Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720150011&lang=es vol. 143 num. 11 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<strong>Efecto de las variantes de VKORC1 y CYP2C9 sobre la dosis de anticoagulantes orales en individuos chilenos</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100001&lng=es&nrm=iso&tlng=es Background: The dose of oral anticoagulants (OAC) shows great variability among patients. Pharmacogenetic studies have shown that common variants in genes CYP2C9 (*2 and *3) and VKORC1 (-1639G>A) are associated with lower requirements of OAC. Aim: To study the association between average maintenance doses of oral anticoagulant therapy required to maintain a stable INR and CYP2C9 and VKORC1 gene variants in Chilean adults. Material and Methods: Prospective study of patients on anticoagulant treatment and with a stable international normalized ratio (INR) for prothrombin time for at least three months. Patients were classified as having high or low acenocoumarol or warfarin requirements. Peripheral blood DNA genotyping was performed by polymerase chain reaction and restriction fragment polymorphism or sequencing and electrophoresis. Results: The study included 185 patients, 125 on acenocoumarol and 60 on warfarin. Patients with VKORC1-1639A allele were more likely to require lower doses of both drugs than patients with the G allele (Odds ratio [OR] for acenocoumarol 9.06, and OR for warfarin = 18.7). There was no association between CYP2C9*2 and*3 and acenocoumarol or warfarin requirements. Conclusions: There is an association between VKORC1-1639A variant and anticoagulant doses. <![CDATA[<strong>Análisis de frecuencias alélicas y genotípicas de las variantes <i>CYP2A6*12 </i>y rs16969968 de <i>CHRNA5</i> y su asociación con el hábito de fumar y el índice de masa corporal (IMC) en sujetos jóvenes del noreste de México</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100002&lng=es&nrm=iso&tlng=es Background: Several studies have reported that variants rs16969968 G&gt;A of the CHRNA5 gene and CYP2A6*12 of the CYP2A6 gene are associated with smoking and smoking refusal, respectively. In addition, some studies report that a higher cigarette consumption is associated with low body mass index (BMI). Aim: To analyze the allele and genotypic frequencies of these variants and their impact on smoking and BMI. Material and Methods: A blood sample was obtained and a survey about smoking habits was answered by 319 university students aged 18 to 35 years (127 women, 171 smokers), living in Northeastern Mexico. Genetic variants were studied by polymerase chain reaction/restriction fragment length polymorphism and their frequencies were associated with smoking and BMI. Results: No associations were found between the analyzed variants and smoking in the study groups. However, there was an association among non-smoking subjects between the A allele of rs16969968 and high a BMI (p < 0.01). Conclusions: This last variant may be involved in food-addiction disorders. <![CDATA[<strong>Valores espirométricos en niños y adolescentes chilenos sanos</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100003&lng=es&nrm=iso&tlng=es Background: Spirometric flow and volume measurement are essential to evaluate patients with pulmonary disease. In Chile, several reference equations are used. Aim: To measure flow and expiratory volumes in healthy children and adolescents and compare their results with theoretical values according to Knudson, Quanjer, Gutierrez and NANHES III. Subjects and Methods: Spirometries were performed according to international standards in 1589 healthy children and adolescents aged 6 to 18 years (861 females) who lived in Santiago, Chile. Results: The obtained values for forced vital capacity, expiratory volume in one second, peak expiratory flow, were significantly higher than those calculated according to the above mentioned standards (p < 0.0001) with differences up to 18.7%. We constructed reference formulas for ages ranging from 6 to 18 years, separated by gender, using age, weight and height as independent variables. The latter had the greater influence on formula construction. Conclusions: The use of these new local formulas with allow the correct interpretation of spirometric results obtained in Chilean children and adolescents. <![CDATA[<strong>Estrategias del aprendizaje inicial de la clínica</strong>: <strong>más allá de los hábitos de estudio. </strong><strong>Percepciones de estudiantes y docentes clínicos</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100004&lng=es&nrm=iso&tlng=es Background: Teaching methods of the undergraduate medical curriculum change considerably from the first years to clinical training. Clinical learning occurs in complex and varied scenarios while caring for patients. Students have to adapt their learning approaches and strategies to be able to integrate theory and clinical practice and become experiential learners. Aim: To identify