Valoración del grado de coagulación y del factor anti-Xa al introducir el dializador AN69ST® con heparina impregnada / Evaluation of coagulation and anti-Xa factor using a heparin-coated AN69ST® dialyser

Introducción: Los sistemas de hemodiálisis tienen capacidad trombogénica, por lo que se utiliza de forma rutinaria la anticoagulación. Su prescripción no se encuentra exenta de riesgos, a pesar de lo cual las recomendaciones respecto a la dosis pautada siguen basándose en criterios muy diversos. Métodos: Se realizó un estudio experimental aleatorizado y cruzado. Seis pacientes realizaron seis sesiones de hemodiafiltración posdilución con el dializador de polisulfona HF80® y anticoagulación habitual con nadroparina, y seis sesiones con el dializador AN69ST® de poliacrilonitrilo con una cubierta de heparina sin el uso de anticoagulación sistémica. Evaluamos cada hora el grado de coagulación del dializador y del circuito extracorpóreo mediante una escala visual y las variaciones en los parámetros de coagulación, entre los que se incluyó el factor anti-Xa. Nuestro objetivo primario fue valorar las variaciones en la actividad del factor anti-Xa en ausencia de diferencias en la tasa de coagulación masiva entre los dos grupos. Resultados: No se coaguló el dializador de forma completa o grado 4 en ninguna de las 36 sesiones realizadas con cada dializador. Se produjo una coagulación parcial del dializador inferior del 25% (grado 1-2) en 32 (88,9%) sesiones con AN69ST® y 35 (97,2%) con el dializador habitual, y superior del 25% (grado 3-4) en 4 (11,1%) sesiones con AN69ST® y en 1 (2,8%) sesión con el dializador con heparina. La coagulación del atrapaburbujas arterial no fue superior al 25% (grados 3 y 4) en ninguna de las sesiones estudiadas, y la cámara venosa en sólo 1 (2,8%) sesión con el dializador habitual y 3 (8,4%) con AN69ST® sin diferencias entre los dos dializadores. El (..) (AU)

Background: Haemodialysis systems are potentially thrombogenic, so anticoagulation is routinely used. Its prescription involves certain risks, despite which the recommendations regarding dosage are still based on very disparate criteria. Methods: We performed a randomised, crossed pilot study. Six patients underwent six sessions of post-dilution haemodiafiltration with a polysulfone HF80® dialyser and standard anticoagulation with nadroparin, and six sessions with heparincoated poliacrylonitrile AN69ST® membrane without the administration of systemic anticoagulation therapy. The coagulation level of the dialyser and extracorporeal circuit was evaluated every hour using a visual scale along with variation in clotting parameters such as anti-Xa factor. Our primary objective was to assess anti-Xa activity in the absence of differences in the rate of massive coagulation between the two groups. Results: No complete or grade 4 dialyser clotting occurred in any of the 36 sessions with either dialyser. Partial clotting of the dialyser occurred below 25% (grade 1-2) in 32 (88.9%) AN69ST® sessions and 35 (97.2%) sessions using the standard dialyser, and partial clotting surpassed 25% (grade 3-4) in 4 (11.1%) AN69ST® sessions and 1 (2.8%) dialysis session with heparin. Arterial chamber blood clotting did not surpass 25% (grade 3 and 4) in any of the studied sessions, and venous chamber coagulation occurred in only 1 (2.8%) session with the usual dialyser and in 3 (8.4%) sessions with the AN69ST®, with no significant differences between the two (..) (AU)

Evaluation of coagulation and anti-Xa factor when using a heparin-coated AN69ST® dialyser.

BACKGROUND: Hemodialysis systems are potentially thrombogenic, so it is routinely used anticoagulation. Its prescription is with risks though which the recommendations regarding the scheduled dose are still based on very different criteria. METHODS: We performed a randomized, crossover pilot study. Six patients underwent six sessions of post-dilution hemodiafiltration with polysulfone HF80® dialyzer and standard anticoagulation with nadroparin, and six sessions with heparin-coated poliacrylonitrile AN69ST® membrane without using systemic anticoagulation. Dialyser and the extracorporeal circuit clotting grade was evaluated through visual scale every hour and coagulation parameters like anti-Xa factor. Our endpoint was to assess anti-Xa activity without differences in the rate of massive clotting between the two groups. RESULTS: No complete or grade 4 dialyzer clotting occurred in any of 36 sessions with each dialyzer. A partial lower 25% (grade 1-2) dialyzer clotting was in 32 (89.7%) AN69ST® sessions and 35 (97.2%) with the usual dialyzer and upper 25% (grade 3-4) in 4 (11.1%) AN69ST® sessions and 1 (2.8%) dialysis session with heparin. Arterial chamber blood coagulation was not greater than 25% (grade 3 and 4) in any of the studied sessions and the venous chamber in only 1 (2.8%) session with the usual dialyzer and 3 (8.4%) with no differences AN69ST® between the two dialyzers. The activated partial thromboplastin time at two hours showed differences between techniques related to administration of low molecular weight heparin (33.3 ± 2.7s with polysulfone and 27.5 ± 2.3s in AN69ST®; P < 0.05) which remained significant at the end of the session (29.8 ± 2.1s with polysulfone and 27.2 ± 1.8s with AN69ST®; P < 0.05). Anti-Xa factor activity was maximal two hours after administration of nadroparin, with differences between the two dialyzers (0.46 ± 0.13 IU / ml in dialysis with polysulfone and 0.04 ± 0.04 IU / ml with AN69ST®p<0.005) and went down after 4 hours (0.17 ± 0.12 IU / ml in dialysis with polysulfone and 0.02 ± 0.03 IU / ml in AN69ST®; p<0.05). One patient in dialysis AN69ST®; had an adverse reaction characterized by generalized pruritus and was excluded from the study, by withdrawing the consent in the first session. CONCLUSION: We demonstrate the low thrombogenicity of the AN69ST®; dialyzer that allows post-dilution hemodiafiltration sessions without systemic anticoagulation, and without increasing the frequency of severe clotting events compared to HF80®; dialyzer with nadroparin and with less risk of bleeding by not modifying the anti-Xa factor activity.