| 1. |
- Glasbey, JC, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 2. |
- Baumgardner, James E., et al.
(författare)
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Effect of Global Ventilation to Perfusion Ratio, for Normal Lungs, on Desflurane and Sevoflurane Elimination Kinetics
- 2021
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Ingår i: Anesthesiology. - : Lippincott Williams & Wilkins. - 0003-3022 .- 1528-1175. ; 135:6, s. 1042-1054
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Tidskriftsartikel (refereegranskat)abstract
- Background: Kinetics of the uptake of inhaled anesthetics have been well studied, but the kinetics of elimination might be of more practical importance. The objective of the authors' study was to assess the effect of the overall ventilation/perfusion ratio (V-A/Q), for normal lungs, on elimination kinetics of desflurane and sevoflurane.Methods: The authors developed a mathematical model of inhaled anesthetic elimination that explicitly relates the terminal washout time constant to the global lung V-A/Q ratio. Assumptions and results of the model were tested with experimental data from a recent study, where desflurane and sevoflurane elimination were observed for three different V-A/Q conditions: normal, low, and high.Results: The mathematical model predicts that the global V-A/Q ratio, for normal lungs, modifies the time constant for tissue anesthetic washout throughout the entire elimination. For all three V-A/Q conditions, the ratio of arterial to mixed venous anesthetic partial pressure P-art/P-mv reached a constant value after 5 min of elimination, as predicted by the retention equation. The time constant corrected for incomplete lung clearance was a better predictor of late-stage kinetics than the intrinsic tissue time constant.Conclusions: In addition to the well-known role of the lungs in the early phases of inhaled anesthetic washout, the lungs play a long-overlooked role in modulating the kinetics of tissue washout during the later stages of inhaled anesthetic elimination. The V-A/Q ratio influences the kinetics of desflurane and sevoflurane elimination throughout the entire elimination, with more pronounced slowing of tissue washout at lower V-A/Q ratios.
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| 3. |
- Bergmann, Astrid, et al.
(författare)
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Data on the effects of remote ischemic preconditioning in the lungs after one-lung ventilation
- 2018
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Ingår i: Data in Brief. - : Elsevier BV. - 2352-3409. ; 21, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- This article contains data on experimental endpoints of a randomized controlled animal trial. Fourteen healthy piglets underwent mechanical ventilation including injurious one-lung ventilation (OLV), seven of them experienced four cycles of remote ischemic preconditioning (RIP) on one hind limb immediately before OLV, seven of them did not receive RIP and served as controls, in a randomized manner. The two major endpoints were (1) pulmonary damage assessed with the diffuse alveolar damage (DAD) score and (2) the inflammatory response assessed by cytokine concentrations in serum and in bronchoalveolar lavage fluids (BAL). The cytokine levels in the homogenized lung tissue samples are presented in the original article. Further interpretation and discussion of these data can be found in Bergmann et al. (in press).
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| 4. |
- Bergmann, Astrid, et al.
(författare)
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Early and late effects of remote ischemic preconditioning on spirometry and gas exchange in healthy volunteers
- 2020
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Ingår i: Respiratory Physiology & Neurobiology. - : Elsevier BV. - 1569-9048 .- 1878-1519. ; 271
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Remote ischemic preconditioning (RIP) may protect remote organs from ischemia-reperfusion-injury (IRI) in surgical and non-surgical patients. There are few data available on RIP and lung function, especially not in healthy volunteers. The null-hypothesis was tested that RIP does not have an effect on pulmonary function when applied on healthy volunteers that were breathing spontaneously and did not experience any intervention. After approval of the Ethics Committee and informed consent of the study subjects, 28 healthy non-smoking volunteers were included and randomized in either the RIP group (n = 13) or the control group (n = 15). In the RIP group, lower limb ischemia was induced by inflation of a blood pressure cuff to a pressure 20 mmHg above the systolic blood pressure. After five minutes the blood pressure cuff was released for five minutes rest. The procedure was repeated three times resulting in 40 min ischemia and reperfusion. Capillary blood samples were taken, and lung function tests were performed at baseline (T1) and 60 min (T2) and 24 h (T3) after RIP. The control group was treated in the same fashion, but the RIP procedure was replaced by a sham protocol.Results: 60 min after RIP capillary pO(2) decreased significantly and returned to baseline level after 24 h in the RIP group. This did not occur in the control group. Capillary pCO(2), variables of lung function tests and pulmonary capillary blood volume remained unchanged throughout the experiment in both groups.Conclusion: Oxygenation is impaired early after RIP which is possibly induced by transient ventilation-perfusion inequality. No late effects of RIP were observed. The null hypothesis has to be rejected that RIP has no effect on respiratory variables in healthy volunteers.
