First assessment of flow phenomena of acute and chronic thrombosis in the jugular veins using new ultrasound vector-flow imaging.

AIM: First assessment of flow changes in the jugular veins using high resolution ultrasound vector flow. MATERIAL UND METHODS: 15 patients (8 males, 7 females) with an age range of 35 to 82 years (mean age 58.53±12.26 years) were examined by an experienced examiner using high power ultrasound equipment (Resona R9, Mindray) with probe technology (Mindray L9-3U Linear Array transducer, 2.5 to 9.0 MHz). This group was compared with five healthy subjects (mean age 35.4±13.79 years) as a reference. To assess flow changes, the color-coded duplex sonography and the novel vector flow technique were used. The evaluation was performed of vector morphology changes, turbulence, and wall resistance measurements. RESULTS: There were changes after acute and chronic thrombosis in 9 cases, and venous compression in 7 cases. Turbulence was measurable from 0.01 % to 64.44 %, the average turbulence was 19.73±22.06 %. Wall resistance measurement showed values from 0.01 Pa to 3.14 Pa, depending on the age of the thrombosis or compression. The reference veins showed turbulence of 0.94±1.5 % and a mean wall resistance of 0.05±0.05 Pa. There are statistically significant differences between normal and thrombotic or compressed veins in terms of maximum wall stress (p = 0.006) and mean degree of turbulence (p = 0.012), while the difference in mean wall stress is not statistically significant (p = 0.058). CONCLUSION: Despite still existing technical limitations, the combination of V-flow and wall stress measurements in jugular vein changes suggests a high diagnostic potential.

Current aspects of multimodal ultrasound liver diagnostics using contrast-enhanced ultrasonography (CEUS), fat evaluation, fibrosis assessment, and perfusion analysis - An update.

Current ultrasound multifrequency probes allow both improved detail resolution and depth of penetration when examining the liver. Also, new developments in vascular diagnostics, elastography with fibrosis assessment, evaluation of possible steatosis, and parametric and time intensity curve (TIC) analysis of dynamic microvascularization of the liver with contrast-enhanced ultrasound sonography (CEUS) complement ultrasound-guided diagnostics. State-of-the-art high-resolution technology includes a high frame rate (HiFR) mode for CEUS, fast shear wave measurements with the sound touch quantify (STQ) mode, artifact-free flow detection using HR flow and glazing flow in combination with a special flow-adapted imaging (Ultra Micro Angiography, UMA) and additionally different assessments of possible fatty liver (UltraSound ATtenuation Imaging Technology, USAT). In 50 cases with focal liver lesions, a multimodal liver diagnosis was performed with a still new high-performance ultrasound system as part of the clarification of questions from the university liver consultation and tumor outpatient clinic.

Quantification of adherent platelets on polymer-based biomaterials. Comparison of colorimetric and microscopic assessment.

BACKGROUND: Platelet adhesion to artificial surfaces is one of the most important indicators for the thrombogenicity of implant materials. Currently, a variety of enzyme activity-based colorimetric assays or microscopy-based techniques are commonly in use to assess this characteristic. Studies about how data of colorimetric assays correlate with the image-based quantification of adherent platelets are scarce. To address this question, the present study compared two colorimetric assays (lactate dehydrogenase (LDH) and acid phosphatase (ACP)) with an image-based quantification of the density of platelets adhering on polymer-based biomaterial surfaces. MATERIALS AND METHODS: Tri-sodium citrated whole blood was collected from apparently healthy subjects and platelet rich plasma (PRP) was prepared according to a standardized protocol. An in vitro static thrombogenicity test was applied to study platelet adhesion from PRP adjusted to 50,000 platelets per µL on three different polymers: medical grade polytetrafluoroethylene (PTFE), silicone and polyethylene terephthalate (PET). For the direct image-based approach, surface adherent platelets were fixed, fluorescently labelled and microscopically visualized. The image-based determination of platelet densities provided reference values for the comparison with data of the colorimetric assays. Correlation between standard platelet concentrations and ACP/LDH absorbance measurements were analysed to estimate accuracy and association of both parameters. ACP and LDH release from resting and ADP-stimulated platelets was studied to estimate how platelet activation influences colorimetric assay results. RESULTS: The density of adherent platelets ranged from 15,693 ± 2,487 platelets·mm-2 (PTFE) to 423 ± 99 platelets·mm-2 (silicone) and 4,621 ± 1,427 platelets·mm-2 (PET) and differed significantly between the three polymers (ANOVA: p <  0.05). Correlation coefficients between microscopic and colorimetric determination of platelet densities ranged between r = 0.93 (LDH, p <  0.001) and r = 0.94 (ACP, p <  0.001). ACP absorbance measurements of platelet standards with different concentrations corresponded well to an ideal linear regression, while LDH data either deceeded or exceeded the expected values. The LDH release during ADP-induced platelet activation was significantly higher compared to the release of ACP. CONCLUSION: For an adjusted platelet concentration of 50,000 platelets·µL-1, both colorimetric assays (ACP and LDH) allowed a similar accurate quantification of the mean platelet density compared to the microscopic evaluation. Better linearity of the assay standards, less variability of the results and a lower influence of platelet activation on the measurements mark the ACP assay as more suitable for the assessment of material surface adherent platelets compared to the LDH assay, particularly, if near physiological platelet concentrations are applied.

