[Anterior knee pain: a simplified assessment and management algorithm]. / Dolor anterior de rodilla: algoritmo simplificado de estudio y manejo.

Anterior knee pain is a common condition that affects adolescent and young adult patients, being one of the most challenging consultations for a knee surgeon. The large number of distinct diagnoses makes it a peculiar syndrome, the only similarities being the presence of retro or peripatellar pain aggravated by at least one activity that loads the joint in flexion. From a pathophysiological perspective, an overuse injury should be considered, where the structural unit of the tissue is damaged or its capacity for reparative response is exceeded. The diagnosis is clinical. Images should be reserved for a particular group of patients. Early intervention is essential to achieve favorable results. Conservative treatment is the gold standard and it is based on multimodal management validated by international consensus. Based on a categorization by clinic and images, we can have a guide to those etiologies that are susceptible to surgical management. The goal of the intervention is to reduce joint stress. The present review defines a simplified algorithm for the study and management of anterior knee pain.

El dolor anterior de rodilla es una condición que afecta a pacientes adolescentes y adultos jóvenes, siendo una de las consultas más comunes y desafiantes para el cirujano de rodilla. La gran cantidad de diagnósticos diferenciales, lo convierten en un síndrome particular, que solo presentan en común la presencia de dolor retro o peripatelar agravado por al menos una actividad que cargue la articulación en flexión. Desde un punto de vista fisiopatológico, debe considerarse una lesión por sobrecarga, donde la unidad estructural del tejido se encuentra dañada o excedida su capacidad de respuesta reparadora. El diagnóstico es clínico. Las imágenes debiesen reservarse para un grupo particular de pacientes. La intervención precoz es fundamental para lograr resultados favorables. El tratamiento conservador es el estándar de oro y se basa en un manejo multimodal validado por consensos internacionales. Basados en una categorización por clínica e imágenes, podemos tener una guía de aquellos cuadros que son susceptibles de manejo quirúrgico. El objetivo de la intervención es reducir el estrés articular. La presente revisión define un algoritmo simplificado de estudio y manejo en dolor anterior de rodilla.

Dolor anterior de rodilla: algoritmo simplificado de estudio y manejo / Anterior knee pain: a simplified assessment and management algorithm

Resumen: El dolor anterior de rodilla es una condición que afecta a pacientes adolescentes y adultos jóvenes, siendo una de las consultas más comunes y desafiantes para el cirujano de rodilla. La gran cantidad de diagnósticos diferenciales, lo convierten en un síndrome particular, que solo presentan en común la presencia de dolor retro o peripatelar agravado por al menos una actividad que cargue la articulación en flexión. Desde un punto de vista fisiopatológico, debe considerarse una lesión por sobrecarga, donde la unidad estructural del tejido se encuentra dañada o excedida su capacidad de respuesta reparadora. El diagnóstico es clínico. Las imágenes debiesen reservarse para un grupo particular de pacientes. La intervención precoz es fundamental para lograr resultados favorables. El tratamiento conservador es el estándar de oro y se basa en un manejo multimodal validado por consensos internacionales. Basados en una categorización por clínica e imágenes, podemos tener una guía de aquellos cuadros que son susceptibles de manejo quirúrgico. El objetivo de la intervención es reducir el estrés articular. La presente revisión define un algoritmo simplificado de estudio y manejo en dolor anterior de rodilla.

Abstract: Anterior knee pain is a common condition that affects adolescent and young adult patients, being one of the most challenging consultations for a knee surgeon. The large number of distinct diagnoses makes it a peculiar syndrome, the only similarities being the presence of retro or peripatellar pain aggravated by at least one activity that loads the joint in flexion. From a pathophysiological perspective, an overuse injury should be considered, where the structural unit of the tissue is damaged or its capacity for reparative response is exceeded. The diagnosis is clinical. Images should be reserved for a particular group of patients. Early intervention is essential to achieve favorable results. Conservative treatment is the gold standard and it is based on multimodal management validated by international consensus. Based on a categorization by clinic and images, we can have a guide to those etiologies that are susceptible to surgical management. The goal of the intervention is to reduce joint stress. The present review defines a simplified algorithm for the study and management of anterior knee pain.

Predicting no-show appointments in a pediatric hospital in Chile using machine learning.

