Evaluación de la anticoagulación con rivaroxaban, en pacientes con fibrilación auricular no valvular de reciente diagnóstico / Evaluation of oral anticoagulation with rivaroxaban, in patients with new onset non valvular atrial fibrillation

Background: Atrial fibrillation (AF) generates a hypercoagulable state with an increased thrombin generation and raised levels of thrombin-antithrombin complexes, which results in a high risk of stroke and thromboembolism. Aim: To evaluate the anticoagulant effect of rivaroxaban by anti-Xa factor activity and its correlation with thrombin-antithrombin complexes, thrombin generation and prothrombin time in patients newly diagnosed with non-valvular AF. Patients and Methods: Prospective study in patients with indication of anticoagulation. Demographic variables, cardiovascular risk factors, CHA2DS2-VASc and HAS-BLED scores were recorded. Blood samples were taken at baseline, at 3 and 24 hours after the administration of the drug and at 30 days. Rivaroxaban levels, anti-Xa activity, prothrombin time, thrombin generation and plasma levels of thrombin-antithrombin complexes were determined. Results: We studied 20 patients aged 76.3 ± 8.0 years (60% female) with a CHA2DS2-VASc score > 2 points. The anti-Xa factor activity correlated with rivaroxaban plasma levels at 3 hours (r = 0.61, p < 0.01), at 24 hours (r = 0.85, p < 0.01) and at 30 days (r = 0.99, p < 0.01), with prothrombin time at 3 hours (r = -0.86, p = 0.019) and at 30 days (r = -0.63, p = 0.02) and with a sustained decrease in thrombin generation at 30 days of follow-up (r = -0.74, p < 0.01). There was no correlation with thrombin-antithrombin complexes (r = -0.02, p = 0.83). Conclusions: Rivaroxaban consistently inhibited the mild pro-coagulant state found in newly diagnosed non-valvular AF patients through the first 24 hours and this effect was maintained at 30 days. Plasma levels of the drug correlated with anti-Xa factor activity, thrombin generation and prothrombin time

Evaluación de docentes clínicos de Postgrado: desarrollo y propiedades psicométricas del instrumento MEDUC-PG14 / Development of MEDUC-PG14 survey to assess postgraduate teaching in medical specialties

Background: Feedback is one of the most important tools to improve teaching in medical education. Aim: To develop an instrument to assess the performance of clinical postgraduate teachers in medical specialties. Material and Methods: A qualitative methodology consisting in interviews and focus-groups followed by a quantitative methodology to generate consensus, was employed. After generating the instrument, psychometric tests were performed to assess the construct validity (factor analysis) and reliability (Cronbach’s alpha). Results: Experts in medical education, teachers and residents of a medical school participated in interviews and focus groups. With this information, 26 categories (79 items) were proposed and reduced to 14 items (Likert scale 1-5) by an expert’s Delphi panel, generating the MEDUC-PG14 survey, which was answered by 123 residents from different programs of medical specialties. Construct validity was carried out. Factor analysis showed three domains: Teaching and evaluation, respectful behavior towards patients and health care team, and providing feedback. The global score was 4.46 ± 0.94 (89% of the maximum). One teachers’ strength, as evaluated by their residents was “respectful behavior” with 4.85 ± 0.42 (97% of the maximum). “Providing feedback” obtained 4.09 ± 1.0 points (81.8% of the maximum). MEDUC-PG14 survey had a Cronbach’s alpha coefficient of 0.947. Conclusions: MEDUC-PG14 survey is a useful and reliable guide for teacher evaluation in medical specialty programs. Also provides feedback to improve educational skills of postgraduate clinical teachers.

