Hypertonic hydroxyethyl starch restores hepatic microvascular perfusion in hemorrhagic shock

The influence of small-volume resuscitation (hypertonic saline-10% hydroxyethyl starch, HS/HES) on liver microcirculation (intravital fluorescence microscopy) was studied in a nonheparinized hemorrhagic shock model [mean arterial pressure (MAP) 40 mmHg for 1 h] in rats. Resuscitation was performed with Ringer lactate (RL, 4-fold shed volume/20 min; n = 7), 10% hydroxyethyl starch 200/0.6 (HES, shed volume/5 min; n = 6), or 7.2% NaCl-10% hydroxyethyl starch 200/0.6 (HS/HES, 10% shed volume/2 min; n = 7). One hour after resuscitation, MAP increased in all groups, but it did not return to preshock values (P < 0.05). HES (16 +/- 2% nonperfused sinusoids) and HS/HES (14 +/- 2% nonperfused sinusoids), but not RL (24 +/- 2% nonperfused sinusoids), reduced (P < 0.05) shock-induced sinusoidal perfusion failure (28 +/- 3%) with restoration of leukocyte velocity in sinusoids (S) and postsinusoidal venules (V). Shock-induced stasis/adherence of leukocytes was further increased (P < 0.05) after resuscitation with RL (S, 38 +/- 6%; V, 55 +/- 20%) and HES (S, 31 +/- 8%; V, 23 +/- 14%). In contrast, resuscitation with HS/HES prevented increased leukocyte stasis in sinusoids (-4 +/- 4%) as well as adherence to endothelial lining of postsinusoidal venules (-5 +/- 10%). We conclude that replacement of only 10% of actual blood loss by means of small-volume resuscitation (HS/HES) can restore hepatic microvascular perfusion and prevent reperfusion-induced leukocyte stasis/adherence.