1,720,978 research outputs found
Reduction of hemodilution in small adults undergoing open heart surgery: a prospective, randomized trial
No full textBackground. Given that there is an association between the degree of hemodilution during cardiopulmonary bypass (CPB) and postoperative complications, patients-outcome might be improved if the nadir hematocrit concentration is kept within an optimal range. Smaller patients are more likely to have a low hematocrit during CPB: this phenomenon may be related, at least partially, to the extreme hemodilution induced by a large fixed CPB priming volume. Methods. Forty patients with a body surface area (BSA) < 1.7m(2) undergoing open heart operations were randomized to either standard CPB with full prime volume ( control group) or reduced prime extracorporeal circuit and vacuum-assisted venous drainage (VAVD) ( study group). Results. There were no significant differences between the groups with respect to baseline characteristics, body surface area, hematologic profile and operative data. Clinical outcomes were similar. Nadir hematocrit and hemoglobin on bypass were significantly lower in the control group ( 22 +/- 2.3 vs 24 +/- 2.5%, p < 0.02 and 7.4 +/- 0.7 vs 8 +/- 0.9 g/ dl, p < 0.04, respectively). Postoperative chest tube drainage was significantly higher in the control group ( 272 +/- 253 vs 139 +/- 84 ml, p < 0.04). There was no difference in blood transfusion in the two groups ( 0.5 +/- 1.14 v 1.0 +/- 1.77 units of packed red blood cells ( PRBC), p = 0.29). Conclusions. Lowering CPB priming volume by means of using a small oxygenator and vacuum-assisted venous drainage ( VAVD) resulted in a significant decrease of intraoperative hemodilution. This technique should be strongly considered for patients with a small BSA ( < 1.7m(2)) undergoing open heart surgery
Heart Failure After 5 Years on LVAD: Diagnosis and Treatment of Outflow Graft Obstruction
No full textHeartWare assist device outflow graft obstruction is an uncommon but severe complication, and it may be because of several reasons. We present a case of recurrence of heart failure in a young patient supported with left ventricular assist device and on the waiting list for heart transplantation. After a complex diagnostic workout, a stenosis of the graft anastomosis was found and successfully stented
ECG changes after CABG: the role of the surgical technique
No full textObjective: The purpose of this study was to determine whether coronary artery bypass grafting (CABG) surgery on the beating heart (BH) is associated with reduction of R-wave potentials on the precordial leads on the surface electrocardiogram (ECG) as previously shown for CABG with cardiopulmonary bypass. Methods: Fifty-four patients undergoing CABG surgery at a single tertiary care university hospital were analyzed. Patients suffering a postoperative cardiac event (myocardial infarction) or nonspecific ECG changes were excluded. ECG results were recorded at arrival in the intensive care unit, after 4 and 18 hours postoperatively; simultaneously, myocardial cell damage biomarkers (CK-MB and cTnl) were assayed. A control group of 31 patients undergoing mitral valve repair was also evaluated. Results: Patients operated with the BH (OPCABG) technique did not show any decrease of R-wave amplitude at 0, 4, and 18 hours postoperatively; whereas those operated with CPB, both for coronary artery surgery and for mitral repair, had a similar extent and pattern of R-wave reduction. The release of myocardial necrosis markers was significantly lower in coronary artery patients operated with BH than in those operated with CPB; however, no statistically significant correlation between the ECG changes and release of myocardial cell damage markers was observed in any of the groups. Conclusions: The findings indicate, for the first time, that CABG surgery on the BH is not followed by any reduction of R-wave amplitude on precordial leads and confirms that the BH technique is associated with a lower release of myocardial cell damage markers. (C) 2004 Elsevier Inc. All rights reserved
Volatile Agents in Medical and Surgical Intensive Care Units: A Meta-Analysis of Randomized Clinical Trials
