| 1. |
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| 2. |
- Dankiewicz, Josef, et al.
(författare)
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Targeted hypothermia versus targeted Normothermia after out-of-hospital cardiac arrest (TTM2): A randomized clinical trial - Rationale and design
- 2019
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Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 217, s. 23-31
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Tidskriftsartikel (refereegranskat)abstract
- Background: Less than 500 participants have been included in randomized trials comparing hypothermia with regular care for out-of-hospital cardiac arrest patients, and many of these trials were small and at a high risk of bias. Consequently, the accrued data on this potentially beneficial intervention resembles that of a drug following small phase II trials. A large confirmatory trial is therefore warranted. Methods: The TTM2-trial is an international, multicenter, parallel group, investigator-initiated, randomized, superiority trial in which a target temperature of 33°C after cardiac arrest will be compared with a strategy to maintain normothermia and early treatment of fever (≥37.8°C). Participants will be randomized within 3 hours of return of spontaneous circulation with the intervention period lasting 40 hours in both groups. Sedation will be mandatory for all patients throughout the intervention period. The clinical team involved with direct patient care will not be blinded to allocation group due to the inherent difficulty in blinding the intervention. Prognosticators, outcome-assessors, the steering group, the trial coordinating team, and trial statistician will be blinded. The primary outcome will be all-cause mortality at 180 days after randomization. We estimate a 55% mortality in the control 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 main secondary neurological outcome will be poor functional outcome (modified Rankin Scale 4–6) at 180 days after arrest. Discussion: The TTM2-trial will compare hypothermia to 33°C with normothermia and early treatment of fever (≥37.8°C) after out-of-hospital cardiac arrest. © 2019
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| 3. |
- Bluth, Thomas, et al.
(författare)
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Effect of Intraoperative High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers vs Low PEEP on Postoperative Pulmonary Complications in Obese Patients : A Randomized Clinical Trial.
- 2019
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 321:23, s. 2292-2305
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Tidskriftsartikel (refereegranskat)abstract
- Importance: An intraoperative higher level of positive end-expiratory positive pressure (PEEP) with alveolar recruitment maneuvers improves respiratory function in obese patients undergoing surgery, but the effect on clinical outcomes is uncertain.Objective: To determine whether a higher level of PEEP with alveolar recruitment maneuvers decreases postoperative pulmonary complications in obese patients undergoing surgery compared with a lower level of PEEP.Design, Setting, and Participants: Randomized clinical trial of 2013 adults with body mass indices of 35 or greater and substantial risk for postoperative pulmonary complications who were undergoing noncardiac, nonneurological surgery under general anesthesia. The trial was conducted at 77 sites in 23 countries from July 2014-February 2018; final follow-up: May 2018.Interventions: Patients were randomized to the high level of PEEP group (n = 989), consisting of a PEEP level of 12 cm H2O with alveolar recruitment maneuvers (a stepwise increase of tidal volume and eventually PEEP) or to the low level of PEEP group (n = 987), consisting of a PEEP level of 4 cm H2O. All patients received volume-controlled ventilation with a tidal volume of 7 mL/kg of predicted body weight.Main Outcomes and Measures: The primary outcome was a composite of pulmonary complications within the first 5 postoperative days, including respiratory failure, acute respiratory distress syndrome, bronchospasm, new pulmonary infiltrates, pulmonary infection, aspiration pneumonitis, pleural effusion, atelectasis, cardiopulmonary edema, and pneumothorax. Among the 9 prespecified secondary outcomes, 3 were intraoperative complications, including hypoxemia (oxygen desaturation with Spo2 ≤92% for >1 minute).Results: Among 2013 adults who were randomized, 1976 (98.2%) completed the trial (mean age, 48.8 years; 1381 [69.9%] women; 1778 [90.1%] underwent abdominal operations). In the intention-to-treat analysis, the primary outcome occurred in 211 of 989 patients (21.3%) in the high level of PEEP group compared with 233 of 987 patients (23.6%) in the low level of PEEP group (difference, -2.3% [95% CI, -5.9% to 1.4%]; risk ratio, 0.93 [95% CI, 0.83 to 1.04]; P = .23). Among the 9 prespecified secondary outcomes, 6 were not significantly different between the high and low level of PEEP groups, and 3 were significantly different, including fewer patients with hypoxemia (5.0% in the high level of PEEP group vs 13.6% in the low level of PEEP group; difference, -8.6% [95% CI, -11.1% to 6.1%]; P < .001).Conclusions and Relevance: Among obese patients undergoing surgery under general anesthesia, an intraoperative mechanical ventilation strategy with a higher level of PEEP and alveolar recruitment maneuvers, compared with a strategy with a lower level of PEEP, did not reduce postoperative pulmonary complications.Trial Registration: ClinicalTrials.gov Identifier: NCT02148692.
