Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 173-178).

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 89-117).

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No. of bitstreams: 1 andrenoronhaarvellos.pdf: 6808287 bytes, checksum: 93e22153b8dde05493e1fda7161ac573 (MD5) Previous issue date: 2011-08-26 / Introdução: Impulsionada pelo crescimento da endourologia, a busca de novas técnicas para o acesso percutâneo, com intuito de tornar o procedimento ainda menos invasivo e mais seguro, teve como marco os trabalhos de Valdivia Uría, que propôs e descreveu primeiramente a técnica de punção do paciente em decúbito dorsal inclinado, mostrando menor tempo de procedimento e melhora nos parâmetros cardiorrespiratórios durante sua realização em relação à técnica clássica em decúbito ventral, com sucesso terapêutico e morbidade semelhantes. Mesmo após mais de 20 anos da descrição da sua técnica e com a publicação de outras séries de casos por outros autores, a mesma não teve a difusão esperada. Pacientes e métodos: Foi realizada análise de exames de tomografia computadorizada de 71 pacientes através de simulações de nefrostomia percutânea nos decúbitos dorsal e ventral, correlacionando-se os resultados com variáveis antropométricas e quantificação da gordura abdominal no seu padrão de distribuição nos compartimentos visceral e subcutâneo. Resultados: Não houve diferença estatística entre o número de lesões de órgãos abdominais para os diferentes decúbitos nas simulações realizadas no plano axial (p=0,5621). Nas simulações oblíquas, os resultados mostraram significância estatística da diferença do decúbito no risco de lesão, sendo o resultado desfavorável ao decúbito ventral (p=0,0295). O órgão mais freqüentemente sob risco foi o cólon, seguido de longe pelo intestino delgado. A avaliação indireta do risco de lesão através de medidas da distância do cólon ao rim mostrou maior proximidade destes na posição de decúbito ventral, para ambos os lados, de forma estatisticamente significativa. Quanto à metodologia de análise, observou-se maior número de lesões nas simulações realizadas no plano axial do que nas simulações oblíquas tanto no decúbito ventral (p= 0,0274) como no dorsal (p= 0,0002). Nas simulações no plano axial, os pacientes que tiveram órgãos lesados mostraram de forma estatisticamente significativa menores peso, índice de massa corpórea (IMC) e quantidade de gordura visceral independente do decúbito. No plano oblíquo, não foi observada associação estatística com tais variáveis. Conclusão: Houve maior risco de lesão de órgãos abdominais (principalmente o cólon) no decúbito ventral, tanto através das simulações de punção, quanto através da análise indireta de risco através das medidas de proximidade do cólon com o rim. A metodologia com as simulações no plano oblíquo mostrou-se mais adequada, com resultados mais próximos das grandes séries de casos onde o procedimento foi realizado. Em relação aos dados antropométricos e padrão de distribuição da gordura abdominal por tomografia computadorizada (TC), os pacientes que tiveram órgãos lesados apresentaram de forma estatisticamente significativa menores peso, IMC e área de gordura visceral nas simulações no plano axial, para a análise conjunta das metodologias em ambos os decúbitos e para a análise conjunta da ocorrência independente da metodologia ou do decúbito. Na metodologia de análise no plano oblíquo, os baixos valores de p para as variáveis peso (0,07) e IMC (0,06) podem representar uma tendência em relação ao risco de lesão, talvez com significância estatística limitada pelo tamanho da amostra. / Introduction: The search for less invasive and safer techniques of percutaneous access in endourology had, as landmark, the studies undergone by Valdivia Uria, who first proposed and described access through the inclined supine position, with shortened procedure time and better cardiorespiratory parameters, compared with the traditional access in the prone position, and also showing similar success and morbidity rates. Although more than 20 years have elapsed since the first publication of the technique, and despite publications by other authors, the technique has not been so widely embraced as expected. Patients and methods: 71 patients underwent simulated percutaneous nephrostomy through computed tomography (CT), in both the supine and prone positions. The results were correlated with anthropometric variables and quantification of abdominal fat distribution in the visceral and subcutaneous compartments. Results: There was no statistical difference between the number of abdominal organ injuries in the two different positions in the axial plane (p=0.5621). In oblique simulations, the difference in the risk of injury to abdominal organs was statistically significant between the two positions, with more injuries happening in the prone position (p=0.0295). The colon was the most frequently injured organ, followed by the small intestine in a distant second. Indirect injury risk assessment by measurement of the colon-kidney distance showed statistically significant greater proximity of these organs in the the prone position, on both sides. Concerning the analysis methodology, there were a greater number of injuries in the axial plane than in the oblique simulations, both in the prone position (p=0.0274) and in the supine position (p=0.0002). In the axial plane simulations, patients who suffered organ injuries had statistically significant lower weight, Body Mass Index (BMI) and visceral fat amount, regardless of the position. In the oblique plane, no such statistical association was found. Conclusion: There was greater risk of injury to abdominal organs (mainly the colon) in the prone position, both in puncture simulations and in indirect risk assessment of risk through the measurement of the colon-kidney distance. Simulation in the oblique plane was the most adequate method, as it provided results that were closer to the ones from large case series in which the procedure was performed. Concerning the anthropometric factors and the pattern of CT-assessed abdominal fat distribution, patients who suffered organ injuries had statistically significant lower weight, BMI and visceral fat amount, in the axial plane, for analysis of the two methods in both positions and for analysis of the injuries regardless of method and position. In the oblique plane analysis methodology the low p values for weight (0.07) and BMI (0.06) may represent a tendency towards the injury risk, maybe with a limited statistical significance owing to the sample size.

