Rapid Thromboelastography Test Provides Coagulopathy Results in 5 Minutes

BOSTON — Rapid thromboelastography identified trauma-induced coagulopathy within 5 minutes, produced results that correlated well with conventional coagulation tests, and predicted the early need for blood products, reported Dr. Bryan A. Cotton from a pilot study.

In the study of 272 adults treated at a trauma center over a 5-month period, the median time to view early rapid thromboelastography (rapidTEG) results, including activated clotting time, R value, and K time, was 5.2 minutes (interquartile range [IQR], 4.3-7.1 minutes), compared with 23 minutes (IQR, 18-50) for platelet count and 27 minutes (IQR, 19-69) for prothrombin time, activated partial thromboplastin time, and international normalized ratio, said Dr. Cotton of the surgery faculty in the division of acute care surgery at the University of Texas at Houston.

“Conventional labs are often quite delayed, and reflect where we were, and not where we are, in our coagulation resuscitation. RapidTEG has recently been noted as a potential solution to this. RapidTEG correlates well with conventional coagulation testing that we’re already doing, and appears to predict [need for] transfusion products in a timely fashion,” he said at the annual meeting of the American Association for the Surgery of Trauma.

In conventional thromboelastography, or TEG, coagulation is initiated with the addition of kaolin, but in rapidTEG the initiator is protein tissue factor. In 2009, Dr. Victor Jeger and colleagues from Bern (Switzerland) University Hospital published a study comparing TEG with rapidTEG in 20 patients. They found that the mean time from resuscitation bay admission until results were available for rapidTEG was 30.8 + 5.72 minutes, compared with 41.5 + 5.66 for TEG, and 64.9 + 18.8 for conventional coagulation tests (J. Trauma 2009;66:1253-7).

Based on these results, Dr. Cotton and colleagues designed a larger study to evaluate the timeliness of rapidTEG results, determine whether they correlated with conventional coagulation tests, and evaluate their ability to predict early transfusion of blood and blood components.

The prospective cohort study involved 272 patients who had the highest-level trauma activations (code 3) and were treated in the University of Texas center from October 2009 through February 2010. The cohort included scene transport patients over age 17; patients transferred from other facilities were excluded.

“Using the remote display function, early rapidTEG values were available within 5 minutes of dropping off a specimen; later values were returned within 15 minutes,” Dr. Cotton said. The late rapidTEG results, which included alpha angle, showing the rate of clot, and maximal amplitude, showing the greatest amplitude of tracing, were returned within a median of 14.9 minutes (IQR, 13.4-19.2).

The time to display rapidTEG values was significantly shorter than that for both prothrombin time and platelet counts (P less than 0.001 for both comparisons).

The investigators assessed the correlation between rapidTEG results and conventional coagulation test results, and found that rapidTEG was significantly correlated with both prothrombin time and activated partial thromboplastin time for activated clotting time, K time, R value, alpha angle, maximal amplitude, and G value. RapidTEG also correlated significantly with platelet count for K time, alpha angle, maximal amplitude, and G value.

The authors also performed a multivariate logistic regression analysis, controlling for demographic and emergency department variables, to determine whether rapidTEG could accurately predict massive transfusion (defined as more than 10 units of packed red blood cells) in the first 6 hours. They found that activated clotting time greater than 128 seconds was significantly associated with the need for transfusion, with an odds ratio of 5.15 (P = .016). Activated clotting time is the earliest rapidTEG result returned, reflecting this value’s potential utility for determining the need for blood products, Dr. Cotton said.

The investigators also found that activated clotting time could significantly predict plasma and platelet transfusion in the first 2 hours. In contrast, international normalized ratio predicted plasma transfusion but failed to predict need for either packed RBC or platelet transfusion, he said.

The invited discussant, Dr. Mitchell Cohen of San Francisco General Hospital and Trauma Center, pointed out that there were no significant differences in timing between completion of the rapidTEG tracing and return of the clinical labs, which occurred at 27 minutes after admission to the trauma bay.

“While many of us, myself included, believe that TEG will ultimately provide faster and, more importantly, more detailed information regarding which part of the coagulation system is perturbed and should be treated, there’s no data or discussion within this paper showing they used TEG in this manner,” he said.

Dr. Cohen said that answering some of the most important questions about TEG will require a randomized observational trial characterizing coagulopathy and hemostatic resuscitation after trauma, and a concurrent or separate randomized trial comparing TEG with clinical judgment and conventional coagulation testing.

There was no industry support for the study. Dr. Cotton has recently received funding for a future study of rapidTEG in trauma from Haemonetics Corp., the manufacturer of the system used in his center. Dr. Cohen said he had no conflicts of interest.

