Normothermic Machine Perfusion Reduces Transfusion Requirements Even After Static Cold Storage: A 1 y Retrospective Single-center Analysis.

Background: Normothermic machine perfusion (NMP) of liver grafts has been shown to reduce intraoperative catecholamine consumption and the need for allogenic blood products after reperfusion compared with organs undergoing classical static cold storage (SCS). This study aimed to investigate the effects of an NMP phase after SCS (NMP after SCS) of liver grafts in terms of postreperfusion hemodynamics and transfusion requirements. Methods: Eighteen recipients of NMP after SCS grafts were matched according to recipient age, donor age, and model for end-stage liver disease score in a 1:2 ratio with recipients of an SCS graft. Postreperfusion hemodynamics and the need for catecholamines, blood products, and clotting factors were compared. Results: After reperfusion of the organ, patients in the NMP after SCS group showed significantly reduced transfusion requirements for packed red blood cells and platelet concentrates compared with patients of the SCS group (P < 0.001 and P = 0.018, respectively). In addition, patients in the NMP after SCS group received less fibrinogen concentrate (NMP after SCS group 0 [0-1.5] g versus SCS group 2 [0-4] g; P = 0.0163). No differences in postreperfusion hemodynamics could be detected between groups. Conclusions: This retrospective analysis shows that NMP reduces postreperfusion requirements of red blood cells, platelet concentrates, and fibrinogen concentrate even if installed after a phase of organ SCS, because it may be practiced on most centers where NMP is available.

Individualised flow-controlled ventilation reduces applied mechanical power and improves ventilation efficiency in a porcine intra-abdominal hypertension model.

BACKGROUND: Aim of this study was to evaluate feasibility and effects of individualised flow-controlled ventilation (FCV), based on compliance guided pressure settings, compared to standard of pressure-controlled ventilation (PCV) in a porcine intra-abdominal hypertension (IAH) model. The primary aim of this study was to investigate oxygenation. Secondary aims were to assess respiratory and metabolic variables and lung tissue aeration. METHODS: Pigs were randomly assigned to FCV (n = 9) and PCV (n = 9). IAH was induced by insufflation of air into the abdomen to induce IAH grades ranging from 0 to 3. At each IAH grade FCV was undertaken using compliance guided pressure settings, or PCV (n = 9) was undertaken with the positive end-expiratory pressure titrated for maximum compliance and the peak pressure set to achieve a tidal volume of 7 ml/kg. Gas exchange, ventilator settings and derived formulas were recorded at two timepoints for each grade of IAH. Lung aeration was assessed by a computed tomography scan at IAH grade 3. RESULTS: All 18 pigs (median weight 54 kg [IQR 51-67]) completed the observation period of 4 h. Oxygenation was comparable at each IAH grade, but a significantly lower minute volume was required to secure normocapnia in FCV at all IAH grades (7.6 vs. 14.4, MD - 6.8 (95% CI - 8.5 to - 5.2) l/min; p < 0.001). There was also a significant reduction of applied mechanical power being most evident at IAH grade 3 (25.9 vs. 57.6, MD - 31.7 (95% CI - 39.7 to - 23.7) J/min; p < 0.001). Analysis of Hounsfield unit distribution of the computed tomography scans revealed a significant reduction in non- (5 vs. 8, MD - 3 (95% CI - 6 to 0) %; p = 0.032) and poorly-aerated lung tissue (7 vs. 15, MD - 6 (95% CI - 13 to - 3) %, p = 0.002) for FCV. Concomitantly, normally-aerated lung tissue was significantly increased (84 vs. 76, MD 8 (95% CI 2 to 15) %; p = 0.011). CONCLUSIONS: Individualised FCV showed similar oxygenation but required a significantly lower minute volume for CO2-removal, which led to a remarkable reduction of applied mechanical power. Additionally, there was a shift from non- and poorly-aerated lung tissue to normally-aerated lung tissue in FCV compared to PCV.

Interleukin-6 Levels During Normothermic Machine Perfusion Impact Postreperfusion Hemodynamics of Liver Graft Recipients: A Prospective Single-center Observational Study.

