Características de las heparinas de bajo peso molecular (HBPM) / Low-Molecular-Weight Heparins (LMWH)

Las heparinas de bajo peso molecular (HBPM) se obtienen a partir de la heparina no fraccionada (HNF) por diversos procedimientos, obteniéndose unos productos con un peso molecular entre los 3.000 y los 9.000 daltons. La heparina tiene una acción anticoagulante que ejerce mediante la formación de un compuesto ternario, uniéndose a la antitrombina y a la trombina (IIa), para lo que se necesitan 18 sacáridos. La otra acción antitrombótica sólo necesita 5 sacáridos para unirse a la antitrombina e inhibir el factor X activado. Como las HBPM tienen una gran proporción de cadenas de menos de 18 sacáridos, poseen una mayor capacidad antitrombótica (anti-Xa) que anticoagulante (anti-IIa). Además tienen una menor afinidad por las proteínas plasmáticas, por las células endoteliales y por los macrófagos que la HNF. Tienen una mayor biodisponibilidad y una eliminación más lenta, por lo que la vida media es más prolongada que en la HNF. Las HBPM tienen una respuesta antitrombótica predecible y no necesitan control de laboratorio, salvo en caso de insuficiencia renal importante, obesidad mórbida o embarazo. En estos casos hay que medir la actividad anti-Xa. Existen menos complicaciones hemorrágicas y trombopenia que con la HNF. Las HBPM disponibles en España son bemiparina, dalteparina, enoxaparina, nadroparina y tinzaparina cuyas características se revisan y se insiste en que son fármacos distintos y no intercambiables. Características de las heparinas de bajo peso molecular (HBPM) (AU)

Sospecha y diagnóstico del tromboembolismo pulmonar en la actualidad / No disponible

No disponible

[Risk factors of a new cardio-embolic cerebral accident in non-valvular atrial fibrillation treated with acenocoumarol]. / Factores de riesgo de un nuevo accidente cerebral cardioembólico en la fibrilación auricular no valvular tratada con acenocumarol.

OBJECTIVES: To investigate the risk factors determining the appearance of a new cardio-embolic cerebral accident on secondary thrombophylaxis of non-valvular auricular fibrillation (NVAF). DESIGN: Controlled observational study on a series of patients treated with acenocoumarol for a period of 2.8 years. SETTING: Anticoagulation Unit of the La Paz Hospital and patients from Madrid Area 5. PARTICIPANTS: 172 patients with NVAF, over 55 and with fibrillation for at least a year, and who had suffered at least one ischaemic cerebral accident. All were treated with acenocoumarol and controlled at an INR of 2.5. The risk factors were determined and the appearance of new cardio-embolic phenomena was watched during the study period. MEASUREMENTS AND MAIN RESULTS: 12 cardio-embolic phenomena were recorded (11 CVA and one peripheral embolism). The univariate study showed there was a significant association between patients who suffered a new ictus and those who suffered heart failure (p < 0.05) and had a history of more than one ictus before the start of the study (p < 0.05). Multivariate analysis found that what had independent predictive value was having suffered more than one ictus. CONCLUSIONS: The greatest threat for developing a new ischaemic CVA during anticoagulation in NVAF is having a history of two or more previous ictus, as if the tendency to recur was due to these patients having more extensive atherosclerosis.

Recomendaciones para el manejo de la enfermedad tromboembólica venosa en urgencias / Recommendations for the Emergency Ward managment (II). Managment of a burned patient

No disponible

Factores de riesgo de un nuevo accidente cerebral cardioembólico en la fibrilación auricular no valvular tratada con acenocumarol / Risk factors of a new cardio-embolic cerebral accident in non-valvular auricular fibrillation treated with acenocoumarol

Objetivos. Investigar los factores de riesgo que determinan la presentación de un nuevo accidente cerebral cardioembólico en la tromboprofilaxis secundaria de la fibrilación auricular no valvular (FANV).Diseño. Estudio observacional, controlado, sobre una serie de pacientes tratados con acenocumarol, durante un período de 2,8 años. Emplazamiento. Unidad de Anticoagulación del Hospital La Paz y enfermos del Área 5 de Madrid. Participantes. Un total de 172 pacientes con FANV, de más de 55 años, con antigüedad de la fibrilación de al menos un año, y que hubieran presentado al menos un accidente cerebral isquémico. Todos fueron tratados con acenocumarol y controlados a un international normalizad ratio (INR) de 2,5. Se precisaron los factores de riesgo y se vigiló la presentación de nuevos fenómenos cardioembólicos durante el tiempo de estudio. Mediciones y resultados principales. Se registraron 12 fenómenos cardioembólicos (11 ACV y un embolismo periférico). El estudio univariante demostró que había una asociación significativa entre los pacientes en que se manifestó un nuevo ictus y los que presentaban insuficiencia cardíaca (p < 0,05), así como antecedentes de más de un ictus previo al inicio del estudio (p < 0,05). Con estudio multivariante se comprobó que el que tenía valor predictivo independiente fue el de haber tenido más de un ictus. Conclusiones. La mayor amenaza para el desarrollo de un nuevo ACV isquémico durante la anticoagulación en la FANV es el antecedente de 2 o más ictus previos, como si la tendencia a recurrir obedeciera a que estos enfermos presentaran una aterosclerosis más extensa. (AU)

A placebo-controlled study of interaction between nabumetone and acenocoumarol.

