Abstracts of Posters Presented at the International Anesthesia Research Society; 72nd Clinical and Scientific Congress; Orlando, FL; March 7-11, 1998: Cardiovascular Anesthesia
INTRODUCTION: Patients with both blunt and penetrating trauma may develop massive blood losses resulting in coagulopathy. Early transfusion with fresh frozen plasma (FFP) and platelets has been recommended in these patients for the correction of coagulopathy. In the acutely bleeding surgical patient, the thromboelastograph (TEG) will show a hypercoagulable profile until there is > 50% of the estimated blood volume (EBV)  lost. After an estimated blood loss (EBL) of >50% of the EBV, the TEG will become suggestive of hypocoagulation. We evaluated patients receiving exploratory laparotomies for blunt or penetrating trauma to evaluate the progressive changes in the TEG profile as they correlate to the changes in other coagulation tests.
METHODS: Following investigational approval, patients who came to the operating within 4 hours of sustaining massive trauma were enrolled in the study. The TEG, PT, PTT, platelet and fibrinogen samples were drawn at skin incision and every subsequent 45 mins for a total of 4 sets of samples per patient. Patients with a known coagulopathy, thrombocytopenia, or prior use of NSAIDs were excluded. Transfusion was left to the discretion of the attending anesthesiologist and was not necessarily based on the TEG or laboratory values of coagulation. We did a linear regression analysis of the TEG values and standard tests of coagulation vs. the EBL.
RESULTS: A total of 24 patients were enrolled in the study. Seven patients received FFP, 6 patients received platelets and 2 patients received cryoprecipitate during the course of the study. None of the factors were given prior to the 3rd sample and did not alter the results, thus were included in the statistical analysis. The patients were found to be uniformly hypofibrinogenemic during the entire course of the study with values approximately 30-60% below normal, except for two patients who had normal fibrinogen values. The platelet count, PT and PTT were abnormal approximately 40-50% of the time. There was a significant difference in the MA and [varies as] values as well as platelet count and fibrinogen (p<0.01) with an EBL >2500ml when compared to patients that had an EBL <2500 ml. There was evidence of abnormal coagulation in those patients with an EBL >2500 ml; however, below an EBL of 2500ml there was no difference in coagulation parameters. This was evaluated using unpaired t-tests.
CONCLUSION: In trauma patients who undergo exploratory laparotomy, the TEG shows a normal to hypercoagulable profile until there is significant EBL (>2500 ml) despite possible abnormalities in the standard tests of coagulation. At an EBL of >2500ml, the TEG showed evidence of coagulation defects. The TEG is a measure of whole blood clotting ability and clot stability while the standard tests measure plasma clotting, thus possibly making the TEG a better predictor of clinical coagulation defects. These patients were also hypofibrinogenemic and the early use of cryoprecipitate may be appropriate in the restoration of normal coagulation in bleeding trauma patients. (Table 1 and Figure 1)
© 1998 International Anesthesia Research Society
1. Anesth Analg 1987;66:856-63.