| 1. |
- Al-Dury, Nooraldeen, 1986, et al.
(author)
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Identifying the relative importance of predictors of survival in out of hospital cardiac arrest : a machine learning study
- 2020
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In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : BioMed Central. - 1757-7241. ; 28:1, s. 1-8
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Journal article (peer-reviewed)abstract
- Introduction: Studies examining the factors linked to survival after out of hospital cardiac arrest (OHCA) have either aimed to describe the characteristics and outcomes of OHCA in different parts of the world, or focused on certain factors and whether they were associated with survival. Unfortunately, this approach does not measure how strong each factor is in predicting survival after OHCA. Aim: To investigate the relative importance of 16 well-recognized factors in OHCA at the time point of ambulance arrival, and before any interventions or medications were given, by using a machine learning approach that implies building models directly from the data, and arranging those factors in order of importance in predicting survival. Methods: Using a data-driven approach with a machine learning algorithm, we studied the relative importance of 16 factors assessed during the pre-hospital phase of OHCA We examined 45,000 cases of OHCA between 2008 and 2016. Results: Overall, the top five factors to predict survival in order of importance were: initial rhythm, age, early Cardiopulmonary Resuscitation (CPR, time to CPR and CPR before arrival of EMS), time from EMS dispatch until EMS arrival, and place of cardiac arrest The largest difference in importance was noted between initial rhythm and the remaining predictors. A number of factors, including time of arrest and sex were of little importance. Conclusion: Using machine learning, we confirm that the most important predictor of survival in OHCA is initial rhythm, followed by age, time to start of CPR, EMS response time and place of OHCA. Several factors traditionally viewed as important e.g. sex, were of little importance.
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| 2. |
- Albert, Malin, et al.
(author)
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Cardiac arrest after pulmonary aspiration in hospitalised patients : a national observational study.
- 2020
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In: BMJ Open. - : BMJ. - 2044-6055. ; 10:3
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To study characteristics and outcomes among patients with in-hospital cardiac arrest (IHCA) due to pulmonary aspiration.DESIGN: A retrospective observational study based on data from the Swedish Registry of Cardiopulmonary Resuscitation (SRCR).SETTING: The SRCR is a nationwide quality registry that covers 96% of all Swedish hospitals. Participating hospitals vary in size from secondary hospitals to university hospitals.PARTICIPANTS: The study included patients registered in the SRCR in the period 2008 to 2017. We compared patients with IHCA caused by pulmonary aspiration (n=127), to those with IHCA caused by respiratory failure of other causes (n=2197).PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was 30-day survival. Secondary outcome was sustained return of spontaneous circulation (ROSC) defined as ROSC at the scene and admitted alive to the intensive care unit.RESULTS: In the aspiration group 80% of IHCA occurred on general wards, as compared with 63.6% in the respiratory failure group (p<0.001). Patients in the aspiration group were less likely to be monitored at the time of the arrest (18.5% vs 38%, p<0.001) and had a significantly lower rate of sustained ROSC (36.5% vs 51.6%, p=0.001). The unadjusted 30-day survival rate compared with the respiratory failure group was 7.9% versus 18.0%, p=0.024. In a propensity score analysis (including variables; year, age, gender, location of arrest, initial heart rhythm, ECG monitoring, witnessed collapse and a previous medical history of; cancer, myocardial infarction or heart failure) the OR for 30-day survival was 0.46 (95% CI 0.19 to 0.94).CONCLUSIONS: In-hospital cardiac arrest preceded by pulmonary aspiration occurred more often on general wards among unmonitored patients. These patients had a lower 30-day survival rate compared with IHCA caused by respiratory failure of other causes.
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| 3. |
- Elfwen, Ludvig, et al.
