EFFECT OF ALPHA-ALPHA-CROSS-LINKED HEMOGLOBIN AND PYRIDOXALATED HEMOGLOBIN POLYOXYETHYLENE CONJUGATE SOLUTIONS ON GASTROINTESTINAL REGIONALPERFUSION IN HEMORRHAGIC-SHOCK

Background: Hemoglobin-based blood substitutes may cause vasoconstrict ion, which could limit organ perfusion during trauma resuscitation, We investigated the effect of two hemoglobin solutions on regional blood Bow and mucosal perfusion in the gastrointestinal tract in a hemorrha gic shock model. Methods: Twenty-four swine were bled 30% of blood vol ume over I hour. Six additional animals were anesthetized and monitore d but did not undergo hemorrhage, Bled animals were resuscitated with alpha alpha-hemoglobin (alpha alpha Hb), pyridoxalated hemoglobin poly oxyethylene conjugate (PW), shed blood, or lactated Ringer's solution. Regional blood flow was measured by radio-labeled microspheres, Gastr ic mucosal perfusion was estimated by measuring intramucosal pH (pHi) by tonometry, Results: PHP and shed blood restored small-bowel flows t o sham values, whereas lactated Ringer's solution and alpha alpha Hb d id not. Shed blood and PHP, but not alpha alpha Hb, restored cardiac i ndex (CI) to baseline (p < 0.05), Mean pulmonary artery pressure was e levated over baseline with alpha alpha Hb and PHP and remained elevate d with alpha alpha Hb (p < 0.05), pHi was significantly lower after re suscitation with PHP than with other fluids, Conclusion: PHP was effic acious in restoring CI and small-bowel flow, but the pHi remained low, indicating possible continued mucosal ischemia, alpha alpha Hb, led t o limited recovery of CI and small-bowel blood flow but restored pHi c lose to baseline, Shed blood was efficacious in restoration of pHi, ga strointestinal blood flows, and systemic hemodynamics.