Biofilm is an increasing problem in the healthcare and have in urinary catheters long been associated with nosocomial urinary tract infections. The infections caused in 2002 alone 13,000 deaths in the US and annual costs have been estimated to over $400 million. These costs are however most likely underestimated. The analysis of biofilm is important to aid the work on increasing patient safety and reducing the financial implications. A literature study was conducted in order to recommend a method for quantification that was fast, accurate and versatile. Methods used for biofilm quantification are primarily based upon light absorption, light scattering and changes in impedance. A few methods utilizing these properties are spectrophotometry, flow cytometry and coulter counters. Samples of biofilm are usually collected via traditional scraping with a sterile blade or with sonication (ultrasound). Flow cytometry was considered the superior method for quantification along with sonication for sample collection. The survey therefore came to the conclusion that biofilm sample collection should be done with sonication and analysis with flow cytometry. / Biofilm är ett ökande problem inom sjukvården och har i urinkatetrar länge varit associerademed sjukvårdsrelaterade urinvägsinfektioner. Infektionerna orsakade under 200213,000 dödsfall i USA och de ekonomiska kostnaderna har uppskattats till över $400miljoner. Kostnaderna antas dock vara underskattade. Analysen av biofilm är viktig förarbetet med att förbättra patientsäkerhet och minska kostnader relaterade till biofilm.En litteraturstudie användes för att rekommendera en metod som var snabb, noggrannoch mångsidig. Mätmetoder som används för kvantifiering är i huvudsak baserade påljusabsorption, ljusspridning samt förändringar i elektrisk impedans. Några metodersom använder detta är t.ex. spektrofotometri, flödescytometri samt coulter counters.Prover av biofilm samlas ofta in via traditionell skrapning med ett sterilt knivblad ellermed hjälp av ultraljud. Flödescytometri ansågs vara den bästa metoden för kvantifieringtillsammans med ultraljud för provtagning. Utifrån undersökningen drogs slutsatsen attprovtagning bör ske med ultraljud och analys med flödescytometri.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 94-97. / by Daniel Michael Chernoff. / M.S.

Bakgrund: Användningen av central venkateter (CVK) underlättar och bidrar till den moderna sjukvården. I Sverige sätts årligen över 45,000 olika former av CVK. Däremot medför användningen av CVK risker för komplikationer såsom trombos och infektion. Syfte: Syftet med studien var att belysa sjuksköterskans åtgärder samt andra faktorer för att förhindra komplikationer relaterat till central venkateter. Metod: Studien genomfördes som en allmän litteraturstudie med elva resultatartiklar av kvantitativ metod som grund. Resultatartiklarna analyserades och sammanfattades till fyra huvudkategorier. Resultat: Kategorierna som togs fram var: sjuksköterskans kunskap, arbetsmiljöns påverkan, desinfektion i samband med CVK hantering och förebyggande åtgärder av trombos. Utbildning genom utbildningsprogram var en åtgärd som minskade CVKrelaterade blodomloppsinfektioner. Arbetsmiljön förbättrades genom minskad arbetsbelastning bland sjuksköterskor vilket i sin tur ökade följsamhet till riktlinjer. Användning av klorhexidin i samband med hanteringen av CVK var en åtgärd för att minska riskerna för komplikationer. Sjuksköterskan hade en betydande funktion vid risk och nytta överväganden. Konklusion: Åtgärder som kontinuerlig utbildning stärkte patientsäkerheten och komplikationer minimerades. En bättre arbetsmiljö där personal kunde arbeta utifrån ett säkert och strukturerat arbetssätt ökade möjligheten till följsamhet av riktlinjer. / Background: Use of central venous catheters (CVC) facilitates and contributes to modern healthcare. In Sweden, over 45,000 different types of CVCs are inserted annually. However, using CVCs can lead to complications such as thrombosis and infection. Aim: To study was to examine the nurses' actions and other factors to prevent complications related to central venous catheters. Method: The study was conducted as a general literature study with eleven quantitative result articles. The result articles were analyzed and summarized into four main categories. Result: The categories formed were: the nurse´s knowledge, the impact of work environment, disinfection in connection with CVC handling and preventive measures of thrombosis. Education through educational programs was one measure that reduced CVC-related bloodstream infections. The work environment is improved through reduced workload among nurses, which in turn increases adherence to guidelines. Use of chlorhexidine in connection with the management of CVC was a measure to reduce the risks of complications. The nurse had a function in risk and benefit considerations. Conclusion: Measures such as continuous education strengthen patient safety and minimize complications. A better working environment where staff could work from a safe and structured approach increases the possibility of compliance.