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| 5. |
- Bergmann, Astrid, et al.
(författare)
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Effect of remote ischemic preconditioning on exhaled nitric oxide concentration in piglets during and after one-lung ventilation
- 2020
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Ingår i: Respiratory Physiology & Neurobiology. - : Elsevier BV. - 1569-9048 .- 1878-1519. ; 276
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Remote ischemic preconditioning (RIP) may protect target organs from ischemia - reperfusion injury, however, little is known on pulmonary effects of RIP prior to, immediately after and several hours after one-lung ventilation (OLV). The present randomized, controlled, animal experiment was undertaken to analyze these issues.METHODS: After animal ethics committee approval, twelve piglets (26 ± 2 kg) were anesthetized and randomly assigned to a control (n = 6) or to a RIP group (n = 6). For RIP, arterial perfusion of a hind limb was suspended by an inflated blood pressure cuff (200 mmHg for 5 min) and deflated for another 5 min, this was repeated four times. After intubation, mechanical ventilation (MV) was kept constant with tidal volume 10 ml/kg, inspired oxygen fraction (FIO2) 0.40, and positive end-expiratory pressure (PEEP) 5cmH2O. FIO2 was increased to 1 after RIP in the RIP group and after the sham procedure in the control group, respectively, for the time of OLV. OLV was established by left-sided bronchial blockade. After OLV, TLV was re-established until the end of the protocol. Exhaled nitric oxide (NO) was measured by ozon chemiluminiscense and ventilatory and hemodynamic variables were assessed according to the protocol.RESULTS: Hemodynamic and respiratory data were similar in both groups. Arterial pO2 was higher in the RIP group after two hours of OLV. In the control group, exhaled NO decreased during OLV and remained at low levels for the rest of the protocol. In the RIP group, exhaled NO decreased as well during OLV but returned to baseline levels when TLV was re-established.CONCLUSIONS: RIP has no effects on hemodynamic and respiratory variables in juvenile, healthy piglets. RIP improves the oxygenation after OLV and prevents the decline of exhaled NO after OLV.
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| 6. |
- Bergmann, Astrid, et al.
(författare)
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Pulmonary effects of remote ischemic preconditioning in a porcine model of ventilation-induced lung injury
- 2019
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Ingår i: Respiratory Physiology & Neurobiology. - : Elsevier. - 1569-9048 .- 1878-1519. ; 259, s. 111-118
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: One-lung ventilation (OLV) may result in lung injury due to increased mechanical stress and tidal recruitment. As a result, a pulmonary inflammatory response is induced. The present randomized, controlled, animal experiment was undertaken to assess the effects of remote ischemic preconditioning (RIP) on diffuse alveolar damage and immune response after OLV.METHODS: Fourteen piglets (26 ± 2 kg) were randomized to control (n = 7) and RIP group (n = 7). For RIP, a blood pressure cuff at hind limb was inflated up to 200 mmHg for 5 min and deflated for another 5 min, this being done four times before OLV. Mechanical ventilation settings were constant throughout the experiment: VT = 10 ml/kg, FIO2 = 0.40, PEEP = 5cmH2O. OLV was performed by left-sided bronchial blockade. Number of cells was counted from BAL fluid; cytokines were assessed by immunoassays in lung tissue and serum samples. Lung tissue samples were obtained for histological analysis and assessment of diffuse alveolar damage (DAD) score.RESULTS: Hemodynamic and respiratory data were similar in both groups. Likewise, no differences in pulmonary tissue TNF-α and protein content were found, but fewer leukocytes were counted in the ventilated lung after RIP. DAD scores were high without any differences between controls and RIP. On the other hand, alveolar edema and microhemorrhage were significantly increased after RIP.CONCLUSIONS: OLV results in alveolar injury, possibly enhanced by RIP. On the other hand, RIP attenuates the immunological response and decreased alveolar leukocyte recruitment in a porcine model of OLV.
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| 7. |
- Kostka, Kristin, et al.
(författare)
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Unraveling COVID-19: A Large-Scale Characterization of 4.5 Million COVID-19 Cases Using CHARYBDIS.
