296 research outputs found
Hypertriglyceridemia: a potential side effect of propofol sedation in critical illness
Purpose: Hypertriglyceridemia (hyperTG) is common among intensive care unit (ICU) patients, but knowledge about hyperTG risk factors is scarce. The present study aims to identify risk factors favoring its development in patients requiring prolonged ICU treatment. Methods: Prospective observational study in the medicosurgical ICU of a university teaching hospital. All consecutive patients staying ≥4days were enrolled. Potential risk factors were recorded: pathology, energy intake, amount and type of nutritional lipids, intake of propofol, glucose intake, laboratory parameters, and drugs. Triglyceride (TG) levels were assessed three times weekly. Statistics was based on two-way analysis of variance (ANOVA) and linear regression with potential risk factors. Results: Out of 1,301 consecutive admissions, 220 patients were eligible, of whom 99 (45%) presented hyperTG (triglycerides >2mmol/L). HyperTG patients were younger, heavier, with more brain injury and multiple trauma. Intake of propofol (mg/kg/h) and lipids' propofol had the highest correlation with plasma TG (r 2=0.28 and 0.26, respectively, both p<0.001). Infection and inflammation were associated with development of hyperTG [C-reactive protein (CRP), r 2=0.19, p=0.004]. No strong association could be found with nutritional lipids or other risk factors. Outcome was similar in normo- and hyperTG patients. Conclusions: HyperTG is frequent in the ICU but is not associated with adverse outcome. Propofol and accompanying lipid emulsion are the strongest risk factors. Our results suggest that plasma TG should be monitored at least twice weekly in patients on propofol. The clinical consequences of propofol-related hyperTG should be investigated in further studie
Are terminally ill patients dying in the ICU suitable for non-heart beating organ donation?
OBJECTIVE: To evaluate the feasibility of implementing a program of controlled non-heart beating organ donation, in patients undergoing the withdrawal of intensive care treatment. DESIGN AND SETTING: Prospective observational study. Medical and Surgical ICUs in a tertiary university hospital. PATIENTS: Consecutive patients younger than 70 years dying in the ICU after treatment withdrawal for dire neurological prognosis. MEASUREMENTS AND RESULTS: We analyzed prospectively collected data from the ICU clinical information system. Seventy-three of 516 ICU deaths (13%) were identified, equally distributed among traumatic, stroke, and anoxic brain injury. The management and the course in these three diagnostic categories were similar. All patients underwent withdrawal of mechanical ventilation and half were extubated. Median time to death was of 4.8 h (IQR 1.4-11.5). In 70% of cases the patient received analgesia and 30% sedation. Such treatment was not related to earlier death. Hypotension was observed in 50% of patients during the 30 min preceding cardiac death. CONCLUSIONS: With our current management of terminal patients controlled non-heart beating organ procedure may be difficult due to the duration and variability of the dying process. This observation suggests that we can perform better by evaluating this process more closely
Quantum Coherence Oscillations in Antiferromagnetic Chains
Macroscopic quantum coherence oscillations in mesoscopic antiferromagnets may
appear when the anisotropy potential creates a barrier between the
antiferromagnetic states with opposite orientations of the Neel vector. This
phenomenon is studied for the physical situation of the nuclear spin system of
eight Xe atoms arranged on a magnetic surface along a chain. The oscillation
period is calculated as a function of the chain constant. The environmental
decoherence effects at finite temperature are accounted assuming a dipole
coupling between the spin chain and the fluctuating magnetic field of the
surface. The numerical calculations indicate that the oscillations are damped
by a rate , where is the number of spins and is
the relaxation time of a single spin.Comment: 10 pages, Latex, two postscript figures; submitted to Phys. Rev.
Proton NMR for Measuring Quantum-Level Crossing in the Magnetic Molecular Ring Fe10
The proton nuclear spin-lattice relaxation rate 1/T1 has been measured as a
function of temperature and magnetic field (up to 15 T) in the molecular
magnetic ring Fe10. Striking enhancement of 1/T1 is observed around magnetic
field values corresponding to a crossing between the ground state and the
excited states of the molecule. We propose that this is due to a
cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir
of the Zeeman levels of the molecule. This effect provides a powerful tool to
investigate quantum dynamical phenomena at level crossing.Comment: Four pages, to appear in Phys.Rev.Let
Are there accurate predictors of long-term vital and functional outcomes in cardiac surgical patients requiring prolonged intensive care?
