• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 661
  • 507
  • 87
  • 44
  • 39
  • 25
  • 22
  • 21
  • 17
  • 14
  • 12
  • 8
  • 8
  • 5
  • 5
  • Tagged with
  • 1667
  • 398
  • 376
  • 298
  • 250
  • 208
  • 185
  • 159
  • 139
  • 139
  • 128
  • 124
  • 112
  • 108
  • 97
  • 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.
541

Parents' Impressions of Their Child's Minor Surgical Procedure with Nitrous Oxide

Shapiro-Stoler, Tina J. 16 December 2009 (has links)
Invasive procedures are often painful and distressing for children and disturbing for their parents. The purpose of this study was to develop a substantive theory of parental perceptions of their school-aged child's responses to an outpatient minor surgical procedure with nitrous oxide. The sample included 22 parents of 21 children who underwent a nitrous procedure. Participants were recruited from the pediatric surgery department at a children's hospital. Semi-structured, audio-recorded interviews were conducted with each participant. Grounded theory method was used to simultaneously collect and analyze the data using the constant comparative method. The findings of the study revealed parental impressions involving a process of various emotions and behaviors. The identified process began at procedural scheduling, progressing through the procedure, and terminated going home. The core category derived from the data was Weathering the Storm before the Calm by Securing Connections. This core category describes the complexity of parental impressions and all categories subsumed by the core category. Six major categories and seven subcategories derived from the data represent parental impressions. Parental feelings of anxiety and fear arose during initial phases of the process. Parents attempted to deal with these stormy feelings in several ways. Parents experienced a sense of calmness after the procedure upon realizing their child was safe. The theme that weaves through the entire process is the parental-child connection and parental presence during the nitrous procedure. Parents also identified barriers and facilitators they faced during this process. The substantive theory that emerged provides nurses with an understanding of the stormy and subsequent calm phases parents endured. This information offers clinicians unique interventions to help parents get through this process. Future research needs extension to other settings such as radiology and other specialties such as plastic surgery and urology. Further research warrants investigating children's perceptions to their procedure with nitrous oxide.
542

Polymeric Microsensors for Intraoperative Contact Pressure Measurement

Pritchard, Emily R 01 May 2010 (has links)
Biocompatible sensors have been demonstrated using traditional microfabrication techniques modified for polymer substrates and utilize only materials suitable for implantation or bodily contact. Sensor arrays for the measurement of the load condition of polyethylene spacers in the total knee arthroplasty (TKA) prosthesis have been developed. Arrays of capacitive sensors are used to determine the three-dimensional strain within the polyethylene prosthesis component. Data from these sensors can be used to give researchers a better understanding of component motion, loading, and wear phenomena for a large range of activities. This dissertation demonstrates both analytically and experimentally the fabrication of these sensor arrays using biocompatible polymer substrates and dielectrics while preserving industry-standard microfabrication processing for micron-level resolution. An array of sensors for real-time measurement of pressure profiles is the long-term goal of this research. A custom design using capacitive-based sensors is an excellent selection for such measurement, giving high spatial resolution across the sensing surface and high load resolution for pressures applied normal to that surface while operating at low power.
543

Chirurgie fonctionnelle des epilepsies réfractaires: nouvelles approches physiopathologiques, diagnostiques et thérapeutiques; Surgery for refractory epilepsy: New concept regarding physiopathology, diagnosis and treatment.