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| 4. |
- Bluth, T., et al.
(författare)
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Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE) : study protocol for a randomized controlled trial
- 2017
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Ingår i: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients.Methods/design: The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index >= 35 kg/m(2) scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH(2)O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH(2)O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint.Discussion: To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs.
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| 5. |
- Harmon, Matthew B.A., et al.
(författare)
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Practice of mechanical ventilation in cardiac arrest patients and effects of targeted temperature management : A substudy of the targeted temperature management trial
- 2018
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572. ; 129, s. 29-36
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Mechanical ventilation practices in patients with cardiac arrest are not well described. Also, the effect of temperature on mechanical ventilation settings is not known. The aims of this study were 1) to describe practice of mechanical ventilation and its relation with outcome 2) to determine effects of different target temperatures strategies (33 °C versus 36 °C) on mechanical ventilation settings. Methods: This is a substudy of the TTM-trial in which unconscious survivors of a cardiac arrest due to a cardiac cause were randomized to two TTM strategies, 33 °C (TTM33) and 36 °C (TTM36). Mechanical ventilation data were obtained at three time points: 1) before TTM; 2) at the end of TTM (before rewarming) and 3) after rewarming. Logistic regression was used to determine an association between mechanical ventilation variables and outcome. Repeated-measures mixed modelling was performed to determine the effect of TTM on ventilation settings. Results: Mechanical ventilation data was available for 567 of the 950 TTM patients. Of these, 81% was male with a mean (SD) age of 64 (12) years. At the end of TTM median tidal volume was 7.7 ml/kg predicted body weight (PBW)(6.4–8.7) and 60% of patients were ventilated with a tidal volume ≤ 8 ml/kg PBW. Median PEEP was 7.7cmH2O (6.4–8.7) and mean driving pressure was 14.6 cmH2O (±4.3). The median FiO2 fraction was 0.35 (0.30–0.45). Multivariate analysis showed an independent relationship between increased respiratory rate and 28-day mortality. TTM33 resulted in lower end-tidal CO2 (Pgroup = 0.0003) and higher alveolar dead space fraction (Pgroup = 0.003) compared to TTM36, while PCO2 levels and respiratory minute volume were similar between groups. Conclusions: In the majority of the cardiac arrest patients, protective ventilation settings are applied, including low tidal volumes and driving pressures. High respiratory rate was associated with mortality. TTM33 results in lower end-tidal CO2 levels and a higher alveolar dead space fraction compared to TTTM36.
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| 6. |
- Caplin, M. E., et al.
