Eficacia de la diálisis con albúmina en el tratamiento de los pacientes con insuficiencia hepática avanzada: primera experiencia en España con el sistema mars / Efficacy of dialysis with albumin for the treatment of patients with advanced liver failure: first experience in Spain with mars system

En la insuficiencia hepática existe una acumulación de sustancias tóxicas debido a la pérdida de función del hígado. Se han realizado varios intentos para eliminar dichas sustancias con numerosas técnicas con resultados diversos y no del todo satisfactorios. Recientemente hemos iniciado en nuestro centro la utilización del sistema MARS (Molecular Adsorbent Recirculating System) para el tratamiento de 3 pacientes con insuficiencia hepática avanzada. Este sistema se compone de un circuito por el que pasa la sangre a través de una membrana de alta permeabilidad e impregnada de albúmina, frente a una solución de diálisis rica en albúmina (20 por ciento). Este dializado recircula por un compartimento de regeneración de la albúmina compuesto por una columna de carbón y otra de intercambio de aniones. Antes de ser regenerada, la solución de albúmina pasa por un dializador con una membrana de baja permeabilidad frente a una solución de diálisis de bicarbonato.Este sistema nos va a permitir la eliminación tanto de sustancias hidrosolubles como de aquellas unidas a la albúmina, que hasta ahora con los métodos convencionales no podían ser eliminadas. Establecimos una serie de criterios de inclusión para aplicar este tratamiento a aquellos pacientes que presentarán una insuficiencia hepática severa y algunas de sus complicaciones. En todos los pacientes se realizó una valoración clínica y bioquímica completa antes y después de cada sesión de MARS y tras cada ciclo de tratamiento. En los 3 pacientes se obtuvo una mejoría tanto clínica (desaparición del prurito y mejoría de la encefalopatía) como bioquímica (disminución de bilirrubina). Coincidiendo con la técnica, en dos de los pacientes se observó un aumento de la creatinina junto a una disminución de la diuresis. No se produjeron complicaciones hemodinámicas ni relacionadas con la técnica. Estos primeros resultados son interesantes, por lo que serán necesarios estudios controlados que permitan confirmarlos. (AU)

Oral microemulsion cyclosporine in the treatment of steroid-refractory attacks of ulcerative and indeterminate colitis.

BACKGROUND: To assess the efficacy of oral microemulsion cyclosporine (CyA Neoral) in the treatment of steroid-refractory attacks of ulcerative an indeterminate colitis. METHODS: In this non-randomized study on the use of oral microemulsion cyclosporine in steroid refractory ulcerative colitis, we used CyA Neoral in 10 patients suffering from ulcerative colitis and in 1 patient suffering from indeterminate colitis with a steroid-refractory attack. The initial dose was 7-7.5 mg kg-1 day-1 adjusted to maintain whole blood cyclosporine levels between 250 and 350 ng/mL, as measured by RIA using monoclonal antibodies. RESULTS: Nine patients presented a favourable response in a mean time of 3.6 days, that is, 81.8% of cases. One initial responder developed megacolon on the 11th day and another did not respond; surgical treatment was performed in both cases. The remaining nine patients, followed for a mean period of 14.6 months (2-36 months). Nine patients presented side effects, the most frequent being slight hand tremor with hypomagnesaemia, followed by hypertension, slight increase in creatinine and hirsutism. No one needed to withdraw from treatment, but the dose was lowered in three cases. CONCLUSIONS: Oral microemulsion cyclosporine is an effective drug in the initial management of patients suffering from a steroid-refractory attack of ulcerative and indeterminate colitis. Additional controlled studies with the new oral formulation are required to confirm these results.

[Efficiency of dialysis with albumin in the treatment of patients with advanced hepatic insufficiency: initial experience with the MARS system in Spain]. / Eficacia de la diálisis con albúmina en el tratamiento de los pacientes con insuficiencia hepática avanzada: primera experiencia en España con el sistema MARS.

During liver failure there is an accumulation of toxic substances secondary to the loss of liver function. In order to eliminate these substances various extracorporeal depuration therapies have been employed. Recently, we have used a new treatment, MARS (Molecular Adsorbent Recirculating System), in 3 patients diagnosed with severe liver failure. This system consists of an albumin rich (20%) dialysate circuit, with two areas of depuration. In one area, the albumin dialysate is in contact with blood through a high-flux albumin coated membrane, where albumin bound substances are eliminated. In the other area, the albumin dialysate is in contact with a standard bicarbonate dialysate through a low-flux membrane, which permits the elimination of water soluble substances. The albumin of the circuit is continuously regenerated through charcoal and ion exchanger filters. In order to determine those liver failure patients suitable to receive MARS therapy we established several inclusion criteria. All patients underwent a complete clinical and biochemical evaluation before and after each treatment. All of them showed an improvement of their clinical (attenuation of pruritus and encephalopathy) and biochemical (decrease of bilirubin levels) parameters. During the period of treatment 2 patients developed an increase in plasma creatinine levels together with a decrease of urinary volume. There were no hemodynamic or technical complications during the treatment. These promising results deserve further controlled studies large enough to permit confirmation.

Effect of inflation on microvascular pressures in lungs of young rabbits.

We have examined the effect of positive pressure inflation on the longitudinal distribution of vascular resistance and intravascular pressures in isolated blood-perfused lungs of 3- to 4-wk-old rabbits. Lungs were perfused in zone 3 at airway inflation pressures (P airway) of 6, 14, and 19 cmH2O (pleural pressure, atmospheric) corresponding to 60, 80, and 90% of total lung capacity. We measured microvascular pressures by the micropipette servo-nulling technique in 20- to 50-microns diameter subpleural arterioles and venules. Pulmonary arterial and left atrial pressures were also measured. Lung blood flow was kept constant at 145 +/- 18 ml X kg body wt-1 X min-1. We found that at P airway of 6 cmH2O, approximately 55% of the total pressure drop was in arteries, approximately 23% in microvessels, and approximately 22% in veins. With increasing P airway and lung volume, there was a significant decrease in arterial and venous resistance, but an increase in resistance in microvessels. We conclude that lung inflation significantly alters the distribution of segmental vascular resistance, and therefore lung volume is an important variable that should be considered during estimation of capillary filtration pressure.

Micropuncture measurement of lung microvascular pressure profile in 3- to 4-week-old rabbits.

We have reported the longitudinal distribution of vascular resistance in the three segments (arteries, microvessels, and veins) of the pulmonary circulation of adult rabbits (J Appl Physiol 60:539-545, 1986). To determine the longitudinal distribution of vascular resistance in lungs of younger animals, we measured microvascular pressures in the subpleural microcirculation in nine isolated blood perfused lungs of 3- to 4-wk-old rabbits. We used micropipettes and the servonull pressure measuring system to directly measure pressures in 20-50 microns diameter subpleural arterioles and venules. We also measured pulmonary arterioles and venules. We also measured pulmonary arterial and left atrial pressures and lung blood flow. To determine the influence of vascular tone on segmental vascular resistance, in four lungs we measured microvascular pressures both before and after paralyzing the vasculature with papaverine. We found that 51% of the total pressure drop in the pulmonary circulation was in arteries, 24.5% in microvessels, and 24.5% in veins. Vascular tone contributed minimally to baseline arterial resistance. The greater arterial and venous resistance in lungs of 3- to 4-wk-old rabbits as compared to that in adult rabbits is probably due to differences in vessel geometry.