the strategies used by medical students to learn during the initial clinical years, as reported by students themselves and by their clinical tutors. Material and Methods: We performed eight focus group discussions with 54 students enrolled in years three to six and we interviewed eight clinical tutors. Both focus group discussions and interviews were audio recorded, transcribed and analyzed according to Grounded Theory. Results: Four main themes were identified in the discourse of both students and tutors: Strategies oriented to theoretical learning, strategies oriented to experiential learning, strategies for integrating theory and practice and strategies oriented to evaluation. The mentioning of individual differences was present across the reports of both students and tutors. Conclusions: Students use a rich variety of strategies to face the challenges of clinical learning. Both students and tutors recognize that the learning approaches and strategies vary according the nature of the task and individual differences. The responses of students bring particular knowledge of the approaches used for the theoretical and practical integration and delve into the social dimension of learning. <![CDATA[<strong>Criterios de médicos tratantes para indicar instalación de gastrostomía en pacientes con demencia avanzada</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100005&lng=es&nrm=iso&tlng=es Background: Decision making concerning patients with advanced dementia is complicated. The indication of a gastrostomy is among these hard decisions, especially considering that there is no consensus about its real benefit. Aim: To explore the criteria used by Chilean physicians to indicate a gastrostomy in patients with advanced dementia. Material and Methods: A questionnaire about the decision making to indicate a gastrostomy was delivered to 72 physicians working in public and private hospitals. Results: The survey was answered by 43 physicians. Fifty one percent had indicated a gastrostomy to patients with advanced dementia in the last year, 79% believed that gastrostomy reduces the risk of aspiration pneumonia, 50% thought that gastrostomy helps in bed sore healing and 74% believed that gastrostomy improves survival. Conclusions: The majority of physicians who answered the survey think that gastrostomy will improve the health status of patients with advanced dementia. <![CDATA[<strong>Factores sociodemográficos y motivacionales asociados a la actividad física en estudiantes universitarios</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100006&lng=es&nrm=iso&tlng=es Background: Physical inactivity is an important risk factor for chronic diseases in Western societies. Aim: To determine the sociodemographic and motivational factors associated with physical activity in college students. Material and Methods: The International Physical Activity Questionnaire (IPAQ) -short form- and the “motives for physical activities measure-revised” (MPAM-R) questionnaire were applied to 900 university students aged 20 ± 3 years (60% women). The frequency, level and motivations for engaging in physical activity and associated demographic factors were analyzed. Results: Twenty two percent of students were classified as having a high level of physical activity, 54.8% had a low level and 13.9% were considered inactive. According to MET consumption, 68.9% of students are inactive and only 16.8% of students classified as very active. Ninety two percent of active students performed physical activity for health reasons. A significant association between gender and social motivation was observed. Conclusions: A high prevalence of physical inactivity was found in these students. Males showed higher levels of physical activity than females. <![CDATA[<strong>Un sistema de asignación de órganos para trasplante que no considere las edades de donante y receptor es inicuo</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100007&lng=es&nrm=iso&tlng=es Background: Kidney transplantation is the best treatment for end stage kidney disease. The allograft allocation system considers immunological factors and time in waiting list, but not the age of donors or recipients, in spite that both have prognostic relevance. Aim: To study the fairness of the allograft allocation system considering the age of donors and recipients. Material and Methods: Based in the age distribution of donors and waiting list of patients for kidney transplantation, we constructed probability functions for receiving a graft as an allocation system based on age changes from a strict to a more lax criteria. Finally, we compared our model with the real transplants performed during 2012. Results: The probability distribution for receiving a kidney transplantation is displaced to the right compared with the age distribution of graft donors. This gap increases as the procuring hospitals enlist progressively older graft candidates without accepting older donors in parallel. An