(författare)
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Pulmonary neuroendocrine (carcinoid) tumors : European Neuroendocrine Tumor Society expert consensus and recommendations for best practice for typical and atypical pulmonary carcinoids
- 2015
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 26:8, s. 1604-1620
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Tidskriftsartikel (refereegranskat)abstract
- Background: Pulmonary carcinoids (PCs) are rare tumors. As there is a paucity of randomized studies, this expert consensus document represents an initiative by the European Neuroendocrine Tumor Society to provide guidance on their management. Patients and methods: Bibliographical searches were carried out in PubMed for the terms 'pulmonary neuroendocrine tumors', 'bronchial neuroendocrine tumors', 'bronchial carcinoid tumors', 'pulmonary carcinoid', 'pulmonary typical/atypical carcinoid', and 'pulmonary carcinoid and diagnosis/treatment/epidemiology/prognosis'. A systematic review of the relevant literature was carried out, followed by expert review. Results: PCs are well-differentiated neuroendocrine tumors and include low-and intermediate-grade malignant tumors, i.e. typical (TC) and atypical carcinoid (AC), respectively. Contrast CT scan is the diagnostic gold standard for PCs, but pathology examination is mandatory for their correct classification. Somatostatin receptor imaging may visualize nearly 80% of the primary tumors and is most sensitive for metastatic disease. Plasma chromogranin A can be increased in PCs. Surgery is the treatment of choice for PCs with the aim of removing the tumor and preserving as much lung tissue as possible. Resection of metastases should be considered whenever possible with curative intent. Somatostatin analogs are the first-line treatment of carcinoid syndrome and may be considered as first-line systemic antiproliferative treatment in unresectable PCs, particularly of low-grade TC and AC. Locoregional or radiotargeted therapies should be considered for metastatic disease. Systemic chemotherapy is used for progressive PCs, although cytotoxic regimens have demonstrated limited effects with etoposide and platinum combination the most commonly used, however, temozolomide has shown most clinical benefit. Conclusions: PCs are complex tumors which require a multidisciplinary approach and long-term follow-up.
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| 7. |
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| 8. |
- Crusco, M., et al.
(författare)
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Gambling and the need for new responses in Public Health with an addiction "sine substantia"
- 2016
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Ingår i: Clinica Terapeutica. - 0009-9074. ; 167:6
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background. The Gambling Disorder (GD) was recently defined as a behavioral addiction by the "The Diagnostic and Statistical Manual of Mental Disorders IV"(DSM-V) since the clinical, neurobiological and psychopathological similarities led it to be defined it as an addiction "sine substantia". The aim of this study is to formulate an "identikit" of the gambler, to evaluate a possible association between GD/emotional specific factors and the correlation between GD/substance abuse, GD/suicide. Method. In the study, 41 subjects were included (31 males and 10 females) and all were diagnosed with GD. A questionnaire was distributed containing 24 questions deriving from South Oaks Gambling Screen and the DSM-IVTR. Results. The study showed that 51% of the respondents makes use of alcohol and/or drugs; that 73% of the patients started playing in order to relieve feelings of dysphoria and suffering consequences on work as well as family life (51%). A great deal of the respondents were indebted (39%) to the extent of needing to ask for loans from usurer (17%). Furthermore, 41% of the respondents in the sample showed that GD could be transformed into an alarming risk of suicide. Discussion. The correlation between GD and drug abuse may depend on the brain function and the neural circuits that support impulsive behavior and the gratification mechanisms. Emotional experiences (stress, low level of education, divorce, poor social support) could constitute a possible risk factor that increases the GD. The committed offenses related to gambling could be explained by "loss of control". Conclusion. The results of the present study contributes to the body of knowledge regarding the size of phenomenon from a statistical and epidemiological point of view, suggesting the necessity for targeted information on the risks connected to GD in order to capture early warning signs which enables the intervention with suitable strategies.
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| 9. |
- Gisela, Lilja, et al.
