oxygenation and Hospital Mortality in Patients With Acute Respiratory Distress Syndrome

10.21203/rs.3.rs-92705/v1 ◽

2020 ◽

Author(s):

Li-Chung Chiu ◽

Shih-Wei Lin ◽

Li-Pang Chuang ◽

Hsin-Hsien Li ◽

Pi-Hua Liu ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Extracorporeal Membrane Oxygenation ◽

Hospital Mortality ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Respiratory System ◽

Distress Syndrome ◽

Mechanical Power ◽

Day Hospital ◽

Membrane Oxygenation

Abstract Background: Mechanical power (MP) refers to the energy delivered by a ventilator to the respiratory system per unit of time. MP normalized to predicted body weight (PBW) or respiratory system compliance have better predictive value for mortality than MP alone in acute respiratory distress syndrome (ARDS). Our objective was to assess the potential impact of consecutive changes of normalized MP on hospital mortality among ARDS patients receiving extracorporeal membrane oxygenation (ECMO).Methods: We performed a secondary analysis of patients with severe ARDS receiving ECMO in a tertiary care referral center in Taiwan between May 2006 and October 2015. Serial changes of MP during ECMO were recorded. Results: A total of 152 patients with severe ARDS rescued with ECMO were analyzed. Overall hospital mortality was 53.3 %. There were no significant differences between survivors and nonsurvivors in terms of baseline values of MP or other ventilator settings. Cox regression models demonstrated that MP alone, MP normalized to PBW, and MP normalized to compliance during the first 3 days of ECMO were all independently associated with hospital mortality. Higher MP normalized to compliance (HR 2.289 [95% CI 1.214-4.314], p = 0.010) was associated with a higher risk of death than MP itself (HR 1.060 [95% CI 1.018-1.104], p = 0.005) or MP normalized to PBW (HR 1.004 [95% CI 1.002-1.007], p < 0.001). The 90-day hospital mortality of patients with high MP (> 14.4 J/min) during the first 3 days of ECMO was significantly higher than that of patients with low MP (≦ 14.4 J/min) (70.7 % versus 46.8 %, p = 0.004), and the 90-day hospital mortality of patients with high MP normalized to compliance (> 0.53 J/min/ml/cm H2O) during the first 3 days of ECMO was significantly higher than that of patients with low MP normalized to compliance (≦ 0.53 J/min/ml/cm H2O) (63.1 % versus 29.5 %, p < 0.001).Conclusions: MP during the first 3 days of ECMO was the only ventilator setting independently associated with 90-day hospital mortality, and MP normalized to compliance during ECMO was more predictive for mortality than was MP alone.

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Mechanical power during extracorporeal membrane oxygenation and hospital mortality in patients with acute respiratory distress syndrome

Critical Care ◽

10.1186/s13054-020-03428-x ◽

2021 ◽

Vol 25 (1) ◽

Author(s):

Li-Chung Chiu ◽

Shih-Wei Lin ◽

Li-Pang Chuang ◽

Hsin-Hsien Li ◽

Pi-Hua Liu ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Extracorporeal Membrane Oxygenation ◽

Hospital Mortality ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Respiratory System ◽

Distress Syndrome ◽

Mechanical Power ◽

Day Hospital ◽

Membrane Oxygenation

Abstract Background Mechanical power (MP) refers to the energy delivered by a ventilator to the respiratory system per unit of time. MP referenced to predicted body weight (PBW) or respiratory system compliance have better predictive value for mortality than MP alone in acute respiratory distress syndrome (ARDS). Our objective was to assess the potential impact of consecutive changes of MP on hospital mortality among ARDS patients receiving extracorporeal membrane oxygenation (ECMO). Methods We performed a retrospective analysis of patients with severe ARDS receiving ECMO in a tertiary care referral center in Taiwan between May 2006 and October 2015. Serial changes of MP during ECMO were recorded. Results A total of 152 patients with severe ARDS rescued with ECMO were analyzed. Overall hospital mortality was 53.3%. There were no significant differences between survivors and nonsurvivors in terms of baseline values of MP or other ventilator settings. Cox regression models demonstrated that mean MP alone, MP referenced to PBW, and MP referenced to compliance during the first 3 days of ECMO were all independently associated with hospital mortality. Higher MP referenced to compliance (HR 2.289 [95% CI 1.214–4.314], p = 0.010) was associated with a higher risk of death than MP itself (HR 1.060 [95% CI 1.018–1.104], p = 0.005) or MP referenced to PBW (HR 1.004 [95% CI 1.002–1.007], p < 0.001). The 90-day hospital mortality of patients with high MP (> 14.4 J/min) during the first 3 days of ECMO was significantly higher than that of patients with low MP (≦ 14.4 J/min) (70.7% vs. 46.8%, p = 0.004), and the 90-day hospital mortality of patients with high MP referenced to compliance (> 0.53 J/min/ml/cm H2O) during the first 3 days of ECMO was significantly higher than that of patients with low MP referenced to compliance (≦ 0.53 J/min/ml/cm H2O) (63.6% vs. 29.7%, p < 0.001). Conclusions MP during the first 3 days of ECMO was the only ventilatory variable independently associated with 90-day hospital mortality, and MP referenced to compliance during ECMO was more predictive for mortality than was MP alone.

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