Yes / Aim: Pelvic radiography is used for the identification of hip joint changes, including pathologies such as osteoarthritis. Several studies have recommended that the position for this radiological procedure should be standing, not supine, to reflect the functional appearances of the hip joint. The aim of this review was to evaluate pelvis radiography positioning with respect to the image appearances and information provided for clinical decision-making. Aside from this, potential recommendations to the radiographic technique for an erect pelvis projection will be considered. Method: A literature search was performed using databases/abstract systems (ScienceDirect, Web of Science, PubMed, and MEDLINE). Only articles written in English were included. Results: Twenty-five articles were identified. Findings from the review describe the effect of repositioning from supine to erect on a series of specific hip measurements. These include pelvic tilt, joint space width, and the acetabular component. Conclusion: Evidence within the literature illustrates that in several studies, there were differences when repositioning from supine to standing for a number of pelvic metrics. Standing positioning is promoted by some authors since this may facilitate the early diagnosis of hip joint pathology and assist in the planning of surgical interventions. Literature is very limited on how to optimally perform erect pelvis radiography, and this should be an area for future research.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / IntroduÃÃo: A ventilaÃÃo nÃo invasiva com pressÃo positiva (VNI) vem tendo uma crescente utilidade na prÃtica clÃnica e o seu uso està bem estabelecido em casos de edema agudo de pulmÃo e nas exacerbaÃÃes da doenÃa pulmonar obstrutiva crÃnica (DPOC), diminuindo a necessidade de intubaÃÃo orotraqueal e melhorando a sobrevida. AlÃm disso, a pressÃo positiva contÃnua em vias aÃreas (CPAP) â modo de VNI â constitui o tratamento de escolha para pacientes portadores da sÃndrome de apnÃia obstrutiva do sono (SAOS), onde geralmente nÃo hà alteraÃÃo no parÃnquima pulmonar. Ainda a aplicaÃÃo de nÃveis elevados de pressÃo positiva expiratÃria final (PEEP) no manejo da sÃndrome do desconforto respiratÃrio agudo (SDRA) està associada tanto ao recrutamento alveolar como à hiperdistensÃo de Ãreas previamente normoaeradas, com resultados ainda indefinidos quanto ao impacto na sobrevida. Um dos recursos para melhora da oxigenaÃÃo nestes pacientes à a posiÃÃo prona e os efeitos da associaÃÃo desta manobra com pressÃo positiva permanecem controversos. A tomografia computadorizada de alta resoluÃÃo (TCAR) constitui um excelente mÃtodo de imagem para avaliaÃÃo qualitativa e quantitativa do parÃnquima pulmonar. O emprego da TCAR pode auxiliar na investigaÃÃo dos efeitos da CPAP de modo nÃo invasivo sobre o parÃnquima pulmonar, contribuindo para a elucidaÃÃo dos efeitos fisiolÃgicos da pressÃo positiva e da posiÃÃo prona. Objetivos: Avaliar e comparar os efeitos de diferentes nÃveis de CPAP de modo nÃo invasivo sobre o parÃnquima pulmonar em indivÃduos sadios nas posiÃÃes supina e prona. CasuÃstica e mÃtodos: Estudo intervencionista com oito voluntÃrios sadios, sem doenÃa cardiopulmonar. Foram realizados cortes tomogrÃficos de alta resoluÃÃo em trÃs regiÃes: Ãpice (2 cm acima do arco aÃrtico), hilo (1 cm abaixo da carina) e base (2 cm acima do diafragma) na posiÃÃo supina, sem CPAP (basal) e com CPAP de 5, 10 e 15 cmH2O; e na posiÃÃo prona, corte em base, sem CPAP e com CPAP de 10 cmH2O. A seqÃÃncia das posiÃÃes e da ordem das pressÃes aplicadas foi randomizada. Aguardava-se um perÃodo de no mÃnimo 5 minutos apÃs completa adaptaÃÃo da mÃscara para realizaÃÃo do exame e o mesmo perÃodo de tempo entre um nÃvel de pressÃo e outro. Os dados foram analisados agrupando-se os cortes tomogrÃficos das trÃs regiÃes e por subdivisÃes em regiÃes ventral, medial e dorsal, sendo calculadas as mÃdias das densidades pulmonares e o percentual do nÃmero de unidades com