- 2022
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Ingår i: Clinical epidemiology. - 1179-1349. ; 14, s. 369-384
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Tidskriftsartikel (refereegranskat)abstract
- Routinely collected real world data (RWD) have great utility in aiding the novel coronavirus disease (COVID-19) pandemic response. Here we present the international Observational Health Data Sciences and Informatics (OHDSI) Characterizing Health Associated Risks and Your Baseline Disease In SARS-COV-2 (CHARYBDIS) framework for standardisation and analysis of COVID-19 RWD.We conducted a descriptive retrospective database study using a federated network of data partners in the United States, Europe (the Netherlands, Spain, the UK, Germany, France and Italy) and Asia (South Korea and China). The study protocol and analytical package were released on 11th June 2020 and are iteratively updated via GitHub. We identified three non-mutually exclusive cohorts of 4,537,153 individuals with a clinical COVID-19 diagnosis or positive test, 886,193 hospitalized with COVID-19, and 113,627 hospitalized with COVID-19 requiring intensive services.We aggregated over 22,000 unique characteristics describing patients with COVID-19. All comorbidities, symptoms, medications, and outcomes are described by cohort in aggregate counts and are readily available online. Globally, we observed similarities in the USA and Europe: more women diagnosed than men but more men hospitalized than women, most diagnosed cases between 25 and 60 years of age versus most hospitalized cases between 60 and 80 years of age. South Korea differed with more women than men hospitalized. Common comorbidities included type 2 diabetes, hypertension, chronic kidney disease and heart disease. Common presenting symptoms were dyspnea, cough and fever. Symptom data availability was more common in hospitalized cohorts than diagnosed.We constructed a global, multi-centre view to describe trends in COVID-19 progression, management and evolution over time. By characterising baseline variability in patients and geography, our work provides critical context that may otherwise be misconstrued as data quality issues. This is important as we perform studies on adverse events of special interest in COVID-19 vaccine surveillance.
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| 8. |
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| 9. |
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| 10. |
- Kozian, Alf, 1969-, et al.
(författare)
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Effects of methacholine infusion on desflurane pharmacokinetics in piglets
- 2015
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Ingår i: Data in Brief. - : Elsevier BV. - 2352-3409. ; 5, s. 939-947
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Tidskriftsartikel (refereegranskat)abstract
- The data of a corresponding animal experiment demonstrates that nebulized methacholine (MCh) induced severe bronchoconstriction and significant inhomogeneous ventilation and pulmonary perfusion (V̇A/Q̇) distribution in pigs, which is similar to findings in human asthma. The inhalation of MCh induced bronchoconstriction and delayed both uptake and elimination of desflurane (Kretzschmar et al., 2015) [1]. The objective of the present data is to determine V̇A/Q̇ matching by Multiple Inert Gas Elimination Technique (MIGET) in piglets before and during methacholine- (MCh-) induced bronchoconstriction, induced by MCh infusion, and to assess the blood concentration profiles for desflurane (DES) by Micropore Membrane Inlet Mass Spectrometry (MMIMS). Healthy piglets (n=4) under general anesthesia were instrumented with arterial, central venous, and pulmonary artery lines. The airway was secured via median tracheostomy with an endotracheal tube, and animals were mechanically ventilated with intermittent positive pressure ventilation (IPPV) with a FiO2 of 0.4, tidal volume (V T)=10 ml/kg and PEEP of 5cmH2O using an open system. The determination of V.A/Q. was done by MIGET: before desflurane application and at plateau in both healthy state and during MCh infusion. Arterial blood was sampled at 0, 1, 2, 5, 10, 20, and 30 min during wash-in and washout, respectively. Bronchoconstriction was established by MCH infusion aiming at doubling the peak airway pressure, after which wash-in and washout of the anesthetic gas was repeated. Anesthesia gas concentrations were measured by MMIMS. Data were analyzed by ANOVA, paired t-test, and by nonparametric Friedman׳s test and Wilcoxon׳s matched pairs test. We measured airway pressures, pulmonary resistance, and mean paO2 as well as hemodynamic variables in all pigs before desflurane application and at plateau in both healthy state and during methacholine administration by infusion. By MIGET, fractional alveolar ventilation and pulmonary perfusion in relation to the V.A/Q. compartments, data of logSDQ̇ and logSDV̇ (the second moments describing global dispersion, i.e. heterogeneity of distribution) were estimated prior to and after MCh infusion. The uptake and elimination of desflurane was determined by MMIMS.
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