930 resultados para Electrical Impedance Tomography, Rats, Ventilation, Ventilation Distribution, Intensive Care


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Nel corso del tempo, nell’ambito dell’idrogeologia sono state sviluppate diverse tecniche per la determinazione conducibilità idraulica (K). Negli ultimi decenni sempre maggiori sforzi sono stati compiuti per integrare le tecniche geofisiche a questo specifico settore di ricerca; in particolare le metodologie geoelettriche sono state fonte di molteplici studi per la determinazione indiretta di K. Su questa idea è stato impostato il lavoro presentato in questo elaborato di tesi. Ciò che questo propone è infatti l’esecuzione di test in campo che prevedono il monitoraggio time lapse con tecnologia ERT (Electrical Resistivity Tomography) di un tracciante salino iniettato nel terreno. Il fine ultimo è quello di poter sviluppare una tecnica indiretta per la stima della conducibilità idraulica verticale dei terreni sciolti. Le immagini tomografiche, realizzate in sequenza nel tempo, premettono la visualizzazione l’avanzamento del plume basso resistivo in movimento nel terreno (causato dalla salamoia iniettata). Un successivo confronto grafico fra queste permette di quantificare lo spostamento nel tempo, in modo da calcolare in seguito la velocità di infiltrazione del tracciante, e in ultimo stimare la K del terreno in analisi. I risultati ottenuti con tale metodologia sperimentale, opportunamente elaborati tramite specifici software, sono stati confrontati, dove possibile, con i valori forniti dall’impiego di altre tecniche più tradizionali, in modo da poter valutare la bontà del dato ottenuto. Le aree studio individuate per condurre tali sperimentazioni ricadono all’interno del territorio regionale del Friuli Venezia Giulia, in particolare nell’area di Alta e Bassa pianura friulana. La strumentazione (resistivimetro multicanale VHR X612-EM della MAE-Molisana Apparecchiature Elettroniche) e il software (Res2dinv) per la raccolta e l’elaborazione delle immagini tomografiche sono stati gentilmente messi a disposizione dalla società Geomok s.r.l. del Dott. Geol. Mocchiutti (Udine) con la cui collaborazione è stato realizzato questo elaborato di tesi.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Diaphragmatic electrical activity (EA(di)), reflecting respiratory drive, and its feedback control might be impaired in critical illness-associated polyneuromyopathy (CIPM). We aimed to evaluate whether titration and prolonged application of neurally adjusted ventilatory assist (NAVA), which delivers pressure (P (aw)) in proportion to EA(di), is feasible in CIPM patients.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

To identify reasons for ordering computed tomography pulmonary angiography (CTPA), to identify the frequency of reasons for CTPA reflecting defensive behavior and evidence-based behavior, and to identify the impact of defensive medicine and of training about diagnosing pulmonary embolism (PE) on positive results of CTPA.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: The medical specialties chosen by doctors for their careers play an important part in the development of health-care services. This study aimed to investigate the influence of gender, personality traits, career motivation and life goal aspirations on the choice of medical specialty. METHODS: As part of a prospective cohort study of Swiss medical school graduates on career development, 522 fourth-year residents were asked in what specialty they wanted to qualify. They also assessed their career motivation and life goal aspirations. Data concerning personality traits such as sense of coherence, self-esteem, and gender role orientation were collected at the first assessment, four years earlier, in their final year of medical school. Data analyses were conducted by univariate and multivariate analyses of variance and covariance. RESULTS: In their fourth year of residency 439 (84.1%) participants had made their specialty choice. Of these, 45 (8.6%) subjects aspired to primary care, 126 (24.1%) to internal medicine, 68 (13.0%) to surgical specialties, 31 (5.9%) to gynaecology & obstetrics (G&O), 40 (7.7%) to anaesthesiology/intensive care, 44 (8.4%) to paediatrics, 25 (4.8%) to psychiatry and 60 (11.5%) to other specialties. Female residents tended to choose G&O, paediatrics, and anaesthesiology, males more often surgical specialties; the other specialties did not show gender-relevant differences of frequency distribution. Gender had the strongest significant influence on specialty choice, followed by career motivation, personality traits, and life goals. Multivariate analyses of covariance indicated that career motivation and life goals mediated the influence of personality on career choice. Personality traits were no longer significant after controlling for career motivation and life goals as covariates. The effect of gender remained significant after controlling for personality traits, career motivation and life goals. CONCLUSION: Gender had the greatest impact on specialty and career choice, but there were also two other relevant influencing factors, namely career motivation and life goals. Senior physicians mentoring junior physicians should pay special attention to these aspects. Motivational guidance throughout medical training should not only focus on the professional career but also consider the personal life goals of those being mentored.