Recent advancements on the phase field approach to brittle fracture for heterogeneous materials and structures.

Recent advancements on the variational approach to fracture for the prediction of complex crack patterns in heterogeneous materials and composite structures is herein proposed, as a result of the frontier research activities undertaken in the FP7 ERC Starting Grant project CA2PVM which focuses on the development of computational methods for the durability and the reliability assessment of photovoltaic laminates. From the methodological viewpoint, the phase field approach to describe the propagation of brittle fracture in the bulk has been coupled for the very first time with the cohesive zone model to depict interface crack growth events, for 2D isotropic and anisotropic constitutive laws, and also for 3D finite elasticity. After a summary of the key aspects underlying the theoretical formulation and the finite element implementation using a monolithic fully implicit solution scheme, an overview of the main technological applications involving layered shells, interface mechanical problems and polycrystalline materials is provided. The examples are selected to show the capability of the proposed approach to investigate complex phenomena such as crack deflection vs. crack penetration at an interface, intergranular vs. transgranular crack growth in polycrystals, and interlayer vs. translayer failure in laminates.

Body composition analysis by dual-energy X-ray absorptiometry in young preschool children.

BACKGROUND/OBJECTIVES: Dual-energy X-ray absorptiometry (DXA) is considered a specific method for measuring body composition to assess obesity and osteoporosis, although few studies have been conducted in preschool children. The aim of this study was to provide sex - and age-specific references for bone mineral density (BMD), bone mineral content (BMC), fat mass (FM) and fat-free mass (FFM) normative data for children aged 2 to <6 years. SUBJECTS/METHODS: One hundred and eighty seven healthy white children from Buenos Aires City suburbs, Argentina, were studied by the Lunar DPX-L DXA, pediatric software: BMC less head (g), BMD (g/cm2), FM (%) and FFM (g). RESULTS: BMD and BMC increased significantly with age (P<0.0001), but only BMD was significantly different between boys and girls of similar age, being greater for boys (P=0.013). FM was not significantly different among the various age groups of boys and girls. However, the FFM/height was higher in boys and the BMC/FFM was higher in girls. The Z-scores and centile curves were derived separately for each sex and age. Q-Q detrended plots and LMS curves produced robust, unbiased fits that generated references for the 3rd, 50th and 97th percentiles for BMD, BMC, FM and FFM data, respectively. CONCLUSIONS: These DXA scans add to the scarcity of accurate measurements of body composition of white young children. The data analyses provided greater accuracy, particularly at the upper and lower ends of the distribution, which is important in clinical settings for identification of children with impaired body composition.

Economic assessment of fidaxomicin for the treatment of Clostridium difficile infection (CDI) in special populations (patients with cancer, concomitant antibiotic treatment or renal impairment) in Spain.

The objective of this paper was to assess the cost-utility of fidaxomicin versus vancomycin in the treatment of Clostridium difficile infection (CDI) in three specific CDI patient subgroups: those with cancer, treated with concomitant antibiotic therapy or with renal impairment. A Markov model with six health states was developed to assess the cost-utility of fidaxomicin versus vancomycin in the patient subgroups over a period of 1 year from initial infection. Cost and outcome data used to parameterise the model were taken from Spanish sources and published literature. The costs were from the Spanish hospital perspective, in Euros (€) and for 2013. For CDI patients with cancer, fidaxomicin was dominant versus vancomycin [gain of 0.016 quality-adjusted life-years (QALYs) and savings of €2,397 per patient]. At a cost-effectiveness threshold of €30,000 per QALY gained, the probability that fidaxomicin was cost-effective was 96 %. For CDI patients treated with concomitant antibiotic therapy, fidaxomicin was the dominant treatment versus vancomycin (gain of 0.014 QALYs and savings of €1,452 per patient), with a probability that fidaxomicin was cost-effective of 94 %. For CDI patients with renal impairment, fidaxomicin was also dominant versus vancomycin (gain of 0.013 QALYs and savings of €1,432 per patient), with a probability that fidaxomicin was cost-effective of 96 %. Over a 1-year time horizon, when fidaxomicin is compared to vancomycin in CDI patients with cancer, treated with concomitant antibiotic therapy or with renal impairment, the use of fidaxomicin would be expected to result in increased QALYs for patients and reduced overall costs.