(author)
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Post-resuscitation myocardial dysfunction in out-of-hospital cardiac arrest patients randomized to immediate coronary angiography versus standard of care
- 2020
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In: IJC Heart & Vasculature. - : ELSEVIER IRELAND LTD. - 2352-9067. ; 27
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Journal article (peer-reviewed)abstract
- Background: Immediate coronary angiography with subsequent percutaneous coronary intervention (PCI) has the potential to reduce post-resuscitation myocardial dysfunction in out-of-hospital cardiac arrest (OHCA) patients. The aim of this study was to see if immediate coronary angiography, with potential PCI, in patients without ST-elevation on the ECG, influenced post-resuscitation myocardial function and cardiac biomarkers.Methods: A secondary analysis of the Direct or Subacute Coronary Angiography in Out-of-Hospital Cardiac Arrest (DISCO) trial (ClinicalTrials.gov ID: NCT02309151). Patients with bystander-witnessed OHCA, without ST-elevations on the ECG were randomly assigned to immediate coronary angiography within two hours of cardiac arrest (n = 38) versus standard-of-care with deferred angiography (n = 40). Outcome measures included left ventricle ejection fraction (LVEF) at 24 h, peak Troponin T levels, lactate clearance and NT-proBNP at 72 h.Results: In the immediate-angiography group, median LVEF at 24 h was 47% (Q1-Q3; 30-55) vs. 46% (Q1-Q3; 35-55) in the standard-of-care group. Peak Troponin-T levels during the first 24 h were 362 ng/L (Q1-Q3; 174-2020) in the immediate angiography group and 377 ng/L (Q1-Q3; 205-1078) in the standard-of-care group. NT-proBNP levels at 72 h were 931 ng/L (Q1-Q3; 396-2845) in the immediate-angiography group and 1913 ng/L (Q1-Q3; 489-3140) in the standard-of-care group.Conclusion: In this analysis of OHCA patients without ST-elevation on the ECG randomized to immediate coronary angiography or standard-of-care, no differences in post-resuscitation myocardial dysfunction parameters between the two groups were found. This finding was consistent also in patients randomized to immediate coronary angiography where PCI was performed compared to those where PCI was not performed.
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| 4. |
- Hessulf, Fredrik, 1986, et al.
(author)
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Adherence to Guidelines is Associated With Improved Survival Following In-hospital Cardiac Arrest in Sweden
- 2020
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In: Resuscitation. - : Lippincott Williams & Wilkins. - 0300-9572 .- 1873-1570. ; 155, s. -21
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Journal article (peer-reviewed)abstract
- Background: Most resuscitation guidelines have recommendations regarding maximum delay times from collapse to calling for the rescue team and initiation of treatment following cardiac arrest. The aim of the study was to investigate the association between adherence to guidelines for cardiopulmonary resuscitation (CPR) after in-hospital cardiac arrest (IHCA) and survival with a focus on delay to treatment.Methods: We used the Swedish Registry for CPR to study 3212 patients with a shockable rhythm and 9113 patients with non-shockable rhythm from January 1, 2008 to December 31, 2017. Adult patients older than or equal to 18 years with a witnessed IHCA where resuscitation was initiated were included. We assessed trends in adherence to guidelines and their associations with 30-day survival and neurological function. Adherence to guidelines was defined as follows: time from collapse to calling for the rescue team and CPR within 1 min for non-shockable rhythms. For shockable rhythms, adherence was defined as the time from collapse to calling for the rescue team and CPR within 1 min and defibrillation within 3 min.Results: In patients with a shockable rhythm, the 30-day survival for those treated according to guidelines was 66.1%, as compared to 46.5% among those not treated according to guidelines on one or more parameters, adjusted odds ratio 1.84 (95% CI 1.52-2.22). Among patients with a non-shockable rhythm the 30-day survival for those treated according to guidelines was 22.8%, as compared to 16.0% among those not treated according to guidelines on one or more parameters, adjusted odds ratio 1.43 (95% CI 1.24-1.65). Neurological function (cerebral performance category 1-2) among survivors was better among patients treated in accordance with guidelines for both shockable (95.7% vs 91.1%, <0.001) and non-shockable rhythms (91.0% vs 85.5%, p < 0.008). Adherence to the Swedish guidelines for CPR increased slightly 2008-2017.Conclusions: Adherence to guidelines was associated with increased probability of survival and improved neurological function in patients with a shockable and non-shockable rhythm, respectively. Increased adherence to guidelines could increase cardiac arrest survival.
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| 5. |
- Jakobsen, Janus Christian, et al.
(author)
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Targeted hypothermia versus targeted normothermia after out-of-hospital cardiac arrest: a statistical analysis plan.
- 2020
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In: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 21:1
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Journal article (peer-reviewed)abstract
- To date, targeted temperature management (TTM) is the only neuroprotective intervention after resuscitation from cardiac arrest that is recommended by guidelines. The evidence on the effects of TTM is unclear.The Targeted Hypothermia Versus Targeted Normothermia After Out-of-hospital Cardiac Arrest (TTM2) trial is an international, multicentre, parallel group, investigator-initiated, randomised, superiority trial in which TTM with a target temperature of 33 °C after cardiac arrest will be compared with a strategy to maintain normothermia and active treatment of fever (≥ 37.8 °C). Prognosticators, outcome assessors, the steering group, the trial coordinating team, and trial statisticians will be blinded to treatment allocation. The primary outcome will be all-cause mortality at 180 days after randomisation. We estimate a 55% mortality in the targeted normothermia group. To detect an absolute risk reduction of 7.5% with an alpha of 0.05 and 90% power, 1900 participants will be enrolled. The secondary neurological outcome will be poor functional outcome (modified Rankin scale 4-6) at 180 days after cardiac arrest. In this paper, a detailed statistical analysis plan is presented, including a comprehensive description of the statistical analyses, handling of missing data, and assessments of underlying statistical assumptions. Final analyses will be conducted independently by two qualified statisticians following the present plan.This SAP, which was prepared before completion of enrolment, should increase the validity of the TTM trial by mitigation of analysis-bias.