BACKGROUND: Hemodynamic instability after liver graft reperfusion increases recipient morbidity after liver transplantation. The etiologies of hemodynamic disturbances appear to be multifactorial and are poorly understood. Normothermic machine perfusion (NMP) provides an opportunity to analyze graft quality prior to transplantation. In the present study, we aim to investigate the influence of interleukin-6 (IL-6) levels during NMP on postreperfusion hemodynamics of the recipient. METHODS: Consecutive NMP-liver transplants at a single-center were prospectively analyzed. Perfusate samples were collected at the beginning, after 6 h, and at the end of perfusion and analyzed for IL-6 levels. Mean arterial pressure (MAP) and catecholamine consumption during surgery were recorded. IL-6 levels at the end of NMP were correlated to donor and perfusion characteristics as well as changes in MAP and catecholamine requirements during the anhepatic and reperfusion phase. RESULTS: IL-6 perfusate measurements were assessed in 77 livers undergoing NMP and transplantation. Donor age, sex, cold ischemic time, and NMP time did not correlate with IL-6 levels. Perfusates of donation after circulatory death grafts showed higher IL-6 levels at the end of NMP than donation after brain death grafts. However, IL-6 levels at the end of NMP correlated with catecholamine requirements and MAP in the reperfusion phase. Per log10 increase in IL-6 levels, an increase of 42% points in administered catecholamine dose was observed, despite MAP being decreased by 3.6% points compared to baseline values. CONCLUSIONS: IL-6 levels may be a predictor for recipient hemodynamic instability during liver reperfusion. Larger studies are needed to confirm this finding.

Hypertonic treatment of acute respiratory distress syndrome.

Many viral infections, including the COVID-19 infection, are associated with the hindrance of blood oxygenation due to the accumulation of fluid, inflammatory cells, and cell debris in the lung alveoli. This condition is similar to Acute Respiratory Distress Syndrome (ARDS). Mechanical positive-pressure ventilation is often used to treat this condition, even though it might collapse pulmonary capillaries, trapping red blood cells and lowering the lung's functional capillary density. We posit that the hyperosmotic-hyperoncotic infusion should be explored as a supportive treatment for ARDS. As a first step in verifying the feasibility of this ARDS treatment, we model the dynamics of alveolar fluid extraction by osmotic effects. These are induced by increasing blood plasma osmotic pressure in response to the increase of blood NaCl concentration. Our analysis of fluid drainage from a plasma-filled pulmonary alveolus, in response to the intravenous infusion of 100 ml of 1.28 molar NaCl solution, shows that alveoli empty of fluid in approximately 15 min. These modeling results are in accordance with available experimental and clinical data; no new data were collected. They are used to calculate the temporal change of blood oxygenation, as oxygen diffusion hindrance decreases upon absorption of the alveolar fluid into the pulmonary circulation. Our study suggests the extraordinary speed with which beneficial effects of the proposed ARDS treatment are obtained and highlight its practicality, cost-efficiency, and avoidance of side effects of mechanical origin.

Flow-controlled versus pressure-controlled ventilation in cardiac surgery with cardiopulmonary bypass - A single-center, prospective, randomized, controlled trial.

STUDY OBJECTIVE: Multifactorial comparison of flow-controlled ventilation (FCV) to standard of pressure-controlled ventilation (PCV) in terms of oxygenation in cardiac surgery patients after chest closure. DESIGN: Prospective, non-blinded, randomized, controlled trial. SETTING: Operating theatre at an university hospital, Austria. PATIENTS: Patients scheduled for elective, open, on-pump, cardiac surgery. INTERVENTIONS: Participants were randomized to either individualized FCV (compliance guided end-expiratory and peak pressure setting) or control of PCV (compliance guided end-expiratory pressure setting and tidal volume of 6-8 ml/kg) for the duration of surgery. MEASUREMENTS: The primary outcome measure was oxygenation (PaO2/FiO2) 15 min after intraoperative chest closure. Secondary endpoints included CO2-removal assessed as required minute volume to achieve normocapnia and lung tissue aeration assessed by Hounsfield unit distribution in postoperative computed tomography scans. MAIN RESULTS: Between April 2020 and April 2021 56 patients were enrolled and 50 included in the primary analysis (mean age 70 years, 38 (76%) men). Oxygenation, assessed by PaO2/FiO2, was significantly higher in the FCV group (n = 24) compared to the control group (PCV, n = 26) (356 vs. 309, median difference (MD) 46 (95% CI 3 to 90) mmHg; p = 0.038). Additionally, the minute volume required to obtain normocapnia was significantly lower in the FCV group (4.0 vs. 6.1, MD -2.0 (95% CI -2.5 to -1.5) l/min; p < 0.001) and correlated with a significantly lower exposure to mechanical power (5.1 vs. 9.8, MD -5.1 (95% CI -6.2 to -4.0) J/min; p < 0.001). Evaluation of lung tissue aeration revealed a significantly reduced amount of non-aerated lung tissue in FCV compared to PCV (5 vs. 7, MD -3 (95% CI -4 to -1) %; p < 0.001). CONCLUSIONS: In patients undergoing on-pump, cardiac surgery individualized FCV significantly improved oxygenation and lung tissue aeration compared to PCV. In addition, carbon dioxide removal was accomplished at a lower minute volume leading to reduced applied mechanical power.