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND AND OBJECTIVE: To investigate whether preemptive administered lornoxicam changes perioperative platelet function during thoracic surgery. METHODS: A total of 20 patients scheduled for elective thoracic surgery were randomly assigned to receive either lornoxicam (16 mg, i.v.; n = 10) or placebo (n = 10) preoperatively. All patients underwent treatment of solitary lung metastasis and denied any antiplatelet medication within the past 2 weeks. Blood samples were drawn via an arterial catheter directly into silicone-coated Vacutainer tubes containing 0.5 mL of 0.129 M buffered sodium citrate 3.8% before, 15 min, 4 h and 8 h after the study medication was administered. Platelet aggregation curves were obtained by whole blood electrical impedance aggregometry (Chrono Log). RESULTS: Platelet aggregation was significantly reduced 15 min, 4 h and 8 h after lornoxicam administration compared to placebo (P < 0.05) for collagen, adenosine diphosphate and arachidonic acid as trigger substances. Adenosine diphosphate-induced platelet aggregation decreased by 85% 15 min after lornoxicam administration, and remained impaired for 8 h. CONCLUSION: Platelet aggregation assays are impaired for at least 8 h after lornoxicam application. Therefore perioperative analgesia by use of lornoxicam should be carefully administered under consideration of subsequent platelet dysfunction.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The authors describe the design, fabrication, and testing of a passive wireless sensor platform utilizing low-cost commercial surface acoustic wave filters and sensors. Polyimide and polyethylene terephthalate sheets are used as substrates to create a flexible sensor tag that can be applied to curved surfaces. A microfabricated antenna is integrated on the substrate in order to create a compact form factor. The sensor tags are fabricated using 315 MHz surface acoustic wave filters and photodiodes and tested with the aid of a fiber-coupled tungsten lamp. Microwave energy transmitted from a network analyzer is used to interrogate the sensor tag. Due to an electrical impedance mismatch at the SAW filter and sensor, energy is reflected at the sensor load and reradiated from the integrated antenna. By selecting sensors that change electrical impedance based on environmental conditions, the sensor state can be inferred through measurement of the reflected energy profile. Testing has shown that a calibrated system utilizing this type of sensor tag can detect distinct light levels wireless and passively. The authors also demonstrate simultaneous operation of two tags with different center passbands that detects light. Ranging tests show that the sensor tags can operate at a distance of at least 3.6 m.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hyperglycaemia is common in acute illness and more severe hyperglycaemia is associated with worse outcomes in critically ill patients in general and after acute myocardial infarction, stroke, and trauma. Normalization of blood glucose by intensive insulin therapy has been shown to reduce morbidity and mortality in one study in surgical intensive care patients; a subsequent study in medical intensive care patients resulted in reduced morbidity but not a reduction in mortality. Multicentre studies and current meta-analyses in the critically ill have not demonstrated improved outcomes when normalization of blood glucose was targeted; furthermore all studies to date have detected an increased risk of hypoglycaemia in patients subjected to intensive insulin therapy. At present, universal treatment guidelines or recommendations to target strict normoglycaemia must be considered premature. Further data will be available after the completion of the NICE-SUGAR study which has recruited 6103 patients; the NICE SUGAR study will add significant power to future meta-analyses and may help define the role of intensive insulin therapy in critically ill patients.