Andrés Aizman

Nuevos anticoagulantes orales

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.

Reanimación cardiopulmonar básica: conocimiento teórico, desempeño práctico y efectividad de las maniobras en médicos generales

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.

Evaluación de docentes clínicos de Postgrado: desarrollo y propiedades psicométricas del instrumento MEDUC-PG14

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.

Eficacia y seguridad del tratamiento anticoagulante oral con antagonistas de vitamina k en pacientes con prótesis valvulares cardíacas

Estudio observacional de pacientes en po-liclinico de anticoagulacion UC sometidos a recambio valvular entre los anos 2005 y 2013. Se estandarizo las dosis de AVK con software Isaza Hytwin Biostac 2.0. Se evaluaron registros de hemorragia mayor y menor (seguridad) y accidentes vasculares y embolias sistemi-cas (efectividad). La efectividad se analizo mediante el tiempo en rango terapeutico (TTR) con metodo de Ro-sendaal.

Evaluación de la anticoagulación con Rivaroxaban, en pacientes con fibrilación auricular no valvular de reciente diagnóstico.

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.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, CHA2DS2VASc 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 CHA2DS2VASc 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.

Proceso de alta hospitalaria, revisión de la literatura

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.

Correlación de valores de TTPa con anti factor Xa para establecer rango terapéutico en tratamiento anticoagulante con heparina sódica

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.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.

Profilaxis de enfermedad tromboembólica en pacientes hospitalizados con patología médica, estrechando la brecha entre las guías y la práctica clínica

Thromboembolic disease is the main preventable cause of in-hospital death. Approximately 10% 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% and the incidence of pulmonary embolism by 35 to 55%. Despite this data and the presence of clinical guidelines, prophylaxis of thromboembolic disease is used only in 40% of medical patients and in 65% 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.

Controversias en tromboembolismo pulmonar masivo

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.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

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.