Cardiocirculatory changes in hemorrhagic shock induced in pigs submitted to three distinct therapeutic methods / Alterações cardiocirculatórias no choque hemorrágico induzido em suínos submetidos a três terapias distintas

PURPOSE: To evaluate and compare the response of pigs submitted to hemorrhagic shock and treated using three different strategies. METHODS: Thirty-five Dalland pigs were divided into four groups: Control; Bleeding; Saline and Saline + Red Cell Concentrate. Parameters evaluated: heart rate (HR), mean arterial blood pressure (MAP) and central vein pressure (CVP).Hemorrhagic shock was induced by removing (624.25±64.55), (619.30±44.94) and (664.23±39.96) ml of blood respectively, with the following treatment: Bleeding Group - zero volume replacement; Saline Group - replacement with 676 ml of 0.9 percent saline solution; Saline + Red Cell Concentrate Group - replacement with 440 ml of 0.9 percent saline solution + 291 ml of red cell concentrate. The treatment was evaluated after 10 (T3), 30 (T4), 45 (T5) and 60 (T6) minutes. RESULTS: HR: No statistically significant difference was found between the Bleeding and Saline [p=1.000], Bleeding and Saline + Red Cell Concentrate [p=1.000], and Saline and Saline + Red Cell Concentrate [p=0.721] groups. MAP; Significant differences were found between all the groups studied. CVP: No significant difference was found between the groups. CONCLUSION: Non-replacement and euvolemic resuscitation maintained a satisfactory hemodynamic pattern in controlled severe hemorrhagic shock in swine. The euvolemic replacement strategies exceeded the limit values of MAP for rebleeding.

OBJETIVO: Avaliar e comparar as respostas cardiocirculatórias em suínos tratados por três terapias diferentes após choque hemorrágico. MÉTODOS: Trinta e cinco suínos Dalland foram divididos em quatro grupos: Controle; Sangria; Salina; Salina + Concentrado de hemácias. Parâmetros cardiocirculatórios avaliados: Frequência cardíaca (FC), pressão arterial média (PAM) e pressão venosa central (PVC). O choque hemorrágico foi induzido retirando (624,25±64,55) (619,30±44,94) e (664,23±39,96) ml do volume sanguíneo. Terapias: Grupo Sangria - Sem reposição volêmica; Grupo Salina - reposição com 676 ml de solução salina 0.9 por cento; Grupo Salina + Concentrado de hemácias - reposição com 440 ml de solução salina 0,9 por cento + 291 ml de concentrado de hemácias. A avaliação do tratamento foi realizada aos 10 (T3), 30 (T4), 45 (T5) e 60 minutos (T6). RESULTADOS: FC; Não houve diferença significativa entre os grupos Sangria e Salina [p=1,000]; Sangria e Salina + Concentrado de hemácias [p=1,000]; Salina e Salina + Concentrado de hemácias [p=0,721]. PAM; Houve diferença entre todos os grupos. PVC; Não houve diferença entre os grupos estudados. CONCLUSÃO: Os procedimentos sem reposição e com reposição euvolêmica mantiveram padrão hemodinâmico satisfatório no choque hemorrágico grave controlado em suínos. As estratégias de reposição euvolêmica ultrapassaram os valores de PAM considerados limites para o resangramento.

Alternativas a la transfusión sanguínea: sustitutos sanguíneos (artículo de revisión) / Alternatives to blood transfusions: blood's sustitutes

El sustituto sanguíneo ideal es aquel que logra reponer volumen y a la vez tiene la capacidad de transportar de oxígeno. Actualmente existen sustancias que tienen una u otra cualidad y algunas podrían tener ambas; como las soluciones de hemoglobina y las emulsiones de perfluorocarbonados que aún se encuentran en estudio. Así, también se han utilizado tratamientos farmacológicos que funcionan profilácticamente para evitar el sangrado o tratar anemias severas sin recurrir al uso de transfusiones sanguíneas. Se presenta una revisión sobre estos temas y algunos puntos de vista controversiales sobre las transfusiones sanguíneas.

Vasoactive proterties of synthetic blood substitutes

There is a great need for the development of a safe and efficient blood substitute, to overcome the important limitations of homologous blood transfusion. Currently available cell-free hemoglobin-based oxygen-carrying solutions present oxygen transport and exchange properties similar to blood and potential benefits over conventional transfusion, including large supply, absence of transfusion reactions, no need for cross-matching, no risk for transmission of disease and long shelf life. Several experimental studies have suggested that cell-free hemoglobin is a vasoactive agent. In animal models of hemorrhagic shock, small doses of cell-free modified hemoglobin restore arterial pressure, promote adequate tissue oxygenation, and improve survival, when compared with fluids with no oxygen-carrying capacity. On the other hand, it has been demonstrated that hemoglobin-induced vasocontriction may result in decreased cardiac output, reduced blood flow to vital organs and severe pulmonary hypertension. Cell-free hemoglobin solutions cause their pressor effects by binding and scavenging nitric oxide. Although hemoglobin within the red blood cells is the natural scavenger of NO, when the hemoglobin is free in solution, NO is inactivated to a greater extend. Cell-free hemoglobins are on advanced clinical trials, despite the fact that development of a safe and efficient blood substitute depends on the availability of these products for critical evaluation by the scientific community before the widespread clinical use of these blood substitutes.

Los sustitutos sanguíneos en el paciente hipovolémico / Blood substitutes in the hypovolemic patient

Objetivo. Presentar un breve análisis de las diferentes alternativas utilizadas como sustitutos de la sangre en la hipovolemia. Obtención de datos. Se definieron las propiedades ideales de un sustituto de la sangre y con base en ellos se seleccionó la información. Selección de estudios. Se tomaron 19 artículos que contuvieron información de la propiedades ideales y fueran comparativos, aleatorios o de revisión del tema. Extracción de datos. Se tomaron parámetros en cuanto a tiempo, grado de recuperación, parámetros hemodinámicos, capacidad de transporte de oxígeno, efecto en microcirculación, facilidad de manipulación y de almacenamiento, y se integraron en cuadros comparativos. Resultados. la solución hipertónica-hiperoncótica presentó los mejores resultados en todos los parámetros evaluados, al igual que el almidón. Sólo son superados en el transporte de oxígeno por los fluorocarbones. La hemoglobina sintética requiere proceso de elaboración y de almacenamiento complicados y costosos. Conclusión. No hay sustituto sanguíneo ideal, y el producto que más se aproxima es la solución hipertónica-hiperoncótica. Falta aún desarrollo de tecnología y de ensayos clínicos en el tema

Factors which affect growth of amniotic fluid cells.

In a study on various factors which are known to influence the growth of amniotic fluid cells for successful cytogenetic analysis in 89 samples, amniotic fluid volume greater than 10 ml enhanced the chance of success (P = 0.0003). The presence of red blood cells reduced the success rate although this was not statistically significant. Among the techniques which proved successful were the use of closed culture method (plastic flasks in which 5% CO2 is blown), and the addition of Ultroser G, which enhances the adhesion and growth of amniotic fluid cells.