Guía de recomendaciones para la profilaxis de la enfermedad tromboembólica venosa en adultos en la Argentina / Venous thromboembolic prophylaxis: Guidelines for adults in Argentina

La enfermedad tromboembólica venosa (ETV) en adultos posee elevada morbimortalidad y puede asociarse a complicaciones crónicas invalidantes. Sin embargo, la adherencia a estándares de cuidado no es óptima. Se analizó la evidencia disponible en tromboprofilaxis y se generaron recomendaciones (1) o sugerencias (2) con diferentes grados de evidencia (A, B o C) para diferentes escenarios y métodos de tromboprofilaxis. En cirugías ortopédicas mayores se recomienda la profilaxis farmacológica con heparinas de bajo peso molecular, HBPM (1B), fondaparinux, dabigatrán y rivaroxaban (1B) que deben iniciarse durante la internación y mantenerse hasta 35 días después de la cirugía de cadera y hasta 10 días posteriores a la artroplastia de rodilla. La artroscopia de rodilla y la cirugía de columna programada no requieren profilaxis farmacológica (2B) salvo que posean factores de riesgo adicionales, en cuyo caso se recomiendan las HBPM. En pacientes con internación clínica y movilidad reducida esperable mayor a tres días, que posean factores de riesgo adicionales, se recomienda tromboprofilaxis con HBPM, HNF o fondaparinux (1B) hasta el alta. Aquellos pacientes neuroquirúrgicos o con HIC deberán recibir inicialmente tromboprofilaxis mecánica (2C) y dependiendo del caso, iniciar HBPM o HNF entre las 24-72 horas posteriores (2C). Estas últimas dos drogas son recomendadas para pacientes críticos. Los pacientes sometidos a cirugías no ortopédicas con bajo riesgo de ETV deberán realizar deambulación precoz (2C) y tromboprofilaxis mecánica (2C), mientras que aquellos en los que el riesgo de ETV sea elevado deberán recibir HBPM y HNF (1B o 2C según su riesgo de sangrado).

The venous thromboembolic disease (VTD) in adults has a high morbidity and mortality. It can be also associated to disabling chronic conditions. In spite of this, prophylaxis in healthcare assistance is still underused. In this article, the available evidence in thromboprophylaxis was analyzed to offer recommendations (1) or suggestions (2) classified according to different levels of evidence (A, B or C). Different medical scenarios and types of thromboprophylaxis were analyzed. In major orthopedic surgeries low molecular weight heparins, LMWH, inhibitors of the Xa and IIa factors are recommended (1B) to be started during hospitalization and continued for 35 days in hip replacement surgery and for 10 days in total knee replacement surgery. Knee arthroscopy and spine surgery do not require pharmacologic treatment (2B) unless the patient has other risks factors for thrombosis. In such cases, LMWH are recommended. Non-surgical patients who have at least one risk factor should receive LMWH, NFH or fondaparinux (1B) if they are to be bedridden or unable to walk for three or more days. Patients undergoing neurosurgery or with intracranial hemorrhage should receive mechanic prophylaxis (2C), and accordingly they should start LMWH or NFH 24 to 72 hours afterwards (2C). The latter two drugs are recommended for critically ill patients. Patients with low risk for VTD undergoing other type of surgeries should be prescribed with mechanical prophylaxis (2C) and encouraged to walk promptly (2C), while those with high risk should be prescribed with LMWH or NFH (1B or 2C according to bleeding risk factors).

Guía de recomendaciones para la profilaxis de la enfermedad tromboembólica venosa en adultos en la Argentina / [Venous thromboembolic prophylaxis. Guidelines for adults in Argentina].

The venous thromboembolic disease (VTD) in adults has a high morbidity and mortality. It can be also associated to disabling chronic conditions. In spite of this, prophylaxis in healthcare assistance is still underused. In this article, the available evidence in thromboprophylaxis was analyzed to offer recommendations (1) or suggestions (2) classified according to different levels of evidence (A, B or C). Different medical scenarios and types of thromboprophylaxis were analyzed. In major orthopedic surgeries low molecular weight heparins, LMWH, inhibitors of the Xa and IIa factors are recommended (1B) to be started during hospitalization and continued for 35 days in hip replacement surgery and for 10 days in total knee replacement surgery. Knee arthroscopy and spine surgery do not require pharmacologic treatment (2B) unless the patient has other risks factors for thrombosis. In such cases, LMWH are recommended. Non-surgical patients who have at least one risk factor should receive LMWH, NFH or fondaparinux (1B) if they are to be bedridden or unable to walk for three or more days. Patients undergoing neurosurgery or with intracranial hemorrhage should receive mechanic prophylaxis (2C), and accordingly they should start LMWH or NFH 24 to 72 hours afterwards (2C). The latter two drugs are recommended for critically ill patients. Patients with low risk for VTD undergoing other type of surgeries should be prescribed with mechanical prophylaxis (2C) and encouraged to walk promptly (2C), while those with high risk should be prescribed with LMWH or NFH (1B or 2C according to bleeding risk factors).

