BACKGROUND: Marked derangements in acid-base status are frequently seen during orthotopic liver transplantaton. To prevent the progression of metabolic acidosis, treatment with sodium bicarbonate has been recommended. However, sodium bicarbonate may exacerbate intracellular acidosis, increase plasma lactate, contribute to hypernatremia. The value of giving bicarbonate has been questioned. Accordingly, we reviewed the intraoperative the acid-base status of patients who underwent orthotopic liver transplatation. METHODS: We reviewed ten patients showed severe metabolic acidosis (7.2 < pH < 7.30 and base deficit (BD) > or = 10). Despite of BD > or = 10, sodium bicarbonate was not given to all. Intraoperative pH and BD were analyzed retrospectively. RESULTS: At the anhepatic and immediate post-reperfusion periods, the pH was decreased (P < 0.05) and BD was increased (P < 0.05), but both were normalized at the end of surgery. The mean blood pressure transiently decreased at the immediate post-reperfusion periods (P < 0.05), but that was acceptable. CONCLUSIONS: This study showed that a severe metabolic acidosis is tolerated by the patients undergoing orthotopic liver transplantation without administration of sodium bicarbonate.