N. Rottler1, N. K. Dhillon1, A. Wang1, R. Mason1, T. Lin1, N. T. Linaval1, G. Barmparas1, E. J. Ley1 1Cedars-Sinai Medical Center,Los Angeles, CA, USA
Introduction: Antithrombin III (AT III) deficiency occurs from hereditary or acquired reduction in AT III levels and leads to an increase in venous thromboembolism (VTE). Low AT III levels have not been characterized in critically ill surgical patients so the management of these patients and the VTE rate is unknown. The objective of this study was to describe AT III levels in this population and to determine if activity levels fluctuated with time.
Methods: AT III levels of all patients admitted to the SICU at a tertiary, urban center were reviewed from 01/2017 to 12/2017. Levels were drawn at the discretion of the critical care team. An AT III level below 80% was considered decreased. For patients that had multiple levels drawn, a fluctuation was defined as a difference of at least 20% in AT III activity between the highest and lowest level during a patient’s stay.
Results: The median age of the 145 patients reviewed was 59 years and 60.0% were male. The median initial AT III level was 64.0% (IQR: 41.0% – 84.5%). Overall, 68.3% of patients had reduced AT III activity initially; after excluding 20 patients with concomitant cirrhosis, 63.2% had decreased activity. There were 52 patients with multiple AT III levels drawn, with 48.1% having a fluctuation; AT III levels of 60.0% of these patients increased over time while it decreased in the remaining.
Conclusion: The majority of critically ill surgical patients have reduced AT III levels activity that fluctuates throughout the SICU course. Further investigation is necessary to understand the clinical implications of this finding.