Relationship between tissue perfusion and coagulopathy in traumatic brain injury

Abstract Background Traumatic brain injury (TBI)–related coagulopathy appears to be most prevalent in patients with tissue hypoperfusion, but evidence for this association is scarce. This study investigated the relationship between tissue perfusion and hemostatic derangements in TBI patients. Materials and methods Coagulation parameters were measured on emergency department admission in patients with TBI (head abbreviated injury scale ≥ 3). The level of hypoperfusion was simultaneously assessed by near-infrared spectroscopy (NIRS) at the forehead and arm, and by base excess and lactate. Coagulopathy was defined as an international normalized ratio > 1.2 and/or activated partial thromboplastin time > 40 s and/or thrombocytopenia ( 9 /L). Results TBI patients with coagulopathy (42%) had more signs of tissue hypoperfusion as indicated by increased lactate levels (2.1 [1.1-3.2] mmol/L versus 1.2 [1.0-1.7] mmol/L; P  = 0.017) and a larger base deficit (−3.0 [−4.6 to −2.0] mmol/L versus −0.1 [−2.5 to 1.8] mmol/L; P P  = 0.051) as marker of fibrinolysis. The presence of coagulopathy was associated with an increased inhospital mortality rate (45.5% versus 6.7%; P  = 0.002). Conclusions This is the first study to investigate the relationship between hemostatic derangements and tissue oxygenation using NIRS in TBI patients. This study showed that TBI-related coagulopathy is more profound in patients with metabolic acidosis and increased lactate levels. Although there was no direct relationship between tissue oxygenation and coagulopathy, we observed an inverse relationship between NIRS tissue oxygenation levels and fibrinolysis.