[Laparoscopic adrenalectomy. Five-year experience]. / Suprarrenalectomía laparoscópica. Experiencia de 5 años.

OBJECTIVE: Adrenal conditions requiring surgery are uncommon and are usually seen in several surgical departments. Our experience in laparoscopic management of adrenal pathology after almost five years of use of laparoscopy for retroperitoneal conditions at our center is reported. MATERIALS AND METHODS: A total of 37 laparoscopic adrenalectomies were performed over 53 months for benign and malignant conditions. The transperitoneal approach was used in most cases (97%) because of the greater surgeon experience with this route. Pregnancy and suspected periadrenal infiltration were considered as absolute contraindications. RESULTS: Mean operating time was 90 minutes, mean intraoperative bleeding 80 ml, and mean hospital stay was 2 days. The main complication was one death. A malignancy was found in 4 patients (10%), while all other patients (90%) had a benign condition, including 8 pheochromocytomas. CONCLUSIONS: Laparoscopy is considered to be the gold standard for benign adrenal conditions. When the malignant mass is a single metastasis from a primary tumor, the laparoscopic approach appears to be reliable. When the malignant lesion is a primary adrenal tumor, laparoscopic management is more controversial, although the results reported by experienced surgeons in their series appear to be adequate.

Suprarrenalectomía laparoscópica. Experiencia de 5 años / Laparoscopic adrenalectomy. Five-year experience

Objetivo: la patología adrenal susceptible de indicación quirúrgica es poco frecuente y normalmente se encuentra dividida entre varios servicios quirúrgicos. Presentamos nuestra experiencia en el manejo laparoscópico tras casi 5 años de implantación de la laparoscopia en la patología retroperitoneal en nuestro centro. Material y métodos: en 53 meses se han realizado un total de 37 suprarrenalectomías por patología benigna y maligna. El abordaje más frecuentemente empleado es el transperitoneal (97%) debido a la mayor experiencia del cirujano con esta vía. La paciente embarazada y la sospecha de infiltración periadrenal se han tomado como contraindicaciones absolutas. Resultados: el tiempo quirúrgico medio es de 90 minutos, sangrado intraoperatorio de 80 cc, estancia media postoperatoria de dos días y la principal complicación ha sido un exitus. En4 ocasiones la patología es maligna (10%), el resto (90%) benigna, con 8 feocromocitomas. Conclusiones: la laparoscopia se considera el patrón oro para la patología benigna adrenal. Cuando la lesión es de naturaleza maligna, en caso de ser una metástasis única procedente de otro tumor primario, parece que el abordaje laparoscópico es fiable. Cuando la lesión maligna es primaria adrenal existe más controversia en este tipo de abordaje, si bien es cierto que en series de cirujanos experimentados los resultados parecen adecuados (AU)

Objective: Adrenal conditions requiring surgery are uncommon and are usually seen in several surgical departments. Our experience in laparoscopic management of adrenal pathology after almost five years of use of laparoscopy for retroperitoneal conditions a tour center is reported. Materials and methods: A total of 37 laparoscopic adrenalectomies were performed over 53months for benign and malignant conditions. The transperitoneal approach was used in most cases (97%) because of the greater surgeon experience with this route. Pregnancy and suspected periadrenal infiltration were considered as absolute contraindications. Results: Mean operating time was 90 minutes, mean intraoperative bleeding 80 ml, and mean hospital stay was 2 days. The main complication was one death. A malignancy was found in 4 patients (10%), while all other patients (90%) had a benign condition, including8 pheochromocytomas. Conclusions: Laparoscopy is considered to be the gold standard for benign adrenal conditions. When the malignant mass is a single metastasis from a primary tumor, the laparoscopic approach appears to be reliable. When the malignant lesion is a primary adrenal tumor, laparoscopic management is more controversial, although the results reported by experienced surgeons in their series appear to be adequate (AU)

[Treatment of Torode and Zieg type IV unstable pelvic fractures in children]. / Tratamiento de las fracturas de pelvis inestable tipo IV de la clasificación de Torode y Zieg en niños.