[Experts reports on the ability to work within the area of tension of medical and social problems]. / Gutachten zur Erwerbsfähigkeit im Spannungsfeld medizinischer und sozialer Problemlagen.

On the basis of § 8 SGB II (Sozialgesetzbuch II), the local public health office of Bremen provides expert reports concerning the ability to work. The clients are district branches (job centres) of the Bremen employment office. The experts raised the question to what extent these expert reports were medically well-founded. Against this background, the expert reports were recorded and analysed for a period of 6 months. Socio-demographic characteristics, medical diagnoses and prognoses, experts' reports regarding the ability to work, as well as the medical justification of the reports were all taken into consideration. The sex ratio and ethnic profile of people included in the study were representative of welfare recipients in Bremen as a whole. Compared with the German population as a whole, the people examined had distinctly less education and professional training. Factors indicating social impacts were found more often among women. Medical diag-noses were strikingly different compared with data from the health insurance companies. More than two thirds of the people examined had considerable restrictions or were considered unable to work. More than four fifths of the expert reports could be justified for medical reasons. The life situations of the people examined were characterised by numerous problems which included medical, social and frequently also cultural aspects, and were taken into account in the experts' reports. In view of the inability to solve the existing social problems, the experts continue, from a medical perspective, to be concerned in this area of tension.

Laser Doppler flux measurement for the assessment of cutaneous microcirculatio--critical remarks.

Back scattered Laser Doppler (LD) signals are composed of two different individual signals. The number of the moving particles and the speed of the particles in the measured tissue volume determine the frequency shift and the band width of the Doppler signal. The dependence of the Laser Doppler flux on the number of scattering particles is highly nonlinear: at very low hematocrit and high speed the axial migration of the cells to the centre of the blood vessels is very strong, so that in these cases - because of the parabolic flow profile - the Doppler flux measurement overestimates the mean real blood flow (up to two- or three-fold). The opposite is the case when the hematocrit is very high, then the blood flow might be underestimated (due to the increased amounts of blood cells near the vessel wall). In addition, a very change in number of moving particles - as can occur during the postprandial phase or during therapy - can change the signal also at a constant cell number. Also, it must be mentioned that the LD signal possibly is not only reflected by moving blood cells in the different skin layers but also by blood cells flowing in tissues below the skin (particularly below atrophied skin areas of older patients) so that in such cases the LD Flux signal reflects not exclusively the skin blood flow. Therefore, LD flux at rest may still be within the normal range even in advanced states of disease, since the scattered light is sampled from a tissue volume which may contain also non-nutritive shunt vessels. This critical analysis of the LD signals of course shall not lead to an overall rejection of the application of laser Doppler systems. Actual progress only can, however, be obtained under the exact consideration of anatomical conditions, technical restrictions and when generalizations are avoided.

Evaluation of a peer support program for staff nurses.

IMPACT (Interactional Meetings--Peers Working And Caring Together) is a task-oriented, voluntary, peer-support program for staff nurses. Evaluation data suggest the program is a cost-effective method for developing and retaining nurses in the hospital.

Teaching registered nurses how to supervise nursing assistants.

To respond to decreasing hospital revenues and the continuing shortage of registered nurses, nurse administrators are increasing their use of nursing assistants. Most nurses who direct these assistants, however, have little knowledge or experience in personnel management. The author describes the implementation of a program to improve nursing assistant supervision and discusses how the program has led to improved distribution of work load and increased nursing assistant productivity.

Nurses and shift work: effects on job performance and job-related stress.

The purpose of this research was to examine the influence of day, afternoon, night and rotating shift schedules on the job performance and job-related stress of nurses. Registered nurses from five hospitals (n = 463) were surveyed using a structured questionnaire which measured both job performance and job-related stress. Analysis of data indicated that both the nurses' job performance and their job-related stress were related to the type of shift they worked. Overall job performance was highest for the nurses on the day shift, followed by the night, afternoon, and rotating shifts. Rotating shift nurses experienced the most job-related stress, followed in turn by the afternoon, day, and night shift nurses. The findings are interpreted within a conceptual framework which examines the social organization of work in the hospital by shift and the effects of shift work on biological rhythm synchronization.