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Context  Clinical studies of omega-3 polyunsaturated fatty acids (PUFAs) have shown a reduction in sudden cardiac death, suggesting that omega-3 PUFAs may have antiarrhythmic effects. Objective  To determine whether omega-3 PUFAs have beneficial antiarrhythmic effects in patients with a history of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Design and Setting  Randomized, double-blind, placebo-controlled trial performed at 6 US medical centers with enrollment from February 1999 until January 2003. Patients  Two hundred patients with an implantable cardioverter defibrillator (ICD) and a recent episode of sustained VT or VF. Intervention  Patients were randomly assigned to receive fish oil, 1.8 g/d, 72% omega-3 PUFAs, or placebo and were followed up for a median of 718 days (range, 20-828 days). Main Outcome Measures  Time to first episode of ICD treatment for VT/VF, changes in red blood cell concentrations of omega-3 PUFAs, frequency of recurrent VT/VF events, and predetermined subgroup analyses. Results  Patients randomized to receive fish oil had an increase in the mean percentage of omega-3 PUFAs in red blood cell membranes from 4.7% to 8.3% (P<.001), with no change observed in patients receiving placebo. At 6, 12, and 24 months, 46% (SE, 5%), 51% (5%), and 65% (5%) of patients randomized to receive fish oil had ICD therapy for VT/VF compared with 36% (5%), 41% (5%), and 59% (5%) for patients randomized to receive placebo (P = .19). In the subset of 133 patients whose qualifying arrhythmia was VT, 61% (SE, 6%), 66% (6%), and 79% (6%) of patients in the fish oil group had VT/VF at 6, 12, and 24 months compared with 37% (6%), 43% (6%), and 65% (6%) of patients in the control group (P = .007). Recurrent VT/VF events were more common in patients randomized to receive fish oil (P<.001). Conclusion  Among patients with a recent episode of sustained ventricular arrhythmia and an ICD, fish oil supplementation does not reduce the risk of VT/VF and may be proarrhythmic in some patients.   相似文献   
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ObjectiveTo explore the perspectives and preferences of pregnant women receiving prenatal care in a rural community regarding delivery location.DesignExploratory qualitative research project.SettingThe La Ronge Medical Clinic in northern Saskatchewan.ParticipantsPregnant women of any parity aged 18 years or older who attended the clinic for prenatal care from March 1, 2018, to March 31, 2019, were invited to participate. The closest obstetric and surgical services are 240 km away.MethodsThis project was undertaken using semistructured interviews. The interviews were audiorecorded, transcribed, and analyzed using an inductive thematic analysis, taking into consideration both saturation and analyst triangulation. The investigators and researchers on this project were family medicine residents and faculty in a remote medical clinic.Main findingsThe factors that played a substantial role in influencing the patients’ decisions regarding delivery location included access to medical services, proximity to home community, perceptions of medical care providers, and some unique features of local hospitals. The participants largely believed they maintained their autonomy in selecting their preferred delivery location while seeking input from their prenatal care providers and families.ConclusionPregnant women in this rural community consider many factors when deciding on their delivery location. These findings can be taken into consideration by physicians when discussing with their rural patients the risks and benefits of delivery in both rural and urban centres. Barriers to local delivery should be addressed, while maintaining a woman’s autonomy to choose where she gives birth.  相似文献   
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BACKGROUND/AIMS: Staging laparoscopy for suspected pancreatic neoplasia is not widely accepted due to its low yield. The aim of this study was to determine if serum carbohydrate antigen (CA19-9) levels could be used to improve the selection of patients for staging laparoscopy. METHODS: The data from a prospectively collected database (1997-2004) with 159 patients who had computed tomography-predicted resectable disease and who had undergone laparoscopic staging were analysed to determine if a low preoperative CA19-9 level (< or =150 kU/l, or < or =300 kU/l with a bilirubin >35 micromol/l) identified patients in whom laparoscopy was not useful. Results: The CA19-9 level was >150 kU/l in 96 patients of whom 75 (78%) were considered resectable following laparoscopic assessment. There were 63 patients with a CA19-9 < or =150 kU/l of whom 60 (95%) were considered resectable following laparoscopic assessment. The sensitivity, specificity, positive predictive value and negative predictive value for CA19-9 < or =150 kU/l in predicting that laparoscopic assessment would judge patients as resectable were 44, 88, 95 and 22%, respectively. A cut-off level of < or =300 kU/l in patients with a bilirubin >35 micromol/l produced values of 30, 94, 94 and 28%, respectively. By using CA19-9 < or =150 kU/l, laparoscopy could have been avoided in 40% of patients, increased to 55% of patients with adjustment for the presence of jaundice; concomitantly, the yield from laparoscopy would have been increased from 15 to 22 and 25%, respectively. Conclusion: Use of serum CA19-9 levels would increase the efficiency of laparoscopic staging in patients with suspected pancreatic malignancy.  相似文献   
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