Venösa infarter används för att ge intravenösa läkemedel samt blodprovstagning. De venösa infarter som används inom sjukvården är perifera venkatetrar, midlines, PICC-lines och andra centralvenösa infarter. Midlinekatetern är en perifer infart med längre kateter och längre livslängd än en sedvanlig perifer venkateter, men räknas ej som en centralvenös infart. Indikation för midlines är patienter som är svårstuckna samt har behov av en perifer infart med en livslängd mellan fyra och fjorton dagar.  Syftet med studien var att undersöka patientsäkerheten av midlinekatetrar hos slutenvårdspatienter.  Studiens metod var en litteraturstudie med systematiskt tillvägagångssätt. I resultatet analyserades kvantitativa- och mixed method-artiklar. En induktiv analysmetod användes.  I resultatet framkom det att lokala och systemiska infektioner var relativt låga vid användning av midlinekatetrar. Dock var mekaniska komplikation av högre frekvens hos patienter med midlinekatetrar jämfört med centralvenösa infarter, men lägre än vid användning av perifera venkatetrar. Midlinekatetrar minskar även insättande av centralvenösa infarter vilka har högre risk för svåra komplikationer.  Slutsatsen är att midlinekatetrar, om de används vid rätt indikation, kan minska användning och därmed komplikationer från centralvenösa infarter samt minska lidande hos patienter på grund av upprepade nålstick. Mer svensk forskning behövs då inga svenska artiklar identifierades. Även ett behov av ytterligare forskning med ett patientcentrerat perspektiv fastställdes. / Venous accesses are used to provide intravenous drugs as well as to draw blood samples. The types of venous accesses that are used in hospitals are peripheral venous catheters, midline catheters, PICC-lines and other central venous access devices. A midline catheter is a peripheral access with a longer catheter and longer lifespan than a conventional peripheral venous catheter, but does not count as a central venous access. Indications for midlines are patients with difficult venous accesses and patients with the need of an access with a lifespan between four to 14 days.  The aim of this review was to investigate the patient safety of midline catheters in hospitalised patients.  The method of the study was a review with a systematic approach. Quantitative and mixed method articles were analysed. An inductive analysis method was used.  The results showed that local and systemic infections were relatively low in the use of midline catheters. However, the prevalence of mechanical complications among patients were higher in midline catheters than in central venous devices, but lower than in peripheral venous catheters. Midline catheters can also reduce the use of central venous accesses, which have a higher risk of severe complications.  The conclusion is that midline catheters, if used with the right indication, could decrease the  use and complications from central venous catheters and decrease patient suffering. More Swedish research is needed as no Swedish articles were found. Furthermore a need for additional research with a patient-centered perspective was identified.

