Superimposed traumatic brain injury modulates vasomotor responses in third-order vessels after hemorrhagic shock

摘要

Background Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of death in trauma. Recent studies suggest that TBI may influence physiological responses to acute blood loss. This study was designed to assess to what extent superimposed TBI may modulate physiologic vasomotor responses in third-order blood vessels in the context of HS. Methods We have combined two established experimental models of pressure-controlled hemorrhagic shock (HS; MAP 50?mmHg/60?min) and TBI (lateral fluid percussion (LFP)) to assess vasomotor responses and microcirculatory changes in third-order vessels by intravital microscopy in a spinotrapezius muscle preparation. 23 male Sprague–Dawley rats (260–320?g) were randomly assigned to experimental groups: i) Sham, ii) HS, iii) TBI?+?HS, subjected to impact or sham operation, and assessed. Results HS led to a significant decrease in arteriolar diameters by 20% to baseline (p? Conclusion Superimposed TBI modulated arteriolar and venular responses to HS in third-order vessels in a spinotrapezius muscle preparation. Further research is necessary to precisely define the role of TBI on the microcirculation in tissues vulnerable to HS.