Continuous versus intermittent infusion of human antithrombin III concentrate in the immediate postoperative period after liver transplantation

Antithrombin‐III (AT‐III) concentrates have been used in the immediate postoperative period after liver transplantation to prevent critical thrombosis. We aimed to investigate a more appropriate method for AT‐III concentrate administration to maintain plasma AT‐III activity level within the target range. In this randomized controlled trial, 130 adult patients undergoing living‐donor liver transplantation were randomized to either the intermittent group or continuous group. In the intermittent group, 500 international units (IU) of AT‐III concentrate were administered after liver transplantation and repeated every 6 h for 72 h. In the continuous group, 3000 IU of AT‐III were continuously infused for 71 h after a loading dose of 2000 IU over 1 h. Plasma AT‐III activity level was measured at 12, 24, 48, 72, and 84 h from the first AT‐III administration. The primary outcome was the target (80%–120%) attainment rate at 72 h. Target attainment rates at other timepoints and associated complications were collected as secondary outcomes. A total of 107 patients were included in the analysis. The target attainment rates at 72 h post‐dose were 30% and 62% in the intermittent group and continuous group, respectively (p = 0.003). Compared to the intermittent group, patients in the continuous group reached the target level more rapidly (12 vs. 24 h, median time, p < 0.001) and were more likely to remain in the target range until 84 h. For maintaining the target plasma AT‐III activity level after living‐donor liver transplantation, continuous infusion of AT‐III seemed to be more appropriate compared to the conventional intermittent infusion regimen.