[Anesthesia for organ transplant patients]. / Anästhesie bei organtransplantierten Patient:innen.

Organ transplant patients who must undergo nontransplant surgical interventions can be challenging for the anesthesiologists in charge. On the one hand, it is important to carefully monitor the graft function in the perioperative period with respect to the occurrence of a possible rejection reaction. On the other hand, the ongoing immunosuppression may have to be adapted to the perioperative requirements in terms of the active substance and the route of administration, the resulting increased risk of infection and possible side effects (e.g., myelosuppression, nephrotoxicity and impairment of wound healing) must be included in the perioperative treatment concept. Furthermore, possible persistent comorbidities of the underlying disease and physiological peculiarities as a result of the organ transplantation must be taken into account. Support can be obtained from the expertise of the respective transplantation center.

COVID-19 Pandemic Did not Influence Number of Oncologic and Emergency Surgeries: A Retrospective Cohort Study from a Tertiary Hospital in Austria.

BACKGROUND: Many articles described a massive decline in surgical procedures during the COVID-19 pandemic waves. Especially the reduction in oncologic and emergency procedures led to the concern that delays and cancelling surgical activity might lead to a substantial increase in preventable deaths. METHODS: Overall numbers and types of surgery were analysed in a tertiary hospital in Austria during the winter period (October-April) from 2015/16 to 2021/22. The half-years 2019/20, 2020/21 and 2021/22 were defined as pandemic half-years and were compared with the mean results of the previous, four, pre-pandemic half-years. RESULTS: A reduction was found for overall numbers and elective surgeries during 2019/20 (4.62%; p < 0.0001 and 12.14; p < 0.0001 respectively) and 2021/22 (14.94%; p < 0.0001 and 34.27; p < 0.0001 respectively). Oncologic surgery increased during 2021/22 (- 12.59%; p < 0.0001) and remained unchanged during the other periods. Emergency surgeries increased during 2019/20 (- 6.97%; p < 0.0001) and during 2021/22 (- 9.44%; p < 0.0001) and remained unchanged during 2020/21. CONCLUSIONS: The concern that the pandemic led to a decrease in oncologic and emergency surgeries cannot be supported with the data from our hospital. A flexible, day-by-day, resource allocation programme with central coordination adhering to hospital resilience recommendations may have helped to adapt to the impact of the COVID-19 pandemic during the first three pandemic half-years.

Loss or Dilution-A New Diagnostic Method to Assess the Impact of Dilution on Standard Laboratory Parameters.

Intraoperative fluid therapy is regularly used in patients undergoing cardiac surgery procedures with cardiopulmonary bypass (CPB). Although fluid administration has several advantages, it unavoidably leads to hemodilution. The hemodilution may further influence the interpretation of concentration-based laboratory parameters like hemoglobin (Hgb), platelet count (PLT) or prothrombin time (PT). These all parameters are commonly used to guide blood product substitution. To assess the impact of dilution on these values, we performed a prospective observational study in 174 patients undergoing elective cardiac surgery. We calculated the total blood volume according to Nadler's formula, and fluid therapy was correlated with a newly developed dilution coefficient formula at the end of CPB. Intravenously applied fluids were measured from the beginning of the anesthesia (baseline, T0) and 15 min after the end of protamine infusion (end of CPB, T1). The amount of the administered volume (crystalloids or colloids) was calculated according to the percentage of the intravascular fluid effect, and intraoperative diuresis was further subtracted. The median blood volume increased by 148% in all patients at T1 compared to the calculated total blood volume at T0. This led to a dilution-dependent decrease of 38% in all three parameters (Hgb 24%, corrCoeff = 0.53; PLT 41%, corrCoeff = 0.68; PT 44%, corrCoeff = 0.54). The dilution-correlated decrease was significant for all parameters (p < 0.001), and the effect was independent from the duration of CPB. We conclude that the presented calculation-based approach could provide important information regarding actual laboratory parameters and may help in the guidance of the blood product substitution and potential transfusion thresholds. Further research on the impact of dilution and related decision-making for blood product substitution, including its impact on morbidity and mortality, is warranted.

