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Surgical Forum Abstracts
functional measurement may better predict mortality in real-time compared to standard laboratory fibrinogen levels. Thrombelastography velocity curve values more accurately predict clinically significant fibrinolysis Matthew J Pommerening, MD, Michael D Goodman, MD, Danny L Farley, BS, Jessica C Cardenas, PhD, Jeanette M Podbielski, RN, Nena Matijevic, PhD, Charles E Wade, PhD, John B Holcomb, MD, FACS, Bryan A Cotton, MD, MPH, FACS University of Texas at Houston Medical School, Houston, TX INTRODUCTION: Clot lysis values (LY30) determined by rapid thrombelastography (rTEG) predict post-injury transfusion needs and mortality risk. However, the parametric velocity values generated from the rTEG curveemaximum rate of lysis (MRL) and total lysis (TL)ehave not been evaluated. While recent data supports use of anti-fibrinolytics in trauma, the population that would benefit remains poorly defined. The purpose of this study was to determine if MRL and TL more accurately predict blood transfusions and early mortality than standard values. METHODS: Eighteen-month retrospective study of all highestlevel activation trauma patients. Arrival rTEG values and velocity curves were assessed. Regression models were developed controlling for age, gender, mechanism, injury severity score, arrival physiology and shock. Substantial bleeding (SB) was defined as 5 or more units RBC in 4 hours or death plus any transfusion. RESULTS: 1625 patients were included. LY30 was able to predict RBC transfusion (p¼0.010), but not plasma transfusion (p¼0.424) within 3 hours of arrival. MRL and TL, however, were able to predict RBC (p< 0.001 and 0.019, respectively) and plasma transfusion (p¼0.032 and 0.038, respectively). MRL>0.5 mm/min (odds ratio [OR] 2.7) was the only rTEG value to accurately predict SB. However, both MRL>0.5 mm/ min (OR 5.1) and TL>60 dynes/cm2 (OR 9.0) predicted 24-hour mortality.
J Am Coll Surg
prophylaxis in these patients. Although ATC is established, no data exists investigating the time course of normalization of coagulation. Thromboelastography (TEG) provides a method to detect the evolution between hypo- and hypercoagulability. We hypothesized that TBI patients transition to a normal coagulation within 24 hours after injury. METHODS: Blood samples were prospectively collected from 405 severely injured patients on arrival and serially to 24h. Citrated rapid TEG (CRT) was performed along with standard coagulation testing. TBI and progression of TBI were adjudicated by an attending neurosurgeon. RESULTS: Of 405 patients, 204 had TBI and 121 had brain injury progression. 6% were coagulopathic, and coagulopathy was associated with increased mortality (p¼0.0001). In the TBI population, the mean CRT-MA value reached its nadir (60.45mm) at 3h and returned to baseline (64.23mm) at 24h (Table). The same nadir and return to baseline pattern occurred with the a-angle (71.49 at 3h, 75.08 at 24h), and median LY30 (0.2% at 12h, 0.5% at 24 h). The K-value also returned to baseline at 24h (1.2min) after reaching a peak at 3h (1.8min). TEG parameter
TBI
0 hour 3 hour 24 hour
ACT (sec) 100.40 99.51 MA (mm) 63.42 60.45 ALPHA (degrees) 74.14 71.49 R (min) 0.50 0.50 K (min) 1.30 1.80 Progression of TBI ACT (sec) 101.59 99.51 MA (mm) 62.74 60.10 ALPHA (degrees) 73.65 71.91 R (min) 0.50 0.50 K (min) 1.30 1.80
102.22 64.23 75.08 0.60 1.20 102.22 63.60 74.44 0.60 1.20
ACT, activated clotting time; MA, maximum amplitude; G, clot strength; Alpha, clot strength through polymerization of fibrinogen; K time, potentiation phase of enzymatic factors; R time, initiation phase of enzymatic factors
CONCLUSIONS: MRL and TL are stronger predictors of SB, early RBC, and plasma transfusion, and risk of early mortality than traditional rTEG values. These values allow for more rapid detection of clinically significant fibrinolysis and may help to guide earlier anti-fibrinolytic therapy.
