[Comparison of dobutamine under different fluids resuscitation for shock induced by ischemia/reperfusion]

To compare the effects of dobutamine under different fluids resuscitation for shock induced by intestinal ischemia/reperfusion (I/R) injury in rabbits.

Thirty-two anesthetized rabbits were randomized into four groups of eight animals each. The groups were followed as: (1) lactated Ringer's solution (LRS) resuscitation; (2) LRS+hydroxyethyl starch solution (HES) resuscitation; (3) LRS resuscitation+dobutamine treatment; (4) LRS+HES resuscitation+dobutamine treatment. All these rabbits underwent the intestinal I/R injury developed by occluding superior mesenteric artery (SMA) with a non-crushing vascular clamp for 60 minutes and then loosing the clamp for 300 minutes. The fluid resuscitation and drug treatment began at the same time of reperfusion. Hemodynamic parameters including mean artery pressure (MAP), heart rate (HR), aortic velocity (AoV, as cardiac output) and SMA blood flow (Qsma) were measured. Tissue oxygenation was assessed indirectly by measuring the tonometric parameters of the gut, including difference between partial pressure of carbon dioxide in intestinal intramucosal and partial pressure of carbon dioxide in arterial blood (Pt-a CO2 gap), intestinal intramucosal pH (pHi), arterial blood lactate acid concentration and oxygen delivery (DO2).

HR, AoV and Qsma as measured in two dobutamine groups were significantly higher in values than LRS and LRS+HES groups (all P<0.05). But MAP as measured in two dobutamine groups were significantly higher in values than only LRS (P<0.05), and in LRS+HES resuscitation+dobutamine treatment group was also significantly higher in values than LRS resuscitation+dobutamine treatment group (P<0.05). Dobutamine in LRS resuscitation+dobutamine treatment and LRS+HES resuscitation+dobutamine treatment group could greatly decrease lactate and Pt-aCO2 gap, significantly improve pHi and DO2 compared with other two resuscitation groups (all P<0.05). Dobutamine in LRS+HES resuscitation+dobutamine treatment group could also greatly decrease lactate and Pt-aCO2 gap, significantly improve pHi compared with LRS resuscitation+dobutamine treatment group (all P<0.05).

Dobutamine could improve hemodynamic parameters and tissue oxygenation in shock induced by intestinal I/R injury in rabbits, being better used under the LRS+HES resuscitation.