INTRODUCTION: Pelvic fractures are infrequent in pediatric patients; they account for 1% of hospital admissions. Acetabular fractures are still more infrequent, but when they are associated, they are life threatening. To distinguish pelvic fractures in children from those in adults, one first needs to know their anatomical differences. The magnitude of the trauma can usually cause injuries in other organs and systems, including the abdominal organs, the genitourinary system, vascular and nerve injuries, etc., as well as long bone, spinal and chest fractures. These injuries may be life threatening and must be treated before the pelvic fracture is addressed. OBJECTIVE: To show the results obtained from the surgical treatment of Torode and Zieg type IV pelvic fractures. METHODS: This is a retrospective, observational, longitudinal, descriptive study of 26 patients with Torode and Zieg type IV unstable pelvic fractures during a two-year period. RESULTS: The age group 14-16 years was the most affected one, with 83.3% of the fractures, followed by the 12-14 years group with 8.33% and the group under this age with 8.33%. The most frequent mechanism of injury was trauma resulting from being run over, with 41.66%, car crash with 37.5%, and falls from a height with 20.83%; 37.5% of patients were polytraumatized and required intensive care; the mortality rate in the study was 7.69%. CONCLUSIONS: According to the results and the patient assessment, we propose that unstable pelvic fractures be managed surgically. The mechanism of injury observed in these patients was not lateral compression, as the literature states, but rather a combined mechanism.

El reto de la prótesis vascular infectada. ¿Es posible el éxito sin su retirada? / The challenge of the infected vascular prosthesis. Is success possible without its removal?

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Eficacia de la monoterapia con Piperacilina-tazobactam en infecciones del área maxilofacial. Discusión / Efficacy of single drug therapy with piperacillin-tazobactam in infections of the maxillofacial area. Discussion

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[Evaluation of an advisory program in antibiotic therapy]. / Evaluación de un programa de asesoría en terapia antibiótica.

BACKGROUND: Increases in microbial resistance and pharmaceutical costs have prompted an interest in antibiotic control programs (ACP). Nevertheless, there is controversy on the optimal ACP design and implementation. An ACP based on the infectious diseases' specialist recommendations was evaluated. METHODS: Interventional study of two hospital departments (medical and surgical). Antibiotic costs, mortality rate, readmissions following an infectious disease, and incidence of MRSA and Clostridium difficile between the intervention period and the same period in the previous year were compared. An anonymous survey among health care workers in both departments was conducted. RESULTS: One-hundred and one antimicrobial therapy courses administered to 80 patients were evaluated. A total of 77 recommendations were issued, which consisted of therapy discontinuation (39%), switch to oral antibiotics (31%), decrease in the antimicrobial spectrum (24%) or enhancing the antimicrobial spectrum (6%). Eighty-five percent of the recommendations were accepted. The antimicrobial use remained stabilized, but the oral administration increased from 12.5 to 18.6 DDD/100 patient-days and parenteral use decreased from 25.9 to 22.3 DDD/100 patient-days. Antimicrobial costs decreased by 19.4% (901,794 pesetas). No changes, either in the mortality rate or in readmission rate due to infectious diseases was observed. In contrast, a decrease in the incidence of both MRSA (3.7% to 0.8%; p < 0.05) and Clostridium difficile (1.2% to 0%; p = 0.05) was observed. All health care workers that responded to the survey thought that ACP should be extended to the rest of the hospital. CONCLUSIONS: Our ACP, based on the advice of an infectious diseases specialist, was very well accepted and allows for a decrease in antibiotic costs by simplified therapy. The ACP did not cause a negative impact on patients' outcomes and would probably help reducing the incidence of some nosocomial pathogens.