Improved ventilation efficiency due to continuous gas flow compared to decelerating gas flow in mechanical ventilation: results of a porcine trial.

In pressure-controlled ventilation (PCV), a decelerating gas flow pattern occurs during inspiration and expiration. In contrast, flow-controlled ventilation (FCV) guarantees a continuous gas flow throughout the entire ventilation cycle where the inspiration and expiration phases are simply performed by a change of gas flow direction. The aim of this trial was to highlight the effects of different flow patterns on respiratory variables and gas exchange. Anesthetized pigs were ventilated with either FCV or PCV for 1 h and thereafter for 30 min each in a crossover comparison. Both ventilation modes were set with a peak pressure of 15 cmH2O, positive end-expiratory pressure of 5 cmH2O, a respiratory rate of 20/min, and a fraction of inspired oxygen at 0.3. All respiratory variables were collected every 15 min. Tidal volume and respiratory minute volume were significantly lower in FCV (n = 5) compared with PCV (n = 5) animals [4.6 vs. 6.6, MD -2.0 (95% CI -2.6 to -1.4) mL/kg; P < 0.001 and 7.3 vs. 9.5, MD -2.2 (95% CI -3.3 to -1.0) L/min; P = 0.006]. Notwithstanding these differences, CO2-removal as well as oxygenation was not inferior in FCV compared with PCV. Mechanical ventilation with identical ventilator settings resulted in lower tidal volumes and consecutive minute volume in FCV compared with PCV. This finding can be explained physically by the continuous gas flow pattern in FCV that necessitates a lower alveolar pressure amplitude. Interestingly, gas exchange was comparable in both groups, which is suggestive of improved ventilation efficiency at a continuous gas flow pattern.NEW & NOTEWORTHY This study examined the effects of a continuous (flow-controlled ventilation, FCV) vs. decelerating (pressure-controlled ventilation, PCV) gas flow pattern during mechanical ventilation. It was shown that FCV necessitates a lower alveolar pressure amplitude leading to reduced applied tidal volumes and consequently minute volume. Notwithstanding these differences, CO2-removal as well as oxygenation was not inferior in FCV compared with PCV, which is suggestive of improved gas exchange efficiency at a continuous gas flow pattern.

Infection with SARS-CoV-2 Is Associated with Elevated Levels of IP-10, MCP-1, and IL-13 in Sepsis Patients.

Immunothrombosis, an excessive inflammatory response with simultaneous overactivation of the coagulation system, is a central pathomechanism in sepsis and COVID-19. It is associated with cellular activation, vascular damage, and microvascular thrombosis, which can lead to multiple organ failure and death. Here, we characterized factors related to immunothrombosis in plasma samples from 78 sepsis patients. In the course of routine clinical testing, SARS-CoV-2 was detected in 14 of these patients. Viral infection was associated with a higher mortality. Both, COVID-19 negative and COVID-19 positive sepsis patients showed increased levels of effectors of immunothrombosis, including platelet factor 4, D-dimer, nucleosomes, citrullinated histone H3, high mobility group box-1 protein, as well as phosphatidylserine-expressing platelet-derived extracellular vesicles, compared to healthy controls (n = 25). Using a 27-plex cytokine bead array, we found that Interleukin (IL)-1ra, IL-6, IL-8, IL-13, tumor necrosis factor (TNF)-α, interferon inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, and granulocyte-colony stimulating factor (G-CSF) were elevated in both, COVID-19 negative and COVID-19 positive sepsis patients, as compared to healthy controls. SARS-CoV-2 infection was associated with elevated levels of IP-10, MCP-1, and IL-13, while all other mediators widely overlapped between COVID-19 negative and COVID-19 positive patients.

