874 resultados para Displacement controlled
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OBJECTIVES: Resuscitation in severe head injury may be detrimental when given with hypotonic fluids. We evaluated the effects of lactated Ringer's solution (sodium 131 mmol/L, 277 mOsm/L) compared with hypertonic saline (sodium 268 mmol/L, 598 mOsm/L) in severely head-injured children over the first 3 days after injury. DESIGN: An open, randomized, and prospective study. SETTING: A 16-bed pediatric intensive care unit (ICU) (level III) at a university children's hospital. PATIENTS: A total of 35 consecutive children with head injury. INTERVENTIONS: Thirty-two children with Glasgow Coma Scores of <8 were randomly assigned to receive either lactated Ringer's solution (group 1) or hypertonic saline (group 2). Routine care was standardized, and included the following: head positioning at 30 degrees; normothermia (96.8 degrees to 98.6 degrees F [36 degrees to 37 degrees C]); analgesia and sedation with morphine (10 to 30 microg/kg/hr), midazolam (0.2 to 0.3 mg/kg/hr), and phenobarbital; volume-controlled ventilation (PaCO2 of 26.3 to 30 torr [3.5 to 4 kPa]); and optimal oxygenation (PaO2 of 90 to 105 torr [12 to 14 kPa], oxygen saturation of >92%, and hematocrit of >0.30). MEASUREMENTS AND MAIN RESULTS: Mean arterial pressure and intracranial pressure (ICP) were monitored continuously and documented hourly and at every intervention. The means of every 4-hr period were calculated and serum sodium concentrations were measured at the same time. An ICP of 15 mm Hg was treated with a predefined sequence of interventions, and complications were documented. There was no difference with respect to age, male/female ratio, or initial Glasgow Coma Score. In both groups, there was an inverse correlation between serum sodium concentration and ICP (group 1: r = -.13, r2 = .02, p < .03; group 2: r = -.29, r2 = .08, p < .001) that disappeared in group 1 and increased in group 2 (group 1: r = -.08, r2 = .01, NS; group 2: r = -.35, r2 =.12, p < .001). Correlation between serum sodium concentration and cerebral perfusion pressure (CPP) became significant in group 2 after 8 hrs of treatment (r = .2, r2 = .04, p = .002). Over time, ICP and CPP did not significantly differ between the groups. However, to keep ICP at <15 mm Hg, group 2 patients required significantly fewer interventions (p < .02). Group 1 patients received less sodium (8.0 +/- 4.5 vs. 11.5 +/- 5.0 mmol/kg/day, p = .05) and more fluid on day 1 (2850 +/- 1480 vs. 2180 +/- 770 mL/m2, p = .05). They also had a higher frequency of acute respiratory distress syndrome (four vs. 0 patients, p = .1) and more than two complications (six vs. 1 patient, p = .09). Group 2 patients had significantly shorter ICU stay times (11.6 +/- 6.1 vs. 8.0 +/- 2.4 days; p = .04) and shorter mechanical ventilation times (9.5 +/- 6.0 vs. 6.9 +/- 2.2 days; p = .1). The survival rate and duration of hospital stay were similar in both groups. CONCLUSIONS: Treatment of severe head injury with hypertonic saline is superior to that treatment with lactated Ringer's solution. An increase in serum sodium concentrations significantly correlates with lower ICP and higher CPP. Children treated with hypertonic saline require fewer interventions, have fewer complications, and stay a shorter time in the ICU.
