Supplementary oxygen for emergency Caesarean section under regional anaesthesia

Background Controversy still exists if the administration of supplementary oxygen to patients having emergency Caesarean section (CS) under regional anaesthesia is beneficial or potentially harmful. Therefore, in a prospective double-blinded study, we randomized patients having emergency CS under regional anaesthesia to receive either air or 60% oxygen until delivery and compared the effects on fetal oxygenation and lipid-peroxidation in the mother and baby. Methods We recruited 131 women having emergency CS under regional anaesthesia. Either 21% (air group) or 60% oxygen (oxygen group) was administered using a Venturi-type facemask until delivery. We compared the oxygen exposure duration, umbilical arterial (UA) and venous (UV) blood gases and oxygen content, and plasma concentration of 8-isoprostane. Subanalysis was performed according to whether or not fetal compromise was considered present. Results Data from 125 patients were analysed. For the oxygen group vs the air group, there were greater values for UA Po2 [mean 2.2 (sd 0.5) vs 1.9 (0.6) kPa, P=0.01], UA O2 content [6.6 (2.5) vs 4.9 (2.8) ml dl−1, P=0.006], UV Po2 [3.8 (0.8) vs 3.2 (0.8) kPa, P