Short time effects of compliance guided flow-controlled ventilation versus standard of care pressure-controlled ventilation: a prospective porcine trial.

BACKGROUND: Flow-controlled ventilation (FCV) represents a novel ventilation method, which guarantees a continuous gas flow during inspiration and expiration. Long term comparison to volume- and pressure-controlled ventilation (PCV) after five- and ten hours have shown improved gas exchange parameters and lung tissue aeration. Aim of this porcine trial was to compare gas exchange parameters and lung tissue aeration in short time application of FCV compared to PCV to determine effects which will most probably pertain in short lasting procedures under general anesthesia. METHODS: After induction of general anesthesia nine pigs were randomly ventilated either with compliance guided FCV settings or standard of PCV with compliance titrated positive end-expiratory pressure and peak pressure set to achieve a tidal volume of 7 mL/kg. Subsequently an arterial blood gas sample was obtained, and a computed tomography scan was performed. Afterwards, each animal was extubated and on the following day the same protocol was performed again with the alternative ventilation method. RESULTS: Primary analysis of 18 datasets from nine animals (with paired comparison) revealed a significantly improved oxygenation with FCV compared to control (paO2 118 vs. 109, 95% CI 2 to 16 mm Hg; P=0.042). The required respiratory minute volume was significantly lower with FCV (7.4 vs. 10.8, 95% CI -4.0 to -2.9 L/min; P<0.001) to achieve similar levels of normocapnia. However, lung tissue aeration did not significantly differ between ventilation methods. CONCLUSIONS: In this short-term ventilation comparison FCV improved gas exchange parameters without differences in lung tissue aeration compared to PCV.

Individualised flow-controlled versus pressure-controlled ventilation in a porcine oleic acid-induced acute respiratory distress syndrome model.

BACKGROUND: A continuous gas flow provided by flow-controlled ventilation (FCV) facilitates accurate dynamic compliance measurement and allows the clinician to individually optimise positive end-expiratory and peak pressure settings accordingly. OBJECTIVE: The aim of this study was to compare the efficiency of gas exchange and impact on haemodynamics between individualised FCV and pressure-controlled ventilation (PCV) in a porcine model of oleic acid-induced acute respiratory distress syndrome (ARDS). DESIGN: Randomised controlled interventional trial conducted on 16 pigs. SETTING: Animal operating facility at the Medical University Innsbruck. INTERVENTIONS: ARDS was induced in lung healthy pigs by intravenous infusion of oleic acid until moderate-to-severe ARDS at a stable Horowitz quotient (PaO 2 FiO 2-1 ) of 80 to 120 over a period of 30 min was obtained. Ventilation was then either performed with individualised FCV ( n  = 8) established by compliance-guided pressure titration or PCV ( n  = 8) with compliance-guided titration of the positive end-expiratory pressure and peak pressure set to achieve a tidal volume of 6 ml kg -1 over a period of 2 h. MAIN OUTCOME MEASURES: Gas exchange parameters were assessed by the PaO 2 FiO 2-1 quotient and CO 2 removal by the PaCO 2 value in relation to required respiratory minute volume. Required catecholamine support for haemodynamic stabilisation was measured. RESULTS: The FCV group showed significantly improved oxygenation [149.2 vs. 110.4, median difference (MD) 38.7 (8.0 to 69.5) PaO 2 FiO 2-1 ; P  = 0.027] and CO 2 removal [PaCO 2 7.25 vs. 9.05, MD -1.8 (-2.87 to -0.72) kPa; P  = 0.006] at a significantly lower respiratory minute volume [8.4 vs. 11.9, MD -3.6 (-5.6 to -1.5) l min -1 ; P  = 0.005] compared with PCV. In addition, in FCV-pigs, haemodynamic stabilisation occurred with a significant reduction of required catecholamine support [norepinephrine 0.26 vs. 0.86, MD -0.61 (-1.12 to -0.09) µg kg -1  min -1 ; P  = 0.037] during 2 ventilation hours. CONCLUSION: In this oleic acid-induced porcine ARDS model, individualised FCV significantly improved gas exchange and haemodynamic stability compared with PCV. TRIAL REGISTRATION: Protocol no.: BMBWF-66.011/0105-V/3b/2019).

