J Trauma Acute Care Surg. 2019; Epub ahead of print

# Thromboelastography On-the-Go: Evaluation of the TEG 6s Device During Ground and High-Altitude Aeromedical Evacuation with Extracorporeal Life Support.

Roberts T, Jones J, Choi J, Sieck K, Harea G, Wendorff D, Beely B, Karaliou V, Cap A, Davis M, Cancio L, Sams V, Batchinsky A

BACKGROUND: Coagulation monitoring capabilities during transport are limited. Thromboelastography (TEG) is a whole-blood clotting test measuring clot formation, stabilization and fibrinolysis; and is traditionally performed in a laboratory. We evaluated a new point-of-care TEG analyzer, TEG 6s (Haemonetics; Braintree, MA), in a large animal model of combat-relevant trauma managed with extracorporeal life support (ECLS) during ground and high-altitude aeromedical evacuation. The objective was to compare TEG 6s used during transport vs. the predicate device, TEG 5000, used in the laboratory. We hypothesized that TEG 6s would be comparable to TEG 5000 during dynamically changing transport conditions.

METHODS: TEG parameters (R, K, Angle, MA, LY30) derived by TEG 6s and TEG 5000 were compared during transport of 8 swine. TEG 6s was transported with animals during ground transport and flight. TEG 5000 was stationary in an adjacent building. TEG 6s activated clotting time (ACT) was compared to a Hemochron Junior ACT analyzer (Accriva Diagnostics; San Diego, CA). Statistics were performed using SAS 9.4 with Deming regressions, Spearman correlations and average differences compared.

RESULTS: Correlation between devices was stronger at sea-level (R r=0.7413, K r=0.7115, Angle r=0.7192, MA r=0.8386, LY30 r=0.9099) than during high-altitude transport (R r=0.4787, K r=0.4007, Angle r =0.3706, MA r=0.6573, LY30 r=0.8481). Method agreement was comparable during stationary operation (R r=0.7978, K r=0.7974, Angle r=0.7574, MA r=0.7841, LY30 r=0.9140) vs. ground transport (R r=0.7927, K r=0.6246, Angle r=0.6967, MA r=0.9163, LY30 r=0.8603). TEG 6s ACT trended higher than Hemochron ACT when subjects were heparinized (average difference=1442±1703 sec) without a methodological difference by Deming regression.

CONCLUSIONS: Mobile TEG 6s during ground and altitude transport is feasible and provides unprecedented information to guide coagulation management. Future studies should assess the precision and accuracy of TEG 6s during transport of critically ill.

LEVEL OF EVIDENCE: Basic science paper, does not require level of evidence.