Correlación de valores de TTPa con anti factor Xa para establecer rango terapéutico en tratamiento anticoagulante con heparina sódica / Correlation between aPTT and antifactor Xa to determine therapeutic ranges for unfractionated heparin

Background: The therapeutic range (TR) of activated partial thromboplastin time (aPTT) for unfractionated heparin (UFH) dosing was established in the 1970 decade. Since then aPTT determination has changed. Current TR may be sub or supra-therapeutic depending on the reagents of the test, and therefore, responsible for complications of therapy. Aim: To establish the TR for UFH dosing in our institution using antifactor Xa analysis as reference standard. Material and Methods: After obtaining an informed consent, 43 blood samples were obtained for aPTT determination and antifactor Xa assay in 23 patients treated with intravenous UFH. Samples were processed at Emergency and Hemostasis Labs. We excluded patients receiving other anticoagulants, with thrombophilia, pregnancy or liver disease. Results: Mean aPTT values in the Hemostasis and Emergency labs ​​were 57.1 ± 18.9 and 56.6 ± 18.3 seconds, respectively (p = 0.77). The squared correlation coefficients between aPTT and antifactor Xa at hemostasis and emergency labs were R2 0.5 and 0.45 respectively, p < 0.001. Using a linear regression analysis, therapeutic aPTT range values ​​in our laboratory were established between 50 and 80 seconds, corresponding to antifactor Xa values of 0.3 to 0.7 IU/mL. Conclusions: According to current recommendations, validation of aPTT determination with reference techniques should be done in every institution.

Cetoacidosis diabética: Casuística 2008-2012, epidemiología y fisiopatología / Treatment of diabetic ketoacidosis using 2009 American Diabetes Association guidelines

Background: During 2009, new guidelines for the treatment of diabetic ketoacidosis were published by the American Diabetes Association. Aim: To assess the impact of new treatment guidelines on the evolution of patients treated for diabetic ketoacidosis (KAD). Patients and Methods: Anonymous data was obtained from computational medical records of patients treated for KAD at our institution two years before (“Traditional Protocol”) and TWO years after (“ADA-2009 Protocol”) the publication of the 2009 American Diabetes Association (ADA) KAD guidelines. Results: Twenty three patients aged 36.5 ± 15.1 years were treated with the traditional method and 23 patients aged 44.4 ± 21.1 years were treated following 2009 ADA guidelines. Among patients treated with the traditional protocol and treated following ADA 2009 guidelines, the diabetes type 1/type 2 ratio was18/5 and 19/16 respectively (p = NS), the glycosylated hemoglobin on admission was 12.6 ± 2.5 and 14.3 ± 2.7% respectively (p = 0.03), minimal blood pH was 7.15 ± 0.14 and 7.19 ± 0.09 respectively (p = NS), bicarbonate was required in seven and no patient respectively (p = 0.01), hypokalemia < 3.5 mEq/L occurred in 78.2 and 48.5% of patients (p = 0.03), the lapse until resolution was 28.7 ± 28.0 and 28.8 ± 20.6 hours (p = NS). Only one patient, treated following ADA 2009 guidelines, died. Conclusions: Introduction of the ADA-2009 protocol for the treatment of KAD resulted in decrease in the use of intravenous bicarbonate and a reduction in the incidence of hypokalemia. There was no impact neither in the lapse until resolution or lethality.

Proceso de alta hospitalaria, revisión de la literatura / The discharge process

Discharge is one of the most important processes that hospitalized patients must endure. This process is complex, requires coordination among several professionals and transfers an overwhelming amount of information to patients. Often, it is limited to the writing of the discharge summary, with a primary emphasis on the drug list. Since the rise of hospitalism in 1996, a greater emphasis has been placed on understanding this process and in developing interventions to make it more effective and safe. In our country, little is known about how this process is taking place. Probably the absence of financial penalties for readmissions has influenced in the lack of study and development of this process. In the USA the knowledge of the discharge process is well advanced, and several strategies have been developed for reducing adverse events, medication errors, and 30-days readmissions. Other interventions have increased patient satisfaction and the degree of knowledge about their conditions. The aim of this paper is to do a comprehensive review of the literature, to provide healthcare teams with various tools that could improve both the discharge process as well as the discharge summary. The final objective is to optimize the safety and satisfaction of our patients and the hospital metrics of quality.