Colligon, Frédéric 21 May 2007 (has links)
Beaucoup de progrès restent à réaliser dans la compréhension de la physiopathologie ainsi que dans la prise en charge thérapeutique de lépilepsie. De nombreux patients restent réfractaires au traitement médical et sont susceptibles dêtre de bons candidats à un traitement chirurgical. Lapport de nouvelles techniques dimagerie est une avancée importante dans la définition des crises et dans la localisation du foyer épileptogène et a permis daméliorer le résultat du traitement chirurgical par une meilleure sélection des candidats. La première partie de notre travail est une introduction générale où sont principalement exposées les techniques actuelles dexploration de lépilepsie ainsi que les résultats à long terme du traitement chirurgical chez 399 patients souffrant dépilepsie réfractaire, de manière à préciser le rôle de la chirurgie ainsi que les facteurs pouvant influencer le résultat postopératoire. La prise en charge des crises dépilepsie réfractaire dont le foyer épileptique se localise au niveau de zone fonctionnelle reste difficile et controversée. Il existe des arguments historiques et physiologiques justifiant une exérèse chirurgicale du foyer au niveau de zones fonctionnelles telles que le cortex sensitivomoteur mais il nexiste pourtant pas dans la littérature moderne de série qui permette dévaluer lefficacité de ce traitement et de le comparer avec dautres techniques chirurgicales comme par exemple les transsections sous- piales multiples. Dans la deuxième partie de ce travail, nous présentons une série de cinq patients provenant de la série des 399 patients exposée dans la première partie de notre travail, qui ont tous bénéficié dune résection corticale au niveau du cortex sensitivomoteur. Nous montrons que la difficulté du traitement de ces patients nest pas tant le geste chirurgical mais la définition et la localisation exacte du foyer épileptogène. Nous démontrons également que la mise au point exhaustive et précise de cette pathologie, en utilisant les méthodes dinvestigation décrites dans la première partie, permet de sélectionner les candidats de manière optimale avec des résultats postopératoires satisfaisants. La physiopathologie des crises dépilepsie est encore mal définie. Le mécanisme le plus souvent évoqué est un déséquilibre synaptique entre les afférences excitatrices et inhibitrices, une anomalie des canaux ioniques membranaires ou encore un trouble du métabolisme neuronal ou glial au niveau dun foyer où les neurones présentent une activité anormale. Une des questions primordiales à éclaircir est de savoir si cest le neurone qui est hyperexcitable, le réseau neuronal présent au sein du foyer ou les deux. Les structures gliales formées par les astrocytes et les oligodendrocytes jouent-elles un rôle accessoire ou primordial dans ce phénomène ? En dehors du rôle que pourraient jouer les connexions synaptiques dans le phénomène épileptique, les jcs semblent être importantes dans le mécanisme physiopatholgique des crises. Elles pourraient favoriser la synchronisation de lactivité épileptique ainsi que la propagation de celle-ci vers les régions cérébrales avoisinantes. La troisième partie de notre travail explore le rôle que pourrait jouer les jcs dans le phénomène épileptique. Les épilepsies mésiotemporales associées à une sclérose hippocampique sont les épilepsies dont le traitement chirurgical est le plus fréquemment proposé lorsque les crises deviennent réfractaires au traitement médical. Lobtention de tissu est dès lors aisée ce qui nous a permis détudier lexpression des jcs au niveau de tissus hippocampiques provenant de patients épileptiques et de la comparer avec celle déterminée au niveau dhippocampes provenant de patients non épileptiques et obtenus postmortem. Notre objectif est de savoir si cette éventuelle contribution au phénomène épileptique est liée à une augmentation de lexpression des jcs au niveau des tissus épileptiques et, si oui au niveau de quels types cellulaires (neurones, astrocytes) et de quelles régions de lhippocampe (gyrus dentelé, CA1 à CA4, subiculum)
544

Metastatic spinal cord compression in prostate cancer : clinical and morphological studies / Ryggmärgskompression vid metastaserande prostatacancer : kliniska och morfologiska studier

