BACKGROUND: During hemorrhagic shock, acidosis was frequently treated with sodium bicarbonate, but various adverse reactions were reported. Most adverse effects of sodium bicarbonate have been attributed to increased CO2 production and paradoxical intracellular acidosis. This study was designed to compare the effects of Carbicarb and sodium bicarbonate on hemodynamics and acid base states in canine hemorrhagic shock. METHODS: 12 mongrel dogs were randomly divided as sodium bicarbanate group (group 1, n=6) and Carbicarb group (group 2, n=6). The study was divided into three successive phases as prehemorrhagic phase (I), hemorrhagic shock phase (II), acid-base correctoin phase (III+1 min, III+5 min, III+15 min, III+30 min). At the beginning of phase III, group 1 received sodium bicarbonate 2.5 ml/kg and group 2 received Carbicarb 2.5 ml/kg. During each phase a complete set of hemodynamic parameters, arterial and mixed venous blood gas measurements were recorded. RESULTS: 1) Arterial and end-tidal CO2 of sodium bicarbonate treated group were increased significantly compared with that of Carbicarb treated group after treatment. 2) Acidosis was improved in both groups, but pH of Carbicarb treated group showed more increase compared with pH of sodium bicarbonate treated group (P <0.05). 3) There was significant hemodynamic improvement on both group after treatment, but there was no statistical significance between groups. CONCLUSION: The treatment of Carbicarb shows more increase in arterial pH and less increase in carbon dioxide compared with sodium bicarbonate to treat metabolic acidosis due to hemorrhagic shock in mongrel dogs. So we suggest that Carbicarb is useful in the treatment of metabolic acidosis during hemorrhagic shock.