(författare)
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Return to Work and Participation in Society After Out-of-Hospital Cardiac Arrest
- 2018
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Ingår i: Circulation-Cardiovascular Quality and Outcomes. - : Ovid Technologies (Wolters Kluwer Health). - 1941-7705 .- 1941-7713. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to describe out-of-hospital cardiac arrest (OHCA) survivors' ability to participate in activities of everyday life and society, including return to work. The specific aim was to evaluate potential effects of cognitive impairment. METHODS AND RESULTS: Two hundred eighty-seven OHCA survivors included in the TTM trial (Target Temperature Management) and 119 matched control patients with ST-segment-elevation myocardial infarction participated in a follow-up 180 days post-event that included assessments of participation, return to work, emotional problems, and cognitive impairment. On the Mayo-Portland Adaptability Inventory-4 Participation Index, OHCA survivors (n=270) reported more restricted participation In everyday life and in society (47% versus 30%; P<0.001) compared with ST-segment-elevation myocardial infarction controls (n=118). Furthermore, 27% (n=36) of pre-event working OHCA survivors (n=135) compared with 7% (n=3) of pre-event working ST-segment-elevation myocardial infarction controls (n=45) were on sick leave (odds ratio, 4.9; 95% confidence interval, 1.4-16.8; P=0.01). Among the OHCA survivors assumed to return to work (n=135), those with cognitive impairment (n=55) were 3x more likely (odds ratio, 3.3; 95% confidence interval, 1.2-9.3; P=0.02) to be on sick leave compared with those without cognitive impairment (n=40; 36%, n=20, versus 15%, n=6). For OHCA survivors, the variables that were found most predictive for a lower participation were depression, restricted mobility, memory impairment, novel problem-solving difficulties, fatigue, and slower processing speed. CONCLUSIONS: OHCA survivors reported a more restricted societal participation 6 months post-arrest, and their return to work was lower compared with ST-segment-elevation myocardial infarction controls. Cognitive impairment was significantly associated with lower participation, together with the closely related symptoms of fatigue, depression, and restricted mobility. These predictive variables may be used during follow-up to identify OHCA survivors at risk of a less successful recovery that may benefit from further support and rehabilitation.
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| 10. |
- Krag, M., et al.
(författare)
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Stress ulcer prophylaxis in the intensive care unit: an international survey of 97 units in 11 countries
- 2015
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 59:5, s. 576-585
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Tidskriftsartikel (refereegranskat)abstract
- Background: Stress ulcer prophylaxis (SUP) may decrease the incidence of gastrointestinal bleeding in patients in the intensive care unit (ICU), but the risk of infection may be increased. In this study, we aimed to describe SUP practices in adult ICUs. We hypothesised that patient selection for SUP varies both within and between countries. MethodsAdult ICUs were invited to participate in the survey. We registered country, type of hospital, type and size of ICU, preferred SUP agent, presence of local guideline, reported indications for SUP, criteria for discontinuing SUP, and concerns about adverse effects. Fisher's exact test was used to assess differences between groups. ResultsNinety-seven adult ICUs in 11 countries participated (eight European). All but one ICU used SUP, and 64% (62/97) reported having a guideline for the use of SUP. Proton pump inhibitors were the most common SUP agent, used in 66% of ICUs (64/97), and H2-receptor antagonists were used 31% (30/97) of the units. Twenty-three different indications for SUP were reported, the most frequent being mechanical ventilation. All patients were prescribed SUP in 26% (25/97) of the ICUs. Adequate enteral feeding was the most frequent reason for discontinuing SUP, but 19% (18/97) continued SUP upon ICU discharge. The majority expressed concern about nosocomial pneumonia and Clostridium difficile infection with the use of SUP. ConclusionsIn this international survey, most participating ICUs reported using SUP, primarily proton pump inhibitors, but many did not have a guideline; indications varied considerably and concern existed about infectious complications.
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| 11. |
- Lilja, Gisela, et al.
(författare)
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Anxiety and depression among out-of-hospital cardiac arrest survivors.
- 2015
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Ingår i: Resuscitation. - : Elsevier BV. - 1873-1570 .- 0300-9572. ; 97, s. 68-75
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Tidskriftsartikel (refereegranskat)abstract
- Survivors of out-of-hospital cardiac arrest (OHCA) may experience psychological distress but the actual prevalence is unknown. The aim of this study was to investigate anxiety and depression within a large cohort of OHCA-survivors.
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| 12. |
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| 13. |
- Ebner, Florian, et al.