Eficacia y seguridad del tratamiento anticoagulante oral con antagonistas de vitamina k en pacientes con prótesis valvulares cardíacas / Safety and efficacy of anticoagulation with vitamin k antagonists in patients with prosthetic heart valves

Introducción: Los pacientes con válvulas mecánicas cardíacas (VMC) representan una proporción significativa del total de pacientes que requieren anticoagulación. Sin embargo, hay pocos estudios que comparen la efectividad de la anticoagulación con distintos antagonistas de vitamina K (AVK). Objetivo: Comparar la efectividad y seguridad del tratamiento con warfarina y acenocumarol en pacientes con VMC. Métodos: Estudio observacional de pacientes en po-liclínico de anticoagulación UC sometidos a recambio valvular entre los años 2005 y 2013. Se estandarizó las dosis de AVK con software Isaza Hytwin Biostac 2.0. Se evaluaron registros de hemorragia mayor y menor (seguridad) y accidentes vasculares y embolías sistémicas (efectividad). La efectividad se analizó mediante el tiempo en rango terapéutico (TTR) con método de Ro-sendaal. Resultados: Se incluyó 365 pacientes con edad promedio de 64,1 +/- 13,2 años, 53,9 por ciento de sexo femenino. El seguimiento promedio fue de 33,3 +/- 18 meses; La mortalidad registrada fue 2,1 por ciento. El promedio de TTR fue 68 +/- 13,3 por ciento (recambio aórtico TTR 66,1 +/- 12,6 por ciento, recambio mitral TTR 65,8 +/- 13,8 por ciento y recambio mitro-aórtico TTR 61,2 +/- 12 por ciento). Acenocumarol presentó un TTR menor que warfarina (65,1 +/- 13,1 vs. 71,2 +/- 13,6, p = 0,001), sin aumento del riesgo de complicaciones. Conclusión: Aunque warfarina ofrece un mejor perfil de TTR, no existen diferencias significativas en la eficacia o seguridad al compararla con acenocumarol.

Background: Patients with cardiac mechanical valves (MHV) represent a significant proportion of all patients requiring anticoagulation. However, there are few studies comparing safety and efficacy of different vitamin K antagonists (VKA). Aim: To compare the efficacy and safety of warfarin and acenocoumarol in patients with MHV. Methods: Observational study of patients who had a mitral and /or aortic valve replacement between 2005 and 2013, followed at the Catholic University anticoagulation clinics. VKA dose adjustments were performed using the Isaza Hytwin Biostac 2.0 software. Major and minor bleeding (safety) and stroke and systemic embolism (effectiveness) were evaluated. The efficacy was estimated by the time in therapeutic range (TTR) with the Rosendaal method. Results: 365 patients were included with a mean age of 64.1 +/- 13.2 years, 53.9 percent of them were females. Mean follow-up was 33.3 +/- 18 months Overall mortality rate was 2.1 percent, which is similar to that of patients treated with VKA for other reasons. The average TTR was 68 +/- 13.3 percent (66,1 +/- 12,6 percent for aortic valves, 65,8 +/- 13,8 percent for mitral valves and 61,2 +/- 12 percent for aortic and mitral valves). TTR was lower with acenocoumarol compared to warfarin (65.1 +/- 13.1 vs. 71.2 +/- 13.6 , p = 0.001 ), However, the risk of complications was not different between groups. Conclusions: Although warfarin provides a better profile of TTR , there were no significant differences in efficacy or safety when compared with acenocoumarol.

Controversias en tromboembolismo pulmonar masivo / Controversies in massive pulmonary embolism

Massive pulmonary embolism (PE) is associated with high mortality. There is still a broad assortment of severity classifications for patients with PE, which affects the choice of therapies to use. The main clinical criteria for defining a PE as massive is systemic arterial hypotension, which depends on the extent of vascular obstruction and the previous cardiopulmonary status. Right ventricular dysfunction is an important pathogenic element to define the severity of patients and short term clinical prognosis. The recommended treatment is systemic thrombolysis, but in centers with experience and resources, radiological invasive therapies through catheters are useful alternatives that can be used as first choice tools in certain cases.