The Chilean public health system serves 74% of the country's population, and 19% of medical appointments are missed on average because of no-shows. The national goal is 15%, which coincides with the average no-show rate reported in the private healthcare system. Our case study, Doctor Luis Calvo Mackenna Hospital, is a public high-complexity pediatric hospital and teaching center in Santiago, Chile. Historically, it has had high no-show rates, up to 29% in certain medical specialties. Using machine learning algorithms to predict no-shows of pediatric patients in terms of demographic, social, and historical variables. To propose and evaluate metrics to assess these models, accounting for the cost-effective impact of possible intervention strategies to reduce no-shows. We analyze the relationship between a no-show and demographic, social, and historical variables, between 2015 and 2018, through the following traditional machine learning algorithms: Random Forest, Logistic Regression, Support Vector Machines, AdaBoost and algorithms to alleviate the problem of class imbalance, such as RUS Boost, Balanced Random Forest, Balanced Bagging and Easy Ensemble. These class imbalances arise from the relatively low number of no-shows to the total number of appointments. Instead of the default thresholds used by each method, we computed alternative ones via the minimization of a weighted average of type I and II errors based on cost-effectiveness criteria. 20.4% of the 395,963 appointments considered presented no-shows, with ophthalmology showing the highest rate among specialties at 29.1%. Patients in the most deprived socioeconomic group according to their insurance type and commune of residence and those in their second infancy had the highest no-show rate. The history of non-attendance is strongly related to future no-shows. An 8-week experimental design measured a decrease in no-shows of 10.3 percentage points when using our reminder strategy compared to a control group. Among the variables analyzed, those related to patients' historical behavior, the reservation delay from the creation of the appointment, and variables that can be associated with the most disadvantaged socioeconomic group, are the most relevant to predict a no-show. Moreover, the introduction of new cost-effective metrics significantly impacts the validity of our prediction models. Using a prototype to call patients with the highest risk of no-shows resulted in a noticeable decrease in the overall no-show rate.

[Genetic predisposition and Pediatric Acute Respiratory Distress Syndrome: New tools for genetic study]. / Predisposición genética y síndrome de distrés respiratorio agudo pediátrico: nuevas herramientas de estudio genético.

Acute respiratory distress syndrome (ARDS) is the most severe form of respiratory failure. Theoretically, any acute lung condition can lead to ARDS, but only a small percentage of individuals actually develop the disease. On this basis, genetic factors have been implicated in the risk of developing ARDS. Based on the pathophysiology of this disease, many candidate genes have been evaluated as potential modifiers in patient, as well as in animal models, of ARDS. Recent experimental data and clinical studies suggest that variations of genes involved in key processes of tissue, cellular and molecular lung damage may influence susceptibility and prognosis of ARDS. However, the pathogenesis of pediatric ARDS is complex, and therefore, it can be expected that many genes might contribute. Genetic variations such as single nucleotide polymorphisms and copy-number variations are likely associated with susceptibility to ARDS in children with primary lung injury. Genome-wide association (GWA) studies can objectively examine these variations, and help identify important new genes and pathogenetic pathways for future analysis. This approach might also have diagnostic and therapeutic implications, such as predicting patient risk or developing a personalized therapeutic approach to this serious syndrome.

Predisposición genética y síndrome de distrés respiratorio agudo pediátrico: nuevas herramientas de estudio genético / Genetic predisposition and Pediatric Acute Respiratory Distress Syndrome: New tools for genetic study

El síndrome de distrés respiratorio agudo (SDRA) es la forma más grave de falla respiratoria. Teóricamente, cualquier noxa pulmonar aguda puede resultar en un SDRA, pero solo un pequeño porcentaje de individuos desarrolla la enfermedad. Sobre este fundamento, factores genéticos han sido implicados en el riesgo de desarrollar SDRA. Basado en la fisiopatología de esta enfermedad, múltiples genes candidatos han sido evaluados como potenciales modificadores, tanto en pacientes como en modelos animales de SDRA. Datos experimentales y estudios clínicos recientes sugieren que variantes de genes implicados en procesos clave de daño tisular, celular y molecular pulmonar pueden influir en la predisposición y el pronóstico del SDRA. Sin embargo, la patogénesis del SDRA pediátrico es compleja y, en consecuencia, es posible anticipar que muchos genes pueden contribuir a ella. Variantes genéticas, tales como polimorfismos de nucleótido simple y variantes del número de copias, están probablemente asociadas con la predisposición al SDRA en niños con lesión pulmonar primaria. El estudio de asociación del genoma completo (GWAS, del inglés Genome-Wide Association Study) puede examinar estas variantes sin sesgos y ayudar a identificar nuevos genes fundamentales y vías patogénicas clave para futuros análisis. Esta aproximación también puede tener implicancias clínicas diagnósticas y terapéuticas, como predecir el riesgo del paciente o desarrollar un enfoque terapéutico personalizado para este grave síndrome.

