Thromboelastography may accurately predict VTE in patients with spine fractures

Rapid thromboelastography testing carried out after severe spine trauma can help physicians accurately predict which patients are at a higher risk of developing in-hospital deep vein thrombosis and pulmonary embolism, according to findings of a retrospective review.

Rapid thromboelastography is a full blood test that looks at the viscoelastic properties of blood. The test can be completed in 15 minutes at the investigator’s institution, as compared with conventional coagulation tests that can take three-times longer, according to Mark L. Prasarn, MD.

Patients who have spine fractures who present with rapid thromboelastography (r-TEG) maximal amplitude (mA) values of 72 have a 4.81-times greater risk for an in-hospital venous thromboembolism (VTE) event, Prasarn said at the Orthopaedic Trauma Association Annual Meeting.

“Patients with spine trauma are at increased risk, spinal cord injury or not, for having a clot, a deep vein thrombosis [DVT] or pulmonary embolism [PE], despite being more hypocoagulable on admission. [A] maximum amplitude of 72 or greater was helpful in being predictive of who would develop a clot,” he said.

Prasarn and colleagues included 722 patients with a spine injury and 2,223 patients without a spine injury who were aged 18 years to 85 years, and were admitted to a level 1 trauma center. Based on the Abbreviated Injury Scale score, patients who had a spine injury were more badly injured than the patients without a spine injury. Patients with a spine injury also had lower systolic blood pressure, a higher pulse and a lower Glasgow Coma Scale score on arrival than patients without a spine injury.

In baseline physiology from r-TEG testing, patients with a spine injury had smaller alpha angles on arrival than patients without a spine injury (72° vs. 73°) and their mA values were lower than those in the group without a spine injury (63 vs. 64). Both of those comparisons were statistically significantly different, which means the patients with a spine injury were more hypocoagulable, Prasarn noted.

However, he said, patients with a spine injury had twice as many VTEs as patients without a spine injury. The PE rates were 5.2% and 2.4% for patients with a spine injury and patients without a spine injury, respectively, Prasarn noted.

Prasarn and colleagues used stepwise regression to generate three values that were predictive of the development of VTE.

“As far as predictive factors go, having a spine fracture, having a higher Injury Severity Score and having a high maximal amplitude value of over 72 were risk factors of having a venous thromboembolic event. As far as looking at the spine fracture patients specifically, having a high maximal amplitude level greater than or equal to 72 was a risk factor for having a venous thromboembolic event with an odds ratio of 4.81,” Prasarn said.

Patients with a spine injury and an elevated mA score of 72 or more are at higher risk for VTE and may benefit from an early, aggressive prophylaxis, according to Prasarn and colleagues. – by Robert Linnehan

Reference:
Prasarn ML, et al. Paper #62. Presented at: Orthopaedic Trauma Association Annual Meeting; Oct. 7-10, 2015; San Diego.

For more information:

Mark L. Prasarn, MD, can be reached at Ironman Sports Medicine Institute at Memorial Herman Plaza, 6400 Fannin St., Suite 1700, Houston, TX 77030; email: markprasarn@yahoo.com.

Disclosure: Prasarn reports he is a member of the speakers bureau and gives paid presentations for DePuy Synthes and Eli Lilly and company.