Antithrombin concentrate use in children on extracorporeal membrane oxygenation (ECMO), a retrospective cohort study

Abstract

Objective: To describe whether receipt of any AT concentrate improves laboratory and clinical outcomes in children undergoing ECMO for respiratory failure during their hospitalization compared to those who did not receive AT. Patients: 64 pediatric patients at a single, tertiary-care institution who underwent ECMO for respiratory failure between January 2007 and September 2011 Methods: This is a retrospective cohort study studying whether exposure to any AT concentrate improves outcomes in children on ECMO for respiratory failure compared to similar children who never received AT concentrate during their ECMO course. Subjects who received at least one dose of AT during their ECMO course were categorized to the AT cohort ("AT+"), whereas subjects who did not receive any AT were categorized to the comparison cohort ("No AT" cohort). Results: Thirty patients received at least one dose of AT during their ECMO course and 34 patients did not receive any. The median age at admission, duration of ECMO or first AT level did not differ significantly between the two cohorts. The mean plasma AT level in those who had never received AT was 42.2% compared to 66% in the AT+ cohort. However, few levels reached the targeted AT level of 120% and those that did fell back to deficient levels within 6.8h. Heparin infusion rates decreased by an average of 10.2 units/kg/h for at least 12h following an AT dose in the AT+ cohort. No statistical differences were noted in the number of ECMO circuit changes, in vivo clots or hemorrhages, transfusion requirements, hospital or intensive care unit length of stay, or in-hospital mortality. Conclusions: Intermittent, on-demand dosing of AT concentrate in pediatric patients on ECMO for respiratory failure increased AT levels, but not typically to the targeted level. However, in this retrospective study, no differences were noted in the measured clinical endpoints. A prospective, randomized study of this intervention may require different dosing strategies; such a study is warranted given the unproven efficacy of this costly product across institutions.