Comparison of various hemoglobin polyoxyethylene conjugate solutions as resuscitative fluids after hemorrhagic shock

Background: Previous research suggested that splanchnic hypoperfusion occur s after resuscitation,vith certain acellular hemoglobin solutions. We exami ned the influence of maltose content and oxygen affinity on resuscitation w ith various hemoglobin polyoxyethylene conjugate solutions after hemorrhage . Methods: Fifteen swine underwent hemorrhage and equal volume resuscitation with pyridoxalated hemoglobin polyoxyethylene conjugate containing 0% or 8% maltose, or low P-50 conjugate, which also contained 8% maltose, Five cont rol animals were monitored but not bled, Regional blood flow was determined by using radioactive microspheres, gastric mucosal perfusion was estimated with tonometry, and gut histopathology was evaluated, Results: All hemoglobin solutions produced vasoconstriction, manifested by elevated mean systemic and pulmonary artery pressures without a significant decrease in cardiac index compared with the sham group, Resuscitation with maltose-containing solutions elevated arterial and regional Pco(2) and dep ressed arterial pH and gastric pH(i) (p < 0.05 for all). Splanchnic and ren al blood flows were reduced in the low P-50 + 8% maltose group (p < 0.05 vs . sham and baseline for renal blood flow), possibly indicating greater regi onal vasoconstriction in this group. Ileal mucosal damage was more severe i n the maltose-containing groups and correlated with decreased pH(i). Conclusion: Vasoconstriction occurred in all groups but was more severe in the low P-50 + 8% maltose group. Maltose-containing solutions caused respir atory acidosis, decreased pH(i), and histologic evidence of mucosal injury. Pyridoxalated hemoglobin polyoxyethylene conjugate without maltose was a s uperior resuscitation solution in this swine model.