Fluid resuscitation with O2 vs. non-O2 carriers after 2 h of hemorrhagic shock in conscious hamsters.

Efficacy of a cell-free o-raffinose cross-linked and oligomerized hemoglobin (Hemo-link) solution in restoring macro- and microcirculatory conditions after 2 h of hemorrhagic shock (40 mmHg) was compared with conventional treatment with autologous whole blood, Ringer lactate (RL), and Dextran 70. Studies were conducted in the dorsal skinfold microcirculation of conscious hamsters. Initial infusion was equivalent to shed blood volume (SBV) for RL and 50% of SBV for remaining solutions. After 2 h all animals received blood at 50% of SBV. Vessel diameter, functional capillary density, microvascular red blood cell velocity, and flow were measured. Arteriolar, venular, and tissue PO2 were determined by phosphorescence decay. Systemic parameters included mean arterial blood pressure, heart rate, arterial blood gases, pH, and base excess. Autologous whole blood and Hemolink, but not Dextran 70 and RL, restored mean arterial blood pressure, systemic blood gas, and metabolic parameters. Tissue PO2 recovered to 40-50% with blood and Hemolink but remained significantly lower (10-15% of control) with Dextran 70 and RL. Initial volume replacement after shock with blood or Hemolink yields equivalent macro- and microhemodynamic improvements not attainable with non-O2-carrying plasma expanders.