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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
481

ePrescribing : Studies in Pharmacoinformatics

Åstrand, Bengt January 2007 (has links)
Det övergripande syftet med den här avhandlingen har varit att, inom området läkemedelsinformatik, studera utvecklingen av elektroniska stöd inom läkemedelsförskrivning; för klinisk praxis, uppföljning och forskning. Under århundraden har det handskrivna receptet varit det sätt, med vilket läkare förmedlat sina läkemedelsordinationer till apotekare, vilket också för patienten blivit en informationskälla för hur läkemedel ska användas för att göra bästa nytta. Nu genomgår receptet en förändring från pappersbaserat till elektroniskt meddelande och att anpassa en traditionell process till en ny elektronisk era innebär både möjligheter och utmaningar. Studierna som ingår i avhandlingen har visat att exponeringen av förskrivna läkemedel i en allmän befolkning har ökat under de senaste tre decennierna. Risken för potentiella interaktioner mellan läkemedel, varmed avses den risk som finns att olika läkemedel kan påverka varandras effekter och biverkningar, har också visat sig öka starkt desto fler läkemedel som används av en individ. Denna ökade samtidiga användning av flera olika läkemedel, så kallad polyfarmaci, medför att det finns en större anledning för förskrivare och farmacevter att uppmärksamma risken för potentiella interaktioner mellan läkemedel. De nyinrättade nationella receptregistren över uthämtad receptförskriven medicin bör användas bland annat för att upptäcka potentiella läkemedelsinteraktioner, såväl i vårdens utövning som inom läkemedelsepidemiologisk forskning. Den svenska läkemedelsförteckningen, som omfattar information om uthämtade receptförskrivna läkemedel för huvuddelen av den svenska befolkningen, bedöms ha en stor klinisk potential. Den enskilde individens historiska information om uthämtade läkemedel är tillgänglig för individen på Internet med hjälp av e-legitimation; även förskrivare och farmacevter på apotek kan ta del av informationen med den enskildes samtycke. Brist på tillgång till enhetliga och säkra autenticeringsmetoder inom hälso- och sjukvården kan dock fördröja tillgången på individuell läkemedelsinformation för förskrivare. I och med att de flesta recepten i Sverige nu skrivs och överförs elektroniskt är det viktigt att kvalitetsmässiga aspekter tas tillvara så att en iakttagen ökad risk för receptförskrivningsfel inte överförs i informationskedjan. Avhandlingens slutsats är att e-förskrivning, med kommunikation och användning av lagrad information om receptexpeditioner, möjliggör att läkemedelsbehandling som process kan följas och studeras på ett helt nytt / The thesis aimed to study the developments, in the area of pharmacoinformatics, of the electronic prescribing and dispensing processes of drugs - in medical praxis, follow-up, and research. For hundreds of years, the written prescription has been the method of choice for physicians to communicate decisions on drug therapy and for pharmacists to dispense medication. Successively the prescription has also become a source of information for the patient about how to use the medication to maximize its benefit. Currently, the medical prescription is at a transitional stage between paper and web, and to adapt a traditional process to the new electronic era offers both opportunities and challenges The studies in the thesis have shown that the exposure of prescribed drugs in the general population has increased considerably over three decades. The risk of receiving potentially interacting drugs was also strongly correlated to the concomitant use of multiple drugs, polypharmacy. The pronounced increase in polypharmacy over time constitutes a growing reason for prescribers and pharmacists to be aware of drug interactions. Still, there were relatively few severe potential drug interactions. Recently established national prescription registers should be evaluated for drug interaction vigilance, both clinically and epidemiologically. The Swedish National Pharmacy Register provides prescription dispensing information for the majority of the population. The medication history in the register may be accessed online to improve drug utilization, by registered individuals, prescribers, and pharmacists in a safe and secure way. Lack of widespread secure digital signatures in healthcare may delay general availability. With a relatively high prevalence of dispensed drugs in the population, the National Pharmacy Register seems justified in evaluating individual medication history. With a majority of prescriptions transferred as ePrescriptions, the detected increased risk for prescription errors warrants quality improvement, if the full potential of ePrescriptions is to be fulfilled. The main conclusion of the studies was that ePrescribing with communication of prescribed drug information, storing and retrieving dispensed drug information, offers new opportunities for clinical and scientific
482

