Effects of fluid resuscitation and dopamine on diaphragm performance, hydrogen peroxide, and apoptosis following hemorrhagic shock in a rat model.

The objective of this study was to determine the effectiveness of lactated Ringer's (LR) solution, sodium hydroxyethyl starch (hetastarch), and dopamine (DA) on diaphragm shortening (DS), diaphragm blood flow (DBF), diaphragm hydrogen peroxide (H2O2), and diaphragm apoptosis following hemorrhagic shock (HS). Sprague-Dawley rats were assigned to the following groups: HS, LR, LR plus DA, hetastarch, and hetastarch plus DA. After removing 40% of the blood volume, with exception of the HS group, an equal volume of resuscitation fluid was administered. The diaphragm was excised so that DBF, H2O2, and apoptosis could be measured. LR did not increase DBF and DS, whereas the other fluids increased DBF and DS. H2O2 and apoptosis decreased with LR administration. H2O2 and apoptosis were decreased to a much greater extent with LR plus DA, hetastarch, and hetastarch plus DA infusions. In conclusion, LR plus DA, hetastarch, and hetastarch plus DA maintained DS and DBF, which may be attributed to the decreases in reactive oxygen species as reflected by H2O2 and apoptosis.