densidade menor que -950 UH (hiperaeradas) para cada uma das regiÃes. Resultados: NÃo houve diferenÃa das mÃdias das densidades pulmonares entre Ãpice, hilo e base para o mesmo nÃvel de pressÃo. Na posiÃÃo supina, houve reduÃÃo da densidade pulmonar e aumento do percentual de pixels nas Ãreas hiperaeradas com nÃveis crescentes de pressÃo: basal -761 UH e 7,25%; CPAP 5: -780 UH e 8,57%; CPAP 10: -810 UH e 11,62%; CPAP 15: -828 UH e 14,65% (p < 0,05). O mesmo foi observado na posiÃÃo prona: basal -759 UH e 6,30%; CPAP 10: -803 UH e 9,94% (p < 0,05). Este aumento da aeraÃÃo tambÃm foi observado nas regiÃes ventral, medial e dorsal. Foi encontrado um gradiente crescente no sentido ventro-dorsal de densidades pulmonares na posiÃÃo supina e o inverso na posiÃÃo prona. A CPAP de 10 cmH2O, na posiÃÃo prona, ocasionou menor aumento do percentual de pixels nas Ãreas hiperaeradas em relaÃÃo à supina. Nas regiÃes nÃo dependentes do pulmÃo (ventral em supina e dorsal em prona), observou-se um menor percentual de pixels nas Ãreas hiperaeradas e aumento nas normoaeradas na posiÃÃo prona em relaÃÃo à supina, praticamente sem diferenÃa nas regiÃes dependentes. ConclusÃes: A aplicaÃÃo de diferentes nÃveis de CPAP, de modo nÃo invasivo, em voluntÃrios sadios, resultou em maior aeraÃÃo com nÃveis crescentes de pressÃo e maior homogeneizaÃÃo da aeraÃÃo pulmonar, tanto na posiÃÃo supina como na prona. Houve menor hiperaeraÃÃo nas regiÃes nÃo dependentes na posiÃÃo prona, em relaÃÃo à supina, sem CPAP e com CPAP de 10 cmH2O, com melhor distribuiÃÃo da aeraÃÃo pulmonar naquela posiÃÃo. / Introduction: Noninvasive positive-pressure ventilation (NIPPV) is an effective means of treating patients with acute respiratory failure and its use has been well established in cardiogenic pulmonary edema and in exacerbations of chronic obstructive pulmonary disease (COPD), reducing the need for endotracheal intubation and improving survival. Furthermore the continuous positive airway pressure (CPAP) â a mode of NIPPV â is the recommended treatment for obstructive sleep apnea syndrome (OSAS), where frequently there is no abnormality in pulmonary parenchyma. Also in the acute respiratory distress syndrome (ARDS), the application of positive end-expiratory pressure (PEEP) may result in alveolar recruitment of nonaerated units as well as in overinflation of the aerated lung areas. Alveolar overinflation is considered an important factor related to ventilator-induced lung injury causing higher mortality. The prone position has beneficial effects on oxygenation in these patients and the additive effect of PEEP with this maneuver is debatable. High resolution computed tomography (HRCT) is an excellent imaging method to evaluate the effects of positive pressure and prone position on pulmonary parenchyma. Objectives: To evaluate the effects of CPAP applied by a nasal mask on pulmonary inflation in normal subjects in supine and prone positions. Patients and methods: This is an interventionist study that evaluated eight healthy volunteers. A protocol of HRCT of the lung was performed in three regions: at the apex (2 cm above the aortic level), hilum (1 cm below the carina) and basis (2 cm above the right diaphragm) in the supine position, without and with CPAP of 5, 10 and 15 cmH2O. Also HRCT slices were performed in the prone position at the lung basis, without and with CPAP of 10 cmH2O. All HRCT slices were obtained at the functional residual capacity. Each CPAP level was maintened at least five minutes and the period between the different levels of CPAP was similar. For analysis the results were divided into regions ventral, medial and dorsal and with slices of apex, hilum and basis together. The mean lung densities (MLD) and the percentual of units with densities lower than -950 UH (overinflated) were calculated for each region. Results: There was no difference between the MLD of apex, hilum and basis for the same level pressure. In the supine position, there were a MLD reduction and an