Tromboembolismo pulmonar: estratificación de riesgo y dilemas terapéuticos / Risk stratification of pulmonary thromboembolism

Background: The prognosis of pulmonary thromboembolism (PE) is related to the cardiopulmonary reserve of the patient and the magnitude of the embolus that impacts pulmonary circulation. The presence of hemodynamic instability (shock) stratifies a group of patients with high mortality, which should be treated with thrombolysis. Patients without shock but with right ventricular dysfunction can have a dismal evolution and should be managed aggressively. CAT scan, echocardiography and serum markers can be of value to define patients with a higher mortality. The available evidence to define the best diagnostic and therapeutic strategy is scanty, controversial and inconclusive. A good combination of clinical, imaging and biological markers should be defined to identify those patients without shock but with a high rate of complications and mortality, that could benefit from aggressive treatments.

Reanimación cardiopulmonar básica: conocimiento teórico, desempeño práctico y efectividad de las maniobras en médicos generales / Basic cardiopulmonary resuscitation: knowledge, practical skills and effectiveness of maneuvers of general physicians

Background: General physicians should be adequately trained to deliver effective resuscitation during ventricular fibrillation (VF). Aim: To assess the degree of knowledge, skills and practical effectiveness in cardiopulmonary resuscitation (CPR) of Chilean general physicians. Materials and Methods: Forty eight general physicians starting Anesthesiology or Internal Medicine residency programs were evaluated. They answered a modified American Heart Association Basic Life Support Course written test and individually participated in a witnessed VF cardiac arrest simulated scenario. Execution of resuscitation tasks in the correct order, the quality of the maneuvers and the use of defibrillator were registered. Results: All participants acknowledged the importance of uninterrupted CPR and early defibrillation. Seventy five percent knew the correct frequency of chest compressions, but only 6.25% knew all the effective chest compression characteristics. Ninety eight percent knew the recommended number of breaths per cycle. In practice, 58% performed effective ventilations, 33% performed uninterrupted compressions, 14% did them with adequate frequency and only 8% performed chest compressions adequately. Forty four percent requested a defibrillator within 30 seconds and 31% delivered the first defibrillation within 30 seconds of defibrillator arrival. Airway, breathing, circulation and defibrillation sequence was correctly performed by 12% of participants and 80% acknowledged that their medical training was inadequate or insufficient for managing a cardiac arrest. Conclusions: Despite an elevated degree of knowledge about key aspects of CPR, this group of Chilean physicians displayed suboptimal practical skills while performing CPR in a simulated scenario, specially delivering effective chest compressions and promptly asking for and using the defibrillator.

Nuevos anticoagulantes orales / New oral anticoagulant drugs

Thromboembolic disease (TED) is the leading cause of morbidity and mortality worldwide. The hallmark of oral long-term anticoagulant therapy has been the use of vitamin K antagonists, whose anticoagulant effect is exerted inhibiting vitamin K epoxide reductase. Warfarin and acenocoumarol are the most commonly used. In the last five years several new drugs for long term anticoagulation have been developed, which can inhibit single clotting factors with the purpose of improving drug therapeutic range and, ideally, minimizing bleeding risks. This review addresses the state of the art on the clinical use of inhibitors of activated factor X and thrombin.

Profilaxis de enfermedad tromboembólica en pacientes hospitalizados con patología médica, estrechando la brecha entre las guías y la práctica clínica / Strategies for the prophylaxis of thromboembolic disease among medical patients

Thromboembolic disease is the main preventable cause of in-hospital death. Approximately 10 percent of nosocomial deaths are attributable to pulmonary embolism and in most cases, the diagnosis is not suspected before the autopsy. There are cost effective measures to decrease the incidence of thromboembolic disease. Pharmacological prophylaxis decreases the incidence of deep venous thrombosis by 65 percent and the incidence of pulmonary embolism by 35 to 55 percent. Despite this data and the presence of clinical guidelines, prophylaxis of thromboembolic disease is used only in 40 percent of medical patients and in 65 percent of surgical patients with recommended indications. We review the evidence that supports the use of thromboprophylaxis and the different strategies that may increase the compliance of physicians with its use. A protocol implemented in our institution is also proposed.

