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1004 Publications visible to you, out of a total of 1004

Ventilatory strategies in septic patients. Results from a nationwide observational trial

SepNet - German Competence Network Sepsis

Abstract (Expand)

BACKGROUND Mortality in intensive care unit (ICU) patients is affected by multiple variables. The possible impact of the mode of ventilation has not yet been clarified; therefore, a secondary analysis …s of the \textquotedblepidemiology of sepsis in Germany\textquotedbl study was performed. The aims were (1) to describe the ventilation strategies currently applied in clinical practice, (2) to analyze the association of the different modes of ventilation with mortality and (3) to investigate whether the ratio between arterial partial pressure of oxygen and inspired fraction of oxygen (PF ratio) and/or other respiratory variables are associated with mortality in septic patients needing ventilatory support. METHODS A total of 454 ICUs in 310 randomly selected hospitals participated in this national prospective observational 1-day point prevalence of sepsis study including 415 patients with severe sepsis or septic shock according to the American College of Chest Physicians/Society of Critical Care Medicine criteria. RESULTS Of the 415 patients, 331 required ventilatory support. Pressure controlled ventilation (PCV) was the most frequently used ventilatory mode (70.6 %) followed by assisted ventilation (AV 21.7 %) and volume controlled ventilation (VCV 7.7 %). Hospital mortality did not differ significantly among patients ventilated with PCV (57 %), VCV (71 %) or AV (51 %, p=0.23). A PF ratio equal or less than 300 mmHg was found in 83.2 % of invasively ventilated patients (n=316). In AV patients there was a clear trend to a higher PF ratio (204\pm70 mmHg) than in controlled ventilated patients (PCV 179\pm74 mmHg, VCV 175\pm75 mmHg, p=0.0551). Multiple regression analysis identified the tidal volume to pressure ratio (tidal volume divided by peak inspiratory airway pressure, odds ratio OR=0.94, 95 % confidence interval 95% CI=0.89-0.99), acute renal failure (OR=2.15, 95% CI=1.01-4.55) and acute physiology and chronic health evaluation (APACHE) II score (OR=1.09, 95% CI=1.03-1.15) but not the PF ratio (univariate analysis OR=0.998, 95 % CI=0.995-1.001) as independent risk factors for in-hospital mortality. CONCLUSIONS This representative survey revealed that severe sepsis or septic shock was frequently associated with acute lung injury. Different ventilatory modes did not affect mortality. The tidal volume to inspiratory pressure ratio but not the PF ratio was independently associated with mortality.

Authors: D. Schädler, G. Elke, C. Engel, H. Bogatsch, I. Frerichs, R. Kuhlen, R. Rossaint, M. Quintel, J. Scholz, F. M. Brunkhorst, M. Loeffler, K. Reinhart, N. Weiler

Date Published: 2013

Publication Type: Journal article

Human Diseases: disease by infectious agent

DOI: 10.1007/s00101-012-2121-2

Citation: Anaesthesist 62(1):27-33

Created: 15th Jul 2020 at 14:33, Last updated: 7th Dec 2021 at 17:58

Comparing measures of association in 2x2 probability tables

Genetical Statistics and Systems Biology

Abstract

Not specified

Authors: Dirk Hasenclever, Markus Scholz

Date Published: 2013

Publication Type: Journal article

Citation: arXiv:1302.6161v1

Created: 14th Sep 2020 at 13:35, Last updated: 7th Dec 2021 at 17:58

Merging concepts - coupling an agent-based model of hematopoietic stem cells with an ODE model of granulopoiesis

Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND\backslashr\backslashnHematopoiesis is a complex process involving different cell types and feedback mechanisms mediated by cytokines. This complexity stimulated various models with different … scopes and applications. A combination of complementary models promises to provide their mutual confirmation and to explain a broader range of scenarios. Here we propose a combination of an ordinary differential equation (ODE) model of human granulopoiesis and an agent-based model (ABM) of hematopoietic stem cell (HSC) organization. The first describes the dynamics of bone marrow cell stages and circulating cells under various perturbations such as G-CSF treatment or chemotherapy. In contrast to the ODE model describing cell numbers, our ABM focuses on the organization of individual cells in the stem population.\backslashr\backslashnRESULTS\backslashr\backslashnWe combined the two models by replacing the HSC compartment of the ODE model by a difference equation formulation of the ABM. In this hybrid model, regulatory mechanisms and parameters of the original models were kept unchanged except for a few specific improvements: (i) Effect of chemotherapy was restricted to proliferating HSC and (ii) HSC regulation in the ODE model was replaced by the intrinsic regulation of the ABM. Model simulations of bleeding, chronic irradiation and stem cell transplantation revealed that the dynamics of hybrid and ODE model differ markedly in scenarios with stem cell damage. Despite these differences in response to stem cell damage, both models explain clinical data of leukocyte dynamics under four chemotherapy regimens.\backslashr\backslashnCONCLUSIONS\backslashr\backslashnABM and ODE model proved to be compatible and were combined without altering the structure of both models. The new hybrid model introduces model improvements by considering the proliferative state of stem cells and enabling a cell cycle-dependent effect of chemotherapy. We demonstrated that it is able to explain and predict granulopoietic dynamics for a large variety of scenarios such as irradiation, bone marrow transplantation, chemotherapy and growth factor applications. Therefore, it promises to serve as a valuable tool for studies in a broader range of clinical applications, in particular where stem cell activation and proliferation are involved.

Authors: Axel Krinner, Ingo Roeder, Markus Loeffler, Markus Scholz

Date Published: 2013

Publication Type: Journal article

DOI: 10.1186/1752-0509-7-117

Citation: BMC Syst Biol 7(1):117

Created: 14th Sep 2020 at 13:35, Last updated: 7th Dec 2021 at 17:58

The management of thyroid nodules: a retrospective analysis of health insurance data

Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND\backslashr\backslashnIn Germany, about 59 000 thyroid operations are performed each year for uni- or multinodular goiter, most of them for diagnostic purposes. The rate of detection of thyroid … cancer in such operations is relatively low, at 1:15. Evidence suggests that the preoperative tests recommended in guidelines for estimating the risk of cancer are not being performed as often as they should. In the present study, we determined the measures that were actually taken to diagnose and treat thyroid nodules and compared the findings with the guideline recommendations.\backslashr\backslashnMETHOD\backslashr\backslashnWe retrospectively analyzed data from a single, large statutory healthinsurance carrier in Germany (AOK), determining the diagnostic and therapeutic measures that were reimbursed for 25 600 patients in whom a uni- or multinodular goiter was newly diagnosed in the second quarter of 2006 (none of these patients had carried such a diagnosis 1 year previously). We recorded the diagnostic measures performed in the preceding 9 months and all other tests and treatments, including surgery and radioactive iodine treatment, in the 2 years thereafter.\backslashr\backslashnRESULTS\backslashr\backslashnAmong patients who underwent surgery for uninodular goiter, the preoperative diagnostic studies included ultrasonography (in 100% of patients), scintigraphy (94%), measurement of thyroid-stimulating hormone (95%), measurement of calcitonin (9%), and fine-needle aspiration cytology (FNAC)(21%). An ultrasonographic examination was billed for only 28% of patients with uninodular goiter in the two years after the diagnosis was made. 13% of patients with uninodular goiter who were not operated on were given L-thyroxine, even though this is against guideline recommendations.\backslashr\backslashnCONCLUSION\backslashr\backslashnInadequate preoperative risk stratification of thyroid nodules may explain the large number of thyroid operations that are performed for diagnostic purposes, resulting in a low percentage of malignancies detected. Preoperative FNAC and calcitonin measurement should be used in the diagnostic evaluation of thyroid nodules far more often than this is now done. As a rule, follow-up ultrasonography should be performed for all thyroid nodules that are not operated on. Patients with non-operated thyroid nodules should not be given thyroxine. A limitation of this study is that diagnostic measures were only recorded if they were performed in the 9 months before surgery, with earlier diagnostic measures (if any) being missed.

Authors: Romy Wienhold, Markus Scholz, Jürgen-Bernhard Adler, Christian Günster, Ralf Paschke

Date Published: 2013

Publication Type: Journal article

DOI: 10.3238/arztebl.2013.0827

Citation: Deutsches Aerzteblatt Online

Created: 14th Sep 2020 at 13:35, Last updated: 7th Dec 2021 at 17:58

More than Four Decades of Medical Informatics Education for Medical Students in Germany - New Recommendations Published

Management of health information systems