Background Flow-controlled ventilation is a novel ventilation method which allows to individualize ventilation according to dynamic lung mechanic limits based on direct tracheal pressure measurement at a stable constant gas flow during inspiration and expiration. The aim of this porcine study was to compare individualized flow-controlled ventilation (FCV) and current guideline-conform pressure-controlled ventilation (PCV) in long-term ventilation. Methods Anesthetized pigs were ventilated with either FCV or PCV over a period of 10 h with a fixed FiO2 of 0.3. FCV settings were individualized by compliance-guided positive end-expiratory pressure (PEEP) and peak pressure (Ppeak) titration. Flow was adjusted to maintain normocapnia and the inspiration to expiration ratio (I:E ratio) was set at 1:1. PCV was performed with a PEEP of 5 cm H2O and Ppeak was set to achieve a tidal volume (VT) of 7 ml/kg. The respiratory rate was adjusted to maintain normocapnia and the I:E ratio was set at 1:1.5. Repeated measurements during observation period were assessed by linear mixed-effects model. Results In FCV (n = 6), respiratory minute volume was significantly reduced (6.0 vs 12.7, MD − 6.8 (− 8.2 to − 5.4) l/min; p < 0.001) as compared to PCV (n = 6). Oxygenation was improved in the FCV group (paO2 119.8 vs 96.6, MD 23.2 (9.0 to 37.5) Torr; 15.97 vs 12.87, MD 3.10 (1.19 to 5.00) kPa; p = 0.010) and CO2 removal was more efficient (paCO2 40.1 vs 44.9, MD − 4.7 (− 7.4 to − 2.0) Torr; 5.35 vs 5.98, MD − 0.63 (− 0.99 to − 0.27) kPa; p = 0.006). Ppeak and driving pressure were comparable in both groups, whereas PEEP was significantly lower in FCV (p = 0.002). Computed tomography revealed a significant reduction in non-aerated lung tissue in individualized FCV (p = 0.026) and no significant difference in overdistended lung tissue, although a significantly higher VT was applied (8.2 vs 7.6, MD 0.7 (0.2 to 1.2) ml/kg; p = 0.025). Conclusion Our long-term ventilation study demonstrates the applicability of a compliance-guided individualization of FCV settings, which resulted in significantly improved gas exchange and lung tissue aeration without signs of overinflation as compared to best clinical practice PCV.

Background: Flow-controlled ventilation is a novel ventilation method which allows to individualize ventilation according to dynamic lung mechanic limits based on direct tracheal pressure measurement at a stable constant gas flow during inspiration and expiration. The aim of this porcine study was to compare individualized flow-controlled ventilation (FCV) and current guideline-conform pressure-controlled ventilation (PCV) in long-term ventilation.Methods: Anesthetized pigs were ventilated with either FCV or PCV over a period of ten hours with a fixed FiO2 of 0.3. FCV settings were individualized by compliance-guided positive end-expiratory pressure (PEEP) and peak pressure (Ppeak) titration. Flow was adjusted to maintain normocapnia and the inspiration to expiration ratio (I:E ratio) was set at 1:1. PCV was performed with a PEEP of 5 cm H2O and Ppeak was set to achieve a tidal volume (VT) of 7 ml/kg. The respiratory rate was adjusted to maintain normocapnia and the I:E ratio was set at 1:1.5. Repeated measurements during observation period were assessed by linear mixed-effects model.Results: In FCV (n=6) respiratory minute volume was significantly reduced (6.0 vs 12.7, MD -6.8 (-8.2 to -5.4) l/min; p<0.001) as compared to PCV (n=6). Oxygenation was improved in the FCV group (paO2 119.8 vs 96.6, MD 23.2 (9.0 to 37.5) torr; 15.97 vs 12.87, MD 3.10 (1.19 to 5.00) kPa; p=0.010) and CO2 removal was more efficient (paCO2 40.1 vs 44.9, MD -4.7 (-7.4 to -2.0) torr; 5.35 vs 5.98, MD -0.63 (-0.99 to -0.27) kPa; p=0.006). Ppeak and driving pressure were comparable in both groups, whereas PEEP was significantly lower in FCV (p=0.002). Computed tomography revealed a significant reduction in non-aerated lung tissue in individualized FCV (p=0.026) and no significant difference in overdistended lung tissue, although a significantly higher VT was applied (8.2 vs 7.6, MD 0.7 (0.2 to 1.2) ml/kg; p=0.025).Conclusion: Our long-term ventilation study demonstrates the applicability of a compliance-guided individualization of FCV settings, which resulted in significantly improved gas exchange and lung tissue aeration without signs of overinflation as compared to best clinical practice PCV.

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Innsbruck Medical University Hospital, Austria, provides the highest level of care for a region of approximately 1.8 million people. During the early COVID-19 outbreak in spring 2020 surgical activity was drastically reduced with the prime goal of preserving hospital capacities, especially intensive care beds. We conducted a retrospective analysis of surgical activities performed at Innsbruck Medical University Hospital during the lockdown period from March 15 to April 14, 2020 and compared these activities to the same period during the previous 5 years. Total surgical activity was reduced by 65.4% compared to the same period during the previous 5 years (p &lt; 0.001); elective surgeries were reduced by 88.7%, acute surgeries by 35.3% and oncological surgeries by 47.8% compared to the previous 5 years (all p &lt; 0.001). This dramatic decrease in acute and oncological surgeries can most likely be ascribed to the fact that many patients avoided health care facilities because of the strict stay-at-home policy and/or the fear of contracting SARS-CoV-2 in the hospital. In view of future waves, the population should be encouraged to seek medical help for acute symptoms and to attend cancer screening programs.