CONCLUSIONS: Functional coagulation after TBI returns to baseline by 24 hours in patients with moderate and severe TBI independent of progression of injury. This data suggests that initiation of DVT prophylaxis is appropriate at 24 hours after TBI.
Normalization of coagulation after traumatic brain injury: When to initiate deep venous thrombosis prophylaxis Cassandra A Ligh, BA, Fangfang Xing, BS, Lucy Z Kornblith, MD, Brittney J Redick, BA, Mary Nelson, RN, MS, Tomoo Inoue, MD, PhD, Geoffrey T Manley, MD, PhD, FACS, Mitchell J Cohen, MD, FACS University of California-San Francisco and San Francisco General Hospital, San Francisco, CA
Fresh frozen plasma resuscitation attenuates platelet dysfunction and endothelial activation in a large animal model of poly-trauma Martin Sillesen, MD, Pa¨r I Johansson, MD, Lars S Rasmussen, MD, PhD, Guang Jin, MD, PhD, Ayesha Imam, MD, John O Hwabejire, MD, MPH, Cecilie H Jepsen, MD, George Velmahos, MD, PhD, FACS, Marc A deMoya, MD, FACS, Hasan B Alam, MD, FACS Massachusetts General Hospital, Boston, MA
INTRODUCTION: Acute traumatic coagulopathy (ATC) after traumatic brain injury (TBI) occurs when TBI is combined with shock and is associated with poor outcomes. Because of this, there is considerable reluctance to start deep venous thrombosis (DVT)
INTRODUCTION: Platelet dysfunction following trauma has been identified as an independent predictor of mortality. We hypothesized that fresh frozen plasma (FFP) resuscitation would
Vol. 217, No. 3S, September 2013
Surgical Forum Abstracts
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by thrombelastography (TEG) and platelet function was assessed using platelet aggregometry.
METHODS: Multisystem trauma (traumatic brain injury, grade IV liver injury, rib fracture and soft tissue injury) with concurrent hemorrhagic shock (40% of blood volume) was produced in 12 swine. Animals were left in shock (mean arterial pressure of 35mmHg) for 2 hrs followed by resuscitation with either 0.9% normal saline (NS, n¼6; volume¼3x shed blood) or FFP (n¼6; volume¼1x shed blood), and monitored for 6 hours. Adenosine diphosphate (ADP) induced platelet aggregation was measured at baseline, after shock, immediately postresuscitation and 6 hours later. Souble markers of in-vivo platelet activation (TGF-B and sP-Selectin) as well endothelial injury (sICAM-1, sVCAM-1) were measured by ELISA. Thromboelastography (TEG) was used to measure clotting.
RESULTS: After shock, VPA treated animals had significantly higher adenosine-diphosphate induced platelet aggregation (71.43U vs 62.70U, p¼0.04). This was associated with a reduction in platelet activation markers TGF-B (1536pg/ml vs 1921pg/ml, p¼0.01) and soluble P-Selectin (7.97ng/ml vs 9.40ng/ml, p¼0.01), as well as increased TEG-measured clot strength. Shedding of the endothelial glycocalyx as measured by Syndecan-1 was also significantly attenuated. In-vivo thrombin generation as measured by prothrombin fragment 1+2 was lower in the TBI/shock+VPA group (148ng/ml vs 289ng/ml, p<0.01) as was activation of the protein C system. No difference in markers of complement and sympatho-adrenal activation was observed.
attenuate platelet activation.