allocation system that maintains age parity between donors and recipients is fairer that other that allows lax criteria for the same allocation. This phenomenon is attenuated if the procurement acceptance criterion allows older donors. Conclusions: It is necessary to reduce the gap between donor and recipient ages for kidney transplantation to improve the fairness of the graft allocation system. <![CDATA[<strong>Seguimiento clínico en pacientes con buena capacidad metabólica en la prueba de esfuerzo con SPECT miocárdico</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100008&lng=es&nrm=iso&tlng=es Background: The evaluation of coronary artery disease (CAD) can be performed with stress test and myocardial SPECT tomography. Aim: To assess the predictive value of myocardial SPECT using stress test for cardiovascular events in patients with good exercise capacity. Material and Methods: We included 102 males aged 56 ± 10 years and 19 females aged 52 ± 10 years, all able to achieve 10 METs and ≥ 85% of the theoretical maximum heart rate and at least 8 min in their stress test with gated 99mTc-sestamibi SPECT. Eighty two percent of patients were followed clinically for 33 ± 17 months. Results: Sixty seven percent of patients were studied for CAD screening and the rest for known disease assessment. Treadmill stress test was negative in 75.4%; 37% of patients with moderate to severe Duke Score presented ischemia. Normal myocardial perfusion SPECT was observed in 70.2%. Reversible defects appeared in 24.8% of cases, which were of moderate or severe degree (> 10% left ventricular extension) in 56.6%. Only seven cases had coronary events after the SPECT. Two major (myocardial infarction and emergency coronary revascularization) and 5 minor events (elective revascularization) ere observed in the follow-up. In a multivariate analysis, SPECT ischemia was the only statistically significant parameter that increased the probability of having a major or minor event. Conclusions: Nearly a quarter of our patients with good exercise capacity demonstrated reversible defects in their myocardial perfusion SPECT. In the intermediate-term follow-up, a low rate of cardiac events was observed, being the isotopic ischemia the only significant predictive parameter. <![CDATA[<strong>Un mayor nivel de actividad física se asocia a una menor prevalencia de factores de riesgo cardiovascular en Chile</strong>: <strong>resultados de la Encuesta Nacional de Salud 2009-2010</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100009&lng=es&nrm=iso&tlng=es Background: Little is known about the relationship between physical activity (PA) and cardiovascular risk factors in the Chilean population. Aim: To investigate the association between different levels and intensities of PA and the prevalence of cardiovascular (CV) risk factors in Chilean adults. Material and Methods: Data from the National Health Survey 2009-10 including 5157 participants, provided by the Epidemiology Department of the Ministry of Health, was analyzed in this study. The prevalence of type 2 diabetes mellitus, hypertension, metabolic syndrome and dyslipidemia were determined using international criteria. PA levels were determined using the Global Physical Activity Questionnaire (GPAQ v2) and different levels of PA were derived from it (transport-related, moderate and vigorous PA). Quartiles of PA were determined to investigate the association between PA and cardiovascular risk factors. Results: Twenty three percent of women and 17.1% of men did not meet the PA recommendation (≥ 600 METs.min.week-1). When prevalence of CV risk factors were compared between inactive individuals (< 600 METs.min.week-1) and active individuals (≥ 9500 METs.min.week-1) a significantly lower prevalence of diabetes mellitus (6.2% and 10%), hypertension (18.0% and 12.4%) and metabolic syndrome (8.9% and 12.1%) for women and men, respectively, was found in the active participants. Similar results were found for high versus low transport-related PA. Conclusions: Increasing levels of PA are associated with a significantly lower frequency of cardiovascular risk factors in Chilean adults. <![CDATA[<strong>Ébola</strong>: <strong>caracterización, historia y manifestaciones cutáneas; lo que debemos saber</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100010&lng=es&nrm=iso&tlng=es Ebola virus (EV) is one of the most virulent human pathogens. Fruits bats are its natural reservoir, the transmission to humans is across wild animals (especially primates) and the propagation in human populations is through bodily fluid contact. The actual outbreak started in December 2013 and crossed continental borders. Up to now, there are 17,145 suspected and confirmed cases with 6,070 deaths, resulting a total case fatality rate of 35%. Clinical manifestations can be divided in 3 phases. In phase I, symptoms are similar to flu, which may appear in a range of 2 to 21 days. In phase II which occurs in over 50% of