2,011 research outputs found

    Acute Stroke Care: Strategies For Improving Diagnostics

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    Stroke is one of the leading causes of death and disability, with a high incidence of over 11 million cases annually worldwide. Costs of treatment and rehabilitation, loss of work, and the hardships resulting from stroke are a major burden both at the individual and at the societal level. Importantly, stroke therapies need to be initiated early for them to be effective. Thrombolytic therapy and mechanical thrombectomy are early treatment options of ischemic stroke. In hemorrhagic stroke, optimization of hemodynamic and hemostatic parameters is central, and surgery is considered in a subset of patients. Efficient treatment of stroke requires early and precise recognition of stroke at all stages of the treatment chain. This includes identification of patients with suspected acute stroke by emergency medical dispatchers and emergency medical services staff, and precise admission diagnostics by the receiving on-call stroke team. Success requires grasping the complexity of stroke symptoms that depend on the brain areas affected, and the plethora of medical conditions that can mimic stroke. The Helsinki Ultra-acute Stroke Biomarker Study includes a cohort of 1015 patients transported to hospital due to suspected acute stroke, as candidates for revascularization therapies. Based on this cohort, this thesis work has explored new avenues to improve early stroke diagnostics in all stages of the treatment chain. In a detailed investigation into the identification of stroke by emergency medical dispatchers, we analyzed emergency phone calls with missed stroke identification. We also combined data on dispatch and EMS and hospital records to identify causes for missing stroke during emergency calls. Most importantly, we found that a patient’s fall at onset and patient confusion were strongly associated with missed identification. Regarding the Face Arm Speech Test (FAST), the most likely symptom to be misidentified was acute speech disturbance. Using prehospital blood sampling of stroke patients, and ultrasensitive measurement, we investigated the early dynamics of the plasma biomarkers glial fibrillary acidic protein (GFAP) and total tau. Utilizing serial sampling, we demonstrate for the first time that monitoring the early release rate of GFAP can improve the diagnostic performance of this biomarker for early differentiation between ischemic and hemorrhagic stroke. In our analysis of early GFAP levels, we were able to differentiate with high accuracy two-thirds of all patients with acute cerebral ischemia from those with hemorrhagic stroke, supporting further investigation of this biomarker as a promising point-of-care tool for prehospital stroke diagnostics. We performed a detailed review of the admission diagnostics of our cohort of 1015 patients to explore causes and predictors of admission misdiagnosis. We then investigated the consequences of misdiagnosis on outcomes. We demonstrate in this large cohort that the highly optimized and rapid admission evaluation in our hospital district (door-to-needle times below 20 minutes) did not compromise the accuracy and safety of admission evaluation. In addition, we discovered targets for improving future diagnostics. Finally, our detailed neuropathological investigation of a case of cerebral amyloid angiopathy (CAA) -related hemorrhage after stroke thrombolysis provided unique tissue-level evidence for this common vasculopathy as a notable risk factor for intracranial hemorrhagic complications in the setting of stroke. These findings support research to improve the diagnostics of CAA, and the prediction of hemorrhagic complications associated with stroke thrombolysis. In conclusion, these proposed targets and strategies will aid in the future improvement and development of this highly important field of diagnostics. Our proof-of-concept discoveries on early GFAP kinetics help guide further study into this diagnostic approach just as highly sensitive point-of-care GFAP measurement instruments are becoming available. Finally, our results support the safety of worldwide efforts to optimize emergency department door-to- needle times when care is taken to ensure sufficient expertise is in place, highlighting the role of the on-call vascular neurologist as a central diagnostic asset.Aivohalvaus on yksi yleisimpiä kuolinsyitä ja pitkäkestoisen työkyvyttömyyden aiheuttajia. Aivohalvauksen aiheuttamat hoito- ja kuntoutuskustannukset, työkyvyn menetys ja arkielämän vaikeudet ovat mittava taakka sekä yksilön, läheisten että yhteiskunnan tasoilla. Tehokkaiden hoitojen vaatima nopeus edellyttää aivohalvauksen varhaista ja tarkkaa tunnistamista hoitoketjun kaikilla askelmilla. Tässä väitöskirjatyössä etsittiin uusia keinoja aivohalvauksen varhaisdiagnostiikan kehittämiseksi hätäkeskuksessa, ensihoidossa ja vastaanottavan sairaalan HYKS:n päivystyspoliklinikalla. Yksityiskohtainen analyysi aivohalvauksen tunnistamisesta hätäkeskuksessa osoitti, että potilaan kaatuminen ja sekavuus olivat puutteellisen tunnistamisen keskeisiä tekijöitä. Face Arm Speech Test (FAST) -seulontaoireista puhehäiriö oli todennäköisimmin väärin tunnistettu. Akuuttivaiheen verinäytteitä ja äärimmäisen herkkää määritysmenetelmää hyödyntäen tutkimme kahden verestä mitattavan merkkiaineen, aivojen tukikudoksen tähtisolujen säikeisen happaman proteiinin (GFAP) ja taun varhaista dynamiikkaa aivohalvauspotilailla. Osoitimme ensimmäistä kertaa, että GFAP:n varhaisen vapautumisnopeuden seurantaa sarjanäytteistä voidaan hyödyntää parantamaan tämän merkkiaineen erottelukykyä iskeemisen ja hemorragisen aivokudosvaurion varhaisdiagnostiikassa. Tulokset viittaavat siihen, että GFAP merkkiaine voisi olla jatkossa kehitettävissä ambulansseissa hyödynnettäväksi pikaverikokeeksi, joka auttaisi aivohalvauksen eri muotojen varhaisessa erottelussa. Päivystysdiagnostiikkaan keskittyvässä osatyössä osoitimme ensimmäistä kertaa suuressa aineistossa, että sairaanhoitopiirissämme vuosia optimoitu erittäin nopea vastaanottoarviointi (liuotushoidon mediaaniviive alle 20 minuuttia sisältäen pään kuvauksen) ei vaaranna aivohalvauspotilaiden diagnostiikan tarkkuutta ja hoidon turvallisuutta. Tässä väitöskirjatyössä esitetyt kehityskohteet ja menetelmät auttavat tämän erittäin tärkeän diagnostisen alan tulevassa kehitystyössä. Työssä kuvatut tulokset sisältävät uraauurtavia havaintoja verestä mitattavan GFAP merkkiaineen kinetiikan käytöstä aivohalvauksen varhaisdiagnostiikassa ja tukevat sairaalapäivystysarvion diagnostista tarkkuutta HYKS:n tunnetusti erittäin nopeassa liuotushoitoketjussa

