Early albumin infusion improves global and local hemodynamics and reduces inflammatory response in hemorrhagic shock

Objective: To evaluate the effects of an early, short-term albumin infusion on mesenteric microcirculation and global hemodynamics in hemorrhagic shock. Design. A prospective, randomized study. Setting. Animal laboratory at a university medical clinic. Subjects. Seventeen Sprague-Dawley rats weighing 250-400 g. Interventions. The rats underwent median laparotomy and exteriorization of an ileal loop for intravital microscopy of the mesenteric microcirculation. Volume-controlled hemorrhagic shock was provoked by arterial blood withdrawal (2.5 mL/100 g body weight for 60 mins), followed by a 4-hr reperfusion period. Albumin (20%) or 0.9% NaCl was administered intravenously as a continuous infusion for 30 mins at the beginning of reperfusion. Reperfusion time mimicked a "prehospital" phase of 30 mins followed by a quasi "in-hospital" phase of 3.5 hrs. The "in-hospital" phase in both groups was initiated by substitution of blood followed by reperfusion with normal saline. Measurements and Main Results: Central hemodynamics, mesenteric microcirculation, and arterial blood gas parameters were monitored before, during, and 60 mins after hemorrhagic shock, and for a 240-min follow-up period after initiation of reperfusion. Application of albumin markedly reduced rolling and adherent leukocytes, maximum velocity, and shear rate in the mesenteric microcirculation. Later, after improvement of mesenteric microcirculation, an intermittent increase of central venous pressure and abdominal blood flow and decrease of hematocrit was observed. Conclusions: Albumin treatment of hemorrhagic shock improves microcirculation and global hemodynamics and attenuates the inflammatory response to reperfusion. It may provide clinical benefit when applied at an early stage of reperfusion during hemorrhagic shock.