The Effects of Class IV Hemorrhagic Hypotensive Shock and Its Resuscitation with Fluids and Adjuvant Vasopressors or Cellular Energy Replenishment on the Splanchnic Microcirculation

Background Traumatic exsanguination leading to class IV hemorrhagic shock as defined by the Committee on Trauma of the American College of Surgeons requires aggressive resuscitation with crystalloids and packed cells together with the temporary administration of either norepinephrine or vasopressin to manage a persistent hypotension that is not corrected by aggressive fluid resuscitation. However, the use of vasopressors in the resuscitation from hemorrhagic hypovolemic shock is controversial as these drugs may worsen the pre-existing splanchnic hypoperfusion by virtue of their vascular action. In previous intravital microscopy studies of the terminal ileum in rats, we demonstrated that adequate resuscitation which restores and maintains central hemodynamics, as clinical end-points of resuscitation, does not restore or maintain splanchnic tissue perfusion, which instead exhibits a persistent and progressive intestinal microvascular vasoconstriction and end-organ tissue hypoperfusion. In other intravital m...