Jämförelse mellan Grocotts manuella och automatiserade färgningsmetod

Kurt, Nour, Sohlé, Jonna January 2017 (has links)
Grocott metoden är den känsligaste metoden för infärgning av svampstrukturer i histologisk vävnad i jämförelse med till exempel Periodic Acid-Schiff (PAS). Handhavandet av det cancerogena oxidationsmedlet kromsyra samt tidsaspekten för Grocott är signifikanta problem. Syftet med studien var att undersöka om den automatiserade färgningsmetoden för Grocott ger likvärdiga resultat som vid den manuella färgningsmetoden. Tolv preparat färgades med både den manuella och den automatiserade metoden för Grocott. Den automatiserade färgningsmetoden använder ett färdigt kit med alla ingående lösningar. Visuell bedömning av preparaten utfördes med hjälp av legitimerade biomedicinska analytiker samt en patolog. Svampstrukturer i åtta av ela preparat samt kontroll bedömdes vara tydligare infärgade med den automatiserade metoden i färhållande till den manuella. Svampstrukturer i endast ett preparat bedömdes vara tydligare infärgade med den manuella metoden. Resterande två preparat visade inga svampstrukturer. Resultaten tyder på att den automatiserade färgningsmetoden för Grocott ger likvärdiga, alternativt tydligare infrägning av svampstrukturer i jämförelse med den manuella metoden. / The Grocott method is the most sensitive staining method for fungal structures in histological tissues in comparison to for example Periodic Acid-Schiff (PAS). Usage of the cancerogenic chromic acid and the time aspect for Grocott are significant problems. The aim of this study was to examine if the automated staining method for Grocott provides equivalent results in comparison to the manual staining method. Twelve tissue sections were stained with both the automated and the manual method. The automated method contains a kit with all solutions. Visual evaluation was conducted with authorized biomedical scientists and a pathologist. Fungi structures in eight of eleven tissue sections and a control were evaluated as more distinct in the automated method in comparison to the manual method. Fungal structures in one of the tissue sections were evaluated more distinct in the manual method. In the remaining two tissue sections, no fungal structures were identified. Results from this study indicates that the automated staining method for Grocott provides equally, alternatively more distinct fungal staining in comparison to the manual method.
483

Epidemiological and statistical basis for detection and prediction of influenza epidemics

Spreco, Armin January 2017 (has links)
A large number of emerging infectious diseases (including influenza epidemics) has been identified during the last century. The emergence and re-emergence of infectious diseases have a negative impact on global health. Influenza epidemics alone cause between 3 and 5 million cases of severe illness annually, and between 250,000 and 500,000 deaths. In addition to the human suffering, influenza epidemics also impose heavy demands on the health care system. For example, hospitals and intensive care units have limited excess capacity during infectious diseases epidemics. Therefore, it is important that increased influenza activity is noticed early at local levels to allow time to adjust primary care and hospital resources that are already under pressure. Algorithms for the detection and prediction of influenza epidemics are essential components to achieve this. Although a large number of studies have reported algorithms for detection or prediction of influenza epidemics, outputs that fulfil standard criteria for operational readiness are seldom produced. Furthermore, in the light of the rapidly growing availability of “Big Data” from both diagnostic and prediagnostic (syndromic) data sources in health care and public health settings, a new generation of epidemiologic and statistical methods, using several data sources, is desired for reliable analyses and modeling. The rationale for this thesis was to inform the planning of local response measures and adjustments to health care capacity during influenza epidemics. The overall aim was to develop a method for detection and prediction of influenza epidemics. Before developing the method, three preparatory studies were performed. In the first of these studies, the associations (in terms of correlation) between diagnostic and pre-diagnostic data sources were examined, with the aim of investigating the potential of these sources for use in influenza surveillance systems. In the second study, a literature study of detection and prediction algorithms used in the field of influenza surveillance was performed. In the third study, the algorithms found in the previous study were compared in a prospective evaluation study. In the fourth study, a method for nowcasting of influenza activity was developed using electronically available data for real-time surveillance in local settings followed by retrospective application on the same data. This method includes three functions: detection of the start of the epidemic at the local level and predictions of the peak timing and the peak intensity. In the fifth and final study, the nowcasting method was evaluated by prospective application on authentic data from Östergötland County, Sweden. In the first study, correlations with large effect sizes between diagnostic and pre-diagnostic data were found, indicating that pre-diagnostic data sources have potential for use in influenza surveillance systems. However, it was concluded that further longitudinal research incorporating prospective evaluations is required before these sources can be used for this purpose. In the second study, a meta-narrative review approach was used in which two narratives for reporting prospective evaluation of influenza detection and prediction algorithms were identified: the biodefence informatics narrative and the health policy research narrative. As a result of the promising performances of one detection algorithm and one prediction algorithm in the third study, it was concluded that both further evaluation research and research on methods for nowcasting of influenza activity were warranted. In the fourth study, the performance of the nowcasting method was promising when applied on retrospective data but it was concluded that thorough prospective evaluations are necessary before recommending the method for broader use. In the fifth study, the performance of the nowcasting method was promising when prospectively applied on authentic data, implying that the method has potential for routine use. In future studies, the validity of the nowcasting method must be investigated by application and further evaluation in multiple local settings, including large urbanizations.
484

