Aktualisierte Kurzfassung der Leitlinien zur Pr?vention, Diagnostik und Therapie der nosokomial erworbenen Pneumonie

Hintergrund:  

Die nosokomiale Pneumonie gehört zu den häufigsten nosokomialen Infektionen und ist die häufigste auf der Intensivstation. Die nosokomiale Pneumonie ist mit einer signifikanten Mortalität und Morbidität assoziiert, und ihr Auftreten verschlechtert die Prognose des Patienten deutlich. Nach der Definition der DRGs auch im deutschen Krankenhaussystem ist die nosokomiale Pneumonie überwiegend Sache des Krankenhauses und kann somit nicht nur das Ergebnis der Patientenbehandlung, sondern auch das finanzielle Ergebnis des Krankenhauses beeinträchtigen.     

General discrete modelling of lung sound production in normal subjects

Lung sound analysis is of a major importance in diagnostic malfunctions of the respiratory system. In normal subjects, it is known that these sounds are caused by the interaction of the respiratory flows with the bronchial tree structure. However, the detailed knowledge of the reasons for the spectral characteristics of such sounds remains to be elucidated. In this paper we propose a model for normal lung sound production based on a discretization of air flow in particle-like elements. Their transport with the involved interactions is implemented using a pseudo-molecular dynamics Monte Carlo procedure. General physical principles were considered for the interaction of these elements with the bronchial tree as well as a two-body interaction potential. The particle-tree interactions and the particle-particle interactions represent the flow-tree and the internal flow interactions, respectively. According to the model, sound is produced in each bronchus with the pitch frequency inversely proportional to its dimensions and with amplitude proportional to the intensity of the interaction, also a function of the bronchus dimensions. The lung sound is then the composition of the sounds produced in each bronchus. The model was successful in approximating the spectral characteristics reported by Gavriely et al (1981, 1995) as a direct consequence of the fractal properties of the bronchial tree and the considered internal fluid interactions. Thus, the reported high-frequency spectrum with its affine property as well as the low-frequency irregularity could be reproduced.     

Three-dimensional isotropic wavelets for post-acquisitional extraction of latent images of atherosclerotic plaque components from micro-computed tomography of human coronary arteries

RATIONALE AND OBJECTIVES: The capability of wavelet transforms to separate signals into frequency bands is the basis for its use in image compression and storage, data management and transmission, and, recently, extraction of latent images of tissue components from noisy medical images. Analysis of temporal variations of radiofrequency backscatter of intravascular ultrasound with one-dimensional wavelets can detect lipid-laden plaque in coronary arteries with a sensitivity and specificity of >80%. In this study we evaluate the capability of a novel, 3-dimensional isotropic wavelet analysis to perform high resolution, non-directionally biased, statistically reliable, non-invasive discrimination between components of human coronary atherosclerotic plaques in micro-CT. MATERIALS AND METHODS: Coronary artery segments (5-15 mm) were excised at necropsy from 18 individuals with advanced coronary atherosclerosis. Specimens were imaged using a GE Locus SP ex vivo micro-CT scanner and processed for histological correlation (833 sections). The isotropic wavelet constructs were applied to the entire volume of CT data of each arterial segment to distinguish tissue textures of varying scales and intensities. Voxels were classified and plaque characterization achieved by comparing the relative magnitudes of these wavelet constituents to that of several reference plaque tissue components. RESULTS: Processing of micro-CT images via these isotropic wavelet algorithms permitted 3-D, color-coded, high resolution, digital discrimination between lumen, calcific deposits, lipid-rich deposits, and fibromuscular tissue providing detail not possible with conventional thresholding based on Hounsfield intensity units. Using the isotropic wavelets (with histology as the gold standard), lipid-rich pools approaching the size of the filter for the isotropic wavelet algorithm (0.25 mm [250 microns] in length) were identified with 81% sensitivity and 86% specificity. Calcific deposits, fibromuscular tissue, and lumen equal to or larger than the wavelet filter size were detected without error (100% sensitivity and specificity). CONCLUSION: Isotropic wavelet analysis permits high resolution, multi-dimensional identification of coronary atherosclerotic plaque components in micro-CT with sensitivity and specificity similar to that achieved with data obtained invasively (from IVUS in vivo) using one-dimensional wavelets. Further studies are necessary to test the applicability of this technology to clinical, multi-detector scanners.     

Incidence of intravenous thrombolytic therapy and fatalities in patients with acute transmural myocardial infarct (Q infarct). A study of observations from 1984 to 1987

All patients admitted to the ICU with acute myocardial infarction (MI) were treated by the same protocol since 1984. We report the results in Q-wave-MI of 1987 compared to 1984. Age (67.2 +/- 12.4 vs. 66.8 +/- 11.4 years), sex distribution (70.1% vs. 71.9% male), time elapse between begin of symptoms and admittance to the hospital (15.5 +/- 27.0 vs. 15.0 +/- 32.5 hours) were similar in both years, but the total number of definite Q-MI decreased by 22% from 135 (1984) to 105 (1987). Inhospital mortality (20% vs. 23%) and ICU mortality (14% vs. 20%) tended to decrease, although differences did not reach statistical significance. This was paralleled by an increase in the rate of i.v. thrombolytic therapy from 17% (1984) to 28% (1987) of all patients with Q-MI. The percentage of patients who definitely received i.v. thrombolysis when all indication criteria were present and all contraindicatory factors excluded increased from 47% (1984) to 97% (1987). We conclude, that the performance of i.v. thrombolysis in all patients, who fulfill the general accepted criteria for thrombolysis may improve clinical course and outcome in a given population of patients with acute Q-wave-infarction.