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| 6. |
- Janke, Leandro, et al.
(author)
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Optimizing power-to-H-2 participation in the Nord Pool electricity market: Effects of different bidding strategies on plant operation
- 2020
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In: Renewable Energy. - : Elsevier BV. - 0960-1481. ; 156, s. 820-836
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Journal article (peer-reviewed)abstract
- The operation of power-to-X systems requires measures to control the cost and sustainability of electricity purchased from spot markets. This study investigated different bidding strategies for the day-ahead market with a special focus on Sweden. A price independent order (PIO) strategy was developed assisted by forecasting electricity prices with an artificial neural network. For comparison, a price dependent order (PDO) with fixed bid price was used. The bidding strategies were used to simulate H2 production with both alkaline and proton exchange membrane electrolysers in different years and technological scenarios. Results showed that using PIO to control H2 production helped to avoid the purchase of expensive and carbon intense electricity during peak loads, but it also reduced the total number of operating hours compared to PDO. For this reason, under optimal conditions for both bidding strategies, PDO resulted in an average of 10.9% lower levelised cost of H2, and more attractive cash flows and net present values than PIO. Nevertheless, PIO showed to be a useful strategy to control costs in years with unexpected hourly price behaviour such as 2018. Furthermore, PIO could be successfully demonstrated in a practical case study to fulfil the on-demand requirement of an industrial captive customer.
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| 7. |
- Janke, Leandro, et al.
(author)
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Techno-Economic Assessment of Demand-Driven Small-Scale Green Hydrogen Production for Low Carbon Agriculture in Sweden
- 2020
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In: Frontiers in Energy Research. - : Frontiers Media SA. - 2296-598X. ; 8
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Journal article (peer-reviewed)abstract
- Wind power coupled to hydrogen (H2) production is an interesting strategy to reduce power curtailment and to provide clean fuel for decarbonizing agricultural activities. However, such implementation is challenging for several reasons, including uncertainties in wind power availability, seasonalities in agricultural fuel demand, capital-intensive gas storage systems, and high specific investment costs of smallscale electrolysers. To investigate whether on-site H2 production could be a feasible alternative to conventional diesel farming, a model was built for dynamic simulations of H2 production from wind power driven by the fuel demand of a cereal farm located on the island of Gotland, Sweden. Different cases and technological scenarios were considered to assess the effects of future developments, H2 end-use, as well as production scale on the levelised- and farmers’ equivalent annual costs. In a single-farm application, H2 production costs varied between 21.20–14.82 €/kg. By sharing a power-to-H2 facility among four different farms of 300-ha each, the specific investment costs could be significantly decreased, resulting in 28% lower H2 production costs than when facilities are not shared. By including delivery vans as additional H2 consumers in each farm, costs of H2 production decreased by 35% due to the higher production scale and more distributed demand. However, in all cases and technological scenarios assessed, projected diesel price in retailers was cheaper than H2. Nevertheless, revenues from leasing the land to wind power developers could make H2 a more attractive option even in single-farm applications as early as 2020. Without such revenues, H2 is more competitive than diesel where power-to-H2 plants are shared by at least two farms, if technological developments predicted for 2030 come true. Also, out of 20 different cases assessed, nine of them showed a carbon abatement cost lower than the current carbon tax in Sweden of 110 €/tCO2, which demonstrate the potential of power-to-H2 as an effective strategy to decarbonize agricultural systems.
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| 8. |
- Jonsson, Martin, et al.
(author)
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Inequalities in Income and Education Are Associated With Survival Differences After Out-of-Hospital Cardiac Arrest : Nationwide Observational Study
- 2021
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In: Circulation. - 0009-7322 .- 1524-4539. ; 144:24, s. 1915-1925
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Journal article (peer-reviewed)abstract
- BACKGROUND: Despite the acknowledged importance of socioeconomic factors as regards cardiovascular disease onset and survival, the relationship between individual-level socioeconomic factors and survival after out-of-hospital cardiac arrest is not established. Our aim was to investigate whether socioeconomic variables are associated with 30-day survival after out-of-hospital cardiac arrest.METHODS: We linked data from the Swedish Registry for Cardiopulmonary Resuscitation with individual-level data on socioeconomic factors (ie, educational level and disposable income) from Statistics Sweden. Confounding and mediating variables included demographic factors, comorbidity, and Utstein resuscitation variables. Outcome was 30-day survival. Multiple modified Poisson regression was used for the main analyses.RESULTS: A total of 31 373 out-of-hospital cardiac arrests occurring in 2010 to 2017 were included. Crude 30-day survival rates by income quintiles were as follows: Q1 (low), 414/6277 (6.6%); Q2, 339/6276 (5.4%); Q3, 423/6275 (6.7%); Q4, 652/6273 (10.4%); and Q5 (high), 928/6272 (14.8%). In adjusted analysis, the chance of survival by income level followed a gradient-like increase, with a risk ratio of 1.86 (95% CI, 1.65-2.09) in the highest-income quintile versus the lowest. This association remained after adjusting for comorbidity, resuscitation factors, and initial rhythm. A higher educational level was associated with improved 30-day survival, with the risk ratio associated with postsecondary education ≥4 years being 1.51 (95% CI, 1.30-1.74). Survival disparities by income and educational level were observed in both men and women.CONCLUSIONS: In this nationwide observational study using individual-level socioeconomic data, higher income and higher educational level were associated with better 30-day survival after out-of-hospital cardiac arrest in both sexes.