Ekokardiografi: jämförelse av erfarenhetens betydelse vid mätningar av strain och strain rate i vänster kammare / Echocardiography: a comparison of the significance of experience when measuring strain and strain rate in the left ventricle

Baker, Sinan, Alcharif, Odai January 2019 (has links)
Bakgrund: Ekokardiografi har en betydande roll i diagnostisering av vänster kammare. Genom undersökning av segmentell och global longitudinell strain samt strain rate kan regional och global kinetik bedömas. Vid kontraktion och relaxation deformeras myokardiet varvid segmentell strain mäter deformationen av respektive segment uttryckt i procent medan strain rate mäter hastigheten av deformationen. Genom summering av medelvärdet från alla segment erhålls global longitudinell strain. Syfte: Syftet med studien var att jämföra ultraljudbaserade segmentell och global strain samt strain rate i vänster kammare. Jämförelse har gjorts mellan mätningar utförd av erfaren biomedicinsk analytiker samt mindre erfarna biomedicinska analytikerstudenter. Metod: Kvantitativ studie där 10 testpersoner undersökts ekokardiografiskt. Bildtagningen och mätresultaten insamlades med Siemens Acuson SC2000. Sammanställning av insamlade mätvärden gjordes på Microsoft Excel och Microsoft Word i diagram och tabeller. För jämförelse av strain segmentellt och globalt samt strain rate har analysmetoden Related-Samples Wilcoxon Signed Rank Test använts. Resultat: Resultatet visade enbart en statistisk signifikant skillnad (p <0,05) vid segmentell strain i basala segmenten i apikala projektioner mellan erfaren biomedicinsk analytiker och student 1. Konklusion: Datamaterialet är inte tillräckligt för att kunna generalisera resultatet till en större population. Det behövs fortsatta studier inom området för att dra en mer säkerställd slutsats. / Background: Echocardiography has a major role for assessment of the left ventricle. By using segmental and global longitudinal strain and strain rate both regional and global kinetics can be assessed. Segmental strain measures deformation of the myocardium as strain rate measures the velocity of the deformation. By summing the average from all segments, global longitudinal strain is obtained. Purpose:  To compare heart ultrasound-based segmental and global strain and strain rate in the left ventricle. Comparisons have been made between experienced biomedical laboratory scientist and less experienced biomedical laboratory scientist’s students. Method: Quantitative study were 10 test subjects have been examined echocardiographically. Imaging and measurements were collected with Siemens Acuson SC2000. Compilation of collected measurements were made on Microsoft Excel and Microsoft Word in charts and tables. For comparison of segmental and global strain and strain rate the analysis method Related-Samples Wilcoxon Signed Rank Test were used. Result: The result shows only one statistically significant difference (p <0.05) of segmental strain in the basal segments of apical projections between experienced biomedical laboratory scientist and student 1.  Conclusion: The data material is not enough to generalize the result to a larger population. Further studies are needed to draw a more secure conclusion.
485

