Experimental hemorrhage in splenectomized and nonsplenectomized dogs.

Ten splenectomized and ten nonsplenectomized conscious dogs were subjected to hemorrhage of 41% of their blood volume over a 15-minute period. Hemodynamic and metabolic variables were monitored for 4 hours after hemorrhage. Mortality (100%) occurred in the splenectomized group. Significant (P < 0.001) hemodynamic responses after hemorrhage included hypotension, tachycardia, low central venous pressure, and decreased ECG voltage of the R wave. Tachypnea was noted in the absence of hypoxia, hypercapnia, and acidosis inthe nonsplenectomized dogs. Significant (P < 0.001) hypocapnia and mean PCO2 values of 13.9 MM of Hg and 23.5 mm of Hg in splenectomized and nonssplenectomized dogs, respectively, was noted. Mean hemoglobin levels were significantly (P < 0.001) decreased after hemorrhage in the splenectomized dogs. The absence of a change in hemoglobin in thenonsplenectomized dogs was attributed to the translocationof extracellular fluid into the vascular space which diluted the high concentration of RBC from splenic contraction. Other changes noted after hemorrhage were hyperglycemia, increased blood cortisol, and increased pyruvate and lacte levels. Changes were not noted in pyruvate-to-lactate ratios.