Abstract 295: Physiologic Response Space Mapping Identifies Synergistic Influences on Clot Strength During Trauma Shock in a Swine Model
Introduction: Traumatic coagulopathy emerges as a result of complex and poorly understood interactions within the coagulation system in response to tissue injury and hypoperfusion. In order to improve our understanding of these processes, we propose the use of a physiologic response space (PRS) which uses multivariate analysis and 3-D contour mapping to visualize important emergent properties of complex systems. These effects are visualized as a 3-D response polygon located within the PRS. We hypothesize that PRS analysis can provide rapid identification of important synergisms regarding coagulation behavior during traumatic shock.
Methods: Physiological and coagulation data were obtained from a swine model of trauma-shock with femur fracture and controlled arterial hemorrhage without fluid resuscitation. Shock severity was standardized by level of oxygen debt (OD), and the variables lactate (as a marker of perfusion) and fibrinogen (as a marker of consumption) were recorded at baseline, when OD=40ml/kg (moderate shock) and 80 ml/kg (severe shock). Clot strength, as maximal amplitude (MA), by thrombelastography represented overall coagulation function and was used as the primary outcome. The resulting MA polygon within the lactate/fibrinogen PRS was then inspected for important features representing loss of clot strength during shock.
Results: N=20 swine achieved goal OD after hemorrhaging 38+/1% of total blood volume. Comparing baseline and severe shock periods, MA was reduced (68.8 vs. 64.4mm, p=0.045), fibrinogen was reduced (174.3 vs. 68.8 mg/dl, p<0.001), and lactate increased (1.5 vs. 7.9 mmol/l, p<0.001).The MA polygon within the lactate/fibrinogen PRS demonstrated a shifting global physiologic milieu where MA fell as shock worsened. Reduced MA was most pronounced in a discrete “valley” within the polygon when fibrinogen was both <100 mg/dl and lactate was >5mmol/l.
Conclusions: PRS mapping readily identified a synergistic effect of increased lactate and decreased fibrinogen resulting in reduced clot strength during traumatic shock in this model. PRS mapping may be useful for identifying other important synergisms underlying early traumatic coagulopathy.
- © 2010 by American Heart Association, Inc.