Acute respiratory distress syndrome (ARDS) is the most severe form of respiratory failure. Theoretically, any acute lung condition can lead to ARDS, but only a small percentage of individuals actually develop the disease. On this basis, genetic factors have been implicated in the risk of developing ARDS. Based on the pathophysiology of this disease, many candidate genes have been evaluated as potential modifiers in patient, as well as in animal models, of ARDS. Recent experimental data and clinical studies suggest that variations of genes involved in key processes of tissue, cellular and molecular lung damage may influence susceptibility and prognosis of ARDS. However, the pathogenesis of pediatric ARDS is complex, and therefore, it can be expected that many genes might contribute. Genetic variations such as single nucleotide polymorphisms and copy-number variations are likely associated with susceptibility to ARDS in children with primary lung injury. Genome-wide association (GWA) studies can objectively examine these variations, and help identify important new genes and pathogenetic pathways for future analysis. This approach might also have diagnostic and therapeutic implications, such as predicting patient risk or developing a personalized therapeutic approach to this serious syndrome.

Disfunción diafragmática inducida por ventilación mecánica / Ventilator-induced diaphragmatic dysfunction

The ventilator-induced diaphragmatic dysfunction is a group of disorders caused by the inactivity of the diaphragm muscle during controlled mechanical ventilation. From a structural point of view, the diaphragm subjected to mechanical ventilation undergoes an atrophy process, in which decreased synthesis and increased muscle protein degradation are observed. Recent research has identified different molecular signaling pathways that link both processes in the diaphragm, describing compelling evidence that shows that oxidative stress contributes to this phenomenon. Also, functional changes characterized by a reduction in stress and fatigue resistance, associated with an increase in the maximum shortening velocity are observed. The purpose of the present review is to analyze the impact of mechanical ventilation on the structure and function of the diaphragm muscle. Clinical implications and potential preventive steps are discussed. Since the duration of mechanical ventilation is the primary responsible for the absence of mechanical stimulation on the diaphragm, the use of ventilatory strategies for successful early weaning and early use of partial modalities should be the main pillars in the prevention of this condition.

La disfunción diafragmática inducida por ventilación mecánica consiste en un conjunto de alteraciones producidas por la inactividad del músculo diafragma durante la ventilación mecánica controlada. A nivel estructural, el diafragma sometido a ventilación mecánica experimenta un proceso de atrofia por desuso, en el que se observa una disminución de la síntesis y aumento en la degradación de proteínas musculares. Recientemente se han identificado diferentes rutas de señalización molecular que vinculan ambos procesos en el diafragma, existiendo evidencia fehaciente que el estrés oxidativo contribuye a este fenómeno. Concomitantemente, se han observado cambios funcionales caracterizados por una reducción de la fuerza y resistencia a la fatiga, asociado a un incremento en la velocidad máxima de acortamiento. El objetivo principal de esta revisión es analizar el impacto de la ventilación mecánica sobre la estructura y función del músculo diafragma. Además se discuten implicancias clínicas y potenciales intervenciones preventivas para esta emergente entidad. Dado que el tiempo de permanencia en ventilación mecánica controlada es el principal factor responsable de la ausencia de estímulo mecánico sobre el diafragma, el empleo de estrategias de destete ventilatorio precoz y el uso temprano de modalidades parciales, debieran constituir los pilares de su prevención.

[Ventilator-induced diaphragmatic dysfunction]. / Disfunción diafragmática inducida por ventilación mecánica.

The ventilator-induced diaphragmatic dysfunction is a group of disorders caused by the inactivity of the diaphragm muscle during controlled mechanical ventilation. From a structural point of view, the diaphragm subjected to mechanical ventilation undergoes an atrophy process, in which decreased synthesis and increased muscle protein degradation are observed. Recent research has identified different molecular signaling pathways that link both processes in the diaphragm, describing compelling evidence that shows that oxidative stress contributes to this phenomenon. Also, functional changes characterized by a reduction in stress and fatigue resistance, associated with an increase in the maximum shortening velocity are observed. The purpose of the present review is to analyze the impact of mechanical ventilation on the structure and function of the diaphragm muscle. Clinical implications and potential preventive steps are discussed. Since the duration of mechanical ventilation is the primary responsible for the absence of mechanical stimulation on the diaphragm, the use of ventilatory strategies for successful early weaning and early use of partial modalities should be the main pillars in the prevention of this condition.