Recent studies suggest that factor (F) XII plays a key role in thrombus stabilization and growth but is dispensable for hemostasis. We have previously shown that histidine-rich glycoprotein (HRG), a protein present in platelets and plasma, binds FXIIa and inhibits FXII autoactivation and FXIIa-mediated activation of FXI, thereby downregulating thrombosis. HRG binds various ligands, including FXIIa, fibrin(ogen), nucleic acids and polyphosphate (polyP). Studies have shown that polyP, released from activated platelets, and artificial surfaces like catheters, can promote FXII activation. This suggests that HRG can downregulate the activation of the contact system. This thesis aims to determine the potential mechanisms by which HRG modulates platelet function and thrombosis induced by polyP or catheters. We show that HRG binds polyP with high affinity and inhibits the procoagulant, prothrombotic and cardiotoxic effects of polyP via at least two mechanisms. First, HRG binds polyP and neutralizes its procoagulant activities and cytotoxic effects. Second, HRG binds FXIIa and attenuates its capacity to promote autoactivation and activate FXI. Also, we identify that HRG serves as a molecular brake for the contact system by attenuating the procoagulant activity of FXIIa regardless of whether FXII activation is triggered systemically with polyP or occurs locally on the surface of catheters. Our studies have identified HRG as a novel ligand for platelet receptor GPIbα on resting platelets, and upon activation, it competes with fibrinogen for binding to GPIIb/IIIa integrin, thereby inhibiting platelet aggregation. These findings suggest that HRG may modulate coagulation as well as platelet function. Therefore, supplementation with HRG or HRG analogs may serve as a potential therapeutic option to attenuate polyP or catheter-induced thrombosis without perturbing hemostasis. / Dissertation / Doctor of Philosophy (PhD)

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Patients in critical care with lung injuries need to be assisted with regards to breathing function, but current methods are not applicable for all situations. The most common method, Extracorporeal Membrane Oxygenation (ECMO) is an expensive procedure and requires trained staff to operate the equipment at all times. Lung injury may lead to the inability of the lungs to be perfused and the blood oxygenated by tracheal intubation, whereas mechanical ventilators can injure the lungs further. Especially at risk are preterm neonates, where congenital disorders or complications during birth render ECMO the only viable option. Respiratory Assist Catheters (RACs) could be used as an alternative because they do not place extra stress on the lungs, are easy to implement, cost-effective and are available for immediate use in clinical settings or in first aid situations. The development of such a device requires knowledge of possible oxygenation methods as well as the risks involved in implementing such a device. The possibility of oxygenating the blood via microbubbles by means of a RAC is promising due to the high gas transfer rates common in bubble oxygenators. It is the aim of this study to develop a prototype that could function as a RAC and to evaluate the feasibility of oxygenation by using microbubbles. The method used to design a prototype included selection of various materials and finalization of a design to be tested. The tests selected were in vivo tests and ex vivo tests using animal models to investigate the dissolution times of the microbubbles, as well as the physiological effects of an intravenously placed device. Measurements of oxygen saturation of the blood in arterial blood (SaO2), venous blood (SvO2) and pulmonary pressure allowed the oxygen transfer rates and risks involved to be evaluated, and also gave an indication regarding the formation dynamics of microbubbles in the blood. An in vitro test was also performed with the aim of determining the rate of dissolving of oxygen, and hence to give an indication regarding microbubble dissolution times. Mathematical simulations based on the dissolution rate of oxygen in venous blood confirmed the abovementioned results. The tests and simulations were analysed in order to evaluate the feasibility of intravenously oxygenating the blood using microbubbles. Approximate bubble dissolution times were an indicator of the feasibility of the concept and showed that very large bubble dissolution times renders intravenous bubble oxygenation unfeasible. These large dissolution times also lessen the possibility of implementing bubble oxygenation in an intravenous device. / AFRIKAANSE OPSOMMING: Pasiënte wat a.g.v. longbeserings in hoë-sorg behandel word het hulp nodig om asem te haal, maar bestaande metodes werk nie in alle omstandighede