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The improvement of the dynamics of flexible manipulators like log cranes often requires advanced control methods. This thesis discusses the vibration problems in the cranes used in commercial forestry machines. Two control methods, adaptive filtering and semi-active damping, are presented. The adaptive filter uses a part of the lowest natural frequency of the crane as a filtering frequency. The payload estimation algorithm, filtering of control signal and algorithm for calculation of the lowest natural frequency of the crane are presented. The semi-active damping method is basedon pressure feedback. The pressure vibration, scaled with suitable gain, is added to the control signal of the valve of the lift cylinder to suppress vibrations. The adaptive filter cuts off high frequency impulses coming from the operatorand semi-active damping suppresses the crane?s oscillation, which is often caused by some external disturbance. In field tests performed on the crane, a correctly tuned (25 % tuning) adaptive filter reduced pressure vibration by 14-17 % and semi-active damping correspondingly by 21-43%. Applying of these methods require auxiliary transducers, installed in specific points in the crane, and electronically controlled directional control valves.
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The following paper introduces the work conducted to create a relative virtual mouse based on the interpretation of head movements and face gesture through a low cost camera and the optical flow of the images. This virtual device is designed specifically as an alternative non-contact pointer for people with mobility impairments in the upper extremities and reduced head control. The proposed virtual device was compared with a conventional mouse, a touchpad and a digital joystick. Validation results show performances close to a digital joystick but far away from a conventional mouse.
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BACKGROUND: Cardiac arrest causes ischaemic brain injury. Arterial carbon dioxide tension (PaCO2) is a major determinant of cerebral blood flow. Thus, mild hypercapnia in the 24 h following cardiac arrest may increase cerebral blood flow and attenuate such injury. We describe the Carbon Control and Cardiac Arrest (CCC) trial. METHODS/DESIGN: The CCC trial is a pilot multicentre feasibility, safety and biological efficacy randomized controlled trial recruiting adult cardiac arrest patients admitted to the intensive care unit after return of spontaneous circulation. At admission, using concealed allocation, participants are randomized to 24 h of either normocapnia (PaCO2 35 to 45 mmHg) or mild hypercapnia (PaCO2 50 to 55 mmHg). Key feasibility outcomes are recruitment rate and protocol compliance rate. The primary biological efficacy and biological safety measures are the between-groups difference in serum neuron-specific enolase and S100b protein levels at 24 h, 48 h and 72 h. Secondary outcome measure include adverse events, in-hospital mortality, and neurological assessment at 6 months. DISCUSSION: The trial commenced in December 2012 and, when completed, will provide clinical evidence as to whether targeting mild hypercapnia for 24 h following intensive care unit admission for cardiac arrest patients is feasible and safe and whether it results in decreased concentrations of neurological injury biomarkers compared with normocapnia. Trial results will also be used to determine whether a phase IIb study powered for survival at 90 days is feasible and justified. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12612000690853 .
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OBJECTIVE: To compare epidural analgesia (EDA) to patient-controlled opioid-based analgesia (PCA) in patients undergoing laparoscopic colorectal surgery. BACKGROUND: EDA is mainstay of multimodal pain management within enhanced recovery pathways [enhanced recovery after surgery (ERAS)]. For laparoscopic colorectal resections, the benefit of epidurals remains debated. Some consider EDA as useful, whereas others perceive epidurals as unnecessary or even deleterious. METHODS: A total of 128 patients undergoing elective laparoscopic colorectal resections were enrolled in a randomized clinical trial comparing EDA versus PCA. Primary end point was medical recovery. Overall complications, hospital stay, perioperative vasopressor requirements, and postoperative pain scores were secondary outcome measures. Analysis was performed according to the intention-to-treat principle. RESULTS: Final analysis included 65 EDA patients and 57 PCA patients. Both groups were similar regarding baseline characteristics. Medical recovery required a median of 5 days (interquartile range [IQR], 3-7.5 days) in EDA patients and 4 days (IQR, 3-6 days) in the PCA group (P = 0.082). PCA patients had significantly less overall complications [19 (33%) vs 35 (54%); P = 0.029] but a similar hospital stay [5 days (IQR, 4-8 days) vs 7 days (IQR, 4.5-12 days); P = 0.434]. Significantly more EDA patients needed vasopressor treatment perioperatively (90% vs 74%, P = 0.018), the day of surgery (27% vs 4%, P < 0.001), and on postoperative day 1 (29% vs 4%, P < 0.001), whereas no difference in postoperative pain scores was noted. CONCLUSIONS: Epidurals seem to slow down recovery after laparoscopic colorectal resections without adding obvious benefits. EDA can therefore not be recommended as part of ERAS pathways in laparoscopic colorectal surgery.