dysfunction
through
reduced
RESULTS: ADP-induced platelet aggregation was significantly higher in the FFP group following resuscitation (54.20U vs 46.05U, p¼0.04), which was sustained over the observation period. This was associated with an attenuation of endothelial activation with an early drop in VCAM-1 (1.25ng/ml vs 3.87ng/ml, p¼0.05), and late decrease in ICAM-1 (21.0ng/ml vs 24.4ng/ml, p¼0.05). In-vivo platelet activation as measured by TGF-B was higher in the FFP group (2138pg/ml vs 1801pg/ml, p¼0.03). TEG confirmed increased clot strength in the FFP group at both of the postresuscitation time points. CONCLUSIONS: In this model, resuscitation with FFP resulted in an immediate and sustained improvement in platelet function and clot strength, with an associated decrease in endothelial activation. Valproic acid attenuates platelet dysfunction, endothelial glycocalyx shedding and protein C activation in a porcine model of traumatic brain injury and shock Martin Sillesen, MD, Per I Johansson, MD, Lars S Rasmussen, MD, PhD, Guang Jin, MD, PhD, Cecilie H Jepsen, MD, Ayesha Imam, MD, John O Hwabejire, MD, MPH, George Velmahos, MD, PhD, FACS, Marc A deMoya, MD, FACS, Hasan B Alam, MD, FACS Massachusetts General Hospital, Boston, MA INTRODUCTION: Treatment with valproic acid (VPA) has been shown to improve outcomes after traumatic brain injury (TBI) and shock, but its effect on trauma-induced coagulopathy remain unknown. We hypothesize that VPA attenuates coagulation and endothelial dysfunction following TBI and shock. METHODS: 36 swine were allocated to either TBI and shock (n¼27, TBI and volume-controlled 40% hemorrhage) or TBI/ Shock+VPA (n¼9). Animals were left hypotensive (mean arterial pressure of 35mmHg) for 2 hours. In the TBI/shock+VPA group, a VPA infusion of 100mg/kg/hour was started 1 hour into shock. Following shock, blood samples were analyzed for markers of coagulation and platelet activation, natural anticoagulation, endothelial activation/glycocalyx shedding, complement/ sympatho-adrenal activation. Coagulation function was measured
CONCLUSIONS: Treatment with VPA attenuated platelet dysfunction and improved clot strength. This was associated with a reduction in platelet activation, thrombin generation and protein C system activation. Furthermore, shedding of the endothelial glycocalyx was attenuated. Obese patients are at increased risk for venous thromboembolism in trauma David A Hampton, MD, Belinda H McCully, PhD, Tim H Lee, MD, Matthew Kutcher, MD, Britt J Redick, BA, Jeanette Podbielski, BS, Timothy Welch, Mitchell J Cohen, MD, FACS, Bryan A Cotton, MD, FACS, Martin A Schreiber, MD, FACS Oregon Health & Science University, Portland, OR INTRODUCTION: Venous thromboembolism (VTE) is a leading cause of late mortality in trauma patients. Elevated BMI is associated with a hypercoagulable state. We hypothesized that obese trauma patients would be hypercoagulable at admission as measured by rapid thrombelastography (r-TEG) and have a higher incidence of VTE compared to lean patients. METHODS: Prospective observational data from three Level-I trauma centers were collected. Patient demographics, admission vital signs, and VTE data were recorded. rTEG data were obtained during the first five days of admission. Data were matched by BMI (lean:25 kg/m2 and obese:>30 kg/m2). Mann-Whitney U and chi-square tests were utilized to assess significance. RESULTS: The study population consisted of 479 trauma patients: lean (n¼281) and obese (n¼198). Obese patients demonstrated a higher TEG-alpha (74o IQR [77,69] versus 73o IQR [76,68], p<0.03) and larger TEG-MA (64mm IQR [68,61] versus 62mm IQR (66,58), p<0.01) than the lean group. Obese patients were more likely to develop DVT (9% versus 3%, p<0.01). There were no differences in PE (4% versus 1%, p¼NS). CONCLUSIONS: Obese patients are more likely to be hypercoagulable after trauma and they have a higher incidence of DVTs. Compared to lean trauma patients, increased attention to prophylaxis and monitoring TEG parameters should be considered.