Evaluación de un programa de asesoría en terapia antibiótica / Evaluation of an advisory program in antibiotic therapy

Objetivo. Los incrementos de la resistencia microbiana y de los costes farmacéuticos están suscitando interés por programas de control del empleo de antibióticos (PCEA).Sin embargo, existe controversia sobre el diseño y la puesta en práctica de los mismos. Evaluamos un PCEA de tipo educativo basado en la elaboración de recomendaciones por un infectólogo. Métodos. Estudio de intervención sobre dos servicios (médico y quirúrgico) del hospital. Comparamos el consumo de antibióticos, la mortalidad, los reingresos por patología infecciosa y la incidencia de Staphylococcus aureus resistente a metilcilina (SARM) y Clostridium difficile entre el período de intervención y el período equivalente del año anterior. Realizamos una encuesta anónima a los trabajadores sanitarios de ambos servicios. Resultados. Evaluamos 101 tratamientos (80 pacientes). Efectuamos 77 recomendaciones que consistieron en suspender los antibióticos (39 por ciento), cambiarlos a la vía oral (31 por ciento), reducir el espectro antimicrobiano (24 por ciento) y ampliar el espectro antimicrobiano (6 por ciento). El 85 por ciento de las recomendaciones fueron aceptadas. El consumo en dosis diarias definidas (DDD)/100 estancias se mantuvo estable, pero el empleo por vía oral pasó de 12,5 a 18,6 DDD/ 100 estancias y el uso por vía parenteral descendió de 25,9 a 22,3 DDD/100 estancias. El gasto en antibióticos disminuyó un 19,4 por ciento (901.794 ptas). No hubo cambios en la mortalidad ni en los reingresos por patología infecciosa. Sin embargo, apreciamos un descenso en la incidencia de casos de SARM (3,7 por ciento a 0,8 por ciento; p < 0,05) y diarrea por C. difficile (1,2 por ciento a 0 por ciento; p = 0,05). El 100 por ciento de los trabajadores sanitarios se mostró partidario de extender el PCEA al resto del hospital. Conclusiones. Nuestro PCEA, basado en la asesoría por infectólogos, es muy bien aceptado y permite reducir el gasto de antibióticos mediante la simplificación del tratamiento. No afecta negativamente a la evolución clínica de los pacientes y podría contribuir, quizá, a disminuir la incidencia de ciertos patógenos nosocomiales (AU)

[The risk factors associated with colonization and bacteremia in non-tunnelled central venous catheters]. / Factores de riesgo asociados a colonización y bacteriemia en catéteres venosos centrales no tunelizados.

OBJECTIVE: To identify risk factors for colonization and bacteremia among patients with non-tunnelled central venous catheters. MATERIALS AND METHODS: A prospective study was conducted of a cohort of patients carrying non-tunnelled central venous catheters. Different parameters were obtained and the degree of its association with colonization of the distal portion of the catheter or with bacteremia associated with colonization was estimated. The CDC (centers for Disease Control) diagnostic criteria of colonization and catheter-related bacteremia were used. RESULTS: A total of 118 catheters were eventually analyzed, corresponding to 114 patients, with a catheterization mean time of 14 +/- 8 days (mean +/- SD); out of these 114 patients, 51 were colonized and in 22 the presence of associated bacteremia was confirmed. The parameters associated with a higher risk for catheter colonization included length of colonization, femoral location, number of lumina and a vital prognosis lower than one month. All these factors, with the exception of the increase in the number of lumina, showed an independent association with colonization on the multivariate analysis [catheterization length (in weeks): OR 1.46; 95% CI: 1.0-2.11; femoral location: OR 3.73; 95% CI: 1.16-11.9; vital prognosis lower than one month: OR 12.7; 95% CI: 1.4-112.7]. As for risk for catheter-related bacteremia, the univariate analysis showed an association with catheterization length and a vital prognosis lower than one month; the latter was the only factor that maintained an independent association in the multivariate analysis (OR 5.75; 95% CI: 1.17-28.27). CONCLUSION: The present study documents the relevance of prolonged catheterization as a consistent risk for colonization of non-tunnelled central venous catheters. This risk increases independently in canalization at femoral site and particularly among severely ill patients. The presence of these factors allows the identification of a high risk population for the development of catheter related bacteremia.