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AIMS: Estimating the effect of a nursing intervention in home-dwelling older adults on the occurrence and course of delirium and concomitant cognitive and functional impairment. METHODS: A randomized clinical pilot trial using a before/after design was conducted with older patients discharged from hospital who had a medical prescription to receive home care. A total of 51 patients were randomized into the experimental group (EG) and 52 patients into the control group (CG). Besides usual home care, nursing interventions were offered by a geriatric nurse specialist to the EG at 48 h, 72 h, 7 days, 14 days, and 21 days after discharge. All patients were monitored for symptoms of delirium using the Confusion Assessment Method. Cognitive and functional statuses were measured with the Mini-Mental State Examination and the Katz and Lawton Index. RESULTS: No statistical differences with regard to symptoms of delirium (p = 0.085), cognitive impairment (p = 0.151), and functional status (p = 0.235) were found between the EG and CG at study entry and at 1 month. After adjustment, statistical differences were found in favor of the EG for symptoms of delirium (p = 0.046), cognitive impairment (p = 0.015), and functional status (p = 0.033). CONCLUSION: Nursing interventions to detect delirium at home are feasible and accepted. The nursing interventions produced a promising effect to improve delirium.
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BACKGROUND: Frequent emergency department users represent a small number of patients but account for a large number of emergency department visits. They should be a focus because they are often vulnerable patients with many risk factors affecting their quality of life (QoL). Case management interventions have resulted in a significant decrease in emergency department visits, but association with QoL has not been assessed. One aim of our study was to examine to what extent an interdisciplinary case management intervention, compared to standard emergency care, improved frequent emergency department users' QoL. METHODS: Data are part of a randomized, controlled trial designed to improve frequent emergency department users' QoL and use of health-care resources at the Lausanne University Hospital, Switzerland. In total, 250 frequent emergency department users (≥5 attendances during the previous 12 months; ≥ 18 years of age) were interviewed between May 2012 and July 2013. Following an assessment focused on social characteristics; social, mental, and somatic determinants of health; risk behaviors; health care use; and QoL, participants were randomly assigned to the control or the intervention group (n=125 in each group). The final sample included 194 participants (20 deaths, 36 dropouts, n=96 in the intervention group, n=99 in the control group). Participants in the intervention group received a case management intervention by an interdisciplinary, mobile team in addition to standard emergency care. The case management intervention involved four nurses and a physician who provided counseling and assistance concerning social determinants of health, substance-use disorders, and access to the health-care system. The participants' QoL was evaluated by a study nurse using the WHOQOL-BREF five times during the study (at baseline, and at 2, 5.5, 9, and 12 months). Four of the six WHOQOL dimensions of QoL were retained here: physical health, psychological health, social relationship, and environment, with scores ranging from 0 (low QoL) to 100 (high QoL). A linear, mixed-effects model with participants as a random effect was run to analyze the change in QoL over time. The effects of time, participants' group, and the interaction between time and group were tested. These effects were controlled for sociodemographic characteristics and health-related variables (i.e., age, gender, education, citizenship, marital status, type of financial resources, proficiency in French, somatic and mental health problems, and behaviors at risk).
