Effects of different modes of delivery on arterial oxygen saturation in the fetus / 中华麻醉学杂志

ABSTRACT

Objective To compare the effects of different modes of delivery on arterial oxygen saturation in the fetus.Methods One hundred and twenty ASA Ⅰ or Ⅱ parturients aged 22-32 yr with a single fetus at full term lying in normal headdown position were divided into 3 groups according to the modes of delivery (n =40 each)group cesarean section (group CS) ; group labor analgesia (group LA) and group spontaneous labor (group SL).In group CS cesarean section was performed under epidural anesthesia with 0.5％ ropivacaine.Epidural catheter was placed at L2,3 interspace in groups CS and LA.In group LA labor analgesia was started from the first stage and maintained until complete cervical dilatation.The patients received epidural PCA (PCEA) with O.125 ％ropivacaine plus fentanyl 2 μg/ml.PCEA setting was as followsa loading dose of 8-10 ml; demand bolus 5 ml;20 min lockout; background infusion 6-10 ml/h.Blood samples were taken from umbilical artery at delivery for blood gas analysis and determination of serum concentrations of lactate,β-endorphin (β-EP) and neuropeptide Y (NP-Y).Apgar score and neurological and adaptive capacity score (NACS) were recorded.Results There was no significant difference in Apgar score,NACS and NP-Y and β-EP concentrations in umbilical arterial blood among the 3 groups.The lactate concentration and the absolute value of BE were significantly higher while pH was lower in group SL than in groups CS and LA.PO2 was significantly higher while PCO2 was lower in group LA than in groups SL and CS,and the lactate concentration and absolute value of BE were significantly lower while pH was higher in group LA than in group SL.Conclusion The 3 modes of delivery have significant effects on arterial oxygenation in fetus but have no clinical significance.