Mätning av kluven Kaspas-3 och kluven PARP i manganbehandlade prostatacancerceller / Mesurement of cleaved Caspase-3 and cleaved PARP in manganese-treated prostate cancer cells

Karim Ali, Hussein January 2019 (has links)
Prostatacancer är den sjätte mest förekommande cancertypen i världen, och den tredje vanligaste cancertypen bland män. De olika typer av behandlingar som finns idag botar oftast inte sjukdomen. Det är därför viktigt att utveckla bättre behandlingsmetoder. Det är sedan tidigare känt att mangan kan orsaka apoptos i olika celltyper. Det ger en möjlighet att använda mangan för att hämma cancer och det är därför viktigt att veta vilka apoptotiska markörer som är involverade. Syftet med projektet var att undersöka om de sker en ökning av de apoptotiska markörerna kluven Kaspas-3 och kluven PARP efter manganbehandling av prostatacancerceller. Därefter kunna avgöra om manganbehandlingen har orsakat celldöd genom att inducera apoptos. Under projektet odlades prostatacancerceller (PC3) som sedan behandlades med 200 µM mangan under 6, 24 och 48 timmar. Därefter mättes mängden av proteinerna kluven Kaspas-3 och kluven PARP med hjälp av ett sandwich-ELISA kit. En tydlig stegvis ökning av apoptosmarkörerna med inkuberingstid hade förväntats. Det förväntade resultatet erhölls inte, för kluven Kaspase-3 ledde manganbehandlingen t.o.m. till en sänkning av koncentrationen. Det kan ha uppstått problem vid analysen som t.ex dålig lysering av cellerna eller ojämn tillväxt av dem. Det behövs fler studier för att utreda detta och för att undersöka andar potentiella apoptosmarkörer. / Prostate cancer is the sixth most common cancer type in the world, and the third most common cancer type among men. The different types of treatments that are available today do not usually cure the disease. It is therefore important to develop better treatment methods. It has previously been stated that manganese can cause apoptosis in different cell types. It provides an opportunity to use manganese to inhibit cancer and it is therefore important to know which apoptotic markers that are involved. The purpose of the project was to investigate whether an increase in the apoptotic markers cleaved Kaspas-3 and cleaved PARP after manganese treatment of prostate cancer cells. Thereafter, it can determine whether manganese treatment has caused cell death by inducing apoptosis. During the project prostate cancer cells (PC3-cells) were cultivated, then treated with 200 µM manganese for 6, 24 and 48 hours. The amount of the proteins cleaved Kaspas-3 and cleaved PARP was measured by using a sandwich ELISA kit. A clear gradual increase of apoptotic markers with incubation time was expected. The expected result was not obtained, for cleaved Kaspase-3 manganese treatment even decreased the concentrations. There may have been problems with the performance of the analysis such as poor lysis of the cells or uneven growth of the cells. More studies are required to investigate this and other potential apoptotic markers.
486

Normalvärden och F-waves vid registrering på tibialis anterior vid undersökning av peroneus communis med elektroneurografi / Normal values and F-waves for registration on tibialis anterior for examination of peroneus communis with electroneurography

