[Perhydrit and sodium bicarbonate improve maternal gases and acid-base status during the second stage of labor]

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, pO2, and O2sat 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 PO2 and O2sat had no statistical difference between Group II and Group III. By comparing the values, we found that pH, PO2 and O2sat 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, PO2 and O2sat declined at the end of the second stage in Group III (P < 0.02 and < 0.01). There were no significant differences of PCO2 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.