No full textObjective To comprehensively assess published randomized peer-reviewed studies related to volatile agents used for sedation in intensive care unit (ICU) settings, with the hypothesis that volatile agents could reduce time to extubation in adult patients. Design Systematic review and meta-analysis of randomized trials. Setting Intensive care units. Participants Critically ill patients. Interventions None. Measurements and Main Results The BioMedCentral, PubMed, Embase, and Cochrane Central Register databases of clinical trials were searched systematically for studies on volatile agents used in the ICU setting. Articles were assessed by trained investigators, and divergences were resolved by consensus. Inclusion criteria included random allocation to treatment (volatile agents versus any intravenous comparator, with no restriction on dose or time of administration) in patients requiring mechanical ventilation in the ICU. Twelve studies with 934 patients were included in the meta-analysis. The use of halogenated agents reduced the time to extubation (standardized mean difference = –0.78 [–1.01 to –0.55] hours; p for effect<0.00001; p for heterogeneity = 0.18; I2 = 32% in 7 studies with 503 patients). Results for time to extubation were confirmed in all subanalyses (eg, medical and surgical patients) and sensitivity analyses. No differences in length of hospital stay, ICU stay, and mortality were recorded. Conclusions In this meta-analysis of randomized trials, volatile anesthetics reduced time to extubation in medical and surgical ICU patients. The results of this study should be confirmed by large and high-quality randomized controlled studies
Diagnosis and Treatment Algorithm for Blood Flow Obstructions in Patients With Left Ventricular Assist Device
No full textBACKGROUND Thrombosis is an uncommon, but severe complication of left ventricular assist devices (LVADs). OBJECTIVES This study analyzed experience with obstruction of blood flow through the LVAD with the purpose of developing optimal diagnosis and treatment of LVAD-related thrombosis. METHODS Between October 2009 and July 2015, a total of 652 LVAD were implanted in 557 patients. Blood flow abnormalities in patients with LVAD (n = 524) were identified and classified as "high-power" and "low-flow" events. RESULTS Three types of late blood flow obstructions were identified: 1) pre-pump via thrombus obstructing the inflow cannula (26 events; 0.037 events per patient-year); 2) intra-pump (70 events; 0.1 events per patient-year); and 3) post-pump via thrombosis of the outflow graft or stenosis of the anastomosis to the aorta (4 events; 0.006 events per patient-year). Pre-pump obstruction was treated by washout maneuver in 9 cases (success rate, 100%), thrombolysis in 9 patients (success rate, 56%), and pump exchange in 9 cases (success rate, 100%); 1 patient died without treatment and 2 were weaned from LVAD. Intra-pump obstruction was treated by thrombolysis (n = 9; success rate, 33%), pump exchange (n = 53; success rate, 94%), and removal due to myocardial recovery (n = 3; success rate, 100%); 7 patients died without treatment and parameters spontaneously normalized in 2 cases. Post-pump obstruction was treated in 2 patients by stenting (success rate, 100%), and was left untreated in 2 cases. CONCLUSIONS We identified 3 types of LVAD-related blood flow obstruction, and developed an algorithm for optimal diagnosis and treatment. (C) 2016 by the American College of Cardiology Foundation
Argatroban anticoagulation for heparin induced thrombocytopenia in patients with ventricular assist devices
No full textPatients receiving implantation of ventricular assist devices (VAD) suffer a high incidence of heparin induced thrombocytopenia (HIT); the occurrence of this condition is associated with increased complications and worse outcomes. We report our experience in the management of patients who were diagnosed with HIT either before (HITpre) or after (HITpost) implantation of VAD with argatroban, a direct thrombin inhibitor.METHODS: This retrospective analysis assessed data of VAD patients diagnosed with HIT at Deutsches Herzzentrum Berlin between November 2005 and April 2009. Argatroban dose requirements, anticoagulation efficacy and adverse events (death, thromboembolism, bleeding) were recorded. Procedural success (discharge from the hospital, heart transplantation, or recovery of the failing heart) was also assessed.RESULTS: Twenty-seven patients were identified (11 HITpre, 16 HITpost). Argatroban was effective in obtaining adequate anticoagulation with a reduced dose regimen (0.02-0.42 mcg/Kg/min starting dose; 0.02-1.5 mcg/Kg/min maintenance dose). We noted 5 thromboembolic complications (18%), 6 cases of major bleeding (22%) and 5 deaths (18%), all cause composite adverse end point occurring in 40% of patients. Procedural success was obtained in 81% of patients (92% HITpre, 69% HITpost). As compared to historical controls of patients treated with lepirudin in the period 2000-2005, results were significantly improved.CONCLUSION: Argatroban anticoagulation is feasible in patients with HIT after VAD implantation, without increasing bleeding risk. Its impact in terms of survival should be reviewed also in the light of the technological improvements of assist devices
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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