BOSTON — Rapid thromboelastography identified trauma-induced coagulopathy within 5 minutes, produced results that correlated well with conventional coagulation tests, and predicted the early need for blood products, reported Dr. Bryan A. Cotton from a pilot study.

In the study of 272 adults treated at a trauma center over a 5-month period, the median time to view early rapid thromboelastography (rapidTEG) results, including activated clotting time, R value, and K time, was 5.2 minutes (interquartile range [IQR], 4.3-7.1 minutes), compared with 23 minutes (IQR, 18-50) for platelet count and 27 minutes (IQR, 19-69) for prothrombin time, activated partial thromboplastin time, and international normalized ratio, said Dr. Cotton of the surgery faculty in the division of acute care surgery at the University of Texas at Houston.

“Conventional labs are often quite delayed, and reflect where we were, and not where we are, in our coagulation resuscitation. RapidTEG has recently been noted as a potential solution to this. RapidTEG correlates well with conventional coagulation testing that we’re already doing, and appears to predict [need for] transfusion products in a timely fashion,” he said at the annual meeting of the American Association for the Surgery of Trauma.

In conventional thromboelastography, or TEG, coagulation is initiated with the addition of kaolin, but in rapidTEG the initiator is protein tissue factor. In 2009, Dr. Victor Jeger and colleagues from Bern (Switzerland) University Hospital published a study comparing TEG with rapidTEG in 20 patients. They found that the mean time from resuscitation bay admission until results were available for rapidTEG was 30.8 + 5.72 minutes, compared with 41.5 + 5.66 for TEG, and 64.9 + 18.8 for conventional coagulation tests (J. Trauma 2009;66:1253-7).

Based on these results, Dr. Cotton and colleagues designed a larger study to evaluate the timeliness of rapidTEG results, determine whether they correlated with conventional coagulation tests, and evaluate their ability to predict early transfusion of blood and blood components.

The prospective cohort study involved 272 patients who had the highest-level trauma activations (code 3) and were treated in the University of Texas center from October 2009 through February 2010. The cohort included scene transport patients over age 17; patients transferred from other facilities were excluded.

“Using the remote display function, early rapidTEG values were available within 5 minutes of dropping off a specimen; later values were returned within 15 minutes,” Dr. Cotton said. The late rapidTEG results, which included alpha angle, showing the rate of clot, and maximal amplitude, showing the greatest amplitude of tracing, were returned within a median of 14.9 minutes (IQR, 13.4-19.2).

The time to display rapidTEG values was significantly shorter than that for both prothrombin time and platelet counts (P less than 0.001 for both comparisons).

The investigators assessed the correlation between rapidTEG results and conventional coagulation test results, and found that rapidTEG was significantly correlated with both prothrombin time and activated partial thromboplastin time for activated clotting time, K time, R value, alpha angle, maximal amplitude, and G value. RapidTEG also correlated significantly with platelet count for K time, alpha angle, maximal amplitude, and G value.

The authors also performed a multivariate logistic regression analysis, controlling for demographic and emergency department variables, to determine whether rapidTEG could accurately predict massive transfusion (defined as more than 10 units of packed red blood cells) in the first 6 hours. They found that activated clotting time greater than 128 seconds was significantly associated with the need for transfusion, with an odds ratio of 5.15 (P = .016). Activated clotting time is the earliest rapidTEG result returned, reflecting this value’s potential utility for determining the need for blood products, Dr. Cotton said.

The investigators also found that activated clotting time could significantly predict plasma and platelet transfusion in the first 2 hours. In contrast, international normalized ratio predicted plasma transfusion but failed to predict need for either packed RBC or platelet transfusion, he said.

The invited discussant, Dr. Mitchell Cohen of San Francisco General Hospital and Trauma Center, pointed out that there were no significant differences in timing between completion of the rapidTEG tracing and return of the clinical labs, which occurred at 27 minutes after admission to the trauma bay.

“While many of us, myself included, believe that TEG will ultimately provide faster and, more importantly, more detailed information regarding which part of the coagulation system is perturbed and should be treated, there’s no data or discussion within this paper showing they used TEG in this manner,” he said.

Dr. Cohen said that answering some of the most important questions about TEG will require a randomized observational trial characterizing coagulopathy and hemostatic resuscitation after trauma, and a concurrent or separate randomized trial comparing TEG with clinical judgment and conventional coagulation testing.

There was no industry support for the study. Dr. Cotton has recently received funding for a future study of rapidTEG in trauma from Haemonetics Corp., the manufacturer of the system used in his center. Dr. Cohen said he had no conflicts of interest.