(författare)
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Associations between partial pressure of oxygen and neurological outcome in out-of-hospital cardiac arrest patients : an explorative analysis of a randomized trial
- 2019
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Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Exposure to hyperoxemia and hypoxemia is common in out-of-hospital cardiac arrest (OHCA) patients following return of spontaneous circulation (ROSC), but its effects on neurological outcome are uncertain, and study results are inconsistent. METHODS: Exploratory post hoc substudy of the Target Temperature Management (TTM) trial, including 939 patients after OHCA with return of spontaneous circulation (ROSC). The association between serial arterial partial pressures of oxygen (PaO2) during 37 h following ROSC and neurological outcome at 6 months, evaluated by Cerebral Performance Category (CPC), dichotomized to good (CPC 1-2) and poor (CPC 3-5), was investigated. In our analyses, we tested the association of hyperoxemia and hypoxemia, time-weighted mean PaO2, maximum PaO2 difference, and gradually increasing PaO2 levels (13.3-53.3 kPa) with poor neurological outcome. A subsequent analysis investigated the association between PaO2 and a biomarker of brain injury, peak serum Tau levels. RESULTS: Eight hundred sixty-nine patients were eligible for analysis. Three hundred patients (35%) were exposed to hyperoxemia or hypoxemia at some time point after ROSC. Our analyses did not reveal a significant association between hyperoxemia, hypoxemia, time-weighted mean PaO2 exposure or maximum PaO2 difference and poor neurological outcome at 6-month follow-up after correction for co-variates (all analyses p = 0.146-0.847). We were not able to define a PaO2 level significantly associated with the onset of poor neurological outcome. Peak serum Tau levels at either 48 or 72 h after ROSC were not associated with PaO2. CONCLUSION: Hyperoxemia or hypoxemia exposure occurred in one third of the patients during the first 37 h of hospitalization and was not significantly associated with poor neurological outcome after 6 months or with the peak s-Tau levels at either 48 or 72 h after ROSC.
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| 14. |
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| 15. |
- Krag, Mette, et al.
(författare)
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Prevalence and outcome of gastrointestinal bleeding and use of acid suppressants in acutely ill adult intensive care patients
- 2015
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 41:5, s. 833-845
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Tidskriftsartikel (refereegranskat)abstract
- To describe the prevalence of, risk factors for, and prognostic importance of gastrointestinal (GI) bleeding and use of acid suppressants in acutely ill adult intensive care patients. We included adults without GI bleeding who were acutely admitted to the intensive care unit (ICU) during a 7-day period. The primary outcome was clinically important GI bleeding in ICU, and the analyses included estimations of baseline risk factors and potential associations with 90-day mortality. A total of 1,034 patients in 97 ICUs in 11 countries were included. Clinically important GI bleeding occurred in 2.6 % (95 % confidence interval 1.6-3.6 %) of patients. The following variables at ICU admission were independently associated with clinically important GI bleeding: three or more co-existing diseases (odds ratio 8.9, 2.7-28.8), co-existing liver disease (7.6, 3.3-17.6), use of renal replacement therapy (6.9, 2.7-17.5), co-existing coagulopathy (5.2, 2.3-11.8), acute coagulopathy (4.2, 1.7-10.2), use of acid suppressants (3.6, 1.3-10.2) and higher organ failure score (1.4, 1.2-1.5). In ICU, 73 % (71-76 %) of patients received acid suppressants; most received proton pump inhibitors. In patients with clinically important GI bleeding, crude and adjusted odds for mortality were 3.7 (1.7-8.0) and 1.7 (0.7-4.3), respectively. In ICU patients clinically important GI bleeding is rare, and acid suppressants are frequently used. Co-existing diseases, liver failure, coagulopathy and organ failures are the main risk factors for GI bleeding. Clinically important GI bleeding was not associated with increased adjusted 90-day mortality, which largely can be explained by severity of comorbidity, other organ failures and age.
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| 16. |
- Lilja, Gisela, et al.