[Emergency missions in Tyrol in spring 2020 : Influence of COVID-19-A retrospective observational study focusing on air rescue]. / Notärztliche Einsätze in Tirol im Frühjahr 2020 : Der Einfluss von COVID-19 ­ eine retrospektive Beobachtungsstudie mit Fokus Luftrettung.

BACKGROUND: Tyrol, a province of Austria with about 760,000 inhabitants, was one of the first regions in Europe, along with northern Italy, to be affected by the pandemic spread of the coronavirus in spring 2020. A lockdown with far-reaching restrictions in all areas of life occurred from 16 March 2020. Restrictions were imposed in the areas of gastronomy, trade and free mobility as well as in recreational sports. The ski resorts were closed and due to the strong winter tourism in Tyrol, this meant that about 340,000 people left the region. In the province of Tyrol comprehensive emergency medical care is provided by 13 ground-based emergency medical systems (NEF) in combination with air rescue (16 emergency medical helicopters, some of which are seasonal). Normally, this system provides emergency medical care for approx. 1 million people; however, in spring 2020 during the first lockdown, the number of people to be cared for was approx. 30% less. In order to protect the emergency medical teams as best as possible from infections and thus the system from failures, the Integrated Control Center Tyrol (Landesleitstelle Tirol GmbH) adapted the release order for emergency medical resources. The aim of the study is to describe the influence of the pandemic in spring 2020 on the emergency medical services in Tyrol in comparison to the three preceding years. METHODS: A retrospective survey of all emergency helicopter missions and ground-based emergency physician missions in Tyrol in the period 15 March 2020-15 May 2020, as well as in the same period of the previous years 2017-2019, was conducted. Detailed figures on medical procedures and patient-related data were collected from 6 ÖAMTC helicopter bases. In addition, all ground-based emergency physician missions from all 13 physician systems including appeal mission diagnoses were collected in the same period. RESULTS: The total number of emergency helicopter missions and ground-based emergency physician missions showed a significant decrease during the observational period (67.3% and 39.8%, respectively). In the area of ground-based emergency medical resources, there was a significant increase in respiratory and CNS diseases during the observational period. The range of emergency helicopter missions showed a significant shift from sports and leisure missions to internal medicine and neurological emergencies and the duration of missions was significantly longer. The NACA score was higher with a significant decrease in NACA 3 scores in favor of NACA 4 and 5. The circulatory status of patients during the observational period was significantly more often documented as unstable. Hypertension, impending shock and circulatory arrest occurred more frequently in the trend. Cardiac massage, oxygen administration, circulatory drugs and specific monitoring were used more frequently in 2020. Analgesics were administered less frequently. In air rescue, there was no infection of rescue workers in the field. CONCLUSION: The first pandemic wave in Tyrol and the consecutive lockdown from 16 March 2020 had a massive impact on emergency medical care in Tyrol, both quantitatively and in terms of the spectrum of operations and emergency medical interventions. The decline in patient numbers was highly relevant, especially in air rescue and can be explained in part by the discontinuation of tourism, the general exit restrictions and the restrictive disengagement order. This decline primarily affected patients in the NACA 3 category and the analgesic administration measure. The patients treated had a higher NACA score and the emergency procedures were more extensive during the observational period. The measures to protect the emergency helicopter team from infections were presumably successful as no infections occurred.

Individualised flow-controlled ventilation versus pressure-controlled ventilation in a porcine model of thoracic surgery requiring one-lung ventilation: A laboratory study.