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BACKGROUND: Frequent emergency department users represent a small number of patients but account for a large number of emergency department visits. They should be a focus because they are often vulnerable patients with many risk factors affecting their quality of life (QoL). Case management interventions have resulted in a significant decrease in emergency department visits, but association with QoL has not been assessed. One aim of our study was to examine to what extent an interdisciplinary case management intervention, compared to standard emergency care, improved frequent emergency department users' QoL. METHODS: Data are part of a randomized, controlled trial designed to improve frequent emergency department users' QoL and use of health-care resources at the Lausanne University Hospital, Switzerland. In total, 250 frequent emergency department users (≥5 attendances during the previous 12 months; ≥ 18 years of age) were interviewed between May 2012 and July 2013. Following an assessment focused on social characteristics; social, mental, and somatic determinants of health; risk behaviors; health care use; and QoL, participants were randomly assigned to the control or the intervention group (n=125 in each group). The final sample included 194 participants (20 deaths, 36 dropouts, n=96 in the intervention group, n=99 in the control group). Participants in the intervention group received a case management intervention by an interdisciplinary, mobile team in addition to standard emergency care. The case management intervention involved four nurses and a physician who provided counseling and assistance concerning social determinants of health, substance-use disorders, and access to the health-care system.
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Turbokoneet ja etenkin höyryturbiinit ovat usein suunniteltu ja optimoitu toimimaan tietyssä toimintapisteessä jossa häviöt on minimoitu ja hyötysuhde maksimoitu. Joissakin tapauksissa on kuitenkin tarpeellista käyttää turbiinia toimintapisteen ulkopuolella. Tällöin turbiinin läpi virtaava massavirta muuttuu ja yleensä heikentää hyötysuhdetta. Turbokoneiden suorituskykyä voidaan parantaa käyttämällä kolmidimensionaalisesti muotoiltuja siipiä. Työssä on vertailtu laskennallisesti kahta kohtuullisesti muotoiltua suutinta (Compound lean ja Controlled flow) niiden suunnitellun toimintapisteen ulkopuolella. Kolmas suutin, ilman kolmidimensionaalista muotoilua on mukana vertailukohteena. Suutinten suorituskykyä tutkitaan laskennallisen virtausmekaniikan avulla olosuhteissa, jotka ovat toimintapisteen ulkopuolella. Virtauksen muutoksia tutkitaan kokonaispainehäviön, isentrooppisen hyötysuhteen ja virtauspinnan yhdenmukaisuuden avulla. Virtauspintoja verrataan ulosvirtauskulman, massavirran ja toisiovirtausvektoreiden jakauman avulla. Erot suutinten suorituskykyvyssä korostavat ylikuormalla. Kun massavirran arvoa on kohotettu eniten, Compound lean suuttimilla hyötysuhde laskee Controlled flow suuttimeen verrattuna vähemmän. Alikuormalla, kun massavirran arvoa lasketaan, erot suuttimien suorituskyvyssä pienenevät ja tutkittujen suuttimien ulosvirtaus on samankaltainen.
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BACKGROUND: Second line endocrine therapy has limited antitumour activity. Fulvestrant inhibits and downregulates the oestrogen receptor. The mitogen-activated protein kinase (MAPK) pathway is one of the major cascades involved in resistance to endocrine therapy. We assessed the efficacy and safety of fulvestrant with selumetinib, a MEK 1/2 inhibitor, in advanced stage breast cancer progressing after aromatase inhibitor (AI). PATIENTS AND METHODS: This randomised phase II trial included postmenopausal patients with endocrine-sensitive breast cancer. They were ramdomised to fulvestrant combined with selumetinib or placebo. The primary endpoint was disease control rate (DCR) in the experimental arm. ClinicalTrials.gov Indentifier: NCT01160718. RESULTS: Following the planned interim efficacy analysis, recruitment was interrupted after the inclusion of 46 patients (23 in each arm), because the selumetinib-fulvestrant arm did not reach the pre-specified DCR. DCR was 23% (95% confidence interval (CI) 8-45%) in the selumetinib arm and 50% (95% CI 27-75%) in the placebo arm. Median progression-free survival was 3.7months (95% CI 1.9-5.8) in the selumetinib arm and 5.6months (95% CI 3.4-13.6) in the placebo arm. Median time to treatment failure was 5.1 (95% CI 2.3-6.7) and 5.6 (95% CI 3.4-10.2) months, respectively. The most frequent treatment-related adverse events observed in the selumetinib-fulvestrant arm were skin disorders, fatigue, nausea/vomiting, oedema, diarrhoea, mouth disorders and muscle disorders. CONCLUSIONS: The addition of selumetinib to fulvestrant did not show improving patients' outcome and was poorly tolerated at the recommended monotherapy dose. Selumetinib may have deteriorated the efficacy of the endocrine therapy in some patients.