Lundström, Malin January 2019 (has links)
För att undersöka misstänkt tillklämningsneuropati i peroneus communis (PC) används elektroneurografi, där elektrisk stimulering möjliggör undersökning av nervledningshastigheter, svarsamplitud och överledningstid. Vid opålitlig registrering på extensor digitorium brevis (EDB), görs registreringen på tibialis anterior (TA). I dagsläget finns dock inga normalvärden eller standardiserad metod för registrering på TA. Syftet med studien var därför att ta fram dessa normalvärden och utveckla en metod för TA-registrering, och samtidigt jämföra de båda registreringspunkterna gällande nervledningshastighet, undersöka sidoskillnaderna vid registrering på TA och undersöka hur kroppslängden påverkade överledningstiden. Det undersöktes om s.k. F-waves kunde påvisas vid registrering på TA och i så fall hur hög svarsandelen och svarslatensen var. 22 deltagare mellan 23-59 år gamla och 154-190 cm i kroppslängd undersöktes. TA undersöktes med den aktiva registreringselektroden på muskeln där den var som störst och med referenselektroden på fotleden. Stimuleringar gjordes på laterala poplitea fossa och 110 mm ned distalt om caput fibula. EDB undersöktes enligt metodbeskrivning. Normalvärdena för TA var 2,2-5,4 mV gällande amplitud, 55-73 m/s gällande nervledningshastighet och 3,8-5,9 ms gällande överledningstid. Sidoskillnaderna var 0-1,4 mV gällande amplitud, 0-8 m/s gällande hastighet och 0-0,8 ms gällande överledningstid. De beräknade gränsvärdena visar på de små sidoskillnaderna som krävs för en klinisk betydelse. Överledningstiden kunde till 23 % förklaras av kroppslängden. Resultaten var likvärdiga med tidigare studier. Jämförelsen av nervledningshastigheten mellan registrering på TA och EDB visade en statistiskt, men inte nödvändigtvis kliniskt signifikant skillnad, med bias + 5 m/s. F-waves återfanns hos samtliga deltagare, med svarsandelen 94-100 %. F-wave svarslatensen kunde till 41 % förklaras av kroppslängden. / Electroneurography is used to examine a suspected entrapmentneuropathy in peroneus communis (PC), where an electric stimulus enables the evaluation of nerve conduction velocity, muscle response amplitude and latency. If registration from the extensor digitorum brevis (EDB) provides unreliable results, the registration can be made from tibialis anterior (TA). Currently there are no normal values available in our laboratory and no standard method regarding the registration on TA. The purpose of this study was therefore to retrieve normal values for this registration and to develop and establish a method, and also compare the different registration sites, to examine the side differences from the registrations on TA, and how the height affected the latency. It was also examined if so called F-waves could be recorded from TA, and if so, determine the response rate and latency. 22 participants between 23-59 years an 154-190 cm were examined. TA was examined with the active registration electrode on the site where the muscle was the largest and the reference electrode on the ankle. Stimulations were made on lateral poplitea fossa and 110 mm lower on distal caput fibula. EDB were examined according to established methods. Normal values for the registration on TA were 2,2-5,4 mV regarding amplitude, 55-73 m/s regarding nerve conduction velocity and 3,8-5,9 ms regarding latency. Side differences were 0-1,4 mV regarding amplitude, 0-8 m/s regarding nerve conduction velocity and 0-0,8 ms regarding latency. The calculated limits show that it only takes small side differences to have a clinical significance. The method gave equivalent results to previous studies. 23 % of the latency could be explained by height. The comparing of the nerve conduction velocity from the different registrations showed a significant statistical, but not necessarily clinical, difference, with the bias 5 m/s. F-waves were retrieved from all participants with a response rate of 94-100 %. 41 % of the F-wave latency could be explained by height.
487

Treatment efficacy of artesunate-amodiaquine and prevalence of Plasmodium falciparum drug resistance markers in Zanzibar, 2002-2017