Crnalic, Sead January 2012 (has links)
Background: Bone metastases occur in most patients with advanced hormone-refractory prostate cancer causing pain, pathologic fractures, and spinal cord compression. Few studies specifically address surgical treatment of metastatic spinal cord compression (MSCC) in prostate cancer. Criteria for identifying patients who may benefit from surgery are poorly defined. Most of the current knowledge regarding tumor biology in prostate cancer is based on studies of primary tumors or soft tissue metastases. The mechanisms regulating growth of bone metastases are not fully established. Aims: a) to evaluate outcome after surgery for MSCC in prostate cancer and to identify prognostic factors for survival and functional recovery; b) to evaluate current practice for referral of prostate cancer patients with MSCC; c) to analyze expression of androgen receptor (AR), cell proliferation, apoptosis, and prostate-specific antigen (PSA) in bone metastases with regard to survival after surgery for complications of bone metastases. Patients and Methods: We retrospectively evaluated the hospital records of 68 consecutive patients operated for metastatic spinal cord compression. Tumor tissue from bone metastases was obtained on spinal surgery (54 patients), fracture surgery (4 patients) and biopsy (2 patients), and analyzed by immunohistochemistry. Results: Study I: Mortality and complication rate after surgery was high. Patients with hormone-naïve disease and those with hormone-refractory disease with good performance status and without visceral metastases had more favorable survival. The ability to walk after surgery was related to better survival. Study II: A new score for prognosis of survival after surgery for spinal cord compression includes: hormone status of prostate cancer, Karnofsky performance status, evidence of visceral metastasis, and preoperative serum PSA. The score is simple, tumor specific, and easy to apply in clinical practice. Study III: Our results suggest that delays in diagnosis and treatment may have negative impact on functional outcome. Pretreatment ability to walk, hormone status of prostate cancer, and time from loss of ambulation influenced neurological recovery after surgery for spinal cord compression. Study IV: High nuclear AR immunostaining in bone metastases and high preoperative serum PSA were associated with a poor outcome after metastasis surgery in patients with hormone-refractory prostate cancer. Short-term effect of castration therapy disclosed that nuclear AR immunostaining was decreased and apoptosis was increased, but cell proliferation remained largely unaffected. Conclusion:  Prostate cancer patients with metastatic spinal cord compression represent a heterogeneous group. We identified prognostic factors for survival and functional outcome, which may help clinicians in making decisions about treatment. Our results also implicate the need for development of local and regional guidelines for treatment of patients with spinal cord compression, as well as the importance of information to patients at risk.
545

Insights into the effect of myocardial revascularisation on electrical and mechanical cardiac function

Ramzy Guirguis, Ihab January 2012 (has links)
Background: Acute coronary syndrome is known for its effect on cardiac function and can lead to impaired segmental and even global myocardial function. Evidence exists that myocardial revascularisation whether pharmacological, interventional or surgical results in improvement of systolic and diastolic left ventricular (LV) function, particularly that of the long axis which represents the sub-endocardial function, known as the most sensitive layer to ischaemia. Objective: We sought to gain more insight into the early effect of pharmacological and interventional myocardial revascularisation on various aspects of cardiac function including endocrine, electrical, segmental, twist, right ventricular (RV) and left atrial (LA) function. In particular, we aimed to assess the response of ventricular electromechanical function to thrombolysis and its relationship with peptides levels. We also investigated the behaviour of RV function in the setting of LV inferior myocardial infarction (IMI) during the acute insult and early recovery. In addition, we aimed to assess in detail LA electrical and mechanical function in such patients. Finally, we studied the early effect of surgical revascularisation on the LV mechanics using the recent novel of speckle tracking echocardiography technology to assess rotation, twist and torsion and the strain deformation parameters as a tool of identifying global ventricular function. Methods: We used conventionally Doppler echocardiographic transthoracic techniques including M-mode, 2-Dimentional, myocardial tissue Doppler, and speckle tracking techniques. Commercially available SPSS as a software was used for statistical analysis. Results: 1-The elevated peptide levels at 7 days post-myocardial infarction correlated with the reduced mechanical activity of the adjacent non-infarcted segment thus making natriuretic peptides related to failure of compensatory hyperdynamic activity of the non-infarcted area rather than the injured myocardial segments. 2-RV segmental and global functions were impaired in acute IMI, and recovered in 87% of patients following thrombolysis. In the absence of clear evidence for RV infarction the disturbances in the remaining 13% may represent stunned myocardium with its known delayed recovery. 3-LA electromechanical function was impaired in acute inferior STEMI and improved after thrombolysis. The partial functional recovery suggests either reversible ischaemic pathology or a response to a non-compliant LV segment. The residual LA electromechanical and pump dysfunction suggest intrinsic pathology, likely to be ischaemic in origin. 4-LV function was maintained in a group of patients with multivessel coronary artery disease who underwent coronary artery bypass graft (CABG) surgery. Surgical myocardial revascularisation did not result in any early detectable change in the three functional components of the myocardium, including twist and torsion, as opposite to conventional percutaneous coronary intervention (PCI). Conclusion: The studied different materials in this thesis provide significant knowledge on various aspects of acute ischaemic cardiac pathology and early effect of revascularisation. The use of non-invasive imaging, particularly echocardiography with its different modalities, in studying such patients should offer immediate thorough bed-side assessment and assist in offering optimum management.
546