increase of the number of pixels on hyperinflated areas according to CPAP levels: without CPAP -761 HU e 7,25%; CPAP 5: -780 HU e 8,57%; CPAP 10: -810 HU e 11,62%; CPAP 15: -828 UH e 14,65% (p< 0,05). The same occurred in the prone position without CPAP: -759 UH e 6,30% and with CPAP 10: -803 UH e 9,94% (p < 0,05). It was observed a crescent ventro-dorsal density gradient in supine position that was inverse in prone position. At CPAP of 10 cmH2O there was lower percentage of pixels on hyperinflated areas in the prone position than in supine. In the non dependent lung regions (ventral in supine and dorsal in prone) there were lower percentage of pixels on hyperinflated areas and higher on normoaerated areas in the prone position than in supine with little differences in the dependent regions. Conclusions: Non invasive CPAP in normal subjects induces progressive overdistension with increase of pressure levels in supine and prone positions. CPAP of 10 cmH2O causes less overdistension of the non dependent regions than the same level of CPAP in supine position, without inducing significant overinflation of the dependent regions. So that the prone position causes a more homogeneous air distribution through the lungs.

BACKGROUND: Magnetic resonance imaging and echo color Doppler (ECD) scan techniques do not accurately assess the cerebral venous return. This generated considerable scientific controversy linked with the diagnosis of a vascular syndrome known as chronic cerebrospinal venous insufficiency (CCSVI) characterized by restricted venous outflow from the brain. The purpose of this study was to assess the cerebral venous return in relation to the change in position by means of a novel cervical plethysmography method. METHODS: This was a single-center, cross-sectional, blinded case-control study conducted at the Vascular Diseases Center, University of Ferrara, Italy. The study involved 40 healthy controls (HCs; 18 women and 22 men) with a mean age of 41.5 +/- 14.4 years, and 44 patients with multiple sclerosis (MS; 25 women and 19 men) with a mean age of 41.0 +/- 12.1 years. All participants were previously scanned using ECD sonography, and further subset in HC (CCSVI negative at ECD) and CCSVI groups. Subjects blindly underwent cervical plethysmography, tipping them from the upright (90 degrees ) to supine position (0 degrees ) in a chair. Once the blood volume stabilized, they were returned to the upright position, allowing blood to drain from the neck. We measured venous volume (VV), filling time (FT), filling gradient (FG) required to achieve 90% of VV, residual volume (RV), emptying time (ET), and emptying gradient (EG) required to achieve 90% of emptying volume (EV) where EV = VV - RV, also analyzing the considered parameters by receiver operating characteristic (ROC) curves and principal component mathematical analysis. RESULTS: The rate at which venous blood discharged in the vertical position (EG) was significantly faster in the controls (2.73 mL/second +/- 1.63) compared with the patients with CCSVI (1.73 mL/second +/- 0.94; P = .001). In addition, respectively, in controls and in patients with CCSVI, the following parameters were highly significantly different: FT 5.81 +/- 1.99 seconds vs 4.45 +/- 2.16 seconds (P = .003); FG 0.92 +/- 0.45 mL/second vs 1.50 +/- 0.85 mL/second (P < .001); RV 0.54 +/- 1.31 mL vs 1.37 +/- 1.34 mL (P = .005); ET 1.84 +/- 0.54 seconds vs 2.66 +/- 0.95 seconds (P < .001). Mathematical analysis demonstrated a higher variability of the dynamic process of cerebral venous return in CCSVI. Finally, ROC analysis demonstrated a good sensitivity of the proposed test with a percent concordant 83.8, discordant 16.0, tied 0.2 (C = 0.839). CONCLUSIONS: Cerebral venous return characteristics of the patients with CCSVI were markedly different from those of the controls. In addition, our results suggest that cervical plethysmography has great potential as an inexpensive screening device and as a postoperative monitoring tool.