cases, visceral symptoms and mucocutaneous manifestations appear within 4 and 5 days of the onset of symptoms. The main symptoms are a macular or maculopapular non-pruritic rash, desquamation and mucosal involvement of eyes, mouth and pharynx. In phase III, recovery or death occurs. The diagnosis is made on clinical grounds, epidemiological suspicion and a positive polymerase chain reaction (PCR) test. The treatment is supportive. If there is a suspected case, it should be notified immediately and all relevant safety measures should be instituted. <![CDATA[<strong>Fotoféresis en el tratamiento de Síndrome de Sézary</strong>: <strong>Caso clínico</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100011&lng=es&nrm=iso&tlng=es Sézary syndrome (SS) is an unusually aggressive T- cell lymphoma characterized by the triad of erythroderma, the presence of more than 1,000 Sézary cells in peripheral blood and lymphadenopathies. It is accompanied by generalized pruritus and poor quality of life. The management of SS depends on its stage, patient comorbidities, and treatment availability. Extracorporeal photopheresis (ECP) is the first line of treatment for patients with T-cell lymphomas in stage IVA1, IVA2 or SS. This treatment comprises three phases: leukapheresis, photoactivation and subsequent reinfusion of lymphocytes. As it is an immunomodulatory therapy it does not produce generalized immunosuppression. We report a 76 year-old male with SS stage IIIb initially treated with 12 sessions of ultraviolet phototherapy without response. After 10 well-tolerated sessions of ECP, itching and skin lesions eventually disappeared. <![CDATA[<strong>Propiedades psicométricas de un cuestionario para evaluar expectativas académicas en estudiantes de primer año de Medicina</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100012&lng=es&nrm=iso&tlng=es Background: Academic Involvement Questionnaire, Expectations version (CIA-A), assesses the expectations of involvement in studies. It is a relevant predictor of student success. However, the evidence of its validity and reliability in Chile is low, and in the case of Medical students, there is no evidence at all. Aim: To evaluate the factorial structure and internal consistency of the CIA-A in Chilean Medical school freshmen. Material and Methods: The survey was applied to 340 Medicine freshmen, chosen by non-probability quota sampling. They answered a back-translated version of CIA-A from Portuguese to Spanish, plus a sociodemographic questionnaire. For psychometric analysis of the CIA-A, an exploratory factor analysis was carried on, the reliability of the factors was calculated, a descriptive analysis was conducted and their correlation was assessed. Results: Five factors were identified: vocational, institutional and social involvement, use of resources and student participation. Their reliabilities ranged between Cronbach’s alpha values of 0.71 to 0.87. Factors also showed statistically significant correlations between each other. Conclusions: Identified factor structure is theoretically consistent with the structure of original version. It just disagrees in one factor. In addition, the factors’ internal consistency were adequate for using them in research. This supports the construct validity and reliability of the CIA-A to assess involvement expectations in medical school freshmen. <![CDATA[<strong>¿Es suficiente el recurso humano nutricionista en el sistema hospitalario público en Chile?</strong>: <strong>Una deuda pendiente</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100013&lng=es&nrm=iso&tlng=es Background: Human resource deficit is an important management problem in Chilean public hospitals. Aim: To analyze the adequacy of Nutritionist (Dietician) resources in public hospitals. Material and Methods: A questionnaire about Nutritionist resources was sent to head Nutritionists of all public Chilean hospitals, asking about the number of Nutritionists per service, number of hospital beds and number of daily rations served. Results were analyzed based on the Technical Guideline about Nutritional and Feeding Services of public hospitals issued by the Chilean Ministry of Health in 2005. Results: According to the guideline, there should be 1,396 nutritionists working in public hospitals and the results of the survey showed that there were only 603 professionals with a 57% deficit. Conclusions: There is a huge gap between the amount of Nutritionists (Dieticians) required and those effectively working in public hospitals. <![CDATA[<strong>Consideraciones acerca de la “interrupción voluntaria del embarazo”, desde el punto de vista ético-médico (a propósito de un proyecto de ley)</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100014&lng=es&nrm=iso&tlng=es “Voluntary termination of pregnancy” can refer to actions intended to make a delivery easier, to provide medical care to the fetus, or to protect the life or health of the mother. All of these are proper