SOE, AUNG PAING January 2019 (has links)
Introduction: Emergence of resistance to artemisinin-based combination therapy (ACT) is a major threat to combat Plasmodium falciparum malaria. Regular therapeutic studies to monitor treatment efficacy is essential, and genotyping of molecular makers is useful for mapping development and spread of resistance. Aims: The study aims are to assess efficacy of artesunate-amodiquine (ASAQ) and prevalence of molecular markers of drug resistance in Zanzibar in 2017. Methods: Treatment efficacy of the clinical trial conducted in 2017 was compared with efficacies in 2002 and 2005. A total of 142 samples were genotyped for single nucleotide polymorphisms (SNPs) in the P. falciparum chloroquine resistance transporter gene (pfcrt) gene, the P. falciparum multi drug resistance 1 (pfmdr1) gene, and in the P. falciparum Kelch 13 (PfK13) propeller region. Prevalence of SNPs were assessed during the period 2002-2017. Results: Cure rate was 100% in 2017, compared to 94% and 96%, in 2002-2003 and 2005, respectively. Day 3 fever clearance rate were also high 93% (2002-3), 99% (2005) and 98% (2017) in all studies. Prevalence of pfcrt 76T, pfmdr1 86Y, 184Y and 1246Y and pfmdr1 (86Y, 184Y and 1246Y) YYY haplotypes were significantly decreased between 2002-3 and 2017 (p &lt; 0.001). No SNP in the PfK13 gene related to artemisinin resistance was identified. Conclusion: Efficacy of ASAQ remains high after fourteen years as first-line treatment, despite the wide-scale use of ASAQ, and there is no evidence of selection of resistance markers in Zanzibar. Continuous monitoring of drug efficacy and resistance markers is recommended. / <p>This master thesis is a collaboration project between Institutionen för kvinnors och barns hälsa, Department of Women's and Children's Health, Uppsala Universtiy and Anders Björkman group, Department of Microbiology, Tumor and Cell Biology (MTC), C1, Karolinska Institutet. Laboratory examinations were mainly conducted at MTC house, Karolinska Institutet.</p>
488

Fyllnadsnivåers påverkan, tidsförlängning innan analys och blodprovers stabilitet / The Impact of Lower Sample Volumes, Pre-analytical Delay and Blood Sample Stability

Chahrour, Yasmin, Ishak, Helen January 2018 (has links)
Bakgrund: Provmaterial för joniserat kalcium är känsligt för pH-förändringar och med tanke på svårstuckna patienter är det betydelsefullt att undersöka lägre fyllnadsnivåers påverkan på analysresultatet. På grund av olika pre-analytiska faktorer kan tidsgränsen (4 timmar) för analys av standardbikarbonat överskridas. Förvaring av post-analytiska serumprover medför att kompletteringsanalyser kan beställas. Begränsad dokumentation finns om avkorkade serumprovers stabilitet i rumstemperatur. Syfte: Syftet var att undersöka hur lägre fyllnadsnivåer av serum påverkar analysresultatet för joniserat kalcium, om standardbikarbonatsprover på helblod kan analyseras senare än 4 timmar och hur länge serumprover kan stå i rumstemperatur utan kork för eventuella kompletteringsanalyser. Metod: Koncentrationen av analyten joniserat kalcium i serumprover med fyllnadsnivåerna 1 mL och 2 mL jämfördes med maximalt fyllda provrör. Kylskåpsförvarade helblodsprover analyserades för standardbikarbonat efter 4-7 timmar. Avkorkade serumprover analyserades för 10 biokemiska analyter efter att ha stått i rumstemperatur 2-8 timmar. Genomsnittlig procentuell avvikelse jämfördes med en analytisk och biologisk imprecisionsgräns för att bedöma analyters stabilitet. Resultat och slutsatser: Analysresultat av joniserat kalcium i lägre fyllnadsnivåer var tillförlitliga. Stabiliteten av standardbikarbonatsproverna kunde inte bedömas och därmed kunde inte en eventuell tidsgränsändring rekommenderas. De biokemiska analyterna var stabila upp till 8 timmar i rumstemperatur. / Background: Ionized calcium concentrations decrease when samples are exposed to air. Due to pre-analytical factors, the 4 hour time limit for analysis of standard bicarbonate, can sometimes be exceeded. There is limited documentation about additional analyses on post-analytic decapped serum samples stored at room temperature. Aim: The aim was to examine how lower sample volumes affect the concentration of ionized calcium, if the time limit for analysis of standard bicarbonate on whole blood can be prolonged and how long decapped serum samples can be stored at room temperature for eventual additional analyses. Methods: The concentration of ionized calcium was analyzed on serum samples filled with 1 mL and 2 mL and were compared to maximally filled samples. Refrigerated whole blood samples were analyzed for standard bicarbonate after 4-7 hours. Ten biochemical analytes were measured in decapped serum samples after 2-8 hours of storage at room temperature. The mean percentage deviation was compared to an analytical and biological imprecision limit to determine analyte stability. Results and conclusions: Ionized calcium concentrations in lower sample volumes were reliable. The stability of standard bicarbonate could not be determined, therefore a longer possible time limit could not be recommended. The biochemical analytes were stable for 8 hours.
489

Påverkan på PK(INR)-värdet efter olika preanalytiska behandlingar i venöst humanblod.

