Effects Of Remifentanil Intravenous Patient-controlled Analgesia On Fetal Heart Rate And Maternal And Perinatal Outcomes

PurposeTo observe the effects of remifentanil intravenous patient-controlled analgesia(IVPCA)on fetal heart rate and maternal and perinatal outcomes and explore its effectiveness and safety to provide clinical evidence for the use of remifentanil for labor analgesia in primary care hospitals.Methods1.Study population:Primipara women who underwent spontaneous labor and delivered singleton babies in the Fifth People's Hospital of Jiangyin City between November 2015 and December 2016 were selected.There were 124 women who had spontaneous onset of labor and signed a written informed consent.The study population was divided into three groups.Group A(n=36)constituted of women who had analgesia in the latent phase,group B(n=54)comprised of those with labor analgesia in the active phase and the control group(n=34)were patients who did not resort to labor analgesia.2.Methods:Groups A and B initiated remifentanil IVPCA in the latent and active phase respectively.The regimen consisted of a loading dose,continuous infusion,and PCA.An initial dose of lmg remifentanil in 100ml normal saline was added to a Bogen PC A pump,with a constant infusion rate of 10ml/h,a 5-min lock-out and a loading dose of 3ml.Use of PCA was stopped when complete cervical dilation was reached.Post analgesia,the patients were monitored during different time intervals.At 5-25 min,30-50 min and 60-80 min time intervals and at full cervical dilation,the vital signs of the patient,fetal heart rate(FHR),FHR variability,contraction stress test(CST),VAS scores,duration of remifentanil administration,amount of drug administered and the number of pushes on infusion pump were noted.The duration of labor,amount of oxytocin used,type of delivery,characteristic of amniotic fluid,amount of bleeding at 2h postpartum,Apgar score and birth weight were noted for the intervention and control groups.SPSS 17.0 software package was used for data analysis and data was expressed as x ± s.Comparison within a group was conducted using repeated measures design analysis of variance and comparison between groups was carried out using one-way ANOVA.?2 test was used to determine significant difference between the frequencies measured.P<0.05 was considered to have statistical significance.Results1.Characteristics of study population:(1)There was no statistical significance in age,gestational age,gravidity,body mass index and vital signs between the intervention and control groups(P>0.05).(2)After initiation of labor analgesia,blood pressure readings at 5 min,30 min and 60 min,heart rate,respiratory rate and oxygen saturation were all respectively lowered in both groups A and B.This difference yielded no statistical significance(P>0.05).By the end of the first stage of labor,the vital signs of the patients in both groups A and B were restored to their pre-analgesic states.The difference was not statistically significant(P>0.05).2.FHR,FHR variability and CST category:(1)Prior to labor analgesia,comparison of FHR and FHR variability in groups A and B yielded no statistical significance(P>0.05).(2)In both intervention groups,post-analgesic FHR and FHR variability between 5-25 min and 30-50 min were significantly reduced as compared with pre-analgesic values.The difference was statistically significant(P<0.05).The comparison of FHR and FHR variability after the first stage of labor in all three groups did not show any statistical significance(P>0.05).(3)Between 5-25 min,30-50 min and 60-80 min after initiation of labor analgesia,there was an increase in the number of patients with CST categories II and III in both groups A and B.The difference had no statistical significance(P>0.05).The comparison of CST categories in the analgesic and non-analgesic groups yielded no statistical significance(P=0.769).3.Analgesic effect:(1)Before initiation of labor analgesia there was no statistical significance in the VAS scores of the three groups(P>0.05).After complete dilation of the cervix,statistical significance was noted between the three groups(P<0.05).(2)In the labor analgesia groups A and B,the VAS scores were significantly lower as compared with those prior to initiation of labor analgesia.The difference between both groups showed no statistical significance(P>0.05).4.Maternal and perinatal outcomes:(1)On comparison of the duration of labor and cesarean section rate with the control group,both groups A and B were noted to have a prolongation of the first stage of labor and a reduction in the cesarean section rate.The difference was statistically significant(P<0.05).(2)No statistical significance was observed(P>0.05)when comparing oxytocin for labor induction,amount of bleeding at 2h postpartum,characteristic of amniotic fluid,Apgar score and birth weight between the three groups.Conclusions1.Use of remifentanil intravenous patient-controlled analgesia resulted in significantly lowered VAS scores providing clear evidence of its analgesic effect.Furthermore,no prolongation of labor was observed and a decrease in the rate of cesarean section was also noted.2.There was no adverse effect observed on FHR,FHR variability,CST categories and Apgar scores.3.No adverse effects on maternal vital signs,labor,oxytocin usage and amount of bleeding at 2h postpartum were documented.