(författare)
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Return to Work and Participation in Society after Out-of-Hospital Cardiac Arrest
- 2018
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Ingår i: Circulation. Cardiovascular Quality and Outcomes. - 1941-7713. ; 11:1, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of this study was to describe out-of-hospital cardiac arrest (OHCA) survivors' ability to participate in activities of everyday life and society, including return to work. The specific aim was to evaluate potential effects of cognitive impairment. Methods and Results: Two hundred eighty-seven OHCA survivors included in the TTM trial (Target Temperature Management) and 119 matched control patients with ST-segment-elevation myocardial infarction participated in a follow-up 180 days post-event that included assessments of participation, return to work, emotional problems, and cognitive impairment. On the Mayo-Portland Adaptability Inventory-4 Participation Index, OHCA survivors (n=270) reported more restricted participation In everyday life and in society (47% versus 30%; P<0.001) compared with ST-segment-elevation myocardial infarction controls (n=118). Furthermore, 27% (n=36) of pre-event working OHCA survivors (n=135) compared with 7% (n=3) of pre-event working ST-segment-elevation myocardial infarction controls (n=45) were on sick leave (odds ratio, 4.9; 95% confidence interval, 1.4-16.8; P=0.01). Among the OHCA survivors assumed to return to work (n=135), those with cognitive impairment (n=55) were 3× more likely (odds ratio, 3.3; 95% confidence interval, 1.2-9.3; P=0.02) to be on sick leave compared with those without cognitive impairment (n=40; 36%, n=20, versus 15%, n=6). For OHCA survivors, the variables that were found most predictive for a lower participation were depression, restricted mobility, memory impairment, novel problem-solving difficulties, fatigue, and slower processing speed. Conclusions: OHCA survivors reported a more restricted societal participation 6 months post-arrest, and their return to work was lower compared with ST-segment-elevation myocardial infarction controls. Cognitive impairment was significantly associated with lower participation, together with the closely related symptoms of fatigue, depression, and restricted mobility. These predictive variables may be used during follow-up to identify OHCA survivors at risk of a less successful recovery that may benefit from further support and rehabilitation. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01946932.
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| 17. |
- Rolo, M. Da Rocha, et al.
(författare)
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A custom readout electronics for the BESIII CGEM detector
- 2017
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Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- For the upgrade of the inner tracker of the BESIII spectrometer, planned for 2018, a lightweight tracker based on an innovative Cylindrical Gas Electron Multiplier (CGEM) detector is now under development. The analogue readout of the CGEM enables the use of a charge centroid algorithm to improve the spatial resolution to better than 130 mu m while loosening the pitch strip to 650 mu m, which allows to reduce the total number of channels to about 10 000. The channels are readout by 160 dedicated integrated 64-channel front-end ASICs, providing a time and charge measurement and featuring a fully-digital output. The energy measurement is extracted either from the time-over-threshold (ToT) or the 10-bit digitisation of the peak amplitude of the signal. The time of the event is generated by quad-buffered low-power TDCs, allowing for rates in excess of 60 kHz per channel. The TDCs are based on analogue interpolation techniques and produce a time stamp (or two, if working in ToT mode) of the event with a time resolution better than 50 ps. The front-end noise, based on a CSA and a two-stage complex conjugated pole shapers, dominate the channel intrinsic time jitter, which is less than 5 ns r.m.s. The time information of the hit can be used to reconstruct the track path, operating the detector as a small TPC and hence improving the position resolution when the distribution of the cloud, due to large incident angle or magnetic field, is very broad. Event data is collected by an off-detector motherboard, where each GEM-ROC readout card handles 4 ASIC carrier FEBs (512 channels). Configuration upload and data readout between the off-detector electronics and the VME-based data collector cards are managed by bi-directional fibre optical links. This paper covers the design of a custom front-end electronics for the readout of the new inner tracker of the BESIII experiment, addressing the relevant design aspects of the detector electronics and the front-end ASIC for the CGEM readout, and reviewing the first silicon results of the chip prototype.
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| 18. |
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