Popliteal Artery Aneurysm : Epidemiology, Surgical Management and Outcome

Ravn, Hans January 2007 (has links)
Even if popliteal artery aneurysm (PAA) is the most common peripheral aneurysm, no single surgeon or institution has enough patients to study this disease with appropriate scientific methods, and no population-based investigation exists. PAA epidemiology, treatment, management, and outcome were studied in a population-based study of 571 patients (717 legs) primarily operated on for PAAs and 100 episodes of preoperative thrombolysis in Sweden between 1987 and 2002. Patients were identified in the Swedish Vascular Registry and case-records were reviewed. Information on amputation and survival was obtained for all patients, and 190 patients were re-examined with ultrasound, after mean 7.2 years (range 2-18) Median age was 71 years; 5.8% were women. Patients with unilateral PAA had AAA in 28%, increasing to 38% when PAAs were bilateral. Crude survival was 91.4% at one and 70% at five years, significantly lower than among age and sex matched controls. The cumulative incidence for operation of PAA in Sweden was estimated to 8.3/million person year. One-year amputation-rate was 8.8 %, increasing to 11% after follow-up (7.2 years). Independent risk factors for amputation within one year were poor run-off, age, emergency procedure, and prosthetic graft. Run-off was improved by preoperative thrombolysis among 87% of legs, when acute ischemia. After surgical repair with a medial approach the risk of late expansion of the aneurysm was 33%, with a posterior approach 8% , p=0.014. Among 190 re-examined patients, 108 (57%) had at least one additional aneurysm at index-operation, increasing to 131 (68%) at re-examination, the total number of aneurysms increasing by 42% (from 244 to 346). Conclusions: Multiple aneurysms are common among patients operated on for PAA. Preoperative thrombolysis improves run-off and decreases the amputation-rate in PAAs with acute ischemia. Vein grafts do better than prosthetic grafts, especially when a long bypass is needed. Posterior approach, when possible, reduces the risk of late expansion. A complete examination of the aorto-iliac and femoro-popliteal arteries is warranted at the time of surgery. All patients should be kept under life-long surveillance in order to detect and treat newly developed aneurysms timely. Normal arterial segments should be re-examined after three years.
547

Professional caregivers’ experiences of caring for women with breast cancer on a surgical ward