    New perspectives in surgical treatment of aortic diseases

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    A Fresh Breeze::Standardization of diagnosis in Congenital Lung Abnormalities

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    Patient specific insights into thoracic aortic disease:Exploring male-female differences

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    There are clear differences between males and females with thoracic aortic aneurysms (TAA). For starters, thoracic aortic aneurysm (TAA) between is known to have a higher incidence in males. Furthermore, females seem to present with thoracic aortic aneurysm at an older age. However, little is known about possible differences between male and female TAA patients in presentation, management and outcomes. Worse outcomes in females after thoracic aortic dissection and elective thoracic aortic surgery have been reported, which lead to uncertainties about optimal timing of preventive thoracic aortic surgery in male and female patients. The mechanisms underlying these male-female differences in outcome remain unclear. As a result, there has been debate about the appropriateness of the use of absolute aortic diameter for the timing of surgery. Currently, sex and body size are not taken into account when timing preventive aortic surgery. However, male-female specific cut-off values for maximal aortic diameter might be helpful. Furthermore, the risk of aortic dissection causes stress and anxiety in TAA patients, which could impact quality of life. The effect of TAA on quality of life might be different in males and females, since male-female differences in emotional functioning, coping strategies and stress (i.e. anxiety/depression) are well known to exist in the general population. Moreover, limited information is available on the safety of daily activities, such as exercise and sports participation in both male and female patients with thoracic aortic disease. All these male-female differences have largely been neglected in patients with heart disease in general and aortic disease in particular. Therefore, research in all these aspects of aortic disease is essential. This thesis is part of the ‘Size Matters’ project, funded by ZonMW, aims to identify male-female differences and other patient specific insights into thoracic aortic aneurysm diagnosis, treatment and outcomes. More accurate identification of patients at risk for thoracic aortic dissection allows for better timing of intervention, and will hopefully contribute to better survival, as well as stress reduction and better quality of life

    A Novel Continuum Overtube with Improved Triangulation for Flexible Robotic Endoscopy

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    This paper presents a novel continuum overtube that consists of a notched tendon-driven 2-DOF continuum joint and a distal deployable structure driven by a flexible screw rod. A smooth bending shape with constant curvature is achieved by adopting an overlapped area between notches to generate uniform stress distribution. The distal deployable structure provides an extensive triangulation for bimanual operations. The presented design achieves high flexibility, sufficient loading and anti-twisting capacity, and an improved layout of functional channels for flexible robotic endoscopy. Design optimization is performed to optimize structural parameters for performance investigation and improvement. The proposed continuum joint achieves an average distal positioning error of 1.48% and 1.20% within -115∘, 115∘ in the two bending planes with minor hysteresis errors of less than 1.5%, indicating the outstanding constant bending curvature characteristics for kinematic modeling and control. The loading capacity achieves 4.27N and provides significant advantages in terms of sufficient rigidity over the commercial endoscope. The designed deployable structure has significantly improved operational triangulation, which can effectively support bimanual operations with two instruments for complex operations. Meanwhile, the torsional stiffness of the designed continuum joint reaches a considerable value of 8.73mNm/∘ and provides stable support for instruments during operations. Ex-vivo experiments of gastric tissue biopsy have been performed to verify the feasibility of the presented design in a practical scenario

    A Fresh Breeze::Standardization of diagnosis in Congenital Lung Abnormalities

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    New perspectives in surgical treatment of aortic diseases

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