[Effects of different fluid resuscitations on mesenteric microcirculation in rabbits of acute hemorrhagic shock]

To explore the effects of blood, crystalloid and colloid on mesenteric microcirculation in rabbits of acute hemorrhagic shock.

Hemorrhagic shock was induced in 28 anesthetized mechanically ventilated rabbits by withdrawing blood to a mean arterial blood pressure (MAP) of 40 mm Hg and maintained for 30 min. The animals were randomized into blank control group, whole blood resuscitation group, Ringer's solution resuscitation (RR) group and volume resuscitation (VR) group (n = 7 each). The data of vital signs, systemic hemodynamic parameters, arterial blood gas analysis and mesenteric microcirculation were collected at baseline, hemorrhagic shock (HS-0), resuscitation 0 min (Res-0) and resuscitation 30 min (Res-30). And side-stream dark field imaging (SDF) was employed to acquire the images of mesenteric microcirculation.

No significant difference existed in the basic status between 4 groups. MAP decreased to around 40 mm Hg in all groups. MAP increased significantly after active fluid resuscitation (P < 0.05). In addition to blank control group, total vascular density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV) and microvascular flow index (MFI) significantly increased after active fluid resuscitation in the other three groups. TVD and PVD were significantly lower at Res-0 in VR than in RR (P < 0.05).

After acute hemorrhagic shock, fluid resuscitation with whole blood and Ringer's solution improves systemic hemodynamics. And the combined regimen of whole blood and Ringer's solution is better at restoring mesenteric microcirculation.