Ödling, Gunvor January 2004 (has links)
The overall aim of the thesis was to describe caregivers’ experiences of caring for women with breast cancer on a surgical ward. The study was based on interviews with narrative parts and tape-recorded clinical supervision sessions. The interviews and clinical supervision sessions were transcribed verbatim, and analysed by content analysis. Nurses (n=10) described life for women with breast cancer as either having freedom or not having freedom, with both physical and existential suffering. Dying occurred either naturally in patients’ own home or unnaturally in hospital. The nurses felt that it is possible to alleviate suffering during dying through providing adequate pain relief but also, through listening, providing information and changing the caring atmosphere (I). Breast cancer as an illness was described from a dark point of view by caregivers (n=37). The descriptions focused on loss of breasts and control, progression of the illness and annihilation. The illness seemed, in the caregivers’ mind, to often end with a painful death. Caregivers who had the opportunity to follow the total care process described a lighter viewpoint (II). According to nurses (=31) the most important needs among women, their relatives and nurses themselves were the needs to talk and receive information. There was a discrepancy between what was described as important needs and the descriptions of how these needs were provided for. Nurses, whose own needs for support were sometimes unsatisfactorily met (III), seemed almost to be unaware of the needs among women and their relatives. In the clinical supervision sessions caregivers reflected on difficult care situations related to women’s, relatives’, and most often caregivers’ feelings (n=38). The care situations were described as evoking feelings of discomfort, powerlessness and reduced self-esteem. These feelings were described by caregivers as arising in connection with caring for especially women with advanced breast cancer in a changing organisation (IV). Caregivers’ descriptions of caring for women with breast cancer show a lot of negative experiences of powerlessness and frustration. They met women and their relatives who suffered in various ways and had considerable need for support. Caregivers often found themselves unable to meet these needs due to organisational obstacles e.g. lack of time and lack of knowledge about other caregivers’ responsibility in the care.
548

Positionsrelaterade nervsymtom efter operation med laparoskopisk teknik och dess betydelse för patientens dagliga liv / Neurological symptoms associated with the patient’s position after laparoscopic surgery and their importance for the patient’s everyday life

Ohlin, Eva January 2008 (has links)
Det har länge varit känt att patientens perioperativa position kan orsaka symtom som förmodas uppstå genom tryck och sträckningar. Positionen vid laparosko-piska operationer anses öka risken för symtom och därför är perioperativ om-vårdnad av betydelse. Syftet var därför att undersöka hur frekvent positions- relaterade symtom förekommer vid laparoskopiska ingrepp och vilken betydelse de har för patienten. Studien genomfördes som en deskriptiv tvärsnittstudie och datainsamlingen gjordes med hjälp av symtomskattning och semistrukturerade intervjuer. Totalt 60 respondenter i åldern 19 till 75 år deltog i studien som pågick under åtta månader. Resultatet visade att en fjärdedel av respondenterna drab-bades av nytillkomna eller förvärrade symtom. Dessa uppmärksammades postoperativt eller några dagar efter operationen och var oberoende av ingrepp, perioperativ tid eller armarnas position. Några av respondenterna upplevde smärta och domningar i nacke, axlar och händer som ledde till inskränkningar i det dagliga livet och krävde hjälp av närstående. Det är viktigt att fortsätta arbetet med att förebygga positionsrelaterade skador, för att förhindra postoperativa symtom, genom att placera patienten så nära ett neutralläge som möjligt och ge denne möjlighet att känna efter hur det känns före nedsövning. / It has long been assumed that a patient’s perioperative position can cause symp-toms which appear from pressure and strains on the body. The position in lapa-roscopic surgery is considered to increase the risk of symptoms, perioperative care is therefore important. The scope of this study was therefore to survey how frequent symptoms associated with the patient’s position occur and why they are important to the patient. The survey was made as a descriptive cross-section study. The data collection was made by way of patients own estimates of their symptoms and by semistructured interviews. 60 respondents aged between 19 and 75 took part in the study. The result showed that a fourth of the respondents experienced new or aggravated symptoms. These were observed postoperatively or a few days after surgery and were independent of operations, perioperative time or position of the arms. Some of the respondents felt pain and numbness in the neck, shoulders and hands which led to restrictions in their daily life and required help from someone close. It is important to continue working with preventing postoperative symptoms, by placing the patient as close to a neutral position as possible and give her the possibility to feel comfortable before the anesthetization.
549