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND Fever and neutropenia (FN) often complicate anticancer treatment and can be caused by potentially fatal infections. Knowledge of pathogen distribution is paramount for optimal patient management. METHODS Microbiologically defined infections (MDI) in pediatric cancer patients presenting with FN by nonmyeloablative chemotherapy enrolled in a prospective multi-center study were analyzed. Effectiveness of empiric antibiotic therapy in FN episodes with bacteremia was assessed taking into consideration recently published treatment guidelines for pediatric patients with FN. RESULTS MDI were identified in a minority (22%) of pediatric cancer patients with FN. In patients with, compared to without MDI, fever (median, 5 [IQR 3-8] vs. 2 [IQR1-3] days, p < 0.001) and hospitalization (10 [6-14] vs. 5 [3-8] days, p < 0.001) lasted longer, transfer to the intensive care unit was more likely (13 of 95 [14%] vs. 7 of 346 [2.0%], p < 0.001), and antibiotics were given longer (10 [7-14] vs. 5 [4-7], p < 0.001). Empiric antibiotic therapy in FN episodes with bacteremia was highly effective if not only intrinsic and reported antimicrobial susceptibilities were considered but the purposeful omission of coverage for coagulase negative staphylococci and enterococci was also taken into account (81% [95%CI 68 - 90] vs. 96.6% [95%CI 87 - 99.4], p = 0.004) CONCLUSIONS: MDI were identified in a minority of FN episodes but they significantly affected management and the clinical course of pediatric cancer patients. Compliance with published guidelines was associated with effectiveness of empiric antibiotic therapy in FN episodes with bacteremia.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: High grade serous carcinoma whether ovarian, tubal or primary peritoneal, continues to be the most lethal gynecologic malignancy in the USA. Although combination chemotherapy and aggressive surgical resection has improved survival in the past decade the majority of patients still succumb to chemo-resistant disease recurrence. It has recently been reported that amplification of 5q31-5q35.3 is associated with poor prognosis in patients with high grade serous ovarian carcinoma. Although the amplicon contains over 50 genes, it is notable for the presence of several members of the fibroblast growth factor signaling axis. In particular acidic fibroblast growth factor (FGF1) has been demonstrated to be one of the driving genes in mediating the observed prognostic effect of the amplicon in ovarian cancer patients. This study seeks to further validate the prognostic value of fibroblast growth receptor 4 (FGFR4), another candidate gene of the FGF/FGFR axis located in the same amplicon. The emphasis will be delineating the role the FGF1/FGFR4 signaling axis plays in high grade serous ovarian carcinoma; and test the feasibility of targeting the FGF1/FGFR4 axis therapeutically. Materials and Methods: Spearman and Pearson correlation studies on data generated from array CGH and transcriptome profiling analyses on 51 microdissected tumor samples were used to identify genes located on chromosome 5q31-35.3 that showed significant correlation between DNA and mRNA copy numbers. Significant correlation between FGF1 and FGFR4 DNA copy numbers was further validated by qPCR analysis on DNA isolated from 51 microdissected tumor samples. Immunolocalization and quantification of FGFR4 expression were performed on paraffin embedded tissue samples from 183 cases of high-grade serous ovarian carcinoma. The expression was then correlated with clinical data to assess impact on survival. The expression of FGF1 and FGFR4 in vitro was quantified by real-time PCR and western blotting in six high-grade serous ovarian carcinoma cell lines and compared to those in human ovarian surface epithelial cells to identify overexpression. The effect of FGF1 on these cell lines after serum starvation was quantified for in vitro cellular proliferation, migration/invasion, chemoresistance and survival utilizing a combination of commercially available colorimetric, fluorometric and electrical impedance assays. FGFR4 expression was then transiently silenced via siRNA transfection and the effects on response to FGF1, cellular proliferation, and migration were quantified. To identify relevant cellular pathways involved, responsive cell lines were transduced with different transcription response elements using the Cignal-Lenti reporter system and treated with FGF1 with and without transient FGFR4 knock down. This was followed by western blot confirmation for the relevant phosphoproteins. Anti-FGF1 antibodies and FGFR trap proteins were used to attempt inhibition of FGF mediated phenotypic changes and relevant signaling in vitro. Orthotopic intraperitoneal tumors were established in nude mice using serous cell lines that have been previously transfected with luciferase expressing constructs. The mice were then treated with FGFR trap protein. Tumor progression was then followed via bioluminescent imaging. The FGFR4 gene from 52 clinical samples was sequenced to screen for mutations. Results: FGFR4 DNA and mRNA copy numbers were significantly correlated and FGFR4 DNA copy number was significantly correlated with that of FGF1. Survival of patients with high FGFR4 expressing tumors was significantly shorter that those with low expression(median survival 28 vs 55 month p< 0.001) In a multivariate cox regression model FGFR expression significantly increased risk of death (HR 2.1, p<0.001). FGFR4 expression was significantly higher in all cell lines tested compared to HOSE, OVCA432 cell line in particular had very high expression suggesting amplification. FGF1 was also particularly overexpressed in OVCA432. FGF1 significantly increased cell survival after