BACKGROUND: Flow-controlled ventilation (FCV) enables precise determination of dynamic compliance due to a continuous flow coupled with direct tracheal pressure measurement. Thus, pressure settings can be adjusted accordingly in an individualised approach. OBJECTIVE: The aim of this study was to compare gas exchange of individualised FCV to pressure-controlled ventilation (PCV) in a porcine model of simulated thoracic surgery requiring one-lung ventilation (OLV). DESIGN: Controlled interventional trial conducted on 16 domestic pigs. SETTING: Animal operating facility at the Medical University of Innsbruck. INTERVENTIONS: Thoracic surgery was simulated with left-sided thoracotomy and subsequent collapse of the lung over a period of three hours. When using FCV, ventilation was performed with compliance-guided pressure settings. When using PCV, end-expiratory pressure was adapted to achieve best compliance with peak pressure adjusted to achieve a tidal volume of 6 ml kg -1 during OLV. MAIN OUTCOME MEASURES: Gas exchange was assessed by the Horowitz index (= P aO 2 /FIO 2 ) and CO 2 removal by the P aCO 2 value in relation to required respiratory minute volume. RESULTS: In the FCV group ( n  = 8) normocapnia could be maintained throughout the OLV trial despite a significantly lower respiratory minute volume compared to the PCV group ( n  = 8) (8.0 vs. 11.6, 95% confidence interval, CI -4.5 to -2.7 l min -1 ; P  < 0.001), whereas permissive hypercapnia had to be accepted in PCV ( P aCO 2 5.68 vs. 6.89, 95% CI -1.7 to -0.7 kPa; P  < 0.001). The Horowitz index was comparable in both groups but calculated mechanical power was significantly lower in FCV (7.5 vs. 22.0, 95% CI -17.2 to -11.8 J min -1 ; P  < 0.001). CONCLUSIONS: In this porcine study FCV maintained normocapnia during OLV, whereas permissive hypercapnia had to be accepted in PCV despite a substantially higher minute volume. Reducing exposure of the lungs to mechanical power applied by the ventilator in FCV offers a possible advantage for this mode of ventilation in terms of lung protection.

Impact of COVID-19 on elective, emergency and oncological surgery during the first and the second wave in a tertiary university hospital : Have we learned the lessons?

BACKGROUND: The COVID-19 pandemic caused an important reduction in surgical activities during the first wave. Aim of this retrospective time-trend analysis was to examine whether also during the second wave in fall and winter 2020/2021 surgical interventions decreased. METHODS: Absolut numbers and types of surgeries in a tertiary university hospital during the second COVID-19 wave in fall/winter 2020/2021 were collected from the surgical planning software and compared with the same time frame over the last 5 years. In a second step, the reduction of surgical interventions during the second wave was compared with the reduction of surgical procedures during the first wave in spring 2020 at the same hospital. RESULTS: Despite a higher 7­day incidence of COVID-19 infection and a higher number of patients needing ICU treatment during the second wave, the reduction of surgical interventions was 3.22% compared to 65.29% during the first wave (p < 0.0001). Elective surgical interventions decreased by 88.63% during the first wave compared to 1.79% during the second wave (p < 0.0001). Emergency and oncological interventions decreased by 35.17% during the first wave compared to 5.15% during the second wave (p : 0.0007) and 47.59% compared to 3.89% (p < 0.0001), respectively. Surgical activity reduction in our institution was less pronounced despite higher occupancy of ICU beds during the second COVID-19 wave in fall/winter 2020/2021. CONCLUSION: Better understanding of the disease, adequate supply of disposables and improved interdisciplinary day by day management of surgical and ICU resources may have contributed to this improvement.

Solid Organ Donation and Transplantation Activity in the Eurotransplant Area During the First Year of COVID-19.

BACKGROUND: Transplantation activity during the first wave of the coronavirus disease 2019 (COVID-19) pandemic was severely affected worldwide. This retrospective analysis aimed to assess the impact of COVID-19 on organ donations and transplantations in the Eurotransplant region during the first 12 mo of the pandemic. Specifically, we compared donor and transplantation numbers during both waves to determine whether transplant systems adapted to this new reality. METHODS: All reported organ donations and transplantations from March 1, 2015, to February 28, 2021, were collected from the Eurotransplant International Foundation registry. The observation period from 2020 to 2021 was divided into three 4-mo periods, which were then compared with the corresponding periods of the preceding 5 y. COVID-19 cases for Eurotransplant countries were retrieved from the OurWorldInData.org database. RESULTS: Overall, the number of organ donors decreased by 18.3% (P < 0.0001) and the number of organ transplantations by 12.5% (P > 0.0001) compared with previous years. Pancreas transplantation was the most affected, followed by kidney, liver, heart, and lung transplant. In detail, during period 1, the number of organ donors decreased by 26.2% (P < 0.0001) and the number of organ transplantations by 16.5% (P < 0.0001), in period 2 by 5.5% (P < 0.0091) and 4.9% (P < 0.0001), and in period 3 by 23.1% (P < 0.0001) and 16.4% (P < 0.0001), respectively. CONCLUSIONS: Organ donation and transplantation decreased drastically also during the second wave; however, despite the severity of the second wave, the decline was comparable with that of the first wave.