EFFECT OF RESUSCITATION SOLUTIONS ON THE IMMUNE STATUS OF DOGS IN HEMORRHAGIC-SHOCK

The purpose of this study is to examine the effects of three different types of fluid resuscitation on the immune system of dogs in hemorrhagic shock. Using a modified Wigger shock model, 18 conditioned male dogs were bled to mean arterial blood pressure of 60 mm Hg for 90 minutes and placed into three groups based on the resuscitative method. Group I: Crystalloid Resuscitation; Group II: Autotransfusion; Group III: Banked Blood. Laboratory methods for immune status evaluation included total lymphocyte count, T4/T8 ratio, total serum immunoglobulins, and immunoglobulin electrophoresis. These values were obtained pre-hemorrhagic shock, just before resuscitation, and subsequently on days 1, 4, and 7. Humoral immunity, represented by total serum immunoglobulin levels (IgA, IgG, IgM), was higher in Groups II and III when compared with group I on all post-resuscitation days. IgA and IgM levels were higher in Group III compared with Groups I and II. IgG level was higher in Group II compared with Groups I and III. Cellular immunity was also affected by transfusion. Total lymphocyte count was increased in Group II on Day 1; however, the three groups were similar with respect to this variable on subsequent days. The absolute T4 helper cell level in Group IT was similar to Groups I and III until Day 7, at which time the level became higher in Group IT. The absolute T8 suppressor cell level was higher in Group III on Days 4 and 7 compared with Group I. The absolute T8 suppressor cell level was also higher compared with Group II, but only on Day four. The T4/T8 ratio was lower in Group III compared with Groups I and II. The humoral response following resuscitation from hemorrhagic shock is blunted with crystalloid. The total serum immunoglobulins rise with banked blood and autotransfusion, IgA and IgM levels rise with banked blood, and IgG with autotransfusion. Autotransfusion results in a similar increase in absolute T4 helper and T8 suppressor cells, and thus no change in the T4/T8 cell ratio. Banked blood resuscitation results in an elevated absolute T8 suppressor cell level, and no change in absolute T4 helper cell levels. T4/T8 cell ratio decreases with banked blood resuscitation.