Perhydrit and
sodium bicarbonate were administered to 99 women during the second stage of labor. Gas analysis was done twice
at the beginning and the end of the second stage. The results showed that 33 women received both perhydrit and
sodium bicarbonate(Group Ⅰ) had significantly higher pH, BE, pO 2, and O 2sat at the end of the second stage than those of 30 controls(Group Ⅲ)(P<0.05 and <0.01). And 33 women received only sodium
Bicarbonate(Group Ⅱ) showed merely higher pH and BE than those of Group Ⅲ. The difference was significant(P<0.05 and <0.01), while PO 2 and O 2sat had no statistical difference between Group Ⅱ and Group Ⅲ. By comparing the values, we found that pH, PO 2 and O 2sat were much higher at the end of the second stage in Group Ⅰ and Group Ⅱ than those at the beginning of the second stage(P<0.05 and<0.01). No statistical difference of BE had been found between both groups. In contrary, BE, pH, PO 2 and O 2sat declined at the end of the second stage in Group Ⅲ (P<0.02 and <0.01). There were no significant differences of PCO 2 among the three groups. It is suggested that the administration of perhydrit and sodium bicarbonate may effectively improve the tendency of maternal metabolic acidosis and tissue oxygen debt caused by consumption and uterine contractions during the second stage, subsequently improve maternal gases and acid base status.