nie. Die mees algemene metode is ekstrakorporeale membraan suurstofverbinding (Extracorporeal Membrane Oxygenation (ECMO)), maar hierdie metode is duur en het voltyds opgeleide personeel nodig om dit te beheer. Longbeserings kan lei tot die onvermoë van die longe om bloed te ontvang en ook dat die bloed suurstof kry d.m.v. trageale intubasie. Meganiese ventilators kan die longe verder beskadig. Vroeggebore babas word blootgestel aan risiko’s veral waar oorerflike afwykings/steurnisse aanwesig is of komplikasies tydens geboorte en dus die EMCO die enigste lewensvatbare opsie maak. Kateters wat asemhaling aanhelp (Respiratory Assist Catheters (RACs)) kan as alternatief gebruik word aangesien dit nie ekstra spanning op die longe plaas nie, maklik is om te implementeer, koste-effektief is en beskikbaar is vir onmiddellike gebruik in kliniese omstandighede of in noodhulpsituasies. Die ontwikkeling van hierdie tipe toestel vereis kennis van moontlike suurstofverbindingsmetodes en ook die risiko’s verbonde aan die implementering van die toestel. Die moontlikheid om die bloed van suurstof te voorsien d.m.v. mikroborrels deur die RAC lyk belowend a.g.v. die hoë gasoordrag-koers wat algemeen is by borrel suurstofverbinders. Hierdie studie het ten doel om ʼn prototipe te ontwikkel wat kan dien as ʼn RAC en ook om die lewensvatbaarheid van suurstofverbinding met mikroborrels te bepaal. Die metode wat gebruik is om die prototipe te ontwerp sluit in die kies van verskeie materiale en die finalisering van die ontwerp wat getoets moet word. Die geselekteerde in vivo en ex vivo toetse is afgeneem deur gebruik te maak van dier-modelle om sodoende ondersoek in te stel na die oplossing van die mikroborrels en ook die fisiologiese gevolge van die toestel wat binne die aar geplaas is. Metings van die suurstofversadiging van bloed in slagaarbloed (SaO2), aarbloed (SvO2) en pulmonêre druk het toegelaat dat die koers en risiko’s verbonde aan suurstofoordrag geëvalueer word. Hierdie metings gee ook ’n aanduiding van die vormingsdinamika van die mikroborrels in die bloed. ’n In vitro toets is gedoen met die doel om die koers te bepaal van die oplossing van suurstof, en dus ’n aanduiding te gee van die tyd verbonde aan die oplossing van die mikroborrels. Wiskundige simulasies gebaseer op die oplossingskoers van suurstof in are het die bogenoemde toetse bevestig. Die toetse en simulasies is geanaliseer om die lewensvatbaarheid te bepaal om suurstof binne-aars te verskaf deur mikroborrels. Geskatte tye waarteen die borrels oplos is as aanduiding gebruik vir die lewensvatbaarheid van die konsep en ook die moontlike inwerkingstelling van die binne-aarse toestel.

As complicações de pacientes com insuficiência renal crônica submetidos ao tratamento hemodialítico representam desafios para os profissionais de saúde. A variabilidade de fatores de risco que predispõem a essas complicações têm sido, freqüentemente, investigada na literatura científica. Nesse sentido, objetivou-se descrever as complicações locais e sistêmicas dos pacientes com insuficiência renal crônica a partir da implantação do cateter temporário de duplo lúmen para hemodiálise até sua retirada definitiva. Trata-se de um estudo de segmento que avaliou prospectivamente os pacientes da implantação do cateter até sua retirada definitiva. Para o estabelecimento do grupo estudado foi considerado um período de seis meses consecutivos de julho a dezembro de 2003. Assim, após a aprovação do Comitê de Ética em pesquisa procedeu-se a coleta dos dados. Para análise dos resultados realizou-se a codificação das variáveis no banco de dados do programa Microsoft Excel mediante dupla digitação, e, utilizou-se o programa Software Statistical Package for Social Sciences, versão 10.0 na análise estatística. Dos 64 pacientes avaliados 38 (59,4%) eram do sexo masculino, 20 (31,2%) tinham como causa provável da insuficiência renal a nefroesclerose hipertensiva, e, 35 (54,7%) implantaram o cateter devido à necessidade do tratamento hemodialítico imediato. Totalizou-se no período 145 cateteres implantados, 29 (45,3%) dos pacientes tiveram implantes únicos, 98 (67,6%) dos acessos foram a veia jugular interna direita, 40 (27,6%) das trocas dos cateteres foram devido a febre. O tempo médio de permanência dos cateteres foi de 30 dias. A complicação local mais freqüente em 41 (64%) dos pacientes foi o funcionamento inadequado do cateter com 26 dias de média para a ocorrência, e, a complicação sistêmica mais freqüente em 24 (37,5%) foi a febre com 34 dias de média para sua ocorrência, 27 (42,2%) dos pacientes apresentaram infecção do sítio de inserção, e, 30 (47%) infecção da corrente sanguínea. O Staphylococcus aureus foi o microrganismo mais isolado em 10 (33,4%) das hemoculturas. Observou-se que 45 (70,4%) dos pacientes retiraram