serum deprivation in all cell lines. Transient knock down of FGFR4 caused significant reduction in cell migration and proliferation in vitro and significantly decreased the proliferative effects of FGF1 in vitro. FGFR1, FGFR4 traps and anti-FGF1 antibodies did not show activity in vitro. OVCA432 transfected with the cignal lenti reporter system revealed significant activation of MAPK, NFkB and WNT pathways, western blotting confirmed the results. Reverse phase protein array (RPPA) analysis also showed activation of MAPK, AKT, WNT pathways and down regulation of E Cadherin. FGFR trap protein significantly reduced tumor growth in vivo in an orthotopic mouse model. Conclusions: Overexpression and amplification of several members of the FGF signaling axis present on the amplicon 5q31-35.3 is a negative prognostic indicator in high grade serous ovarian carcinoma and may drive poor survival associated with that amplicon. Activation of The FGF signaling pathway leads to downstream activation of MAPK, AKT, WNT and NFkB pathways leading to a more aggressive cancer phenotype with increased tumor growth, evasion of apoptosis and increased migration and invasion. Inhibition of FGF pathway in vivo via FGFR trap protein leads to significantly decreased tumor growth in an orthotopic mouse model.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Within the past 15 years, significant advances in the imaging of multiorgan and complex trauma primarily due to the improvement of cross-sectional imaging have resulted in the optimization of the expedient diagnosis and management of the polytrauma patient. At the forefront, multidetector computed tomography (MDCT) has become the cornerstone of modern emergency departments and trauma centers. In many institutions, MDCT is the de facto diagnostic tool upon trauma activation. In the setting of pelvic imaging, MDCT (with its high spatial resolution and sensitivity as well as short acquisition times) allows for rapid identification and assessment of pelvic hemorrhage leading to faster triage and definitive management. In trauma centers throughout the world, angiography and minimally invasive catheter-based embolization techniques performed by interventional radiologists have become the standard of care for patients with acute pelvic trauma and related multiorgan hemorrhage. In an interdisciplinary setting, embolization may be performed either alone or as an adjunct procedure with open or closed reduction and stabilization techniques. A team-based approach involving multiple disciplines (e.g., radiology, traumatology, orthopedic surgery, intensive care medicine) is crucial to monitor and treat the actively bleeding patient appropriately.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OBJECTIVES/HYPOTHESIS Study of the clinical evolution of a primary ear, nose, and throat infection complicated by septic thrombophlebitis of the internal jugular vein. STUDY DESIGN Retrospective case-control study. PATIENTS AND METHODS From 1998 to 2010, 23 patients at our institution were diagnosed with a septic thrombosis of the internal jugular vein. Diagnostics included microbiologic analysis and imaging such as computed tomography, magnetic resonance imaging, and ultrasound. Therapy included broad-spectrum antibiotics, surgery of the primary infectious lesion, and postoperative anticoagulation. The patients were retrospectively analyzed. RESULTS The primary infection sites were found in the middle ear (11), oropharynx (8), sinus (3), and oral cavity (1). Fourteen patients needed intensive care unit treatment for a mean duration of 6 days. Seven patients were intubated, and two developed severe acute respiratory distress syndrome. An oropharynx primary infection site was most prone to a prolonged clinical evolution. Anticoagulation therapy was given in 90% of patients. All 23 patients survived the disseminated infection without consecutive systemic morbidity. CONCLUSION In the pre-antibiotic time, septic internal jugular vein thrombophlebitis was a highly fatal condition with a mortality rate of 90%. Modern imaging techniques allow early and often incidental diagnosis of this clinically hidden complication. Anticoagulation, intensive antibiotic therapy assisted by surgery of the primary infection site, and intensive supportive care can reach remission rates of 100%. LEVEL OF EVIDENCE 3b. Laryngoscope, 2014.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OPINION STATEMENT Children who present with acute neurological symptoms suggestive of a stroke need immediate clinical assessment and urgent neuroimaging to confirm diagnosis. Magnetic resonance imaging (MRI) is the investigation of first choice due to limited sensitivity of computed tomography (CT) for detection of ischaemia. Acute monitoring should include monitoring of blood pressure and body temperature, and neurological observations. Surveillance in a paediatric high dependency or intensive care unit and neurosurgical consultation are mandatory in children with large infarcts at risk of developing malignant oedema or haemorrhagic transformation. Thrombolysis and/or endovascular treatment, whilst not currently approved for use in children, may be considered when stroke diagnosis is confirmed within 4.5 to 6 h, provided there are no contraindications on standard adult criteria. Standard treatment consists of aspirin, but anticoagulation therapy is frequently prescribed in stroke due to cardiac disease and extracranial dissection. Steroids and immunosuppression have a definite place in children with proven vasculitis, but their role in focal arteriopathies is less clear. Decompressive craniotomy should be considered in children with deteriorating consciousness or signs of raised intracranial pressure.