881 research outputs found
A prospective observational study
Background: Severe bacterial infections remain a major challenge in intensive
care units because of their high prevalence and mortality. Adequate antibiotic
exposure has been associated with clinical success in critically ill patients.
The objective of this study was to investigate the target attainment of
standard meropenem dosing in a heterogeneous critically ill population, to
quantify the impact of the full renal function spectrum on meropenem exposure
and target attainment, and ultimately to translate the findings into a tool
for practical application. Methods: A prospective observational single-centre
study was performed with critically ill patients with severe infections
receiving standard dosing of meropenem. Serial blood samples were drawn over 4
study days to determine meropenem serum concentrations. Renal function was
assessed by creatinine clearance according to the Cockcroft and Gault equation
(CLCRCG). Variability in meropenem serum concentrations was quantified at the
middle and end of each monitored dosing interval. The attainment of two
pharmacokinetic/pharmacodynamic targets (100%T>MIC, 50%T>4×MIC) was evaluated
for minimum inhibitory concentration (MIC) values of 2 mg/L and 8 mg/L and
standard meropenem dosing (1000 mg, 30-minute infusion, every 8 h).
Furthermore, we assessed the impact of CLCRCG on meropenem concentrations and
target attainment and developed a tool for risk assessment of target non-
attainment. Results: Large inter- and intra-patient variability in meropenem
concentrations was observed in the critically ill population (n = 48).
Attainment of the target 100%T>MIC was merely 48.4% and 20.6%, given MIC
values of 2 mg/L and 8 mg/L, respectively, and similar for the target
50%T>4×MIC. A hyperbolic relationship between CLCRCG (25–255 ml/ minute) and
meropenem serum concentrations at the end of the dosing interval (C8h) was
derived. For infections with pathogens of MIC 2 mg/L, mild renal impairment up
to augmented renal function was identified as a risk factor for target non-
attainment (for MIC 8 mg/L, additionally, moderate renal impairment).
Conclusions: The investigated standard meropenem dosing regimen appeared to
result in insufficient meropenem exposure in a considerable fraction of
critically ill patients. An easy- and free-to-use tool (the MeroRisk
Calculator) for assessing the risk of target non-attainment for a given renal
function and MIC value was developed
A Study of 323 Asymptomatic Volunteers
Background The understanding of the individual shape and mobility of the
lumbar spine are key factors for the prevention and treatment of low back
pain. The influence of age and sex on the total lumbar lordosis and the range
of motion as well as on different lumbar sub-regions (lower, middle and upper
lordosis) in asymptomatic subjects still merits discussion, since it is
essential for patient-specific treatment and evidence-based distinction
between painful degenerative pathologies and asymptomatic aging. Methods and
Findings A novel non-invasive measuring system was used to assess the total
and local lumbar shape and its mobility of 323 asymptomatic volunteers (age:
20–75 yrs; BMI <26.0 kg/m2; males/females: 139/184). The lumbar lordosis for
standing and the range of motion for maximal upper body flexion (RoF) and
extension (RoE) were determined. The total lordosis was significantly reduced
by approximately 20%, the RoF by 12% and the RoE by 31% in the oldest (>50
yrs) compared to the youngest age cohort (20–29 yrs). Locally, these decreases
mostly occurred in the middle part of the lordosis and less towards the lumbo-
sacral and thoraco-lumbar transitions. The sex only affected the RoE.
Conclusions During aging, the lower lumbar spine retains its lordosis and
mobility, whereas the middle part flattens and becomes less mobile. These
findings lay the ground for a better understanding of the incidence of level-
and age-dependent spinal disorders, and may have important implications for
the clinical long-term success of different surgical interventions
A Comparative Study of the Ethics of Christine M. Korsgaard and Jean-Paul Sartre
Christine M. Korsgaard and Jean-Paul Sartre both locate the source of ethical normativity in human reflective consciousness. Korsgaard’s claims that human beings are essentially rational, and that our rational nature is an adequate source of ethical content. Sartre argues that a conception of human nature this minimal is insufficient to provide ethical content, and that we must look to our particular projects and identities to provide moral content. I will argue that Sartre is correct that a view of human nature this minimal is inadequate to generate moral content, but that because Sartre is unable to demonstrate how norms based contingent projects and identities can produce universally binding ethical norms, his theory also fails. The failure of both projects illustrates the weakness of a conception of ethics as universal obligation because it fails by its own standard to produce it goal of universally binding ethical norms with content
Nesiritide: Harmful or Harmless?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90328/1/phco.26.10.1465.pd
Endothelial NOS (NOS3) impairs myocardial function in developing sepsis
Endothelial nitric oxide synthase (NOS)3-derived nitric oxide (NO) modulates inotropic response and diastolic interval for optimal cardiac performance under non-inflammatory conditions. In sepsis, excessive NO production plays a key role in severe hypotension and myocardial dysfunction. We aimed to determine the role of NOS3 on myocardial performance, NO production, and time course of sepsis development. NOS3(−/−) and C57BL/6 wildtype mice were rendered septic by cecum ligation and puncture (CLP). Cardiac function was analyzed by serial echocardiography, in vivo pressure and isolated heart measurements. Cardiac output (CO) increased to 160 % of baseline at 10 h after sepsis induction followed by a decline to 63 % of baseline after 18 h in wildtype mice. CO was unaltered in septic NOS3(−/−) mice. Despite the hyperdynamic state, cardiac function and mean arterial pressure were impaired in septic wildtype as early as 6 h post CLP. At 12 h, cardiac function in septic wildtype was refractory to catecholamines in vivo and respective isolated hearts showed impaired pressure development and limited coronary flow reserve. Hemodynamics remained stable in NOS3(−/−) mice leading to significant survival benefit. Unselective NOS inhibition in septic NOS3(−/−) mice diminished this survival benefit. Plasma NO(x)- and local myocardial NO(x)- and NO levels (via NO spin trapping) demonstrated enhanced NO(x)- and bioactive NO levels in septic wildtype as compared to NOS3(−/−) mice. Significant contribution by inducible NOS (NOS2) during this early phase of sepsis was excluded. Our data suggest that NOS3 relevantly contributes to bioactive NO pool in developing sepsis resulting in impaired cardiac contractility. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00395-013-0330-8) contains supplementary material, which is available to authorized users
Ist Behinderung eine soziale Konstruktion?: Zur Kritik sozialkonstruktivistischer Auffassungen in den (deutschsprachigen) Disability Studies
What exactly do we mean when we refer to disability as a social construction? How viable are the
justifications for this? These questions are explored in this paper. To this end, various theories that are
influential in German-language disability studies are examined and criticised. These include Oliver's social
model, furthermore the "Thomas theorem", Berger and Luckmann's sociology of knowledge, Foucault's
discourse theory and Waldschmidt's theory. Subsequently, social constructivist approaches of Watzlawick
and Gergen and Gergen are discussed. It is shown that a relativistic understanding of social construction can
be used to deny facticity and thus undermines the foundations of scientific knowledge. This danger must be
taken seriously when defending the scientificity of disability studies
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