Kinematics and Kinetics of Total Hip Arthroplasty Patients during Gait and Stair Climbing: A Comparison of the Anterior and Lateral Surgical Approaches

Varin, Daniel 27 January 2011 (has links)
New surgical approaches for total hip arthroplasty (THA) are being developed to reduce muscle damage sustained during surgery, in the hope to allow better muscle functioning afterwards. The goal of this study was to compare the muscle sparing anterior (ANT) approach to a traditional lateral (LAT) approach with three-dimensional motion analysis. Kinematics and kinetics were obtained with an infrared camera system and force plates. It was hypothesized that (1) the ANT group would have closer to normal range of motion, moments and powers, compared to the LAT group, and that (2) the ANT group would have higher peak hip abduction moment than the LAT group. Forty patients undergoing unilateral THA for osteoarthritis between the ages of 50 and 75 (20 ANT, 20 LAT) were asked to perform three trials of walking, stair ascent and stair descent. Patients were assessed between six to twelve months postoperatively. Twenty age- and weight-matched control participants (CON) provided normative data. Results indicated that both THA groups had gait anomalies compared to the CON group. Both THA groups had reduced hip abduction moment during walking (CON vs. ANT: p<0.001; CON vs. LAT: p=0.011), and the ANT group had a significantly lower hip abduction moment compared to the LAT group (p=0.008). Similar results were observed during stair descent, where the ANT group had reduced peak hip abduction moment compared to the CON group (p<0.001) and the LAT group (p=0.014). This indicates that the anterior approach did not allow better gait and stair climbing ability after THA. It is therefore thought that other variables, such as preoperative gait adaptations, trauma from the surgery, or postoperative protection mechanisms to avoid loading the prosthetic hip, are factors that might be more important than surgical approach in determining the mechanics of THA patients after surgery.
550

Exploring the Role of 'Slowing Down When You Should' in Operative Surgical Judgment

Moulton, Carol-anne 31 August 2010 (has links)
Context: The study of expertise in medical education has tended to follow the traditions of describing either the analytic processes or the non-analytic resources that experts acquire with experience. We argue that a critical function of expertise is the ability to transition from the automatic mode to the more effortful mode when required – a transition referred to as ‘slowing down when you should’. Objectives: To explore the phenomenon of ‘slowing down when you should’ in operative surgical practice and its role in intra-operative surgical judgment, and to develop conceptual models of the factors involved in the display of this transition in surgical operative practice. Design: In Phase 1A, 28 surgeons were interviewed about their views of surgical judgment in general and their perceptions of the role of this phenomenon in operative judgment. In Phase 1B, a subset of surgeons from Phase 1A was re-interviewed to explore their perceptions of automaticity in operative practice. In Phase 2, observational sessions (and brief interviews) were conducted of surgeons in the operating room to explore the nature of this phenomenon in its natural environment. Results: The surgeons in this study recognized the phenomenon of ‘slowing down’ in their operative practice and acknowledged its link to surgical judgment. Two main initiators were described and observed: proactively planned ‘slowing down’ moments occurring intra-operatively initiated by critical events anticipated pre-operatively and situationally responsive ‘slowing down’ moments initiated by emergent cues intra-operatively. Numerous influences of this transition were uncovered. A control dynamic emerged as surgeon’s negotiated ‘slowing down’ moments through trainees in their supervisory academic practice. Numerous manifestations of this phenomenon were observed in the operating room and considered using a cognitive psychology attention capacity model. Conclusions: This study offers a conceptual framework for understanding the role of ‘slowing down when you should’ in operative surgical practice, providing a vocabulary that will allow more explicit consideration of what contributes to surgical expertise. Consideration of this framework with its consequent ability to make surgical practices more explicit has implications for self-regulation in practice, surgical error, and surgical training.

Page generated in 0.0309 seconds