Evaluation of the altitude impact on a point-of-care thromboelastography analyzer measurement: prerequisites for use in airborne medical evacuation courses.

PURPOSE

Hemorrhagic shock is the first cause of preventable death in combat. Evacuations of wounded by aircraft are increasingly used and severely injured patients can spend consequent time in the air, mostly during strategic evacuation. In these situations, monitoring of blood coagulation may be pivotal in the management of blood product transfusion. Viscoelastic-guided transfusion is relevant in these situations. However, evaluation of these devices used in aircraft is lacking, especially the impact of decreased atmospheric pressure. The aim of this study is to evaluate the performance of an easy-to-carry viscoelastic system (TEG 6s, Haemonetics).

METHODS

First, TEG 6s repeatability, reproducibility, and correlation with chronometric methods and TEG-5000 were assessed on quality controls, healthy volunteers, and patients. Secondly, we tested the influence of vibrations and altitude on TEG 6s parameters (0ft vs. 8000 ft = 2428 m) and on quality control samples (normal and hypocoagulable).

RESULTS

TEG 6s exhibited good correlation with the reference method and TEG 5000. Repeatability and reproducibility CVs were satisfactory. The tests performed in the hypobaric chamber revealed that performance at 0 ft and 8000 ft (2428 m) for 9 out of 13 parameters was not significantly different. However, we showed a significant increasing of CRT.Alpha (p = 0.049), CK.Alpha, CK.MA (p < 0.001 and p < 0.01, respectively) and CFF.MA increased (p < 0.05).

CONCLUSION

Our study provides proof of concept to validate testing in an actual aeromedical situation. Indeed, TEG 6s appears to ease of use, resistance to high altitude conditions, and reliability on healthy humans. It is necessary to carry out a study on hemorrhagic injured patients in an aircraft.