BACKGROUND AND OBJECTIVE: The decision to maintain intensive treatment in cardiac surgical patients with poor initial outcome is mostly based on individual experience. The risk scoring systems used in cardiac surgery have no prognostic value for individuals. This study aims to assess (a) factors possibly related to poor survival and functional outcomes in cardiac surgery patients requiring prolonged (> or = 5 days) intensive care unit (ICU) treatment, (b) conditions in which treatment withdrawal might be justified, and (c) the patient's perception of the benefits and drawbacks of long intensive treatments. METHODS: The computerized data prospectively recorded for every patient in the intensive care unit over a 3-year period were reviewed and analyzed (n=1859). Survival and quality of life (QOL) outcomes were determined in all patients having required > or =5 consecutive days of intensive treatment (n=194/10.4%). Long-term survivors were interviewed at yearly intervals in a standardized manner and quality of life was assessed using the dependency score of Karnofsky. No interventions or treatments were given, withhold, or withdrawn as part of this study. RESULTS: In-hospital, 1-, and 3-year cumulative survival rates reached 91.3%, 85.6%, and 75.1%, respectively. Quality of life assessed 1 year postoperatively by the score of Karnofsky was good in 119/165 patients, fair in 32 and poor in 14. Multivariate logistic regression analysis of 19 potential predictors of poor outcome identified dialysis as the sole factor significantly (p=0.027) - albeit moderately - reducing long-term survival, and sustained neurological deficit as an inconstant predictor of poor functional outcome (p=0.028). One year postoperatively 0.63% of patients still reminded of severe suffering in the intensive station and 20% of discomfort. Only 7.7% of patients would definitely refuse redo surgery. CONCLUSIONS: This study of cardiac surgical patients requiring > or =5 days of intensive treatment did not identify factors unequivocally justifying early treatment limitation in individuals. It found that 1-year mortality and disability rates can be maintained at a low level in this subset of patients, and that severe suffering in the ICU is infrequent
Q-dependence of the inelastic neutron scattering cross section for molecular spin clusters with high molecular symmetry
For powder samples of polynuclear metal complexes the dependence of the
inelastic neutron scattering intensity on the momentum transfer Q is known to
be described by a combination of so called interference terms. They reflect the
interplay between the geometrical structure of the compound and the spatial
properties of the wave functions involved in the transition. In this work, it
is shown that the Q-dependence is strongly interrelated with the molecular
symmetry of molecular nanomagnets, and, if the molecular symmetry is high
enough, is actually completely determined by it. A general formalism connecting
spatial symmetry and interference terms is developed. The arguments are
detailed for cyclic spin clusters, as experimentally realized by e.g. the
octanuclear molecular wheel Cr8, and the star like tetranuclear cluster Fe4.Comment: 8 pages, 1 figures, REVTEX
Macroscopic quantum coherence in mesoscopic ferromagnetic systems
In this paper we study the Macroscopic Quantum Oscillation (MQO) effect in
ferromagnetic single domain magnets with a magnetic field applied along the
hard anistropy axis. The level splitting for the ground state, derived with the
conventional instanton method, oscillates with the external field and is
quenched at some field values. A formula for quantum tunneling at excited
levels is also obtained. The existence of topological phase accounts for this
kind of oscillation and the corresponding thermodynamical quantities exhibit
similar interference effects which resembles to some extent the electron
quantum phase interference induced by gauge potential in the Aharonov-Bohm
effect and the -vacuum in Yang-Mills field theory..Comment: 12 pages, 4 figures, to appear in Phys. Rev.
Weight status and hypertension among adolescent girls in Argentina and Norway: Data from the ENNyS and HUNT studies
<p>Abstract</p> <p>Background</p> <p>To provide data on overweight, obesity and hypertension among adolescent girls in Norway and Argentina.</p> <p>Methods</p> <p>Data was obtained from two population-based, cross-sectional and descriptive studies containing anthropometric and blood pressure measurements of 15 to 18 year old girls. The study included 2,156 adolescent girls from Norway evaluated between 1995 and 1997, and 669 from Argentina evaluated between 2004 and 2005.</p> <p>Results</p> <p>Around 15% of adolescent girls in Norway and 19% in Argentina are overweight or obese. Body mass index (BMI) distribution in these two countries is similar, with a low percentage (< 1%) of girls classified as thin. Norwegian adolescents show a height mean value 8 cm taller than the Argentinean. Obesity is strongly associated with systolic hypertension in both populations, with odds ratios of 11.4 [1.6; 82.0] and 28.3 [11.8; 67.7] in Argentina and Norway, respectively. No direct association between BMI and systolic hypertension was found, and only extreme BMI values (above 80<sup>th </sup>- 90<sup>th </sup>percentile) were associated with hypertension.</p> <p>Conclusion</p> <p>This study confirms a current world health problem by showing the high prevalence of obesity in adolescents and its association with hypertension in two different countries (one developed and one in transition).</p
Malnutrition and inflammation in acute kidney injury due to earthquake-related crush syndrome
<p>Abstract</p> <p>Background</p> <p>Malnutrition and inflammation are common and serious complications in patients with acute kidney injury (AKI). However, the profile of these complications in patients with AKI caused by crush syndrome (CS) remains unclear. This study describes the clinical characteristics of malnutrition and inflammation in patients with AKI and CS due to the Wenchuan earthquake.</p> <p>Methods</p> <p>One thousand and twelve victims and eighteen healthy adults were recruited to the study. They were divided into five groups: Group A was composed of victims without CS and AKI (904 cases); Group B was composed of patients with CS and AKI who haven't received renal replacement therapy (RRT) (57 cases); and Group C was composed of patients with CS and AKI receiving RRT (25 cases); Group D was composed of earthquake victims with AKI but without CS (26 cases); and Group E was composed of 18 healthy adult controls. The C-reactive protein (CRP), prealbumin, transferrin, interleukin-6 and TNF-α were measured and compared between Group E and 18 patients from Group C.</p> <p>Results</p> <p>The results indicate that participants in Group C had the highest level of serum creatinine, blood urea nitrogen and uric acid. Approximately 92% of patients with CS who had RRT were suffering from hypoalbuminemia. The interleukin-6 and CRP levels were significantly higher in patients with CS AKI receiving RRT than in the control group. Patients in Group C received the highest dosages of albumin, plasma or red blood cell transfusions. One patient in Group C died during treatment.</p> <p>Conclusions</p> <p>Malnutrition and inflammation was common in patients with earthquake-related CS and had a negative impact on the prognosis of these subjects. The results of this study indicate that the use of RRT, intensive nutritional supplementation and transfusion alleviated the degree of malnutrition and inflammation in hemodialysis patients with crush syndrome.</p
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