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The rheoencephalogram (REG) is the change in the electrical impedance of the head that occurs with each heart beat. Without knowledge of the relationship between cerebral blood flow (Q) and the REG, the utility of the REG in the study of the cerebral vasculature is greatly limited. The hypothesis is that the relationship between the REG and Q when venous outflow is nonpulsatile is^ (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)^ where K is a proportionality constant and Q is the mean Q.^ Pulsatile CBF was measured in the goat via a chronically implanted electromagnetic flowmeter. Electrodes were implanted in the ipsilateral cerebral hemisphere, and the REG was measured with a two electrode impedance plethysmograph. Measurements were made with the animal's head elevated so that venous flow pulsations were not transmitted from the heart to the cerebral veins. Measurements were made under conditions of varied cerebrovascular resistance induced by altering blood CO(,2) levels and under conditions of high and low cerebrospinal fluid pressures. There was a high correlation (r = .922-.983) between the REG calculated from the hypothesized relationship and the measured REG under all conditions.^ Other investigators have proposed that the REG results from linear changes in blood resistivity proportional to blood velocity. There was little to no correlation between the measured REG and the flow velocity ( r = .022-.306). A linear combination of the flow velocity and the hypothesized relationship between the REG and Q did not predict the measured REG significantly better than the hypothesized relationship alone in 37 out of 50 experiments.^ Jacquy proposed an index (F) of cerebral blood flow calculated from amplitudes and latencies of the REG. The F index was highly correlated (r = .929) with measured cerebral blood flow under control and hypercapnic conditions, but was not as highly correlated under conditions of hypocapnia (r = .723) and arterial hypotension (r = .681).^ The results demonstrate that the REG is not determined by mean cerebral blood flow, but by the pulsatile flow only. Thus, the utility of the REG in the determination of mean cerebral blood flow is limited. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objetivo: Analizar la mortalidad en la Unidad de Cuidados Intensivos (UCI) del Hospital Central de Mendoza y evaluar el valor predictivo de la escala APACHE II (Evaluación Fisiológica Aguda y de Salud Crónica). Material y Método: Se realizó un estudio retrospectivo y observacional de los pacientes ingresados a la Unidad de Cuidados Intensivos del Hospital Central de Mendoza, desde el 01/11/06 hasta el 31/03/08. Se calculó la distribución de sexos y de edades de la muestra, la estadía promedio, principales motivos de ingreso a la UCI y la puntuación APACHE II en las primeras 24 horas de internación. Se calculó la mortalidad esperada y la mortalidad obtenida global y se analizó el coeficiente entre ambas mortalidades. Resultados: Se incluyeron 904 pacientes, 61,82% masculinos y 38,18% femeninos, con una edad media 46 años (±19,36). Estadía promedio en la UCI 8,5 días promedio. El principal motivo de internación fueron los Traumatismos Encéfalocraneanos (TEC) con un 27,7% del total (86% asociados a politraumatismo grave). La mortalidad global obtenida fue del 41,48% vs. 24,08% esperable, con un coeficiente de mortalidad de 1,72 (p<0,0001). Conclusiones: La UCI estudiada presenta por las características de la población asistida un elevado índice de mortalidad global. La mortalidad obtenida fue 72% mayor a la mortalidad esperable según la puntuación APACHE II, demostrando esta Escala un bajo valor predictivo en nuestra UCI. La diferencia entre mortalidades podría parcialmente explicarse por la alta prevalencia de entidades con mortalidades subvaloradas por este modelo pronóstico, como pacientes politraumatizados y neurocríticos. En nuestro estudio, la Escala APACHE II presentó una franca subestimación de la mortalidad en ambas patologías. Sugerimos la realización de un estudio de regresión logística local para determinar un factor de corrección y/o adicionar puntos al valor APACHE II según el diagnóstico de ingreso del paciente. Asimismo, proponemos evaluar el empleo de medidas alternativas para predecir mortalidad, como sistemas de tercera generación (por ejemplo: APACHE III, MPM II y SAPS II).