definitivamente o cateter devido à punção da fístula arteriovenosa. O estudo apontou aspectos preocupantes, dentre eles, o tempo de permanência do cateter, que expõe sobremaneira o paciente a diferentes complicações, em especial, a infecção. A confecção da fístula arteriovenosa representa uma importante alternativa que contrapõe o uso do cateter temporário. / Complications in chronic renal insufficiency patients under dialysis treatment represent important challenges to health professionals. The variety of risk factors predisposing towards these complications have frequently been discussed in scientific literature. Thus, this study aimed to describe the local and systemic complications of chronic renal insufficiency patients who were using a temporary double-lumen catheter for hemodialysis treatment, until its final withdrawal. A segment research prospectively studied patients from the moment the catheter was inserted until its final withdrawal. A period of six consecutive months, from July to December 2003, was considered to determine the group of patients ti be studied. Thus, after ethical approval, data were collected through interviews, clinical exams and patient record evaluation. For the result analysis, the variables were coded in a database through double data entry in Microsoft Excel and Software Statistical Package Social Sciences, version 10.0 was used for statistical analysis. 38 (59.4%) of the 64 patients were men, 20 (31.2%) showed hypertensive nephrosclerosis as the probable cause of insufficiency renal and 35 (54.7%) inserted the catheter due to the need for immediate hemodialysis treatment. 145 catheters were inserted during the period, 29 (45.3%) of which were single implants and the right internal jugular vein was the access in 98 cases (67.6%). Average catheter permanence time was 30 days. Catheters were substituted in 40 cases (27.6%) due to fever. The most frequent local complication was inadequate functioning in 41 (64%) cases, with an average occurrence of 26 days, while the most frequent systemic complication was fever in 24 cases (37.5%), with an average occurrence of 34 days. Infection of the insertion site occurred in 27 (42.2%) cases and infection of the blood flow associated with the catheter in 30 (49%) cases. Sthaphylococos aureus was the most frequently isolated microorganism in 10 (33.4%) blood cultures. 45 (70.4%) final catheter withdrawals were due to arterio-venous fistula puncture. This analysis revealed various preoccupying aspects, including the catheter permanence time, which highly exposes the patient to different complications, particularly infection.

Compliant and flexible cardiac catheters provide direct access to the inside of the heart via the vascular system without requiring clinicians to stop the heart or open the chest. However, the fast motion of the intracardiac structures makes it difficult to modify and repair the cardiac tissue in a controlled and safe manner. In addition, rigid robotic tools for beating heart surgery require the chest to be opened and the heart exposed, making the procedures highly invasive. The novel robotic catheter system presented here enables minimally invasive repair on the fast-moving structures inside the heart, like the mitral valve annulus, without the invasiveness or risks of stopped heart procedures. In this thesis, I investigate the development of 3D ultrasound-guided robotic catheters for beating heart surgery. First, the force and stiffness values of tissue structures in the left atrium are measured to develop design requirements for the system. This research shows that a catheter will experience contractile forces of 0.5 – 1.0 N and a mean tissue structure stiffness of approximately 0.1 N/mm while interacting with the mitral valve annulus. Next, this thesis presents the catheter system design, including force sensing, tissue resection, and ablation end effectors. In order to operate inside the beating heart, position and force control systems were developed to compensate for the catheter performance limitations of friction and deadzone backlash and evaluated with ex vivo and in vivo experiments. Through the addition of friction and deadzone compensation terms, the system is able to achieve position tracking with less than 1 mm RMS error and force tracking with 0.08 N RMS error under ultrasound image guidance. Finally, this thesis examines how the robotic catheter system enhances beating heart clinical procedures. Specifically, this system improves resection quality while reducing the forces experienced by the tissue by almost 80% and improves ablation performance by reducing contact resistance variations by 97% while applying a constant force on the moving tissue. / Engineering and Applied Sciences