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| 9. |
- Kalita, Saurav, et al.
(author)
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Soil Carbon Modelling in Salix Biomass Plantations: Variety Determines Carbon Sequestration and Climate Impacts
- 2021
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In: Forests. - : MDPI AG. - 1999-4907. ; 12
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Journal article (peer-reviewed)abstract
- Short-rotation coppice (SRC) Salix plantations have the potential to provide fast-growing biomass feedstock with significant soil and climate mitigation benefits. Salix varieties exhibit significant variation in their physiological traits, growth patterns and soil ecology—but the effects of these variations have rarely been studied from a systems perspective. This study analyses the influence of variety on soil organic carbon (SOC) dynamics and climate impacts from Salix cultivation for heat production for a Swedish site with specific conditions. Soil carbon modelling was combined with a life cycle assessment (LCA) approach to quantify SOC sequestration and climate impacts over a 50-year period. The analysis used data from a Swedish field trial of six Salix varieties grown under fertilized and unfertilized treatments on Vertic Cambisols during 2001–2018. The Salix systems were compared with a reference case where heat is produced from natural gas and green fallow was the land use alternative. Climate impacts were determined using time-dependent LCA methodology—on a land-use (per hectare) and delivered energy unit (per MJheat) basis. All Salix varieties and treatments increased SOC, but the magnitude depended on the variety. Fertilization led to lower carbon sequestration than the equivalent unfertilized case. There was no clear relationship between biomass yield and SOC increase. In comparison with reference cases, all Salix varieties had significant potential for climate change mitigation. From a land-use perspective, high yield was the most important determining factor, followed by SOC sequestration, therefore high-yielding fertilized varieties such as ‘Tordis’, ‘Tora’ and ‘Björn’ performed best. On an energy-delivered basis, SOC sequestration potential was the determining factor for the climate change mitigation effect, with unfertilized ‘Jorr’ and ‘Loden’ outperforming the other varieties. These results show that Salix variety has a strong influence on SOC sequestration potential, biomass yield, growth pattern, response to fertilization and, ultimately, climate impact.
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| 10. |
- Lagedal, Rickard, et al.
(author)
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Income is associated with the probability to receive early coronary angiography after out-of-hospital cardiac arrest
- 2020
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In: Resuscitation. - : Elsevier. - 0300-9572 .- 1873-1570. ; 156, s. 35-41
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Journal article (peer-reviewed)abstract
- Introduction: Low socioeconomic status has been associated with worse outcome after cardiac arrest. This study aims to investigate if patients income influences the probability to receive early coronary angiography in out-of-hospital cardiac arrest (OHCA) patients.Methods: In this nationwide retrospective observational study, 3906 OHCA patients admitted alive and registered in the Swedish Registry for Cardiopulmonary Resuscitation were included. Individual data on income and educational level, prehospital parameters, coronary angiography results and comorbidity were linked from SWEDEHEART and other national registers.Results: Patients were divided into quarters depending on their income level. In the unadjusted model there was a strong correlation between income level and rate of early coronary angiography where 35.5% of patients in the highest income quarters received early angiography compared to 15.4% in the lowest income quarters. When adjusting for educational level, sex, age, comorbidity and hospital type, there were still higher chance of receiving early coronary angiography with increasing income, OR 1.31 (CI 1.01-1.68) and 1.67 (CI 1.29-2.16) for the two highest income quarters respectively compared to the lowest income quarter. When adding potential mediators to the model (first recorded ECG rhythm by the EMS, location, response time, bystander cardiopulmonary resuscitation and if the arrest was witnessed) no difference in early angiography related to income level where found. The main mediator was first recorded ECG rhythm.Conclusion: Income level is associated with the probability to undergo early coronary angiography in OHCA patients. This association seems to be mediated by the initial ECG rhythm.
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