Effects Of Spinal Analgesia For Labor On The Postpartum Pain Thresholds In The Nullipara

Objective We choose the nullipara as our research subjects,and set two groups according to matermal's choice,trying to discover the influences of spinal analgesia for labor on the postpartum pain threshold in the nullipara.Methods 90 nulliparas aged 20~35 year,ASA ?-?,were enrolled with a single birth.Combining coagulation disorders,gestational diabetes,gestational hypertension,mental or nervous system disease,Local Anesthesia drugs or Opioid drugs allergy,Opioid addiction and refused to attend the experimenters are excepted.When the failure occurred on the block in the process of test,a local anesthetic complications of Spinal analgesia,into a cesarean section,or are not willing to cooperate to complete the subjects is out.They were allocated into 2 groups: a labor analgesia group(LA Group)and a control group(L Group)by whether or not to choose labor analgesia.Nullipara in LA Group administer the spinal analgesia when the cervicle run up to 3 cm or 4 cm.Nullipara in L Group delivery without any anesthesia procedure.Mechanical pain thresholds blew the umbilicus and superior to popliteal space were measured by electronic Von Frey instrument.The primary outcome was the mechanical pain thresholds blew the umbilicus and superior to popliteal space.Secondary outcomes included VAS scores,the duration of first stage of labor and second stage of labor,Intrauterine after childbirth,the Apgar scores of neonate and the willing to have a second baby.Results There were no significant differences in mechanical pain thresholds before delivery(P>0.05).But the nullipara in LA Group had a higher mechanical pain thresholds on postpartum 12 h,24 h and 48 h(P<0.05).There were no significant differences in VAS scores when the cervicle run up to 3 cm and 48 h after delivery(P>0.05).But the nullipara in LA Group had a lower VAS scores when the cervicle run up to 10 cm,postpartum 12 h and postpartum 24 h(P<0.05).There were no significant differences in intrauterine blood volume on 2 h postpartum after delivery(P>0.05).There were no significant differences in Apgar scores in 1 min after birth,5 min after birth and 10 min after birth(P>0.05).And nulliparas in LA Group seems to have a stronger willing to have another baby,and through the Logistic regression analysis,we found that the change of postpartum pain thresholds and the VAS scores when the cervicle run up to 10 cm will be the independent influential factors for it.Conclusion Labor pain can reduce the postpartum pain thresholds in nullipara and may induce hyperanalgesia.Spinal analgesia for labor can mitigate the change of postpartum pain effectively thresholds in nullipara,and decrease the incidence of hyperanalgesia.