Khashayar, Mahdavisabet January 2015 (has links)
Venous thromboembolism that cause blood clotting in blood vessels, prevent blood circulation, depending on changes in one or more of the coagulation factors II, VII, IX and X. Patients who have had a blood clot or cardiovascular diseases are treated with oral anti-vitamin K (Warfarin®) to reducing and prevent relapse. Warfarin is also used as a preventive treatment before the disease. An overdose of Warfarin® may cause bleeding-complications and low dose cause blood clotting. The dosage of the drug is controlled by measuring prothrombin in plasma. The aim of this study was to investigate if prothrombin-complex value changes due to re-spinning and re-analysis after six hours. Fitty whole blood samples from warfarin-treated patients were divided into three subgroups, those with protrombinkomplex-values of 2-4 (n=20), &gt;4 (n=15) and &lt;2 (n=15). The samples were centrifugated and measured (Method A), re-centrifugated and measured (Method B) or re-analysed after six hours (Method C). All results were compared in a Bland-Altman plot as follows: Method B vs. Method A and Method C vs. Method A. The scatter graph yielded a strong correlation between Method A and Method B (R2=0.9984) and Method A and Methods C (R2=0.9977). The results from t-test showed a significance level (p&lt;0.001) for both analyses (statistical significance=p&lt;0.05). In this study we showed that prothrombin complex value ware stable after re-centrifugation and re-measurement after six hours. Statistical calculations yielded a strong correlation between the methods (A, B, C), and there was no significance difference between the methods.
490

Pathophysiological and Histomorphological Effects of One-Lung Ventilation in the Porcine Lung

Kozian, Alf January 2009 (has links)
Thoracic surgical procedures require partial or complete airway separation and the opportunity to exclude one lung from ventilation (one-lung ventilation, OLV). OLV is commonly associated with profound pathophysiological changes that may affect the postoperative outcome. It is injurious in terms of increased mechanical stress including alveolar cell stretch and overdistension, shear forces secondary to repeated tidal collapse and reopening of alveolar units and compression of alveolar vessels. Ventilation and perfusion distribution may thus be affected during and after OLV. The present studies investigated the influence of OLV on ventilation and perfusion distribution, on the gas/tissue distribution and on the lung histomorphology in a pig model of thoracic surgery. Anaesthetised and mechanically ventilated piglets were examined. The ventilation and perfusion distribution within the lungs was assessed by single photon emission computed tomography. Computed tomography was used to establish the effects of OLV on dependent lung gas/tissue distribution. The pulmonary histopathology of pigs undergoing OLV and thoracic surgery was compared with that of two-lung ventilation (TLV) and spontaneous breathing. OLV induced hyperperfusion and significant V/Q mismatch in the ventilated lung persistent in the postoperative course. It increased cyclic tidal recruitment that was associated with a persistent increase of gas content in the ventilated lung. OLV and thoracic surgery as well resulted in alveolar damage.  In the present model of OLV and thoracic surgery, alveolar recruitment manoeuvre (ARM) and protective ventilation approach using low tidal volume preserved the ventilated lung density distribution and did not aggravate cyclic recruitment of alveoli in the ventilated lung. In conclusion, the present model established significant alveolar damage in response to OLV and thoracic surgery. Lung injury could be related to the profound pathophysiological consequences of OLV including hyperperfusion, ventilation/perfusion mismatch and increased tidal recruitment of lung tissue in the dependent, ventilated lung.  These mechanisms may contribute to the increased susceptibility for respiratory complications in patients undergoing thoracic surgery. A protective approach including sufficient ARM, application of PEEP, and the use of lower tidal volumes may prevent the ventilated lung from deleterious consequences of OLV.

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