Breanna Carter, BCCCP, BCPS, PharmD
Erlanger Health System, Tennessee
Disclosure information not submitted.
Megan Van Berkel Patel, BCCCP, PharmD, FCCM
Clinical Pharmacy Specialist
n/a
Disclosure information not submitted.
Jenny Holcombe, Phd
Associate Lecturer
The University of Tennessee Chattanooga, United States
Disclosure information not submitted.
Robert Maxwell, MD, FACS
Acute Care Surgeon
University Surgical Associates, United States
Disclosure information not submitted.
Philip Smith, MD, FACS
Acute Care Surgeon
University Surgical Associates, United States
Disclosure information not submitted.
Title: Clinical Effects of Antithrombin III Level on Anticoagulation in Extracorporeal Membrane Oxygenation
INTRODUCTION/HYPOTHESIS: Unfractionated heparin (UFH) relies on circulating antithrombin III (ATIII) to exhibit its anticoagulant activity and is the most frequently used anticoagulant in extracorporeal membrane oxygenation (ECMO). Acquired ATIII deficiency is commonly reported during ECMO but without a consensus regarding its management.
Methods: This single center, retrospective study included adult patients receiving UFH for anticoagulation during veno-arterial or veno-venous ECMO between November 2016 to July 2020 and who had at least one ATIII level drawn at least 24 hours after ECMO initiation. The primary outcome was a correlation between ATIII levels and time in goal activated clotting time (ACT) range. In cases where ATIII replacement was administered, the corresponding ATIII value, ACT levels, and UFH dose were excluded from the primary outcome analysis. Secondary outcomes included correlation of ATIII levels with UFH doses, and differences in UFH doses required before and after ATIII supplementation. UFH dose and percentage of ACT values before and after ATIII supplementation were also evaluated. Pearson’s correlation coefficient was used for all correlations and paired t-test was used for parametric data.
Results: A total of 22 patients were included with a median of two ATIII levels per patient (range 1-77). There were 150 ATIII levels included in the primary analysis. There was no correlation between the percent of ACT values within goal range and the ATIII level (r=0.037; p=0.652) or between UFH dose requirements and ATIII level (r=0.063; p=0.442). In the 16 cases where ATIII supplementation was given, no significant difference was found in mean UFH dose before and after supplementation (19.04 units/kg/hr ± 9.6 vs 20.66 units/kg/hr ±7.31; p=0.207) and no correlation was found with ATIII supplementation and the percentage of ACT values within goal range (r= -0.029; p=0.914).
Conclusions: Higher ATIII concentrations did not correlate to an increased ability to achieve goal ACT levels or to lower UFH doses. Additionally, supplementation of ATIII did not change the mean UFH dose or frequency of ACT values within goal range. Despite the small sample size, these findings corroborate with previous literature that ATIII concentrations should not be routinely monitored or replaced.