Evaluación de trastorno de personalidad a partir de estudios de Neuro-SPECT / Assessment of personality disorder by means of NeuroSPECT

We report on functional imaging results in 24 patients of Personality Disorder (P.D.) performed with NeuroSPECT by means of Tc99m HMPAO, in Basal state and during frontal cortical activation by means of the Wisconsin Card Sorting Test. Results demonstrate that we can make the diagnosis of P.D. when we detect significant hypoperfusion (- 2 Stand/ Deviations below the normal mean for the same age group) in the subgenual area (Area 25 of Brodmann) and in Area 24 of Brodmann, the anterior cingulated gyrus. Both areas are paradoxically more hypoperfused during the Wisconsin Test. Among patients diagnosed with P.D. NeuroSPECT can distinguish between patients of Cluster B from the ones from Cluster C in both Basal and Activation State, while Cluster A from B could be differentiated only in Basal State. On the other hand Motor Impulsivity patients could be differentiated from the Cognitive group due to paradoxical hypoperfusion in motor areas 1,2,3, and 4 of Brodmann. While the number of patients studied appears reduced these results demonstrate the capability of diagnosing Personality Disorder and also the capability to improved understanding of the subgroups of this Disorder.

Se comunican los resultados de 24pacientes con Trastornos de Personalidad estudiados mediante Neuro-SPECT HMPAO Tc99m, técnica de imagenología funcional cerebral en condicionas basales y durante activación de la corteza frontal ejecutiva mediante la prueba de Wisconsin. Los resultados demuestras fehacientemente que el diagnóstico de Trastorno de Personalidad se basa en la presencia de disminución de perfusión (- 2 Desviaciones Standard bajo el promedio normal para el mismo grupo etario) en el Cingulado Anterior y región subgenual, exageradas paradojalmente durante la prueba de Wisconsin. Dentro de los pacientes demostrados como Trastorno de Personalidad, Neuro-SPECT es capaz de distinguir los pacientes del Cluster B de los del Cluster C en ambos estados de medición,(Estado Basal vs Prueba de Wisconsin) mientras los Cluster A y B fueron diferenciables en estado Basal solamente. Por otra parte, la Impulsividad Motora pudo ser distinguida de la Cognitiva por la hipoperfusión paradojal de las áreas frontales de Brodmann motoras 1,2,3 y 4. Si bien el número total de pacientes reportados en este trabajo, es relativamente limitado, abre posibilidades interesantes a la imagenología funcional cerebral en estado basal y durante activación mediante la prueba de Wisconsin para el diagnóstico y exploración del Trastorno de Personalidad.

Demanda de consultas al servicio de urgencia del Instituto Psiquiátrico Dr. José Horwitz B. de Santiago: comparación entre 1988 y 1994 / Consultation demand at emergency service of Instituto Psiquiátrico Dr. José Horwitz B. at Santiago: comparison between 1988-1994

Materials and methods: A random sample of 439 patients charts, corresponding to 3 percent of all consultations during 1994, were analyzed. The results were compared with consultations during 1998, analyzed in a previous study. Results: During 1994, patients were older, came alone to the emergency wards and consulted during the night with greater frequency than during 1988. In both years psychosis were the main cause of consultation. Compared to 1988, during 1994 there was an increase in the frequency of affective disorders (16 and 12 percent of all consultations respectively) and substance abuse (15 and 3 percent respectively). Conclusions: The increase in consultations due to affective disorders and substance abuse in 1994 is in accordance with changes in the epidemiological profile of psychiatric disorders in Santiago

Experiencia en torno al proceso de alta en pacientes crónicas del departamento 11 (mujeres) del servicio B, Hospital Psiquiátrico Dr. José Horwitz Barak / Experience in the discharge process in chronical patients of the Department 11 (women) of the Service B, Psychiatric Hospital Dr. José Horwitz Barak

Se describe la experiencia en torno al egreso de pacientes crónicos con largas estadías en el hospital. El alta se concreta tras un proceso que comprende múltiples actividades: elección de candidatas al egreso, psicoterapia de grupo dirigida a las mismas, evaluación de la tolerancia de la familiade origen o sustituta. Se detalla la estrategia de negociación del alta con los familiares. Se ilustra nuestra experiencia en dos casos clínicos. Finalmente comentamos respecto a algunas conclusiones de acuerdo a los resultados, y se exponen ideas en relación al proceso de alta y concepto de rehabilitación