Dry matter production and partitioning of maize hybrids and dwarf unes at four plant populations / Produção e distribuição de matéria seca de híbridos e linhagens anãs de milho em quatro populações

This experiment was conducted in Ames, Iowa, USA, to compare dry matter accumulation patterns of maize genotypes contrasting in height and leafiness, and to test whether reduction in plant height an leaf number through the use of dwarfing genes or earliness can improve grain dry matter allocation. Five plant genotypes were tested: a full season hybrid adapted to central lowa (NK 4525), a short season hybrid adapted to northern Minnesota (C1070), and three dwarf lines (156-A, 302-E and I17- A). The dwarves contained, respectively, the homozygous, independent, recessive dwarfing genes d3, d1 and br2. Each genotype was sown at four plant populations: 25, 50, 75 and 100.000 plants. ha-1. Hybrids had the greatest rates of decrease in total biomass and grain dry matter per plant when population was increased, though they also had larger absolute values of these variables at any given density. Hybrids produced more grain dry matter per unit of leaf area, and a higher harvest index, regardless the plant population used. Reduction in plant height or leaf number did not improve maize efficiency in producing and partitioning dry matter to the grain.

Este experimento foi conduzido em Ames, Iowa, Estados Unidos, tendo como objetivos comparar os padrões de produção e distribuição de matéria seca de genótipos de milho contrastantes quanto a estatura e número de folhas, e verificar se a redução nestas características, mediante a utilização de genes para nanismo ou cultivares precoces, pode aumentar a eficiência da planta em alocar matéria seca para a produção de grãos. Cinco genótipos foram testados: um híbrido de ciclo normal adaptado à região central de lowa (NK 4525), um híbrido de ciclo precoce adaptado à região norte do estado de Minnesota (C 1070), e três linhagens anãs (156-A, 302-E and 117-A), contendo os genes recessivos de nanismo d3, d1 and br2, respectivamente Cada genótipo foi semeado em quatro populações, equivalentes a 25, 50, 75 e 100,000 plantas.ha-1. Os híbridos tiveram maiores laxas de redução na matéria seca dos grãos do que as linhagens anãs com o aumento na população. Contudo, eles também apresentaram maiores valores absolutos para esta variável do que os materiais de porte baixo em todas as densidades avaliadas. Os híbridos produziram maior quantidade de matéria seca de grãos por unidade de área foliar e maior índice de colheita do que as linhagens anãs. A redução na estatura ou número de folhas por planta não aumentou a eficiência do milho em alocar matéria seca para a produção de grãos.

Agronomic performance of male-sterile and fertile maize genotypes at two plant populations / Performace agronômica de genótipos macho-estéreis e férteis de milho em duas densidades de semeadura

This experiment was conducted in 1994 at Ames, Iowa, US to test whether cytoplasmic male-sterility can be used to decrease barrenness and to increase grain yield of maize at two plant populations. Four genotypes were tested: a hybrid (NK 6330) and an inbred, wifh sterile and fertile counterparts. Each genotype owas evaluated at plant populations equivalent to 25,000 and 75,000 pl. ha-1. Hybrids produced higher grain yield than inbreds at both plant populations. Gram yield was higher at 75,000 than at 25,000 pl. ha-1. No difference in gram yield, number of ears per plant, number of grains per ear, tassel length, and tassel number of branches was found between sterile and fertile counterparts of the inbred and hybrid, regardiess of plant population. Fertile genotypes bore heavier tassels at anthesis than their sterile counterparts. Adequate precipitation distribution and high fertility level in the soil probably decreased competition between tassel and ears, mitigating potential yield benefits of suppressing genetically pollen production.

Este experimento foi conduzido em Ames, Iowa, US durante o ano agrícola de 1994, tendo como objetivo avaliar se a macho-esterelidade genético-citoplasmática pode ser utilizada para aumentar o rendimento de grãos de milho em diferentes populações de planta. Quatro genótipos foram utilizados: um híbrido (NK 6330) e uma linhagem, ambos em suas versões fértil e macho-estéril. Cada genótipo foi avaliado em duas densidades de semeadura, equivalentes a 25.000 e 75.000 pl.ha-1. Os híbridos produziram maiores rendimentos de grão do que as linhagens nas duas populações utilizadas. O rendimento de grãos por área foi maior em 75.000 do que em 25.000 pl.ha-1. Nenhuma diferença significativa em termos de rendimento de grãos, número de espigas por planta, número de grãos por espiga, comprimento e número de ramos do pendão, foi observada entre genótipos férteis e macho-estéreis, independentemente da população de plantas. As versões férteis apresentaram pendões mais pesados do que os genótipos macho-estéreis. A adequada distribuição da precipitação e a alta fertilidade do solo possivelmente diminuíram a competição entre o pendão e as espigas, minimizando os benefícios da supressão genética da produção de pólen sobre o rendimento de grãos.