AIMS: The use of nonsteroidal anti-inflammatory drugs (NSAIDs) in patients treated with oral anticoagulants is generally discouraged due to the risk of interactions that could increase the risk of bleeding complications. Available data suggest the NSAID, nabumetone, does not produce such an interaction. We investigated whether nabumetone would interact with acenocoumarol, an oral anticoagulant widely used in some European countries. METHODS: A double-blind, randomized, placebo-controlled study was conducted evaluating nabumetone (1-2 g daily for up to 4 weeks) in osteoarthritis patients with thromboembolic risk previously stabilized on acenocoumarol. The primary efficacy end point was the proportion of patients whose International Normalized Ratio (INR) remained within established margins and whose acenocoumarol dose was not changed. Fifty-six patients were randomized to receive nabumetone (n=27) or placebo (n=29). RESULTS: Eighteen patients in each group (67% for nabumetone and 62% for placebo) completed the study without showing INR or acenocoumarol dose changes, and were considered as study successes. Nine patients (33%) with nabumetone and 11 (38%) with placebo were considered study failures in the intention-to-treat analysis (one patient on nabumetone and four on placebo did not complete the study due to reasons not related to INR and acenocoumarol dose changes). No significant differences were found between groups with regard to study successes. There were two minor bleeding complications, one in each group. Six patients per group presented with eight adverse experiences in each group. CONCLUSIONS: Treatment with nabumetone did not alter INR levels compared with placebo in patients stabilized on oral acenocoumarol who require NSAID therapy. These results suggest that nabumetone does not produce a clinically relevant interaction with acenocoumarol. In orally anticoagulated patients without other associated risk factors, treatment with nabumetone for up to 4 weeks does not require increased monitoring of INR levels.

[An analog-digital system of external pressure for loco-regional treatment of deep venous thrombosis with fibrinolytics]. / Sistema analógico-digital de presión externa para tratamiento loco-regional de las trombosis venosas profundas con fibrinolíticos.

A new method, by external pressure, analogic-digital system, is presented to be used in loco-regional treatment of "Deep Venous Thrombosis" with fibrinolytic agents; in order to allow a great concentration of drug and a better derivation of it toward the deep venous system.

Coagulation abnormalities in patients with eosinophilia.

Haematological variables in patients with eosinophilia and in healthy control subjects were studied in order to determine whether there were abnormalities in the coagulation system in patients. We found significantly elevated levels of fibrinogen, fibrin degradation products, platelet number and beta-thromboglobulin in patients. The abnormalities were not related to the causes of eosinophilia nor to its severity. This lack of correlation could be due to the heterogeneity of human peripheral blood eosinophils.

Dysfibrinogenaemia associated with a defect in the aggregation of the fibrin monomers (Almeria I fibrinogen). A preliminary study.

A patient with functionally defective fibrinogen has been studied. Fibrinogen Almeria I was found to have a prolonged of latency time (LT) and a decrease in rate of gelation (RG) when plasma or isolated fibrinogen were activated by thrombin or reptilase. This fibrinogen also has the unusual formation of cross-linked fibrin; the existence of unpolymerized alpha chains was confirmed.

[Congenital deficiency of factor VII (author's transl)]. / Deficiencia congénita del factor VII.

Authors report a four month old patient, admitted to hospital because of blood in stools. Diagnosis of congenital deficiency of factor VII was established because such factor was practically absent; on the contrary, other coagulation factors were normal. His parents and sister presented a mild deficit of factor VII without clinical manifestations. An up-to date review of the problem is presented.

[Congenital factor VII deficiency (author's transl)]. / Déficit de factor VII.

A new case of factor VII congenital deficiency is presented in a four year old girl, with a factor VII level of 3.9%. The patient had no history of bleeding and her coagulation disorder was a casual finding. Clinical features of the disease and its therapeutic guidelines are discussed. It seemed appropriate to continue the study in order to evaluate the factor VII capacity of inhibiting an specific antibody, to confirm heterozygosity of partents and to prove that this case is a genetic variant of factor VII deficiency with good prognosis.