Factores de riesgo asociados a colonización y bacteriemia en catéteres venosos centrales no tunelizados / Risk factors associated with colonization and bacteremia in non-tunnelled central venous catheters

Objetivo. Identificar factores de riesgo de colonización y de bacteriemia en pacientes con catéteres venosos centrales no tunelizados. Material y métodos. Se estudió de forma prospectiva una cohorte de pacientes portadores de catéteres venosos centrales no tunelizados. Se recogieron diferentes variables y se calculó la magnitud de su asociación con la colonización del segmento distal del catéter o con bacteriemia asociada a dicha colonización. Se utilizaron los criterios diagnósticos de colonización y bacteriemia asociada a catéter establecidos por los Centers for Diseases and Control. Resultados. Se analizaron finalmente 118 catéteres, correspondientes a 114 pacientes, cuya media de cateterización fue de 14 ñ 8 días (media ñ DE), de los que 51 resultaron colonizados y de los que en 22 se confirmó la presencia de bacteriemia asociada. Las variables asociadas con un mayor riesgo de colonización del catéter fueron la duración de cateterización, la localización femoral, el número de luces y un pronóstico vital inferior a un mes; todos ellos, salvo el incremento en el número de luces, demostraron una asociación independiente con colonización en el análisis multivariante [duración de cateterización (en semanas): OR 1,46; IC95 por ciento: 1,0-2,11; localización femoral: OR 3,73; IC95 por ciento: 1,16-11,9; pronóstico vital inferior a un mes: OR 12,7; IC95 por ciento: 1,4-112,7]. En relación al riesgo de bacteriemia asociada a catéter, el análisis univariante demostró asociación con la duración de la cateterización y el pronóstico vital inferior a un mes; este último es el único que se mantuvo asociado de forma independiente en el análisis multivariante (OR 5,75; IC95 por ciento: 1,17-28,27). Conclusión. El presente trabajo confirma la importancia de la cateterización prolongada como un claro riesgo de colonización de los catéteres venosos centrales no tunelizados, incrementándose este riesgo de forma independiente en las canalizaciones a nivel femoral, y sobre todo en los pacientes graves. La presencia de estos factores nos permite identificar una población de alto riesgo para el desarrollo de bacteriemia asociada a catéter (AU)

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120-hour 5-fluorouracil (5-FU) continuous infusion (CI) plus BCNU in advanced colorectal cancer.

Seventy-five previously untreated patients with measurable advanced colorectal cancer were treated with 5 fluorouracil 1,000 mg/m2 as a 24-hour intravenous (i.v.) continuous infusion during days 1-5 and 28-32 every cycle, plus 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), 200 mg/m2 i.v. bolus on day 1, all given every 8 weeks up to 6 cycles. Median Karnofsky performance status (KPS) was 100. Sites of disease at entry were mainly the abdomen (45%) and liver (33%). All patients were evaluable for response and survival. There were two complete responses and seven partial responses (PR) for an overall response rate of 12% (95% confidence limits: 5-20%). Four out of 25 patients with liver metastases alone had PR. Stabilization was seen in 40 patients (53%). Median time to progression was 9.3 months and overall median survival was 12.5 months, whereas median survival for patients with liver metastases alone was 16 months. Toxicity was mild except for 8% with WHO grade 4 mucositis. Only KPS had statistical significance in the multivariate analysis of prognostic factors. It is concluded that this regimen is relatively active and well tolerated in patients with advanced colorectal cancer.

Solución de morfina mas lidocaína peridural en el dolor crónico neoplásico, manejo médico y de enfermería: informe preliminar / Morphine solution and peridural lidocaine in chronic neoplasic pain, medical and nursery management: preliminary report

Generalmente al paciente portador de dolor crónico neoplásico (DCN) se deja morir en paz, la realidad es que lo hace con gran sufrimiento. Este informe preliminar evaluó el rendimiento como analgésico de una solución de morfina más lidocaína a través de un catéter peridural en forma permanente en 36 pacientes portadores de DCN. En 94,5 per cent se logró analgesia, todos presentaron a lo menos una reacción adversa a medicamento (RAM) que fué de fácil manejo domiciliario, las mínimas complicaciones del catéter y el bajo costo, hacen de esta técnica una excelente indicación para el tratamiento del DCN