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Clinical experience and experimental data suggest that intradialytic hemodynamic profiles could be influenced by the characteristics of the dialysis membranes. Even within the worldwide used polysulfone family, intolerance to specific membranes was occasionally evoked. The aim of this study was to compare hemodynamically some of the commonly used polysulfone dialyzers in Switzerland. We performed an open-label, randomized, cross-over trial, including 25 hemodialysis patients. Four polysulfone dialyzers, A (Revaclear high-flux, Gambro, Stockholm, Sweden), B (Helixone high-flux, Fresenius), C (Xevonta high-flux, BBraun, Melsungen, Germany), and D (Helixone low-flux, Fresenius, Bad Homburg vor der Höhe, Germany), were compared. The hemodynamic profile was assessed and patients were asked to provide tolerance feedback. The mean score (±SD) subjectively assigned to dialysis quality on a 1-10 scale was A 8.4 ± 1.3, B 8.6 ± 1.3, C 8.5 ± 1.6, D 8.5 ± 1.5. Kt/V was A 1.58 ± 0.30, B 1.67 ± 0.33, C 1.62 ± 0.32, D 1.45 ± 0.31. The low- compared with the high-flux membranes, correlated to higher systolic (128.1 ± 13.1 vs. 125.6 ± 12.1 mmHg, P < 0.01) and diastolic (76.8 ± 8.7 vs. 75.3 ± 9.0 mmHg; P < 0.05) pressures, higher peripheral resistance (1.44 ± 0.19 vs. 1.40 ± 0.18 s × mmHg/mL; P < 0.05) and lower cardiac output (3.76 ± 0.62 vs. 3.82 ± 0.59 L/min; P < 0.05). Hypotension events (decrease in systolic blood pressure by >20 mmHg) were 70 with A, 87 with B, 73 with C, and 75 with D (P < 0.01 B vs. A, 0.05 B vs. C and 0.07 B vs. D). The low-flux membrane correlated to higher blood pressure levels compared with the high-flux ones. The Helixone high-flux membrane ensured the best efficiency. Unfortunately, the very same dialyzer correlated to a higher incidence of hypotensive episodes.
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Introduction The benefit of corticosteroids as adjunctive treatment in patients with severe community-acquired pneumonia (CAP) requiring hospital admission remains unclear. This study aimed to evaluate the impact of corticosteroid treatment on outcomes in patients with CAP. Methods This was a prospective, double-blind and randomized study. All patients received treatment with ceftriaxone plus levofloxacin and methyl-prednisolone (MPDN) administered randomly and blindly as an initial bolus, followed by a tapering regimen, or placebo. Results Of the 56 patients included in the study, 28 (50%) were treated with concomitant corticosteroids. Patients included in the MPDN group show a more favourable evolution of the pO2/FiO2 ratio and faster decrease of fever, as well as greater radiological improvement at seven days. The time to resolution of morbidity was also significantly shorter in this group. Six patients met the criteria for mechanical ventilation (MV): five in the placebo group (22.7%) and one in the MPDN group (4.3%). The duration of MV was 13 days (interquartile range 7 to 26 days) for the placebo group and three days for the only case in the MPDN group. The differences did not reach statistical significance. Interleukin (IL)-6 and C-reactive protein (CRP) showed a significantly quicker decrease after 24 h of treatment among patients treated with MPDN. No differences in mortality were found among groups. Conclusions MPDN treatment, in combination with antibiotics, improves respiratory failure and accelerates the timing of clinical resolution of severe CAP needing hospital admission.