Diaspirin crosslinked hemoglobin (DCLHb): more effective than lactated Ringer's solution in restoring central venous oxygen saturation after hemorrhagic shock in rats.

Central venous oxygen saturation (ScvO2) has been shown to reflect tissue oxygen consumption in hemorrhagic shock. The purpose of this study was to test whether the "blood substitute" diaspirin crosslinked hemoglobin (DCLHb, Baxter Healthcare, Round Lake, IL) might be more effective than lactated Ringer's solution (LR) at restoring tissue oxygenation, as measured by ScvO2, when used as a resuscitative fluid following hemorrhage. Conscious male Sprague-Dawley rats (250-350 gm) were bled through a jugular venous catheter to a target central venous base deficit of 15 +/- 2 mmol/L. Animals were immediately resuscitated with either 10% DCLHb (1:1) or LR (3:1), based on shed blood volume, followed by a maintenance infusion of LR until completion of the experiment. Central venous blood was sampled at baseline, prior to resuscitation and every 15 minutes for the first hour following resuscitation. While the baseline and pre-resuscitation ScvO2 values were not significantly different between groups, ScvO2 values were greater (P < or = 0.01) in the DCLHb group at all times following resuscitation. Furthermore, DCLHb restored SvO2 to baseline by 15 minutes after resuscitation, whereas LR resuscitation never restored ScvO2 to baseline. Since venous desaturation is one of the major compensatory mechanisms by which oxygen consumption is maintained under conditions of limited oxygen supply, these data suggest that animals resuscitated with DCLHb had a more rapid restoration of tissue oxygenation than those resuscitated with LR in this model of hemorrhagic shock.