Bakgrund: Vårdrelaterade infektioner är ett stort problem inom dagens sjukvård och en av de vanligaste vårdrelaterade infektionerna inom intensivvården är kateterrelaterade. En central venkateter (CVK) är en kärlaccess som är vanligt förekommande inom intensivvården och handhavandet av dessa utförs till största del av sjuksköterskan. Sjuksköterskans förebyggande arbete är därför viktigt för att minska förekomsten av CVK-relaterade infektioner samt öka patientsäkerheten. Syfte: Syftet med litteraturstudien var att beskriva vilka CVK-relaterade åtgärder utförda av sjuksköterskor hos vuxna patienter inom intensivvård som minskar risken för vårdrelaterade infektioner. Metod: En strukturerad litteraturstudie som sammanställt kvantitativ forskning med en induktiv innehållsanalys. Antal studier som inkluderades i resultatet var 18 stycken. Huvudresultat: Litteraturstudiens huvudresultat baserades på fem teman, samtliga beskrev preventiva omvårdnadsåtgärder. Resultatet inom respektive tema var vikten av mekanisk rengöring med desinfektionsmedel av injektionsportar och trevägskranar, daglig utvärdering av patientens behov av en CVK, en klorhexidinkomponent i förbandet, daglig helkroppsavtvättning med tvättlappar innehållande klorhexidin samt utbildning av personalen kring evidensbaserade riktlinjer. Samtliga dessa områden sågs minska risken och förekomsten av CVK-relaterade infektioner. Slutsats: Det är angeläget att det finns sjukhusövergripande riktlinjer som baseras på den bästa tillgängliga evidensen i syfte att minska CVK-relaterade infektioner inom intensivvården. Dessa bör vara samstämmiga med de nationellt övergripande riktlinjerna. Detta för att skapa en så jämlik och patientsäker vård som möjligt. / Introduction: Healthcare-related infections are a major problem in today's healthcare and one of the most common care related infections in the intensive care unit is catheter related. A central venous catheter (CVC) is a vascular access commonly found in intensive care units, and the maintenance is commonly performed by the nurses. The preventive work is therefore important in reducing the incidence of CVC-related infections and by that increasing the patient safety.   Aim: The aim of the study was to describe what part of maintenance regarding the CVC performed by nurses in adult patients in the intensive care unit that reduces the risk of healthcare-related infections. Method: A structured literature study was conducted and studies with a quantitative design were compiled. The results were analyzed with an inductive content analysis. The number of articles included in the results were 18. Main results: The main results of the study were based on five themes which were preventive measures. The results were mechanical cleaning with disinfectants of needleless connectors and three-way stop cork, daily evaluation of the patients need for a CVC, chlorhexidine dressing, daily chlorhexidine baths and education of staff. These areas were seen to reduce the risk and incidence of CVC-related infections. Conclusion: It is important that there is a consensus of the guidelines regarding the preventions of CVC-related infections both locally and nationally. The guidelines should be based on the best available evidence to reduce CVC-related infections in the intensive care unit. The purpose is to perform equal care and to promote patient safety.

O uso de cateteres venosos centrais (CVC) para fins diagnósticos e terapêuticos está incorporado à prática médica diária. Complicações sérias, com elevada morbidade e mortalidade, como a sepse, estão associadas a este procedimento. O diagnóstico das infecções relacionadas a cateter é fundamentado em sinais clínicos e laboratoriais. Os fatores de risco para infecção devem ser considerados por ocasião da utilização de CVC e estão relacionados ao paciente, ao cateter, ao tipo de solução administrada, ao profissional que manipula o cateter e ao agente etiológico. A identificação destes fatores permite a intervenção precoce sobre os mesmos e o manejo adequado do CVC e das complicações clínicas relacionadas. / The use of central venous catheters (CVC) for diagnosis and treatment is common in the medical practice. This procedure is associated with severe complications that present high morbidity and mortality rates, such as sepsis. The diagnosis of catheter-related infections is based on clinical signs and laboratorial confirmation through semi-quantitative or quantitative culture of the catheter tip. The risk factors for infection should be considered when using CVC. These factors may be related to the patient, to the catheter, to the type of solution administered, to the professional who handles the catheter and to the etiological agent. The identification of these factors will early intervention and ensure adequate management of CVC- related complications.