[Hemoglobin-oriented and coagulation factor-based algorithm : Effect on transfusion needs and standardized mortality rate in massively transfused trauma patients].

BACKGROUND: Bleeding and trauma-induced coagulopathy (TIC) are major contributors to death related to trauma in the first 24 h and the major preventable contributors. Early surgical therapy and aggressive correction of TIC are key steps to prevent death in patients suffering from hemorrhage. Therefore, a standard operating procedure (SOP) using a hemoglobin (Hb)-oriented and coagulation factor-based algorithm for early correction of TIC was introduced in this level 1 trauma center. This SOP uses the correlation of the Hb values measured in the trauma bay and standard coagulation tests as the basis for various aggressive coagulation therapies.

OBJECTIVE: The aim was to investigate the effectiveness of the SOP in trauma patients requiring massive transfusions. The main objective was the effect on the transfusion requirements and the standardized mortality ratio (SMR), the ratio of observed deaths to expected/predicted deaths, in the cohort of massively transfused trauma patients after introduction of the SOP compared with a historical cohort.

METHOD: A retrospective, single center study was carried out at a supraregional trauma center between 2005 and 2014. After introduction of the Hb-oriented, coagulation factor-based SOP for correction of TIC in 2011 a before/after comparison of all trauma patients requiring massive transfusions during trauma bay resuscitation and intensive care unit (ICU) admission was carried out. Main outcome parameters were the transfusion requirement and the SMR. The historical cohort of massively transfused trauma patients before introduction of the SOP (group 1) was compared with the cohort after introduction of the SOP (group 2). Furthermore, the two cohorts were compared regarding injury severity, expected death calculated with the revised injury severity classification (RISC), hemostatic results on trauma bay and ICU admission, clotting therapy and outcome.

RESULTS: Of the 952 patients investigated 86 (9%) required massive transfusion (45 in group 1 and 41 in group 2). Both groups were comparable regarding injury severity but showed slight differences in hemostatic results on trauma bay admission, with a trend to worse results in group 2. Differences were recorded for platelet count on trauma bay admission with significantly lower values in group 2. The RISC predicted a significant difference in the mortality rate (46.5% group 1 and 65.3% group 2) but no significant differences in the observed mortality (44.4% group 1 and 47% group 2) were recorded. The SMR decreased from 0.95 in group 1 to 0.72 in group 2, meaning that in group 1 from 21 predicated trauma deaths 20 occurred and in group 2 from 27 predicated trauma deaths 19 occurred. This difference is not statistically significant (p = 0.16) due to the small sample size but is clinically relevant. A significant reduction in the requirement of red blood cell transfusions (22.8 ± 8.1 units vs 17.6 ± 7.6 units) was achieved (p = 0.003). Significant differences between the groups were observed regarding frequency and quantity of the coagulation-promoting drugs. Compared with group 1 the SOP used in group 2 achieved significantly better hemostatic results on ICU admission for fibrinogen and Quick's value and a clear trend to better results for international normalized ratio (INR) and PTT.

CONCLUSION: The SOP based on coagulation factor values and standardized clotting therapy showed a clear trend to reduction of the SMR in massively transfused trauma patients. On the other hand the SOP achieved a significant reduction in the transfusion requirements and a significant improvement in the hemostatic results in the most severely injured patients. This can be interpreted as an effective use of coagulation factors in the early hospital treatment of trauma patients with ongoing bleeding.