Diagnóstico y manejo de la hipoglicemia en adultos diabéticos hospitalizados: evaluación de competencias en un equipo profesional multidisciplinario de salud / Competences on hypoglycemia management among healthcare professionals in a clinical hospital

Background: A tight glycemic control of hospitalized patients increases the risk of hypoglycemia, whose management is not always optimal. Aim: To assess the hypoglycemia management competences of a multidisciplinary team in a clinical hospital. Material and Methods: An anonymous questionnaire about hypoglycemia management was answered by 11 staff physicians, 42 residents and 28 nurses of the department of medicine and critical care unit ofa university hospital. Results: Respondents had a mean of 60 percent of correct answers, without significant differences between groups. The capillary blood glucose level that defines hypoglycemia was known by most of the respondents, but the value that defines severe episodes was known only by 60 percent. The initial management and follow up was well known only for severe episodes. Less than 50 percento knew the blood glucose value that required continuing with treatment. Conclusions: Although most professionals are able to recognize hypoglycemia, the knowledge about is management if insufficient.

Hipoglicemia recurrente como causa reversible de síndrome demencial en adultos mayores diabéticos, a propósito de un caso / Cognitive impairment probably related to repeated episodes of hypoglycemia. Report of one case

We report a 78 year-old diabetic woman, treated with gliburide and metformin, consulting in the emergency room for a non fuctuating impairment in consciousness. She had a history of similar episodes in the last two months. A brain CAT scan showed an old putamen lacunar infarction. Noteworthy was the presence of a low glycosilated hemoglobin level of 5.2 percent. Hypoglycemic medications were discontinued and the patient was discharged in good conditions. After six months of follow up, the patient did not have further episodes of impairment of consciousness.

Enfrentamiento de la hiponatremia: Más allá de la corrección del sodio. A propósito de un caso clínico / Secondary adrenal insufficiency presenting as hyponatremia: Report of one case

Hyponatremia can be a marker of an underlying disease. We report a 52 years-old male with Diabetes Mellitus who consulted for an episode of nausea and vomiting lasting four days. His baseline serum sodium was 118 mEq/L. He had no neurological deficit. Hyponatremia was initially interpreted in context of gastrointestinal fluid loss but correction with saline solution was poor. His urine sodium was 105 mEq/L and his urine osmolality was 281 mOsm/L, so an Inappropriate Secretion of Antidiuretic Hormone Syndrome was suspected. Later, we found that the patient had a two year history of fatigue, weakness, anorexia, frequent nausea, vomiting and diarrhea, loss of libido and decreased axillary and pubic hair. Thyroid-Stimulating Hormone (TSH) was normal and serum Cortisol < 1 µg/dL. A CT scan showed a sellar mass compatible with a macroadenoma. There was also a moderately high serum prolactin and low testosterone, thyroxin and growth hormone levels. The visual fi eld exami-nation showed right temporal hemianopsia. The patient was treated with steroids with a very good clinical response and serum sodium normalization. Subsequently a transsphenoidal excision of the tumor was performed and replacement of the other hormones was started. Now the patient remains asymptomatic.

Medicina hospitalaria / Hospital Medicine

Hospital medicine was created over 10 years ago aiming to provide an integral care to hospitalized patients. Hospital specialists are physicians mainly devoted to the global care of hospitalized patients. Their professional functions include patient care, teaching, clinical research and managing activities. The main difference with other specialties is their exclusive dedication to hospital work. The impact of this specialty on patient care has been demonstrated by a significant reduction in the hospitalization days and costs and higher level of patient satisfaction. In clinical hospitals, the presence of tutors during the complete working day, has resulted in better pre and postgraduate teaching activities and a higher availability of supervisors for trainees. Four years ago, hospital medicine was established as a discipline at the Clinical Hospital of Pontificia Universidad Católica de Chile. In this period, these specialists became essential for student training and an integral part of the faculty staff.

Fiebre de origen desconocido como forma de presentación atípica de mieloma múltiple: Caso clínico / Fever of unknown origin caused by multiple myeloma: Report of one case

Fever of unknown origin (FUO) can be caused by tumors, especially those arising from the hematopoietic system. Multiple myeloma can also cause fever but it is not a common cause of fever of unknown origin. We report a 53 year-old man presenting with fever lasting eight weeks. An extensive study for common causes of FUO was negative. The appearance of hypercalcemia and proteinuria during the evolution suggested the presence of a multiple myeloma, that was confirmed with a bone marrow biopsy. Thalidomide and dexametasone were prescribed with resolution of fever.