medical actions and are by definition voluntary. In other cases, the expression denotes a termination of pregnancy before the embryo or fetus is viable, leading to the death of the latter. This action is constitutive of abortion under current Chilean law. The product of conception living being, who develops in the womb during pregnancy, is an individual, both in the sense that it is different from its mother and father, and in that it is a biological individual. For these reasons, such living being constitutes another patient in itself. The free and voluntary medical action of health care professionals is geared toward disease prevention or health recovery and medical terminations of pregnancy, as distinguished from abortion, are not criminalized in our country. Therefore, the idea of legalizing abortive terminations of pregnancy so that they become “legitimate health care services” is a call to the medical community, which should engage in a debate about the meaning and consequences of an eventual mandate of the State that would be at odds with the Hippocratic tradition. A woman can feel that her health is at risk due to her pregnancy, and she certainly has the right to request medical help. Health professionals should care both at the medical and emotional level for all those who require their services, especially when such persons are undergoing situations of vulnerability and distress. When requested to perform an abortion, the physician faces dilemmas that should be addressed in line with the present state of the medical art. <![CDATA[<strong>Leucoencefalopatía tóxica fatal</strong>: <strong>tres casos asociados al consumo de pasta base de cocaína</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100015&lng=es&nrm=iso&tlng=es The prevalence of drug-associated toxic encephalopathy is unknown, but it is an uncommon condition. Toxic leukoencephalopathy was described associated with heroin consumption, it has been less commonly described with the use of cocaine and there are no reports of its association with consumption pasta base of cocaine (PBC). We report two females aged 31 years and a male aged 19 years, consumers of PBC who developed a fatal toxic leukoencephalopathy. They initiated their disease with severe and persistent headache, sequential focal neurologic deficits and a progressive impairment of consciousness that culminated with their death. Laboratory parameters such as blood count, cerebrospinal fluid analyses or infectious biological indices were normal. MRI showed multifocal lesions in brain white matter of both hemispheres confirming the leukoencephalopathy. There was no response to the use of methylprednisolone. <![CDATA[<strong>Déficit adquirido de factor X en leucemia mielomonocítica crónica</strong>: <strong>reporte de un caso</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100016&lng=es&nrm=iso&tlng=es Bleeding disorders are commonly associated with hemato-oncologic diseases. We report a 68 years old male with a chronic myelomonocytic leukemia derived from a long lasting mielodysplastic syndrome that did not respond to treatment with Azacitidine. The patient was hospitalized due to tonic clonic seizures. A CAT scan showed a hematoma in the frontal lobe. A new assessment of hemostasis revealed an isolated deficiency of Factor X. We speculate that this deficit could be secondary to consumption due to the chronic Myelomonocytic Leukemia. <![CDATA[<strong>Perspectiva de género y vulnerabilidad en salud</strong>: <strong>¿cuándo empezamos a incluir a los hombres?</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100017&lng=es&nrm=iso&tlng=es Bleeding disorders are commonly associated with hemato-oncologic diseases. We report a 68 years old male with a chronic myelomonocytic leukemia derived from a long lasting mielodysplastic syndrome that did not respond to treatment with Azacitidine. The patient was hospitalized due to tonic clonic seizures. A CAT scan showed a hematoma in the frontal lobe. A new assessment of hemostasis revealed an isolated deficiency of Factor X. We speculate that this deficit could be secondary to consumption due to the chronic Myelomonocytic Leukemia. <![CDATA[<strong>Una nueva herramienta en imágenes por resonancia magnética para el diagnóstico en la enfermedad de Parkinson</strong>: <strong>visualización del Nigrosoma 1</strong>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872015001100018&lng=es&nrm=iso&tlng=es Bleeding disorders are commonly associated with hemato-oncologic diseases. We report a 68 years old male with a chronic myelomonocytic leukemia derived from a long lasting mielodysplastic syndrome that did not respond to treatment with Azacitidine. The patient was hospitalized due to tonic clonic seizures. A CAT scan showed a hematoma in the frontal lobe. A new assessment of hemostasis revealed an isolated deficiency of Factor X. We speculate that this deficit could be secondary to consumption due to the chronic Myelomonocytic Leukemia.