BOSTON — Rapid thromboelastography identified trauma-induced coagulopathy within 5 minutes, produced results that correlated well with conventional coagulation tests, and predicted the early need for blood products, reported Dr. Bryan A. Cotton from a pilot study.

In the study of 272 adults treated at a trauma center over a 5-month period, the median time to view early rapid thromboelastography (rapidTEG) results, including activated clotting time, R value, and K time, was 5.2 minutes (interquartile range [IQR], 4.3-7.1 minutes), compared with 23 minutes (IQR, 18-50) for platelet count and 27 minutes (IQR, 19-69) for prothrombin time, activated partial thromboplastin time, and international normalized ratio, said Dr. Cotton of the surgery faculty in the division of acute care surgery at the University of Texas at Houston.

“Conventional labs are often quite delayed, and reflect where we were, and not where we are, in our coagulation resuscitation. RapidTEG has recently been noted as a potential solution to this. RapidTEG correlates well with conventional coagulation testing that we’re already doing, and appears to predict [need for] transfusion products in a timely fashion,” he said at the annual meeting of the American Association for the Surgery of Trauma.

In conventional thromboelastography, or TEG, coagulation is initiated with the addition of kaolin, but in rapidTEG the initiator is protein tissue factor. In 2009, Dr. Victor Jeger and colleagues from Bern (Switzerland) University Hospital published a study comparing TEG with rapidTEG in 20 patients. They found that the mean time from resuscitation bay admission until results were available for rapidTEG was 30.8 + 5.72 minutes, compared with 41.5 + 5.66 for TEG, and 64.9 + 18.8 for conventional coagulation tests (J. Trauma 2009;66:1253-7).

Based on these results, Dr. Cotton and colleagues designed a larger study to evaluate the timeliness of rapidTEG results, determine whether they correlated with conventional coagulation tests, and evaluate their ability to predict early transfusion of blood and blood components.

The prospective cohort study involved 272 patients who had the highest-level trauma activations (code 3) and were treated in the University of Texas center from October 2009 through February 2010. The cohort included scene transport patients over age 17; patients transferred from other facilities were excluded.

“Using the remote display function, early rapidTEG values were available within 5 minutes of dropping off a specimen; later values were returned within 15 minutes,” Dr. Cotton said. The late rapidTEG results, which included alpha angle, showing the rate of clot, and maximal amplitude, showing the greatest amplitude of tracing, were returned within a median of 14.9 minutes (IQR, 13.4-19.2).

The time to display rapidTEG values was significantly shorter than that for both prothrombin time and platelet counts (P less than 0.001 for both comparisons).

The investigators assessed the correlation between rapidTEG results and conventional coagulation test results, and found that rapidTEG was significantly correlated with both prothrombin time and activated partial thromboplastin time for activated clotting time, K time, R value, alpha angle, maximal amplitude, and G value. RapidTEG also correlated significantly with platelet count for K time, alpha angle, maximal amplitude, and G value.

The authors also performed a multivariate logistic regression analysis, controlling for demographic and emergency department variables, to determine whether rapidTEG could accurately predict massive transfusion (defined as more than 10 units of packed red blood cells) in the first 6 hours. They found that activated clotting time greater than 128 seconds was significantly associated with the need for transfusion, with an odds ratio of 5.15 (P = .016). Activated clotting time is the earliest rapidTEG result returned, reflecting this value’s potential utility for determining the need for blood products, Dr. Cotton said.

The investigators also found that activated clotting time could significantly predict plasma and platelet transfusion in the first 2 hours. In contrast, international normalized ratio predicted plasma transfusion but failed to predict need for either packed RBC or platelet transfusion, he said.

The invited discussant, Dr. Mitchell Cohen of San Francisco General Hospital and Trauma Center, pointed out that there were no significant differences in timing between completion of the rapidTEG tracing and return of the clinical labs, which occurred at 27 minutes after admission to the trauma bay.

“While many of us, myself included, believe that TEG will ultimately provide faster and, more importantly, more detailed information regarding which part of the coagulation system is perturbed and should be treated, there’s no data or discussion within this paper showing they used TEG in this manner,” he said.

Dr. Cohen said that answering some of the most important questions about TEG will require a randomized observational trial characterizing coagulopathy and hemostatic resuscitation after trauma, and a concurrent or separate randomized trial comparing TEG with clinical judgment and conventional coagulation testing.

There was no industry support for the study. Dr. Cotton has recently received funding for a future study of rapidTEG in trauma from Haemonetics Corp., the manufacturer of the system used in his center. Dr. Cohen said he had no conflicts of interest.